SINGLE-MODE KTIOPO4 OPTICAL PARAMETRIC OSCILLATOR

A tunable KTiOPO4 optical parametric oscillator (OPO) operating in a s ingle longitudinal mode of its resonator is described. Single-mode ope ration has been achieved by use of an intracavity Fabry-Perot etalon i n a short-length OPO resonator. The crystal is pumped by the second ha rmonic of an injection-seeded Nd:YAG laser. The tuning range observed with a crystal cut at 60 degrees is 0.75-0.87 mu m for the signal beam and 1.83-1.37 mu m for the idler beam. The linewidth of the OPO is ap proximately 200 MHz (0.0066 cm(-1)), which is close to the Fourier-tra nsform limit. The total output energy was measured to be as much as 0. 6 mJ per pulse. (C) 1995 Optical Society of America