Deep-UV Raman spectroscopy is a powerful tool to identify a variety of gas, liquid, and solid materials in the universe. Compact and ultrastable deep-UV laser sources can be used for planetary compositional, geological, and mineralogical analyses, planetary sample acquisition and habitability assessment, the search for past life on Mars, and human protection in aerospace. Deep UV sources can be broadly used for Raman spectroscopy, laser cooling and trapping, laser inspection, optical data storage, metrology, biomedical applications, and laser lithography. Besides as ultra-stable narrow-linewidth laser sources for nonlinear wavelength converter, the single-frequency fiber lasers at 976 nm can also be used for low noise laser pumps for a variety of lasers at 1 ??m and 1.5 ??m. The 488 nm blue lasers have potential applications in submarine imaging, sensing, communications, data storage, undersea oil exploration, full color displays, and medicine.