TEMPERATURE-TUNED NONCRITICALLY PHASE-MATCHED PICOSECOND LIB3O5 OPTICAL-PARAMETER OSCILLATOR

Efficient picosecond optical parametric oscillation in LiB3O5 is demonstrated using approximately 55 ps pump pulses at 523.5 nm, obtained from a frequency-doubled, mode-locked, Q-switched, diode-laser-pumped Nd:YLF laser. By exploiting temperature tuning under noncritical type I phase matching, continuously tunable radiation over the range 0.909-1.235-mu-m has been generated at external power conversion efficiencies approaching 50%. The oscillator has a pump power threshold of 4.5 mW, corresponding to a Q-switched pulse energy of 9-mu-J, and can provide a total average output power of 8 mW at 500 Hz, in pulses of approximately 33 ps duration. At five times above threshold, the internal pump depletion of the oscillator was 54%.