Continuous parametric generation of picosecond light pulses

An investigation was made of an optical parametric oscillator (OPO) in which a Ba₂NaNb₅O₁₅ crystal was pumped synchronously and the repetition frequency of picosecond pulses was 140 MHz. The OPO was pumped by the second harmonic of the radiation from a cw YAG:Nd³⁺ laser with active (acoustooptic) mode locking. The average power of the OPO radiation reached 56 mW near the degenerate regime; the energy efficiency was 12% and the duration of the output pulses was 37 ps.