Talk:Optical fiber

Photonic crystal fibres

Should there be a mention (or link) of photonic crystal fibers somewhere in the article. This seems to me to be a major (and interesting) development in the field of optical fibres, with an entirely new method of guiding light (for example light can be guided in air, with less loss etc) User:DMB 14:33, 5 January 2006 (UTC)

Yes, it would be very appropriate to mention them somewhere in the article. I added a link in the "see also" section, but this is probably not sufficient.--Srleffler 02:28, 6 January 2006 (UTC)

added to the history section - could someone please clean up the citations, as I cannot do it! Also, please feel free to edit with more appropriate information.

Agreed this is an important area of current research, and beginning to be commercialized, but I'm generally somewhat sceptical of anything with the level of hype surrounding it as photonic crystals. I've tried keep the important information in what you wrote, while removing some of the NPOV phrases. For example, I removed "entirely new" because as pointed out in the photonic crystal article, these structures have existed in nature forever. I also replaced "many advantages" with two examples of specific advantages. -- The Photon 06:06, 7 January 2006 (UTC)

OK, maybe I should have said "entirely different" rather than "entirely new", but the current revision seems good to me. DMB 16:06, 7 January 2006 (UTC)

electrical resistance

In the section "Comparison with electrical transmission", the article mentiones High electrical resistance for fiber optic cables. I'm wondering whether this means higher electrical resistance than electric cables, or complete electrical resistance instead. Would be nice if someone cleared that up.

• Well, electical resistance is never "complete" - it's always some finite value, even if it's really high. In general, the electical resistance of glass fibre is as high as any other piece of glass, i.e. pretty damn high. --Bob Mellish 15:27, 17 November 2005 (UTC)

• • Stupid me.. I mixed up with "Immunity to electromagnetic interference", which is printed just above it!!! Thanks anyway  :)

Corning

I was surprised to see Corning refered to as a British company. Unless there is something very subtle (like their distant origins), Corning is surely american - based in Corning, NY. Keck and co-workers, I am certain, did their pioneering work in the USA.

There are at least three different histories of the development of optical fibre - British, Japanese and American. The British credits Kao and Hockham and the Post Office Research Centre, The Japanese credits Nakahara and Sumitomo, the American credits Keck and Corning. That's a very simplistic summary, but the essence is correct - it depends mostly on the nationality of the author / teller of the history. My view? It was an idea whose time had come and all parties were innovating at the same time and contributed to the progress. —The preceding unsigned comment was added by 138.130.64.75 (talk • contribs) .

Actually, they each made complimentary contributions to the art. The BPO, known then, establihed the requirements through the Kao Hockman papers. Corning invented a viable process and material for making fiber. Other companies in Japan and elsewhere created many needed components for fiber systems. Numerous patent trials through the 1980's established the primacy of Corning's (a NY company) inventions, on a world wide basis. This is not to discredit the contributions of others in many very important areas. The case is clearly laid out in "The Silent War" Magaziner 1990. —The preceding unsigned comment was added by 66.24.214.136 (talk • contribs) .

Corning's roots are very American -- it was founded in the 19th century in Corning, New York where it is still headquartered; the company was named after the town. Today, the company is very global and I would not be surprised if they have as many, if not, more employees overseas as in the U.S. --A. B. 17:31, 13 October 2006 (UTC)

Who published the first research? Which journal was it published in? When was it published? Who holds the patent?Ghostofnemo (talk) 15:35, 27 November 2011 (UTC)

Inconsistency in range

Which is correct? The article states "Typical single mode fibre optic cables can sustain transmission distances of 80 to 140 km" but then "Recent advances in fiber technology have reduced losses so far that no amplification of the optical signal is needed over distances of hundreds of kilometers". One or the other is the state of the art... which is it!!!! I need to know!

>> "Recent Advances" vs. "Typical Fiber". ;)

јјјјјј —Preceding unsigned comment added by 62.162.216.230 (talk) 17:27, 19 June 2010 (UTC)

optical waveguide cables

While editing another wikipedia article (translated from German/Deutsch, if that makes any difference), I see the term "optical waveguide cables". Is that exactly the same thing as "optical fiber", or something different ? Is this phrase common enough to mention in the article ? --DavidCary 21:44, 17 May 2005 (UTC)

Yes the optical fiber is used as a waveguide purpose, you see for any communication purpose we require a communication channel, and the term optical waveguide cable means this communication channel.--Mascotmayank (talk) 05:58, 12 June 2008 (UTC)

Fiber vs Fibre

Is there a reason why fibre is used instead of fiber 4 times in the article? The only mention I see is at the beginning, where it states that fibre is the British term. I can't see any contextual differences between the use of fiber and fibre, and unless someone has a reason, will change all instances to fiber.

>1. It helps with search engines >2. Brits and Aussies editing the page will use fibre, while USA uses fiber.

While I certainly want people to come read this page, whether they type "fibre" or "fiber" into their search engines, it just seems inconsistent for the article title to say "fiber" while the article text uses "fibre". --DavidCary 21:44, 17 May 2005 (UTC)

Please see Wikipedia:Manual of Style#National varieties of english. The guideline is for each article to be internally consistent. I have made all the uses of fibre consistent with the article title (fiber). The main gotcha would be if the Fibre Channel standard should be mentioned, the title of that standard uses the British spelling. To aid the search engines, there should be a "redirect page" from "Optical Fibre" to this page. If it's not there, I will figure out how to create it.--The Photon 16:18, 12 October 2005 (UTC)

Any reason why there's a 'See also Muggle' under the prospects for the future of fiber optic technologies? Seems to me some kid playing a prank. . .

It makes sense to keep both so that users searching the topic can find the information despite how they usually hear it expressed. It doesn't detract from the consistency unless the use is exchanged within section. Otherwise, it should be accepted. — Preceding unsigned comment added by Tmarquee (talk • contribs) 03:38, 3 December 2011 (UTC)

Optical fiber in waveguides

“Optical fiber in waveguides” piece probably refers to some advanced integrated optics application, or some optical backplane application. However in present form is uninformative and misleading. Could somebody please correct this paragraph. Or, may be, we should remove it. --Sergiusz 23:27, 3 Jun 2005 (UTC)

I support removing the sectionThe Photon 05:01, 12 October 2005 (UTC)

Unless its meant to be a reference to something like [1], in which case, somebody please write it up so it makes sense.--The Photon 04:49, 23 October 2005 (UTC)

I am removing this section from the main article. Here is the old text in case someone would like to recreate it (--The Photon 05:05, 28 October 2005 (UTC)):

Optical fiber in waveguides

Waveguides are silicon chips with extremely thin and extremely flexed optical fibers on them. Companies like JDS Uniphase manufacture these waveguides for use in computers and in splitting boxes. A waveguide separates the different colors of light, and allows it to have the same signal sent in many directions. (see waveguides)

Britishisms

While I fully support alternate spellings, isn't claiming the Corning corporation a bit much?

Tb/s

"Large data-carrying capacity (thousands of times greater, reaching speeds of up to 1.6 Tb/s in field deployed systems and up to 10 Tb/s in lab systems)" these are Terabits or Terabytes?

Ans: Terabits

To be included, FO Transmission Records

RELEASE FRIDAY MARCH 22, 2002. Bell Labs scientists transmit 64 channels of data at 40 gigabits per second per channel (2.56 Tbps) over 4000 kilometers (2500 miles)

In OFC 2005 paper by a group from Agere Systems -- a record-setting fiber optic transmission rate of 3.2 Tbps. --Sergiusz 20:49, 16 September 2005 (UTC)

Added Manufacturing

Hello,

I added manufacturing by MCVD, but was unsure how to reference the article. Can someone please have a look at this? Thanks.

You did fine! One thing you might want to do now is to find those terms in your new text that reference other Wikipedia articles, and make them Wikilinks by enclosing the term in square brackets like so: [[Chemical vapor deposition]]. You can also reference an article using a different term than the actual article name, like so: [[Chemical vapor deposition|Modified Chemical Vapor Deposition]]; the first part is the actual article title and the second part is what will show up here in the article, for example: Modified Chemical Vapor Deposition.

Remember, though, Wiki standard practice is to only make a term a Wikilink the first time that it appears in the article. Subsequent reuses of the term aren't Wikilinked.

Also, you may want to "sign" your talk postings (here) by putting four tildes (~~~~) after your post. When you press "Save page", these will be replaced by your username or IP address in a handy Wikilinked format. A timestamp will also be included.

Atlant 13:54, 3 October 2005 (UTC)

Removed text on Svetlana Plant, Saint Petersburg

I removed this text:

Svetlana plant in Saint Petersburg, Russia was first who decided to use fiberoptics in house aronments and decorations. Namely in Fiberoptic UFO lamp, which look like this. [url]http://www.thingsthatglow.com/html/images/8612.jpg[/url]

The lamp from light travels through painted glass, then through fiberoptics.

Reason: Hecht mentions decorative lamps of this type around 1958, but gives no solid citation.

If there's any citation for these lamps at an earlier date in St Petersburg, please re-add the text with citation. If the St Petersburg lamp doesn't predate 1958, but if the image is available under a free license, consider using it to illustrate the "Other uses of Fiber Optics" section.

--The Photon 00:07, 30 October 2005 (UTC)

Plastic

This article mentions plastic optical fiber a couple times, but the rest of the article is glass-centric (don't worry, no NPOV here... <g>). POF and it's uses should be added as a new section, and the rest of the sections called glass-specific.

