William M. Grossman

Subnanosecond pulse generation from diode-pumped acousto-optically Q-switched solid-state lasers

Miniature diode-pumped acousto-optically Q-switched solid-state lasers deliver pulse durations as short as 600 ps at wavelengths near 1 µm. Specifically, Nd:YVO(4) lasers operating at 1.064 µm produce 600-ps/5-kW pulses at 1 kHz, 1.0-ns/2-kW pulses at 20 kHz, and 1.9-ns/0.5-kW pulses at 100 kHz. A Nd:YLF laser at 1.047 µm generates 700-ps/15-kW pulses at 1 kHz, and 1.2-ns/4-kW pulses at 10 kHz. At 1.342 µm, a Nd:YVO(4) laser produces 3.3-ns/0.8-0.6-kW pulses at 1-10 kHz.

Multipass diode-pumped solid-state optical amplifier

A new diode-pumped solid-state multipass amplifier produced 38-dB small-signal gain at 1.047 μm in Nd:YLF with 1.6-W pump power and 37% extraction efficiency near saturation. The amplifier had a 1:1 confocally reimaging multipass design that generated both high gain and high efficiency. The same amplifier design with 13 W of pump power was tested with Nd:YAG at 1.064 μm, which gave 38-dB small-signal gain and 3.2 W of output power, and with Nd:YVO4, also at 1.064 μm, which gave >50-dB small-signal gain and 4.3 W of output power.

Short-pulse Q-switched 1.3- and 1-μm diode-pumped lasers

Acousto-optically Q-switched diode-pumped lasers emit short pulses at kilohertz repetition rates. We describe a compact laser cavity design that employs either Nd:YLF or Nd: YAG and has all internal Brewster surfaces. Pulsed operation at 1.047, 1.053, 1.064, 1.313, 1.319, and 1.338 μm is observed, with pulse widths ranging from 3 to 39 nsec at low repetition rates. The laser generates peak powers of 20 kW at 1.047 μm and 1.7 kW at 1.321 μm.

Multipass diode-pumped Nd:YAG optical amplifiers at 1.06 /spl mu/m and 1.32 /spl mu/m

We have built two versions of a diode-pumped Nd:YAG amplifier using a compact multipass confocal geometry with a fiber-coupled input. This confocal geometry provided efficient power and high gain in a volume of approximately 100 cm/sup 3/. When pumped with a commercially mature 2 W 809 nm laser diode, the 1.06 /spl mu/m version produced 460 mW and a small signal gain of 51 dB. The 1.32 /spl mu/m version produced 170 mW and a small signal gain of 29 dB. Such an efficient amplifier, especially at 1.32 /spl mu/m would be useful as a power booster in fiber optic telecommunications.<<ETX>>