New mid-infrared laser system could detect atmospheric chemicals
Researchers at MIT and elsewhere have found a new way of using mid-infrared lasers to turn regions of molecules in the open air into glowing filaments of electrically charged gas, or plasma. The new method could make it possible to carry out remote environmental monitoring to detect a wide range of chemicals with high sensitivity. The new system makes use of a mid-infrared ultra-fast pulsed laser system to generate the filaments, whose colors can reveal the chemical fingerprints of different molecules. The finding is being reported this week in the journal Optica, in a paper by principal investigator Kyung-Han Hong of MIT’s Research Laboratory of Electronics, and seven other researchers at MIT; in Binghamton, New York; and in Hamburg, Germany. Hong explains that such filaments, as generated by lasers in the near-infrared part of the electromagnetic spectrum, have been widely studied already because of their promise for uses such as laser-based rangefinding...