With frequency doubling, laser light in the UV and visible regions can be generated. It has several advantages over other mid-infrared lasers, including high reliability, lower power consumption, room temperature operation, and compact size. The NASA connection to the laser's creation is part geological, part biological, and part atmospheric. Mid-infrared laser sources are of interest because many geologically and biologically important gases have strong absorption lines in this spectral region. Absorption is the process in which radiant energy is retained by a substance.
Absorption spectroscopy can perform simple, direct measurements of gas concentrations.
Measurement of the ratio of carbon dioxide gases is particularly important for tracing material sources and studying biological activity. Sometime in the 21st century, human crews will adventure to Mars. Those future missions are likely to include onboard mid-infrared laser sources for analysis of Mars rock and soil and atmosphere. Mid-infrared spectroscopy has several additional NASA applications, including the monitoring of gas concentrations in spacecraft cabins, measuring atmospheric gas concentrations, and analyzing meteorites. Commercial applications for mid-infrared gas sensing include pollution monitoring of factory and automobile emissions.