Ultrashort pulse laser
An ultrashort pulse laser is a laser that emits ultrashort pulses of light, generally of the order of femtoseconds to ten picoseconds. They are also known as ultrafast lasers owing to the speed at which pulses "turn on" and "off"—not to be confused with the speed at which light propagates, which is determined by the properties of the medium (and has an upper limit), particularly its index of refraction, and can vary as a function of field intensity (i.e. self-phase modulation) and wavelength (chromatic dispersion).
Common current ultrashort pulse laser technologies include Ti-sapphire lasers and dye lasers. High output peak power usually requires chirped pulse amplification of a seed pulse from a modelocked laser. Dealing with high optical powers also needs the nonlinear optical phenomena to be taken in account.
Use in Pathogen Inactivation
Tsen and colleagues developed a SEPHODIS (selective photonic disinfection) technology using an ultrashort pulse laser to kill viruses including HIV, influenza virus, and noroviruses. The technique appears to damage viral capsids while preserving other proteins and biological materials, although these claims have been disputed elsewhere. The ultrashort pulse laser treatment may have potential applications in the disinfection of medicines, in the production of inactivated vaccines, and in the possible future treatment of blood-borne viral infections from agents such as HIV and Ebola virus.
- Weiss, Peter (November 12, 2002). "Hot flashes, cold cuts: ultrafast lasers give power tools a new edge". Science News. Society for Science & the Public.
- Paschotta, Rüdiger. "Ultrashort pulses". Encyclopedia of Laser Physics and Technology. RP Photonics. Retrieved Oct 21, 2014.
- Christensen, Bill (November 19, 2007). "Laser Zaps Viruses". Live Science.
- "Laser treatment 'could kill HIV'". BBC News. November 6, 2007.
- Won, Rachel (2010). "Biophotonics: Selective disinfection". Nature Photonics. 4 (3): 136. Bibcode:2010NaPho...4..136W. doi:10.1038/nphoton.2010.10.
- Tsen, Shaw-Wei D; Wu, Tzyy; Kiang, Juliann G; Tsen, Kong-Thon (2012). "Prospects for a novel ultrashort pulsed laser technology for pathogen inactivation". Journal of Biomedical Science. 19: 62. doi:10.1186/1423-0127-19-62. PMC 3495397. PMID 22768792.
- Wigle, Jeffrey C.; Holwitt, Eric A.; Estlack, Larry E.; Noojin, Gary D.; Saunders, Katharine E.; Yakovlev, Valdislav V.; Rockwell, Benjamin A. (2014). "No effect of femtosecond laser pulses on M13,E. coli, DNA, or protein". Journal of Biomedical Optics. 19 (1): 15008. Bibcode:2014JBO....19a5008W. doi:10.1117/1.JBO.19.1.015008. PMID 24474502. S2CID 20774027.
- "Tsen Technologies". Tsen Technologies (Company).
- Tsen, Shaw-Wei (2016). Selective photonic disinfection: A ray of hope in the war against pathogens. San Rafael, CA: Morgan & Claypool. ISBN 978-1681743523.
- Ultrafast Lasers: An animated guide to the functioning of Ti:Sapphire lasers and amplifiers.
- Tsen, Kong-Thon (2009). "Selective destruction of viruses with ultrashort pulsed lasers". SPIE Newsroom. CiteSeerX 10.1.1.506.3551. doi:10.1117/2.1200911.1845.