PERIODICALLY POLED LITHIUM-NIOBATE AND QUASI-PHASE-MATCHED OPTICAL PARAMETRIC OSCILLATORS

Since their introduction two years ago, quasi-phase-matched (QPM) opti cal parametric oscillators (OPO's) have moved into the mainstream of O PO research. This has been made possible by continuing improvements an d availability of the microstructured nonlinear material periodically poled lithium niobate (PPLN), Demonstrations of PPLN OPO's now span th e range of pulse formats and power levels. The most significant area o f development is low-peak-power devices where operation with conventio nal materials is difficult. In this paper, we describe the current sta te of this research, including OPO's pumped by high-repetition-rate (> 30 kHz) Q-switched diode-pumped solid-state lasers, and CW singly reso nant OPO's with >3-W output power in the 3-4-mu m range.