Talk:Ultrafast monochromator

Delete page[edit]

I do not believe this material is valid at all. Narrowband light by definition is spread out in time, and short pulses are by definition wideband. There is no literature using this term. Does anyone object to deleting this page? Interferometrist (talk) 19:35, 22 July 2014 (UTC)[reply]

I remember being a bit up in the air on this when I stumbled across this article: the described device does exist (e.g., [1]), but it's unusual enough that it's hard to tell whether the exact term "ultrafast monochromator" is widely accepted or used outside limited groups. I really don't have great journal access any more to follow up on such questions.

As to the physical objections, I really didn't clean this article up enough. The selection in this case isn't as narrow as you imagine from the word monochromator. The common use is to select a band of extreme ultraviolet wavelengths associated with a higher order harmonic of a Ti:sapph. Laura Scudder | talk 23:20, 29 July 2014 (UTC)[reply]

Hi, thanks for the response. Well I looked into it a bit further and skimmed a few papers. Both because there were ONLY a few such papers, and I don't think I've seen one yet where Luca Poletto wasn't one of the authors. Which suggests it's a rather narrow topic, but not beyond notability criteria for WP. A few observations:

Yes you're right, "monochromator" is misleading since it involves selecting a rather broad (by my standards) wavelength range in the XUV. So my original objection that monochromaticity is incompatible with short pulses was misplaced. The intention is to keep the pulses compact in time relative to the bandwidth selected, which as they point out will be the case when using a grating with the minimum number of grooves required for the bandwidth selected. But which isn't the case for one used at grazing incidence, which I guess is what they have to use for those short wavelengths, hence the problem.
The term "Time-preserving monochromator" appears more appropriate, is used in the same papers, and generates more Google hits, and is probably preferred ("ultra-fast" sounds like hype). In other words, not to extend the UV pulse much longer than the original femtosecond pulse was.
The article at the very end mentions "A major application is the extraction, without time-broadening, of a single high-order harmonic pulse out of the many generated by an ultrafast laser pulse interacting with a gas target." But actually that is its ONLY application, and in fact its only context, so that should rather have been placed at the start. (Not a criticism of the editor who wrote that, for that fact wouldn't have been obvious).
And since that is the only context for this topic, I'd suggest that the material should rather be merged into Ultrashort pulse#Pulse shape control where this issue is more thoroughly discussed. Although that page doesn't (yet) discuss High harmonic generation where it could also be mentioned, but the issue of avoiding pulse broadening appears most prominently on the Ultrashort pulse page.

Do you not agree, and would you have any interest in performing such a transplant? It seems like a lot of work for one esoteric topic, but it would get read a lot more there by people who were interested in the context but never ran across the term and thus never looked it up. The Ultrashort pulse page gets a lot more traffic whereas one would more likely only stumble on Ultrafast monochromator by accident (like I did!). And in any case to link it closely to High harmonic generation. How does that sound? Interferometrist (talk) 16:50, 31 July 2014 (UTC)[reply]

P.S. If you are interested in further editing this topic, and you are limited in your journal access, I'd happily send you copies of the papers (I have downloaded 3). For something less intensive, there's a powerpoint which you'd have access to (but I CANNOT send its URL because of the blacklist, but search Google for "time-preserving monochromator luca_polleto.pdf" and it should pop up). And if you can't download another paper, I could proably get it and possibly send it by email. Interferometrist (talk) 17:06, 31 July 2014 (UTC)[reply]

I think transplanting sounds like a reasonable solution. Thanks for the offer on the papers; you can email me at my username at gmail. I don't think the topic really warrants a bunch of fleshing out, but some referencing will sure be called for. Laura Scudder | talk 18:25, 31 July 2014 (UTC)[reply]