Unfortunately, I don't know much about POF.

XPav 03:52, 14 December 2005 (UTC)

Plastic optical fiber has its own article, but it wouldn't be a bad idea to summarize it here, in Wikipedia:Summary style. In relation to what's here, POF is multimode step-index fiber, with relatively high attenuation (~1 dB/m). The applications I know about are mostly in audio electronics.

The Photon 04:44, 14 December 2005 (UTC)

Is this the same Peter Schultz?

Is this Peter Schultz the same one referenced in the "History" section of this article?

Based on the biography at shultz.scripps.edu, I'd say say "No." -- The Photon 05:17, 4 January 2006 (UTC)

Put the history first.....

Hi..

i would like to see the history section be after the principle..... it doesn't make sense putting it at the end..... Jayant, 17 Years, India|^(Talk) 05:30, 24 February 2006 (UTC)

For articles on technical and scientific topics, the history is often not all that important compared to the technical details and applications.--Srleffler 06:58, 24 February 2006 (UTC)

Actually, this is a very important technical innovation, and I think the history section should be expanded. Can you imagine an article about the telephone that doesn't go into some detail as to who developed the device, how it was conceived, and where was it developed? In whose lab was this developed? Who made the breakthrough to make a glass rod into flexible fibers and clad the fibers in a plastic coating? Who holds the patent? Who gets credit for this amazing breakthrough? We know about the light bulb, the automobile, the telephone, the airplane, but all of this amazing modern technology, like integrated circuits, digital electronics, and fiber optics just....appears. Edison, Ford, Bell, the Wright brothers were all famous men.Ghostofnemo (talk) 15:31, 27 November 2011 (UTC)

Found this: "In 1954, Dutch scientist Abraham Van Heel and British scientist Harold. H. Hopkins separately wrote papers on imaging bundles. Hopkins reported on imaging bundles of unclad fibers while Van Heel reported on simple bundles of clad fibers. He covered a bare fiber with a transparent cladding of a lower refractive index. This protected the fiber reflection surface from outside distortion and greatly reduced interference between fibers. At the time, the greatest obstacle to a viable use of fiber optics was in achieving the lowest signal (light) loss." at http://inventors.about.com/library/weekly/aa980407.htm Ghostofnemo (talk) 15:54, 27 November 2011 (UTC)

Fiber optic cable

I think the whole area of fiber optic cable should either be expanded or else moved to a separate article with a summary and link here. Your thoughts?--A. B. 01:19, 2 June 2006 (UTC)

No need to ask -- be bold and expand the section. If it gets too out of balance with the rest of this article, that's the time to split it out to its own article. -- The Photon 01:36, 2 June 2006 (UTC)

Wavelengths in vacuum or in fiber ?

"The fiber absorption is minimal for 1550 nm light and dispersion is minimal at 1310 nm making these the optimal wavelength regions for data transmission. A local minimum of absorption is found near 850 nm..." Are these wavelengths of light in vacuum or in fiber ? 83.17.206.178 16:10, 10 June 2006 (UTC)

Glass (i.e., fiber).

P.S. Welcome to Wikipedia -- I encourage you to get your own user name; the IP address you originally edited from appears to be a shared IP address and has been used by someone for vandalism. As a result, you could encounter hassles editing Wikipedia. An account takes just a minute or two to set up and makes you and your contributions independent of the ISP you use. See Wikipedia:Tutorial (Registration)--A. B. 16:12, 10 June 2006 (UTC)

I don't think you're right, A. B. I'm pretty sure these are vacuum/air wavelengths. If you are right, I spent four years developing a telecomm laser for the wrong wavelength. --Srleffler 16:35, 10 June 2006 (UTC)

You're right; I stand corrected:

• pp 418-420, Hecht, Jeff, Understanding Fiber Optics, 4th ed., Prentice-Hall, Upper Saddle River, NJ, USA 2002 (ISBN 0130278289)
• pp 252-253, Ramaswami, R., Sivarajan, K. N., Optical Networks: A Practical Perspective, Morgan Kaufmann Publishers, San Francisco, 1998 (ISBN 1558604456)

speed of transmission

The light travels at 2/3 the speed of light in a vacuu system like 10baseT? Does the fact that the light bounces off the walls at an angle mean that light has to travel further than the straight line length of the fiber? --Gbleem 19:42, 26 June 2006 (UTC)

Copper and fibre have roughly-similar propagation velocities.

The path length on a multi-mode optical fiber definitely does vary depending on the angle that any given ray launches into the fibre at. For single-mode optical fiber, everything tends to propagate basically straight, which is why you can go a much longer distance in such a fibre without your pulses "smearing" out into mush.

Atlant 20:26, 26 June 2006 (UTC)

Fiber-end polishing styles?

One web site offers angled, flat or conical polishing. Why would I want one or the other. --Gbleem 20:52, 26 June 2006 (UTC)

Angled polish is used on singlemode fiber to get very low backreflection. The angle causes any backreflected light to leak out of the fiber, so it does not go back down the fiber to the originating equipment.

There is a lot more to be said about fiber polishes, but I don't have time right now.--Srleffler 23:22, 26 June 2006 (UTC)

Some common fiber polishes:

• flat: might be used for multimode fiber, or for coupling from fiber to free space optics, or for splicing (I'm not sure)
• physical contact (PC): Used for mating singlemode fiber. The surface is slightly curved, so that the fibers touch only at their cores. Some manufacturers might call this "flat", in contrast to APC (below).
• angled physical contact (APC): Same as PC, but the slightly-curved surface is tilted (8°, I think) from perpendicular to the fiber axis. This increases loss, but decreases backreflection. APC fiber ends must only be mated to other APC fiber ends. The strain relief on an APC connector should always be green to indicate this. Jacks on instruments are not always marked.
• angled flat: a flat polish, tilted (at 8°, I think). This is used for coupling from fiber to free-space optics, with low backreflection. This polish is fairly rare.

There are several grades of PC polish, typically identified by manufacuters as regular, "super" and "ultra". The higher grades provide lower insertion loss and backreflection, typically at higher cost. The latter two are sometimes identified as SPC and UPC polish. All of the PC polishes except APC are compatible with one another.

I'm not sure what the conical polish is. It may be for some special purpose.--Srleffler 04:03, 4 July 2006 (UTC)

Conical polish approximates a lens at the output, focussing the output beam. I'm not sure if this is ever used outside research labs. -- The Photon 02:37, 16 July 2006 (UTC)

Uses of Optical fibre as a replacement of traditional "copper" lines for the transfer of data

This is a very useful article, but I am missing some additional input from experts out there (there is bound to be somebody) on the use of optical fibre instead of copper fibre. Any takers?—The preceding unsigned comment was added by 81.169.127.6 (talk • contribs) .

See article on FTTP for practical application of PON technology to replace existing copper wire with fiber optic plant, and Verizon's FiOS roll out using BPON technology. This is a very broad subject, if there is anything you are specifically curious about, I'll be happy to discuss. --Toddyboy711 19:19, 16 May 2007 (UTC)

Principle of operation

I re-reorganized the Principle of operation section. The article needs to start with a section that focuses on how an optical fiber works, rather than focusing on cataloguing types of fiber. We can do both, but not the way the previous reorganization structured it. In particular, that edit implied that one can divide fiber into four distinct types: step index, graded index, multimode, and singlemode. That's misleading. Multimode and singlemode fiber can each be either step index or graded index (although graded index singlemode fiber is not used commercially as far as I know). I think it flows better to divide into single- and multimode, and deal with step vs. graded within the sections. That allows us to focus on how fiber works, without totally rewriting the section.--Srleffler 04:08, 19 September 2006 (UTC)

Fragility and disaster preparedness?

The article doesn't mention how fragile the lines are compared to copper wires. What kind of estimates are there for this service in emergencies? —The preceding unsigned comment was added by 71.103.84.158 (talk • contribs) .

Actually, fiber optic lines are probably more likely to survive many disasters. For example, pure fiber optic lines are essentially immune to EMP, lightning, and other electrical disturbances. (The same can't be said, unfortunately, of fiber optic lines that contain electrical repeaters, though.) Fiber cables are also quite likely to be more immune to prompt failures from fire.

If you're thinking that glass is fragile, this really isn't so. The fiber is usually quite loose within a toughened over-jacket and often uses Kevlar fibers as strength members, so even modest elongation of the jacket won't break the fiber. I've seen demonstrations where a piece of fiber optic cable is thrown over a busbar in a lab, and a heavy engineer hauls himself off the floor by the cable while the circuit remains completely operational.

Atlant 18:39, 11 October 2006 (UTC)

Great question. We really need a much more detailed and expanded section on fiber optic cable design (on my to-do list for way too long)

Atlant makes good points -- especially that the cable design protects the fibers. As for mechanical characteristics, you're comparing apples to, if not oranges, then pears. I'd say a lot depends on the copper pair count and the exact nature of the fault. Underground cables are more likely to get cut in the U.S. due to construction activity. Buried cables formerly were formerly considered more reliable than aerial cables,but the underground construction tempo has increased over the last two decades. Digging and drilling equipment will usually ruin either cable type with little effort. As for problems (storms, broken poles, etc) with either cable design installed aerially -- I'd say the survivability of either cable type will depend more on how strongly the cable is attached to the poles than on the particular cable type.

