Room-Temperature cw Operation of a GaAs1−xPx Diode-Pumped YAG:Nd Laser

Abstract

Room‐temperature (20°C) cw operation of a YAG: Nd laser pumped by GaAs_1−xP_x electroluminescent diodes is reported. A linear array of sixty‐four 0.46‐mm‐diam domed diodes was coupled to a 1.5‐mm‐diam × 50‐mm‐long laser rod by a semielliptical cylindrical reflector. At an electrical input to the diode array of 30 W, the optical pumping power was 0.90 W (average diode efficiency ≈ 3%) and the laser output power was 1.4 mW. The laser was also operated with 1‐ and 2‐msec pulses of pump power. At an electrical input of 30 W, the laser output at the end of a 1‐msec pulse was 4.9 mW, and at an electrical input of 44 W, the output was 15.7 mW. The discrepancy between the pulsed and cw output powers has been attributed primarily to heating effects in the diodes. When the laser rod was cooled to 0°C, the pulsed output at an input of 44 W was 55 mW.