Compact 2 Micron Seed Laser

This proposal is for the development of new compact, high power and extremely reliable 2 micron seed laser using newly developed Tm3+ doped germanate glass fibers, which exhibit high quantum efficiency. This type of fiber based seed laser is needed for constructing high energy pulsed 2 micron Ho-doped crystal lasers for LIDAR applications. We propose to use highly Tm3+ doped germanate glass fibers with high gain per unit length to form a short linear cavity to generate single frequency fiber laser operation. Germanate glass exhibits lower phonon energy compared to silica glass, increasing the quantum efficiency of 3F4 level of Tm3+ ions. Importantly, Tm3+ can be highly doped into germanate glasses, which results in so called cross-relaxation, dramatically improving the gain per unit length and the quantum efficiency. The single frequency fiber laser will be used to construct seed lasers by integrating with controlling electronics.