Then there are the very robust OPGW and ADSS cables used by power utilities. OPGW (optical groundwire) is essentially a metal conductor with fibers in it used as the transmission line's groundwire. ADSS (all-dielectric self-supporting) cable is a plastic-jacketted fiber cable but with much, much more aramid yarn (such as DuPont's Kevlar). Their much greater strength, combined with their location high off the ground on very robust structures makes ADSS and OPGW installations much more durable than traditional fiber or copper installations.

Fiber restoration used to take longer because the splicing equipment was expensive and scarce, as were fiber splicing crews. That's no longer true and I'd say you can nowadays restore a fiber cable faster than a high pair count copper cable that's been cut.

--A. B. 19:13, 11 October 2006 (UTC)

Thank you for meantioning backhoe fade; I clearly missed that point. One big difference worth mentioning is that often, when the backhoe wipes out the fiber, it takes a lot of capacity with it, whereas even a copper coax usually wasn't carrying that much traffic.

Atlant 19:24, 11 October 2006 (UTC)

Although fibre is completely imune to EMP it is, unfortunately, not imune to the effects of a nuclear blast. The gamma radiation pulse affects the fibre when it is irradiated substantially blackening the fibre in the process (thus effectively cutting off its ability to transmit light). A short time later, it 'anneals' and emits the absorbed radiation as a burst of light loosing much (but not all) of its blackness in the process. I witnessed a practical demonstration of this many years ago now. A piece of glass rod (of the same type used in fibre optics) had been cooled in liquid nitrogen and exposed to gamma rays in an atomic reactor. The liquid nitrogen prevents the glass from anealing once removed from the radiation. The glass rod was very black before being removed from the liquid nitrogen. Once removed it quickly warmed up and emitted enough light that you could see easily in a darkened lecture hall. The rod was still darkened (but not black) once the glow had subsided. 86.183.175.94 (talk) 17:02, 18 April 2011 (UTC)

Fiber-optic communication

It sounds like a lot of you have specialized experience that would be useful for improving the Fiber-optic communication article, especially the optical fiber section of that article johnpseudo 19:18, 11 October 2006 (UTC)

Raman Probes?

Should we perhaps mention that optical fibres are being used in Raman Spectroscopy probes or should that go in the Raman page? GreatMizuti 06:40, 13 October 2006 (UTC)

Laser Focus World and other publications

LFW added a link to Laser Focus World. This link was deleted as overly commercial and it's quite possible that it was added to enhance Laser Focus World's Google rankings more than the interests of Wikipedia. Nevertheless, putting aside my personal feelings about possible link-spammers, would links to a few industry periodicals such as Laser Focus World, Lightwave, fibers.org, Light Reading and/or others be beneficial to readers?
--A. B. 17:41, 13 October 2006 (UTC)

P.S. Interesting coincidence isn't it -- Laser Focus World's intials are also LFW.

(Speaking just for myself) I often find it difficult to decide what's linkspam and what isn't, and my opinion varies a lot depending on how big a Pandora's box I think we might be opening by admitting "just a little linkspam" into any given article. For example, on the hot tub article, I'm ruthless. Every #&##ed person with a hot tub shop or internet hot tub parts business seems to come along and think they can promote themselves there, so I routinely cut it all out. But if we had an obscure topic like (I'm making this up) "Neutrino communication networks" and there were one journal (say, Neutrino Trans-Planet Monthly) that is alone in covering the topic worldwide, then I at least would probably let that bit of spam stay; it would help someone who wants to learn all they can about neutrino communications networks.

Others doubtless feel differently.

With regard to this topic, I'm open to persausion either way. One of the ways that I'm negatively persuaded (BTW, hint to the spammer!) is just how many articles they feel the need to post their spam into. I'm also negatively persuaded when the spam is added by the party who stands to benefit from its presence (and no, logging out and spamming anonymously isn't going to fool anyone).

Atlant 17:51, 13 October 2006 (UTC)

I subscribed to LFW for years. It is not specific enough to fiber optics to qualify as a suitable Wikipedia external link on this article.--Srleffler 21:46, 13 October 2006 (UTC)

I don't disagree. What about Lighwave and fibers.org? --A. B. 22:17, 13 October 2006 (UTC)

Easy Reading

I'm in middle school and I have to do a one page report about optical fiber for science homework. However, checking out this Wikipedia article, I noticed a glaring problem: It's way to hard to read. There's too many technical terms for someone like me to understand! Could someone PLEASE make this article in Simple English form? I saw this was chosen as a good article, but I can't agree with that if I can't even understand half of what it's saying! 65.65.183.135 20:26, 22 October 2006 (UTC)Jimmie

I started a simple English article here.--Srleffler 23:44, 22 October 2006 (UTC)

I have the idea if it would make the article more accessible to general readers (non-physicists, non-engineers) to move the Priciple of operation section further down. Instead, start with an introductory overview, slightly longer than the lede, then History, then Applications, then finally Principle of operation and all the remaining setions. I'll start a draft of the introduction section at Talk:Optical fiber/Draft introduction. -- The Photon 01:56, 24 October 2006 (UTC)

I object to putting the history section directly under the intro. For articles on scientific and technical topics, the history of the subject is often of secondary importance compared to a description of what the thing is or how it works. The intro needs to be followed by a description of how an optical fiber works. What could work, though, is to start with a simple explanation, and move the technical details into a section further down in the article (after Applications). That would better meet the needs of the general reader.--Srleffler 23:47, 24 October 2006 (UTC)

I think you have to consider the audience. This article is of broad interest even to people outside of science and technology, as shown by the first post in this topic. To them, other things are more important than how it works. For example, how it affects daily life, the economic world, and how its used. I don't think the original poster really needed a version of the article that explained Optical fiber in simpler language; s/he just needed an article that emphasized what's really important about optical fiber to the whole world, before getting him/her lost in the details that are only important to technologists.

There are cases where I agree the "Principle-of-operation-first" rule would be best. One is when some detail of the physics is needed just to explain what it is, or how its different from other similar things. For example: Aspheric lens or Bipolar junction transistor. For optical fiber we can summarize the operating principle in one sentence: "it carries light from one end to the other." and have enough background to explain its important effects on everybody.

Another case is when the topic is so obscure that only readers who already have some background (or got lost) are likely to read the article. Again, the question that started this section shows that doesn't apply to optical fiber.

Another case is topics that are only notable (in the Wikipedia technical sense) because of their importance in technolgical or scientific context, like Gaussian beam or Snell's law. Once a topic is discussed regularly in Time magazine or daily newspapers, this doesn't apply and Wikipedia should have an article that addresses the topic in general terms.

Something I worry about is that many editors (not especially you) tend to think of Wikipedia as something that is there for our entertainment, and not something that's meant to provide information to the whole world. A second, more subtle, version of this is to think that all the readers will have the same priorities as us. Then we might think that the most important thing about optical fiber is that it works by total internal reflection, and not the fact that it has been part of reducing telecommunications costs dramatically, enabling wide access to the internet, increasing access to world-wide communications, and also enabling globalization of the economy affecting everyone in the world.

See Nuclear weapon for an especially egregious example of this. The device that created the cold war and set the course of the last 50+ years of history, starts with Types of nuclear weapons before going on to other topics. In that case I'm certain 90% of general readers would be beter served by a different arrangement, and the rest of us could still find the technical explanation if it were later in the article.

-- The Photon 02:18, 26 October 2006 (UTC)

I would be fine with having the Applications section follow the intro, provided the intro gives at least some idea of what an optical fiber is. I mainly just objected to the proposal to stick History right under the intro. I agree that a general audience may prefer to read about applications before the details of how it works. They are not likely to want to know the history of optical fiber in any detail before finding out what it is used for.--Srleffler 04:36, 26 October 2006 (UTC)

Thanks for the responses (not saying this this section is over or anything). Here's another thing I noticed about this article: Whenever it explained something using several technical terms, it would always try to explain what the term means using even more technical terms. That should really be fixed.

Thanks to Srleffler for making the Simple English version. I found it to be a lot better. There really are a lot of Wikipedia articles that need Simple English versions but don't have them.

And to The Photon: I'm male.

Is there anything "faster"?

ok, that may sound silly and irrelevant but it seems like useful information for an encyclopedia. are there other ways that can provide faster telecommunication? --87.194.72.129 01:33, 15 November 2006 (UTC)

Free Space Optics is about 50% faster.--Srleffler 02:27, 15 November 2006 (UTC)

hah, very interesting, thanks. (hm, i didn't know irda was part of that technology..) --87.194.72.129 01:19, 16 November 2006 (UTC)

Add image?

I was about to add this image that I created to the article:

Schematic of three primary modes for fiber optics: (going from top to bottom) multimode, graded-index, and single-mode. The refractive index profile of the fiber is shown on the left.

However I didn't add the image, because it seems like the article already has quite a few images. I was worried that the article would become too cluttered. I would like a second (or third) opinion on this. —The preceding unsigned comment was added by Kebes (talk • contribs) 20:07, 3 January 2007 (UTC).

