High Efficiency 0.5J, 20Hz Two Micron Laser

Coherent Technologies Inc. (CTI) proposes to design a 0.5J, 20Hz, single frequency Q-switched two micron laser, with high wall plug efficiency. With passive cooling, the unit will operate with a wall-plug power efficiency of 5-6%, meeting the performance requirements for practical deployment of a Doppler lidar on a free-flying satellite for space-based remote sensing. When used in a coherent laser radar system this system will have the capability to measure: 1) hard target range and velocity (including precision microDoppler) to ranges up to 500 km from a space-borne or airborne platform, 2) atmospheric winds globally from a space-borne platform, and 3) atmospheric winds to heights and ranges beyond 20 km from a ground-based platform. The improvement in performance over previous two micron lasers will be accomplished by achieving super-mode operation and elimination of thermal birefringence loss and spatial hole burning in the injection-seeded laser. Also, the proposed effort will integrate a dual temperature refrigeration unit into the laser design, for an efficient and practical means of cooling both the pump laser diodes and the laser rod, as needed for airborne or ground based deployment of a lidar system based on this laser.