Fibertek, Inc. successfully demonstrated a short-pulse, conductively-cooled diode-pumped solid state laser operating at 532 nm with an output power of 23 Watts. The laser is passively Q-switched and generates pulses < 2 ns at a repetition rate of 100 Hz. The laser is being developed by Fibertek as part of a compact and lightweight 3-D imaging laser radar system for the Missile Defense Agency (MDA) Discriminating Interceptor Technology Program. This short-pulse, high power laser technology is important for a number of applications including space-based and underwater LIDAR.
The laser transmitter consists of a diode-pumped Nd:YAG mini-slab oscillator which is passively Q-switched in a Cr4+:YAG crystal. This short cavity laser generates 1 mJ, TEM00, 1.3 ns pulses. The single-pass preamplifier is a small, diode-pumped Nd:YAG slab device which amplifies the signal to approximately 7 mJ. The beam is magnified in a mode-matching telescope and passed through another optical isolator into the main power amplifier slabs. The 2 power amplifiers are diode-pumped Nd:YAG slabs arranged in a double pass geometry. The amplified pulse is approximately 355 mJ at 1.06 microns, and is efficiently frequency doubled in a KTP crystal to produce 230 mJ at 532 nm. The 1.3 ns output pulse from the power amplifiers is shown at left.