I personally really like this image - it explains a lot. I would support it being added to the article. fonetikli 01:56, 8 January 2007 (UTC)

Looks good to me. Put it near the top where there's plenty of room. Dicklyon 03:40, 8 January 2007 (UTC)

This is a great idea, and looks good. I think the illustration for "single mode" may be a bit misleading, however. It seems to show a single ray of light propagating straight down the center of the fiber, not even touching the walls of the core. Perhaps it would be better to draw it with the core smaller, so that the "ray" fills it. (In fact, the light propagating in a singlemode fiber not only fills the core, but extends beyond it into the cladding.) Also, the caption should be rephrased "Schematic of propagation in three types of optical fiber:..." to avoid confusion over the word "mode".--Srleffler 04:38, 8 January 2007 (UTC)

Pigtails

I often read about fiber-pigtails in connectors or isolators. Why are they not mentioned here? How can the modes be matched, if going from a fibre to a crystal (modulator, isolator, diode)? How can one make optical waveguides out of crystals? Are they all etched into the surface of large crysals with some doping to change the index of refraction? What if I do not want to dope? Arnero 19:52, 24 March 2007 (UTC)

If your crystal has a waveguide, like in a laser diode, you mode match with a tiny lens or other optics. If the crystal doesn't have a waveguide, you just use a lens to collimate the beam from the fiber. Waveguides are usually made in crystals by doping.--Srleffler 04:52, 31 October 2007 (UTC)

WDM

What about http://en.wikipedia.org/wiki/Wavelength_division_multiplexing

Please add info about color coding of cables/connectors

Quote (http://www.thefoa.org/tech/connID.htm): Color Codes: Since the earliest days of fiber optics, orange, black or gray was multimode and yellow singlemode. However, the advent of metallic connectors like the FC and ST made color coding difficult, so colored boots were often used. The TIA 568 color code for connector bodies and/or boots is Beige for multimode fiber, Blue for singlemode fiber, and Green for APC (angled) connectors.

I was looking for this info, but didn't find it on wikipedia.

Singlemode fiber

Under the heading "Singlemode fiber" it is said: "Fiber with a core diameter less than about ten times the wavelength of the propagating light...". The adjacent image (http://en.wikipedia.org/wiki/Image:Singlemode_fibre_structure.png) describes a singlemode fiber with a core diameter of 8 μm (and this is consistent with the fact that generally singlemode fibers have a core with a diameter around 10 μm). However, it means that this will act as a singlemode fiber for wavelengths more than 10 times longer, i.e. more than 80 μm (80,000 nm!). So visible (or near IR) light (say, 1,000 nm) will NOT regard this core as a singlemode core ?! In other words, according to the sentence cited above, a singlemode fiber with cutoff wavelength of 488 nm (I am using these daily) should have a core diameter of ~ 50 nm... Can anybody sort out this discrepancy?

--Microspot 06:10, 2 July 2007 (UTC)

The diameter of the fibre is 10 times the wavelength, so the 10 μm fibre can handle 1 μm wavelength, which is longer than visible light. I think you got the ten times round the wrong way. GB 09:15, 2 July 2007 (UTC)

Equipment costs to be added?

I think equipment costs for fusion splicing should be included in the article considering the pieces of equipment involved can exceed £50,000.

Optical fiber lifespan

what is the known lifespan of the optic fibre in different environments? —The preceding unsigned comment was added by 196.35.5.145 (talk • contribs).

With the exception of optical runaway PDF, I'm not sure there are any practical limits to the life of a passive piece of fiber optic cable. Cable with electrical repeaters would be a different story, of course.

Atlant 23:31, 15 August 2007 (UTC)

At least some cable is known to spontaneously break if you bend it, depending on bend radius, after some time (months-decades). The shorter the radius, the quicker it goes. In an ocean environment I think hydrogen contamination can occur (IRC), and that limits life.WolfKeeper 03:41, 31 October 2007 (UTC)

Also, Just a simple table showing maximum distances/bandwidth would be good. —Preceding unsigned comment added by 203.4.223.195 (talk) 06:54, August 30, 2007 (UTC)

That's a really complicated question, it depends on modulation technique, whether there is dispersion compensation on or for the cable, and whether you are using optical repeaters.WolfKeeper 03:41, 31 October 2007 (UTC)

14 PB/s?

Um... source?

You can't just multiply the channels by 40G.... it turns out that the channels aren't actually independent, the fiber is not completely linear in several different ways, so there's intermodulation between different channels that tend to mess each other up. Even going from 10G to 40G you have to double the channel spacing. There's many, many complications.

AFAIK the current practical limit is more like 14TB/s or a factor higher, but not 1PB, that's currently out of reach, barring some breakthrough. And even ~14TB/s needs a large number of racks of lasers to get all the different channels lit, and there lots of couplers needed... all kinds of mess.

If it's not referenced it needs to come out.WolfKeeper 06:45, 31 October 2007 (UTC)

It looks like some theoretical number for the upper limit of a fiber's information-carrying capacity. Still, it's been marked "citation needed" for a while and it seems better to yank it out until a citable source can be found. 123davidn found a reference to that limit in a discussion forum posting, but that's not a citable source. I presume the discussion forum is not the original source, but that they may have seen the number quoted somewhere.--Srleffler 03:43, 1 November 2007 (UTC)

Uncited material removed from article:--Srleffler 03:43, 1 November 2007 (UTC)

In total, an optical cable can carry enough channels to carry data at rates as high as 14.4 Pb/s (circa 14 million Gb/s).

I remember that Lucent's Bell Labs calculated the theoretical limit of a fiber and published it. A quick google search gave only the hint, that it was a Nature article in 2001 and that they came up with 100 Tbit/s. Still needing an exact reference... Michilans (talk) 08:25, 1 October 2008 (UTC)

Brand-rex

Is brand rex a notable fibre producer? I found an abstract of Elliot's fibre optic cabling that mentions them, Previously I have read the book and recall is small, but full of good information for connecting, layout and routing of fibre, as well as other good things. I don't have the book on me at the moment, can anyone confirm if it is mentioned in Elliot's book? Abstract Fiber Optic Cabling, Second Edition (Newnes) ? A quick search seems to show lots of cabling connectors, more than fibres. User A1 (talk) 02:51, 17 November 2007 (UTC)

Merge with Colour coding of optical fibers

I oppose merging in Colour coding of optical fibers here. I'm not sure that material needs its own article, but it's too specialized for the article on optical fibers. Perhaps we need a article on optical fiber cables, which could incorporate that material and some material from this article.--Srleffler (talk) 02:24, 23 November 2007 (UTC)

That would work. We do need an article on optical fibre cabling. 132.205.99.122 (talk) 21:28, 23 November 2007 (UTC)

I support Srleffler's position and proposal. In fact, since it's more than a week since his comments, I'll make the new article at Optical fiber cable. The Photon 16:53, 1 December 2007 (UTC)

Speed

I removed the following from the article:

An often read misconseptions is, that information in optical fibers would travel at the speed of light. Actually the information is transmitted at "only" 200 000 km/s (300 000km/h devided by the refractive index of the optical fiber, which is n = 1.5 for silica fibers).

The first problem with this is that light by definition does travel at the speed of light. It's just that the speed of light in silica happens to be slower than the speed of light in vacuum. Beyond this, though, the speed of signals in fiber is not just governed by the propagation speed of light in silica. This is easiest to see in multimode fiber, where the light can be thought of as bouncing back and forth between the surfaces of the core as it travels. On average, the light follows a longer path than it would if it went straight down the fiber. The propagation speed of signals in the fiber is therefore less than the speed of light in silica. I was going to replace the paragraph above with something along these lines, but I don't have a citation handy to support it.--Srleffler (talk) 22:02, 29 September 2008 (UTC)

I agree with you, it wasn't very clear, what I wrote.

Your argument about multimode fiber (longer distance to travel) is negligible. In the pictures you always see these zick-zack rays, but actually the photons don't bounce back and for that often. In nature they are travelling much more straight, only hitting the walls every now and then. So the distance of the lightray is only marginally longer than the length of the fiber.

I agree with you, that a citation would be good, but aren't standard physics laws not enough. Every persons working with optical fibers, knows that the speed of light in a fiber is the speed of light in vacuum devided by the refractive index of the medium.

I found similar information as I orignally wrote, in the article Speed of light, where it says:

"When light is travelling around the globe in an optical fiber, the actual transit time is longer, in part because the speed of light is slower by about 35% in an optical fiber[10] depending on its refractive index n, v = c / n and straight lines rarely occur in global communications situations, but also because delays are created when the signal passes through an electronic switch or signal regenerator."

