Efficient operation of cw mode-locked singly resonant optical parametric oscillators (OPO's) of critically phase-matched KTiOPO<sub>4</sub> is demonstrated. The OPO's are synchronously pumped by the 1053-nm fundamental or the 527-nm second harmonic of a 76-MHz-repetition rate mode-locked Nd:YLF laser with pump-pulse lengths of 40 and 30 ps, respectively. Tuning of the OPO's is accomplished by changing the phase-matching angle. The 527-nm-pumped system has been investigated in the tuning range from 1.01 to 1.1 µm. At a pump power of 1.3 W this OPO generated 14-ps-long pulses with a total average power of 580 mW, yielding an efficiency of 44%. The 1053-nm-pumped OPO produced powerful infrared radiation in the ranges from 1.55 to 1.56 µm (signal wave) and from 3.22 to 3.28 µm (idler wave). For 14 W of pump power the average output power of the 12-ps-long pulses exceeded 2.0 W for the signal wave and 0.8 W for the idler wave. The total output power corresponds to an efficiency of 21%.
© 1993 Optical Society of America
Ch. Grässer, D. Wang, R. Beigang, and R. Wallenstein, "Singly resonant optical parametric oscillator of KTiOPO4 synchronously pumped by the radiation of a continuous-wave mode-locked Nd:YLF laser," J. Opt. Soc. Am. B 10, 2218-2221 (1993)