A narrow-linewidth, deep-UV laser developed by Photon Systems (Covina, CA) is at the heart of Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals (SHERLOC) instrument that was selected by NASA for the Mars 2020 rover arm. SHERLOC is a deep-UV fluorescence/Raman instrument that enables spatial mapping of fluorescence emissions and Raman scatter of organics and astrobiologically relevant minerals on abraded surfaces and boreholes created by the rover coring system.
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The Photon Systems 400 gram neon-copper (NeCu) laser provides excitation at 248.6 nm with a linewidth less than 0.5 pm. Its sub-250 nm excitation is key to enabling simultaneous detection of Raman and fluorescence emissions. The Photon Systems NeCu laser turns on instantly without the need for preheating, warm-up, or temperature regulation at ambient temperatures in a range from minus 135 to plus 70 degrees Celsius. The laser has been tested over these temperature extremes as well as at three times the shock and vibration limits imposed for similar Mars missions without failure. Photon Systems says these lasers have previously been vetted on many expeditions to harsh environments on Earth such as Antarctica, the Arctic, and the deep Ocean.
SOURCE: Photon Systems; http://www.photonsystems.com/downloads/sherloc_jpl.pdf