I'm not really happy with the statement, because it mixes up time used for electronics (slow!!!), longer fiber than the pure point to point distance and the physical consequences of a refractive index higher than 1. But better than nothing! Michilans (talk) 08:38, 1 October 2008 (UTC)

The effect of the zig-zag geometry on propagation velocity is responsible for modal dispersion, which is a pretty important effect. I agree it's negligible for gross purposes such as figuring out how long it takes a signal to arrive at its destination. We just have to word whatever we add to the article carefully, so we don't say that the speed is exactly c/n. I would have written that the speed is approximately c/n, but I couldn't remember for sure whether the waveguide geometry in singlemode fiber has any effect on propagation speed nor whether things like photonic crystal fiber have odd propagation velocities.--Srleffler (talk) 23:50, 1 October 2008 (UTC)

Application examples

I find it dismal that I can't find Synchronous optical networking (SONET), Fiber distributed data interface (FDDI), or TOSLINK anywhere on this page. This article is very heavy on theory and lacking any real examples of application except the caption on the picture of the TOSLINK cable. For shame! Someone please come back to Earth and throw us a few practical examples of your lofty conceptions. Stephen Charles Thompson (talk) 07:43, 25 October 2008 (UTC)

This article is an overview of optical fiber and fiber optics. It contains brief summaries of how optical fiber is used, but if you want to get into technical details you should be reading a more specific article, such as Fiber-optic communication, which has links to all of the articles you mentioned. The short section on fiber optic communications here begins with a link to the more detailed article on the topic.--Srleffler (talk) 14:09, 25 October 2008 (UTC)

Actually, the link to the main article Fiber-optic communication does not list Synchronous optical networking (SONET), Fiber distributed data interface (FDDI), or TOSLINK as examples either. It doesn't even mention or link Verizon FIOS as it discusses "..telecommunications companies to transmit telephone signals, Internet communication, and cable television signals...". Again, as I said, this is dismal. It lacks involvement with the general community by failing to provide examples or references to common objects they may be familiar with. It lacks participation with the reader at large. (e.g. Circus mentions Clowns and P.T. Barnum.) Stephen Charles Thompson (talk) 17:05, 25 October 2008 (UTC)

I'm not sure I understand your complaint. The article Fiber-optic communication certainly does contain links to the articles on SONET, FDDI, and TOSLINK. They are in the section on "Governing Standards". Perhaps you feel they should be discussed in some other way in the article? I'm not sure what you have in mind, though. You refer to them as "examples", but I'm not sure that is a good description. These are technical standards, two of which are probably of little importance to most readers. Similarly, you seem surprised we have no link to an article on a specific phone company's fiber optic service. Why would we? There are thousands of phone companies in the world. Should we have links to all of them in the main article on optical fiber? It's not even clear to me that the article on fiber optic communication should link to individual vendors, nor is it clear that Wikipedia should have an article on Verizon FiOS. --Srleffler (talk) 19:24, 25 October 2008 (UTC)

Proposed merger of optical fiber cable

Not that there's much to merge as the topic is fully covered in this article. Anyone mind a plain redirect? ˉˉ^anetode╦╩ 12:00, 12 November 2008 (UTC)

I mind. I reversed your edits. The fiber cable article had been vandalized a month ago, deleting most of its content. I restored the pre-vandal version. The articles are separate due to Summary style. That article treats the construction of fiber cables in more detail than this article. I also undid your change in categories. This is an odd case—we have a category on fiber optics as a discipline, and a category on optical fibers. The latter is for articles on specific types of optical fiber. There is no article on the field of fiber optics, however. This article is the "main article" for Category:Fiber optics, and also for Category:Optical fiber. Yes, it means the article is in a category and the parent category. Exception to the rule...--Srleffler (talk) 18:55, 12 November 2008 (UTC)

Ah, I didn't realize there was more to the cable article. I don't see the necessity in duplicating categories since the categorization scheme itself is not linearly hierarchical, but that's a minor issue. ˉˉ^anetode╦╩ 03:36, 13 November 2008 (UTC)

Fiber Optic Cable Testing

Hullo,

This is a request for information on

1. Fibre optic cable testing using an optical power source and an optical power meter

2. Wavelength (why only specific values like 630, 780, 850 ..... and not any other number)

3. Wavelenght dependency, polarization dependency and power range of the meter.

4. The spectral halfwidth of the source

5. The relevance of power measured in dBm.

and any other point relevant to testing of fiber optical fibers

NManju (talk) 10:35, 18 December 2008 (UTC)

Temperature figures are incorrect

1800 Kelvins isn't 2200 Celsius, but around 1530. And that's very close to the point at which glass forms. Could someone double-check this? —Preceding unsigned comment added by 87.252.237.202 (talk) 14:38, 9 February 2009 (UTC)

Yes, 1800 K is 1526.85 °C exactly; I believe the 1800 K is intended to be a figure rounded to the nearest hundred, so the conversion without false precision would be 1500 °C. I'm going to fix that. --A. di M. (talk) 16:33, 9 February 2009 (UTC)

GA Reassessment

This discussion is transcluded from Talk:Optical fiber/GA1. The edit link for this section can be used to add comments to the reassessment.

I've tweaked the article a little, but there are whole sections without references, counter-intuitive links, and excessive unexplained jargon. A. di M. (talk) 17:48, 1 February 2009 (UTC)

One week has passed since I nominated this for reassessment, and, apart for an added picture and the correction of statement in "History", the only improvements to the article since then were spelling fixes and the retargeting of some links to redirects. I'm going to delist this article from the GA list if no-one objects in three days. --A. di M. (talk) 22:55, 8 February 2009 (UTC)

User:Logger9/Strength of glass fiber

I copied this from my discussion page.--Afluegel (talk - WP Glass) 07:02, 11 April 2009 (UTC)

Somewhere recently here, I saw a question about why bundles of glass fiber don't crack or fail when they are dropped the floor. Well folks: here is my first shot at the answer. I would welcome input, as the article should improve somewhat with time. I'm still trying to dig up old articles I had when I was working in fiber optics development. I would like to get it up and running ASAP (with the appropriate Wiki tag for an article under construction) so please advise ! -- logger9 (talk) 06:53, 10 April 2009 (UTC)

Very good! I think you could easily include in the planned article also the strength of glass in general. I will copy this to the discussion pages of the articles Optical fiber and Fiberglass.--Afluegel (talk - WP Glass) 07:00, 11 April 2009 (UTC)

Mechanisms of attenuation

I have added a much-needed section on the mechanisms of attenuation (light scattering and bond stretching/absorption) in the UV-Vis-IR portions of the EM spectrum. -- logger9 (talk) 07:26, 12 April 2009 (UTC)

Added Section on Optical Fiber Coatings

Strangely absent in the article - polymeric coatings are critical to the fiber manufacturing process and even more so to the long term performance of the fiber. Someone commented on why optical fiber doesn't break. Due in a big way to FO coatings. Visit this Web site for more information —Preceding unsigned comment added by Pfoarde (talk • contribs) 22:19, 8 October 2009 (UTC)

Good catch. Not sure how we managed to miss that. I moved the new material up to another section in the article, and will copyedit it.--Srleffler (talk) 04:46, 9 October 2009 (UTC)

Thanks. It does seem ot fit better under the process section. I would also like to add some information about microbending and its relationship to signal attenuation. I'm not sure where that might best be placed. —Preceding unsigned comment added by 74.244.15.101 (talk) 10:55, 9 October 2009 (UTC)

Dielectric waveguide

I reverted some edits today. I think that trying to cram the definition of "dielectric" into the first sentence of that section breaks the flow of the sentence too much, and it just isn't that important. The key distinction is not whether the guide conducts electricity, but rather how the guide confines light. A metallic waveguide confines electromagnetic waves by simple reflection from the metal. A dielectric guide confines them by total internal reflection from a dielectric interface. This is the most important thing to say about a dielectric waveguide. The definition of "dielectric" follows in the second sentence of the section, both via a link to dielectric and the definition that a dielectric is an electrically nonconducting material.--Srleffler (talk) 21:09, 11 October 2009 (UTC)

FIBER OPTICS

THE BASICS OF FIBER OPTIC CABLE (Single-mode multi-mode)

a Tutorial

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BRIEF OVER VIEW OF FIBER OPTIC CABLE ADVANTAGES OVER COPPER: • SPEED: Fiber optic networks operate at high speeds - up into the gigabits • BANDWIDTH: large carrying capacity • DISTANCE: Signals can be transmitted further without needing to be "refreshed" or strengthened. • RESISTANCE: Greater resistance to electromagnetic noise such as radios, motors or other nearby cables. • MAINTENANCE: Fiber optic cables costs much less to maintain.

In recent years it has become apparent that fiber-optics are steadily replacing copper wire as an appropriate means of communication signal transmission. They span the long distances between local phone systems as well as providing the backbone for many network systems. Other system users include cable television services, university campuses, office buildings, industrial plants, and electric utility companies.

A fiber-optic system is similar to the copper wire system that fiber-optics is replacing. The difference is that fiber-optics use light pulses to transmit information down fiber lines instead of using electronic pulses to transmit information down copper lines. Looking at the components in a fiber-optic chain will give a better understanding of how the system works in conjunction with wire based systems.

At one end of the system is a transmitter. This is the place of origin for information coming on to fiber-optic lines. The transmitter accepts coded electronic pulse information coming from copper wire. It then processes and translates that information into equivalently coded light pulses. A light-emitting diode (LED) or an injection-laser diode (ILD) can be used for generating the light pulses. Using a lens, the light pulses are funneled into the fiber-optic medium where they travel down the cable. The light (near infrared) is most often 850nm for shorter distances and 1,300nm for longer distances on Multi-mode fiber and 1300nm for single-mode fiber and 1,500nm is used for for longer distances.

Think of a fiber cable in terms of very long cardboard roll (from the inside roll of paper towel) that is coated with a mirror on the inside. If you shine a flashlight in one end you can see light come out at the far end - even if it's been bent around a corner.

Light pulses move easily down the fiber-optic line because of a principle known as total internal reflection. "This principle of total internal reflection states that when the angle of incidence exceeds a critical value, light cannot get out of the glass; instead, the light bounces back in. When this principle is applied to the construction of the fiber-optic strand, it is possible to transmit information down fiber lines in the form of light pulses. The core must a very clear and pure material for the light or in most cases near infrared light (850nm, 1300nm and 1500nm). The core can be Plastic (used for very short distances) but most are made from glass. Glass optical fibers are almost always made from pure silica, but some other materials, such as fluorozirconate, fluoroaluminate, and chalcogenide glasses, are used for longer-wavelength infrared applications.

