We demonstrate an eye-safe KTP-based optical parametric oscillator (OPO) driven intracavity by a diode-pumped 1064-nm Nd:YAG laser, passively <i>Q</i>-switched by a Cr<sup>4+</sup>:YAG crystal. The characteristics of this system, which operates at 1570 nm with a repetition rate as high as 50 Hz, are studied as a function of Cr<sup>4+</sup>:YAG optical density. Under optimum conditions the OPO generates 1.5-mJ, 3.4 ∓ 0.1-ns pulses in a single transverse mode. For a Cr<sup>4+</sup>:YAG <i>Q</i>-switch element with an optical density of 0.5 the conversion efficiency of the intracavity energy is ~45% with the ratio of OPO to Nd:YAG peak-pulse intensity exceeding unity. These and other OPO characteristics compare favorably with a simple rate equation model of the OPO dynamics.
© 1999 Optical Society of America
Yuri Yashkir and Henry M. van Driel, "Passively Q-Switched 1.57-µm Intracavity Optical Parametric Oscillator," Appl. Opt. 38, 2554-2559 (1999)