Ultrastable and Compact Deep UV Laser Source for Raman Spectroscopy

Deep-ultraviolet (UV) Raman spectroscopy is a powerful method to collect chemically specific information about complex samples because deep-UV (?? < 250 nm) excitation shows an over 200-fold greater efficiency compared to commonly used 785 nm excitation and has the ability to avoid fluorescence background in the Raman spectra. The availability of compact, robust, and reliable deep-UV laser sources has been always considered a major bottleneck problem on implementing this spectroscopic technique for NASA's space-borne applications. TIPD proposes to develop an ultrastable, compact, and long-lived deep-UV laser source for Raman spectroscopy based on our substantial experiences and facilities in developing single-frequency fiber lasers and solid-state deep-UV laser sources. Cooperating with the University of Arizona, we will develop an ultrastable and compact high power single-frequency single-polarization fiber laser system at 976 nm. The deep-UV laser source at 244 nm will be generated through two successive frequency doubling systems. In this phase I program, we will demonstrate deep-UV generation though frequency quadrupling of a 976 nm single-frequency fiber laser. In phase II, a deep-UV laser prototype meeting all the criteria of NASA's applications will be developed.