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There are three types of fiber optic cable commonly used: single mode, multimode and plastic optical fiber (POF).

Transparent glass or plastic fibers which allow light to be guided from one end to the other with minimal loss.

Fiber optic cable functions as a "light guide," guiding the light introduced at one end of the cable through to the other end. The light source can either be a light-emitting diode (LED)) or a laser.

The light source is pulsed on and off, and a light-sensitive receiver on the other end of the cable converts the pulses back into the digital ones and zeros of the original signal.

Even laser light shining through a fiber optic cable is subject to loss of strength, primarily through dispersion and scattering of the light, within the cable itself. The faster the laser fluctuates, the greater the risk of dispersion. Light strengtheners, called repeaters, may be necessary to refresh the signal in certain applications.

While fiber optic cable itself has become cheaper over time - a equivalent length of copper cable cost less per foot but not in capacity. Fiber optic cable connectors and the equipment needed to install them are still more expensive than their copper counterparts.

Single Mode cable is a single stand (most applications use 2 fibers) of glass fiber with a diameter of 8.3 to 10 microns that has one mode of transmission. Single Mode Fiber with a relatively narrow diameter, through which only one mode will propagate typically 1310 or 1550nm. Carries higher bandwidth than multimode fiber, but requires a light source with a narrow spectral width. Synonyms mono-mode optical fiber, single-mode fiber, single-mode optical waveguide, uni-mode fiber.

Single Modem fiber is used in many applications where data is sent at multi-frequency (WDM Wave-Division-Multiplexing) so only one cable is needed - (single-mode on one single fiber)

Single-mode fiber gives you a higher transmission rate and up to 50 times more distance than multimode, but it also costs more. Single-mode fiber has a much smaller core than multimode. The small core and single light-wave virtually eliminate any distortion that could result from overlapping light pulses, providing the least signal attenuation and the highest transmission speeds of any fiber cable type.

Single-mode optical fiber is an optical fiber in which only the lowest order bound mode can propagate at the wavelength of interest typically 1300 to 1320nm.

jump to single mode fiber page

Multi-Mode cable has a little bit bigger diameter, with a common diameters in the 50-to-100 micron range for the light carry component (in the US the most common size is 62.5um). Most applications in which Multi-mode fiber is used, 2 fibers are used (WDM is not normally used on multi-mode fiber). POF is a newer plastic-based cable which promises performance similar to glass cable on very short runs, but at a lower cost.

Multimode fiber gives you high bandwidth at high speeds (10 to 100MBS - Gigabit to 275m to 2km) over medium distances. Light waves are dispersed into numerous paths, or modes, as they travel through the cable's core typically 850 or 1300nm. Typical multimode fiber core diameters are 50, 62.5, and 100 micrometers. However, in long cable runs (greater than 3000 feet [914.4 meters), multiple paths of light can cause signal distortion at the receiving end, resulting in an unclear and incomplete data transmission so designers now call for single mode fiber in new applications using Gigabit and beyond.

The use of fiber-optics was generally not available until 1970 when Corning Glass Works was able to produce a fiber with a loss of 20 dB/km. It was recognized that optical fiber would be feasible for telecommunication transmission only if glass could be developed so pure that attenuation would be 20dB/km or less. That is, 1% of the light would remain after traveling 1 km. Today's optical fiber attenuation ranges from 0.5dB/km to 1000dB/km depending on the optical fiber used. Attenuation limits are based on intended application.

The applications of optical fiber communications have increased at a rapid rate, since the first commercial installation of a fiber-optic system in 1977. Telephone companies began early on, replacing their old copper wire systems with optical fiber lines. Today's telephone companies use optical fiber throughout their system as the backbone architecture and as the long-distance connection between city phone systems.

Cable television companies have also began integrating fiber-optics into their cable systems. The trunk lines that connect central offices have generally been replaced with optical fiber. Some providers have begun experimenting with fiber to the curb using a fiber/coaxial hybrid. Such a hybrid allows for the integration of fiber and coaxial at a neighborhood location. This location, called a node, would provide the optical receiver that converts the light impulses back to electronic signals. The signals could then be fed to individual homes via coaxial cable.

Local Area Networks (LAN) is a collective group of computers, or computer systems, connected to each other allowing for shared program software or data bases. Colleges, universities, office buildings, and industrial plants, just to name a few, all make use of optical fiber within their LAN systems.

Power companies are an emerging group that have begun to utilize fiber-optics in their communication systems. Most power utilities already have fiber-optic communication systems in use for monitoring their power grid systems.

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jump to Illustrated Fiber Optic Glossary pages

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Fiber

by John MacChesney - Fellow at Bell Laboratories, Lucent Technologies

Some 10 billion digital bits can be transmitted per second along an optical fiber link in a commercial network, enough to carry tens of thousands of telephone calls. Hair-thin fibers consist of two concentric layers of high-purity silica glass the core and the cladding, which are enclosed by a protective sheath. Light rays modulated into digital pulses with a laser or a light-emitting diode move along the core without penetrating the cladding.

The light stays confined to the core because the cladding has a lower refractive index—a measure of its ability to bend light. Refinements in optical fibers, along with the development of new lasers and diodes, may one day allow commercial fiber-optic networks to carry trillions of bits of data per second.

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Total internal refection confines light within optical fibers (similar to looking down a mirror made in the shape of a long paper towel tube). Because the cladding has a lower refractive index, light rays reflect back into the core if they encounter the cladding at a shallow angle (red lines). A ray that exceeds a certain "critical" angle escapes from the fiber (yellow line).

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STEP-INDEX MULTIMODE FIBER has a large core, up to 100 microns in diameter. As a result, some of the light rays that make up the digital pulse may travel a direct route, whereas others zigzag as they bounce off the cladding. These alternative pathways cause the different groupings of light rays, referred to as modes, to arrive separately at a receiving point. The pulse, an aggregate of different modes, begins to spread out, losing its well-defined shape. The need to leave spacing between pulses to prevent overlapping limits bandwidth that is, the amount of information that can be sent. Consequently, this type of fiber is best suited for transmission over short distances, in an endoscope, for instance.

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GRADED-INDEX MULTIMODE FIBER contains a core in which the refractive index diminishes gradually from the center axis out toward the cladding. The higher refractive index at the center makes the light rays moving down the axis advance more slowly than those near the cladding. Also, rather than zigzagging off the cladding, light in the core curves helically because of the graded index, reducing its travel distance. The shortened path and the higher speed allow light at the periphery to arrive at a receiver at about the same time as the slow but straight rays in the core axis. The result: a digital pulse suffers less dispersion.

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SINGLE-MODE FIBER has a narrow core (eight microns or less), and the index of refraction between the core and the cladding changes less than it does for multimode fibers. Light thus travels parallel to the axis, creating little pulse dispersion. Telephone and cable television networks install millions of kilometers of this fiber every year.

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BASIC CABLE DESIGN

1 - Two basic cable designs are:

Loose-tube cable, used in the majority of outside-plant installations in North America, and tight-buffered cable, primarily used inside buildings.

The modular design of loose-tube cables typically holds up to 12 fibers per buffer tube with a maximum per cable fiber count of more than 200 fibers. Loose-tube cables can be all-dielectric or optionally armored. The modular buffer-tube design permits easy drop-off of groups of fibers at intermediate points, without interfering with other protected buffer tubes being routed to other locations. The loose-tube design also helps in the identification and administration of fibers in the system.

Single-fiber tight-buffered cables are used as pigtails, patch cords and jumpers to terminate loose-tube cables directly into opto-electronic transmitters, receivers and other active and passive components.

Multi-fiber tight-buffered cables also are available and are used primarily for alternative routing and handling flexibility and ease within buildings.

2 - Loose-Tube Cable In a loose-tube cable design, color-coded plastic buffer tubes house and protect optical fibers. A gel filling compound impedes water penetration. Excess fiber length (relative to buffer tube length) insulates fibers from stresses of installation and environmental loading. Buffer tubes are stranded around a dielectric or steel central member, which serves as an anti-buckling element.

The cable core, typically uses aramid yarn, as the primary tensile strength member. The outer polyethylene jacket is extruded over the core. If armoring is required, a corrugated steel tape is formed around a single jacketed cable with an additional jacket extruded over the armor.

Loose-tube cables typically are used for outside-plant installation in aerial, duct and direct-buried applications.

3 - Tight-Buffered Cable With tight-buffered cable designs, the buffering material is in direct contact with the fiber. This design is suited for "jumper cables" which connect outside plant cables to terminal equipment, and also for linking various devices in a premises network.

Multi-fiber, tight-buffered cables often are used for intra-building, risers, general building and plenum applications.

The tight-buffered design provides a rugged cable structure to protect individual fibers during handling, routing and connectorization. Yarn strength members keep the tensile load away from the fiber.

As with loose-tube cables, optical specifications for tight-buffered cables also should include the maximum performance of all fibers over the operating temperature range and life of the cable. Averages should not be acceptable.

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Connector Types

Gruber Industries cable connectors

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here are some common fiber cable types

Distribution Cable

Distribution Cable (compact building cable) packages individual 900µm buffered fiber reducing size and cost when compared to breakout cable. The connectors may be installed directly on the 900µm buffered fiber at the breakout box location. The space saving (OFNR) rated cable may be installed where ever breakout cable is used. FIS will connectorize directly onto 900µm fiber or will build up ends to a 3mm jacketed fiber before the connectors are installed.

Indoor/Outdoor Tight Buffer

FIS now offers indoor/outdoor rated tight buffer cables in Riser and Plenum rated versions. These cables are flexible, easy to handle and simple to install. Since they do not use gel, the connectors can be terminated directly onto the fiber without difficult to use breakout kits. This provides an easy and overall less expensive installation. (Temperature rating -40ºC to +85ºC).

Indoor/Outdoor Breakout Cable

FIS indoor/outdoor rated breakout style cables are easy to install and simple to terminate without the need for fanout kits. These rugged and durable cables are OFNR rated so they can be used indoors, while also having a -40c to +85c operating temperature range and the benefits of fungus, water and UV protection making them perfect for outdoor applications. They come standard with 2.5mm sub units and they are available in plenum rated versions.

Corning Cable Systems Freedm LST Cables

Corning Cable Systems FREEDM® LST™ cables are OFNR-rated, UV-resistant, fully waterblocked indoor/outdoor cables. This innovative DRY™ cable with water blocking technology eliminates the need for traditional flooding compound, providing more efficient and craft-friendly cable preparation. Available in 62.5µm, 50µm, Singlemode and hybrid versions.

Krone Indoor Outdoor Dry Loose Tube Cable

KRONE’s innovative line of indoor/outdoor loose tube cables are designed to meet all the rigors of the outside plant environment, and the necessary fire ratings to be installed inside the building. These cables eliminate the gel filler of traditional loose tube style cables with super absorbent polymers.

Loose Tube Cable

Loose tube cable is designed to endure outside temperatures and high moisture conditions. The fibers are loosely packaged in gel filled buffer tubes to repel water. Recommended for use between buildings that are unprotected from outside elements. Loose tube cable is restricted from inside building use, typically allowing entry not to exceed 50 feet (check your local codes).

Aerial Cable/Self-Supporting

Aerial cable provides ease of installation and reduces time and cost. Figure 8 cable can easily be separated between the fiber and the messenger. Temperature range ( -55ºC to +85ºC)

Hybrid & Composite Cable

Hybrid cables offer the same great benefits as our standard indoor/outdoor cables, with the convenience of installing multimode and singlemode fibers all in one pull. Our composite cables offer optical fiber along with solid 14 gauge wires suitable for a variety of uses including power, grounding and other electronic controls.

Armored Cable

Armored cable can be used for rodent protection in direct burial if required. This cable is non-gel filled and can also be used in aerial applications. The armor can be removed leaving the inner cable suitable for any indoor/outdoor use. (Temperature rating -40ºC to +85ºC)

Low Smoke Zero Halogen (LSZH)

Low Smoke Zero Halogen cables are offered as as alternative for halogen free applications. Less toxic and slower to ignite, they are a good choice for many international installations. We offer them in many styles as well as simplex, duplex and 1.6mm designs. This cable is riser rated and contains no flooding gel, which makes the need for a separate point of termination unnecessary. Since splicing is eliminated, termination hardware and labor times are reduced, saving you time and money. This cable may be run through risers directly to a convenient network hub or splicing closet for interconnection.

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What's the best way to terminate fiber optic cable? That depends on the application, cost considerations and your own personal preferences. The following connector comparisons can make the decision easier.

Epoxy & Polish

Epoxy & polish style connectors were the original fiber optic connectors. They still represent the largest segment of connectors, in both quantity used and variety available. Practically every style of connector is available including ST, SC, FC, LC, D4, SMA, MU, and MTRJ. Advantages include:

• Very robust. This connector style is based on tried and true technology, and can withstand the greatest environmental and mechanical stress when compared to the other connector technologies. • This style of connector accepts the widest assortment of cable jacket diameters. Most connectors of this group have versions to fit onto 900um buffered fiber, and up to 3.0mm jacketed fiber. • Versions are. available that hold from 1 to 24 fibers in a single connector.

Installation Time: There is an initial setup time for the field technician who must prepare a workstation with polishing equipment and an epoxy-curing oven. The termination time for one connector is about 25 minutes due to the time needed to heat cure the epoxy. Average time per connector in a large batch can be as low as 5 or 6 minutes. Faster curing epoxies such as anaerobic epoxy can reduce the installation time, but fast cure epoxies are not suitable for all connectors.

Skill Level: These connectors, while not difficult to install, do require the most supervised skills training, especially for polishing. They are best suited for the high-volume installer or assembly house with a trained and stable work force.

Costs: Least expensive connectors to purchase, in many cases being 30 to 50 percent cheaper than other termination style connectors. However, factor in the cost of epoxy curing and ferrule polishing equipment, and their associated consumables.

Pre-Loaded Epoxy or No-Epoxy & Polish

There are two main categories of no-epoxy & polish connectors. The first are connectors that are pre-loaded with a measured amount of epoxy. These connectors reduce the skill level needed to install a connector but they don't significantly reduce the time or equipment need-ed. The second category of connectors uses no epoxy at all. Usually they use an internal crimp mechanism to stabilize the fiber. These connectors reduce both the skill level needed and installation time. ST, SC, and FC connector styles are available. Advantages include:

• Epoxy injection is not required. • No scraped connectors due to epoxy over-fill. • Reduced equipment requirements for some versions.

Installation Time: Both versions have short setup time, with pre-loaded epoxy connectors having a slightly longer setup. Due to curing time, the pre-loaded epoxy connectors require the same amount of installation time as standard connectors, 25 minutes for 1 connector, 5-6 minutes average for a batch. Connectors that use the internal crimp method install in 2 minutes or less.

Skill Level: Skill requirements are reduced because the crimp mechanism is easier to master than using epoxy. They provide maximum flexibility with one technology and a balance between skill and cost.

Costs: Moderately more expensive to purchase than a standard connector. Equipment cost is equal to or less than that of standard con¬nectors. Consumable cost is reduced to polish film and cleaning sup-plies. Cost benefits derive from reduced training requirements and fast installation time.

No-Epoxy & No-Polish

Easiest and fastest connectors to install; well suited for contractors who cannot cost-justify the training and supervision required for standard connectors. Good solution for fast field restorations. ST, SC, FC, LC, and MTRJ connector styles are available. Advantages include: • No setup time required. • Lowest installation time per connector. • Limited training required. • Little or no consumables costs.

Installation Time: Almost zero. Its less than 1 minute regardless of number of connectors.

Skill level: Requires minimal training, making this type of connector ideal for installation companies with a high turnover rate of installers and/or that do limited amounts of optical-fiber terminations.

Costs: Generally the most expensive style connector to purchase, since some of the labor (polishing) is done in the factory. Also, one or two fairly expensive installation tools may be required. However, it may still be less expensive on a cost-per-installed-connector basis due to lower labor cost.

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jump to Calculating fiber loss and distance

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jump to related fiber optic equipment pages

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jump to Telebyte Fiber tutorial pages

(very good write up)

2. The Fiber Optic Data Communications Link For the Premises Environment

   2.1 The Fiber Optic data Communications Link, End-to-End
   2.2 Fiber Optic Cable
   2.3 Transmitter
   2.4 Receiver
   2.5 Connectors
   2.6 Splicing
   2.7 Analyzing Performance of a Link

jump to The Complete Telebyte Fiber tutorial pages

jump to In-depth - very technical - Fiber optic write up

jump to The Belden Cable Company's Fiber tutorial

jump to Fiber 101 by Corning Incorporated a good animated Tutorial

jump to WDM basics (Wavelength Division Multiplexing) URL

jump to DWDM basics (Dense Wavelength Division Multiplexing) URL

jump to Fiber Optics Training Provider also view

http://en.wikipedia.org/wiki/Optical_fiber The Fiber Optic Association FOA color code for connectors Lennie Lightwave's Guide To Fiber Optics "Fibers", article in RP Photonics' Encyclopedia of Laser Physics and Technology How Fiber Optics are made In video "Fibre optic technologies", Mercury Communications Ltd, August 1992. "Photonics & the future of fiber", Mercury Communications Ltd, March 1993

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ARC Electronics 800-926-0226 arc@arcelect.com jump to... Home Page —Preceding unsigned comment added by 188.116.220.6 (talk) 15:36, 19 March 2010 (UTC)

Maximum number of fusions

Is there a maximum number of splice fusions for a (SM and MM) optical fiber cable?--Jdvillalobos (talk) 16:56, 29 March 2010 (UTC)

That would depend on how bad the splices are. If you can get a near-zero dB loss, you can repeat it as many times as you want.Toddyboy711 (talk) 02:30, 2 April 2010 (UTC)

Manfred Börner

In 1965 Manfred Börner from the german Telefunken AG fabricated the first Optical-Fiber-Data-Conduction-System, constructed out of a laser diode, fiberglass and photodiode. 1966 he patented this System (Manfred Börner, Mehrstufiges Übertragungssystem für Pulscodemodulation dargestellte Nachrichten, DBP Nr. 1254513, 1966 / French Pat.Nt. 1548972 / Brit. Pat. Nr. 1202418 / US Pat. Nr. 3845-293). Matzei (talk) 00:53, 27 April 2010 (UTC)

If this person is who you say he is, then he should be very notable. Try making a stub of a wikipedia page for him. I don't think I'm being "anglosphere-centric" when a google search of his name gives no indication of his notability. johnpseudo 12:29, 27 April 2010 (UTC)

Some links for you:
- Joachim Hagenauers speech at the ITG Festveranstaltung 26. April 2004 Citation Prof. Dr. Joachim Hagenauer: "So der leider verstorbene Professor Börner, der aus den Forschungslabors von AEG/Telefunken hervorging und bis 1994 an der TU München lehrte. Er gilt als der visionäre Erfinder der Glasfaserübertragung (English: He is the visionary inventor of the Optical-Fiber-Conduction), einer Technik, die heute das Rückgrad der weltweiten Kommunikation darstellt.
- Südwestrundfunk SWR2, Datenströme durch die Tiefsee, 16. Januar 2006, 08.30 Uhr Text MP3 Download Citation Prof. Reinhold Noé: „In den 60er Jahren wurden Glasfasern mit niedrigem Verlust entwickelt. Im Jahre 1966 hat der spätere Professor Manfred Börner erstmalig Licht moduliert und damit Daten übertragen (English: In 1966 Manfred Börner was the first, who modulated light [laser diode -> fiberglass -> photodiode] to transfer datas “
- http://www.heise.de/ct/artikel/Synergien-zerbroeselt-289306.html Citation: "Im Forschungsinstitut Ulm sicherte Manfred Börner 1966 dem Unternehmen weltweit das erste Patent für ein Glasfaser-Übertragungssystem." (English: At the researche institute in Ulm Manfred Börner registered for the company [Telefunken] the first patent for the Optical-Fiber-Data-Conduction
- http://klausdietz.de/KLausElektronikGeschichte.html
- http://de.wikipedia.org/wiki/Manfred_B%C3%B6rner
Matzei (talk) 04:49, 28 April 2010 (UTC)

It seems like you have a handful of personal accounts from German physicists and a link to a German wikipedia article that you wrote. Can you show me a link to a reliable source? Something official, written on behalf of an establishment (like a research journal, magazine, newspaper, etc.)? johnpseudo 12:35, 28 April 2010 (UTC)

Hi Johnpseudo, i'll name you some official sources:
- M. J. Howes and D. V. Morgan, eds., Optical Fiber Communications,. p. 4 (Chapter 1, P.Russer, Introduction to optical communications), Wiley, New York. (1980): Citation: "The first suggestions to use fibers as a transmission medium for optical communication were made in 1966 by Kao and Hockham, Werts, and Boerner."
- Hans-Georg Unger, Vater der Glasfaserkommunikation, Physik Journal (2009) Nr. 12, Wiley-VCH Verlag, Weinheim
- http://www.heise.de/ct/artikel/Synergien-zerbroeselt-289306.html Citation: "Im Forschungsinstitut Ulm sicherte Manfred Börner 1966 dem Unternehmen weltweit das erste Patent für ein Glasfaser-Übertragungssystem." (English: At the researche institute in Ulm Manfred Börner registered for the company [Telefunken] the first patent for the Optical-Fiber-Data-Conduction" -> C't Magazin is a prestigious german Magazin
- Wolfgang Kaiser, Eduard-Rhein-Preis für Prof Dr. Manfred Börner, TUM Mitteilungen 1 - 90/91, Seite 30f, Citation: "Der Systemvorschlag von Prof. Börner beruht auf dem sinnvollen Zusammenwirken von Laserdiode als Lichtsender, Glasfaser als Übertragungsmedium und Photodiode."
Matzei (talk) 13:49, 29 April 2010 (UTC)

That seems to be pretty good sourcing to me. But I still think your original wording overstates his significance. "Until today all optoelectronic Data-Conduction-Systems are based on his suggestion." doesn't really seem supported by your sources. He was one of several scientists who came to the same conclusion. It also doesn't seem like he really "fabricated the first Optical-Fiber-Data-Conduction-System". He just patented the first system. johnpseudo 13:19, 30 April 2010 (UTC)

Good morning Johnpseudo, my original wording comes from Wolfgang Kaisers Laudatio on Manfred Börner, as he got the very distinguished Eduard-Rhein-Preis in 1990 (Award Winners). Source: TUM Mitteilungen 1 - 90/91, Seite 30f, Citation: "[...] sein vor bereits 25 Jahren gemachter, richtungsweisender Vorschlag, digitale optische Übertragungssysteme auf der Basis von Streckenabschnitten aufzubauen, die aus Halbleiter-Laserdioden, Glasfaserleitungen und Photodioden bestehen. Alle optischen Weitverkehrs-Übertragungssysteme arbeiten heute nach diesem, von Prof. Börner angegebenen Systemprinzip. (English: His 25 years old, trend-setting suggestion, to build optical conduction-systems based on segments out of laser diodes, fiberglasses and photodiodes. Today all optical long-distance-conduction-systems are working with this form Prof. Börner proposed principle system)." Matzei (talk) 04:10, 1 May 2010 (UTC)

I'm just trying to reconcile the fact that Börner seems to be relatively obscure for a person who invented fiber-optic communication. Perhaps Wolfgang Kaiser was a little generous with the facts in his "Laudatio". Perhaps Börner was only one of several people who made the same suggestion, as your other more-reliable sources state. It would be only natural for someone to exaggerate a little when presenting such a prize. johnpseudo 15:41, 3 May 2010 (UTC)

Do you also think the same about the Nobel Prize and the Nobel Prize Encomiums? Don't answer, because i don't want to continue this conversation. I don't wast my time to discuss with a totaly ignorant interlocutor. The historians will finde out the truth, i know and i'am sure. Matzei (talk) 22:09, 24 May 2010 (UTC)

...And when they do that, it will become appropriate for us to put it here on wikipedia. I'm sorry you came away feeling upset. Schönen Tag noch! johnpseudo 15:25, 25 May 2010 (UTC)

...No hard feelings. Until honesty! Auch Dir, Johnpseudo, eine gute Zeit! Matzei (talk) 01:39, 26 May 2010 (UTC)

Well this link from the German article on Börner to the original patent application constitutes enough proof of his significance. In contrast to this, using - in the case of Nishizawa - one of this researcher's own, later works as a reference for his claim to have devised optical data transmission over an optical fibre already in 1963 doesn't live up to the standard's you wish to apply in Börner's case, Johnpseudo, does it? Inclusion of Börner in this article is fully warranted, hence I have added a respective sentence. -- HenryH 85.180.181.194 (talk) 10:10, 27 December 2011 (UTC)

New lead sentence

As it stands, the article starts talking about optical fibers without explaining what they are. I originally added a lead sentence saying that it was a medium designed for carrying light messages. However, DKquerty reverted "per WP:NPOV: there are many uses for fiber optics beyond "messages"". As a compromise, how about saying that it is just a medium designed to carry light? (X! · talk)  · @632  ·  14:10, 17 July 2010 (UTC)

Perhaps "a medium designed to carry light, often as discrete information." DKqwerty (talk) 22:04, 17 July 2010 (UTC)

I find the lead to be a generally good introduction. I'm inclined to remove the rewrite tag from the top of the article. --Kvng (talk) 03:42, 23 September 2010 (UTC)

Contribution

The following sections were contributed by 59.161.83.214 (talk · contribs). I don't feel they're ready for inclusion in the article mainly due to WP:OR concerns but maybe someone can improve the material - Talk:Optical fiber/59.161.83.214

misleading illustrations

The illustrations of light beams literally bouncing off the cylindrical boundry of the fiber are misleading. Actual light in actual fibers does not act like that. Reasoning is: If a beam of light is to be propagated by a certain distance, its diameter cannot be arbitrarily small. After a distance called Rayleigh length the beam diverges to the double crossection. After several Rayleigh lengths the beam diameter is larger than the fiber diameter which obviously yields a different picture.
The image with the green beam seems to contradict the above reasoning with nice reflections. However, the acrylic rod is not a fiber. Its diameter is more than tenfold the diameter of the largest glass fibers available. It is more than hundredfold the dimension of the most popular multimode fibers. Now, try to scale the experiment down. The diameter of the laser beam is about a thenth of the diameter of the rod. The diameter of a typical multimode fiber is about 100 micron. This implies a laser beam diameter of about 10 microns to yield smilar relations as with the acrylic rod. But the rayleigh length of a green beam with 10 micron width is 0.6 mm, only. It quickly diverges and fills the whole fiber after about a centimeter. For the largest available fibers the core is about 1 mm. In this case the rayleigh length of the laser beam is not that small. But after a few meters the fiber is still completely filled by the beam.
Note, that reflections from the strongly curved wall will make the beam diverge even faster. So the image of a narrow beams bouncing off the walls is inappropriate to illustrate the way a multimode fiber actually works and should be removed.-----<(kaimartin)>--- (talk) 00:09, 7 February 2011 (UTC)

Radiation Effects on Optical Fiber Systems

Why is not the radiation effects on optical fiber systems mentioned? I know that optical fiber have improved their resistant to radiation. But should it not be mention from an historic point of view at least.

Some research has been don on the subject. Radiation Effects on Optical Fiber Systems —Preceding unsigned comment added by 193.12.210.241 (talk) 08:37, 15 March 2011 (UTC)