连续波单共振光学参量振荡器(SRO)的阈值和稳定运转与共振信号光在谐振腔内传播一周所产生的损耗密切相关。考虑非线性晶体的线性吸收和内腔倍频(IFD)引入的非线性损耗, 在平面波近似下建立了描述连续波IFD-SRO输出特性的理论模型, 并给出了解析解; 理论计算结果与实验结果较好地吻合。根据该结果, 预测了532 nm绿光抽运的IFD-SRO在共振信号光波长为780 nm时的输出特性和1064 nm红外光抽运的IFD-SRO在共振信号光波长为1560 nm时的输出特性。该理论模型简单、易于计算, 为优化设计连续波IFD-SRO提供了指导。

The threshold and stable operation of a continuous-wave singly resonant optical parametric oscillator (SRO) are closely related with the roundtrip loss of the resonant signal travelling in the resonant cavity. Under the plane-wave approximation, a theoretical model considering the linear absorption of the nonlinear crystal and the nonlinear loss introduced by intracavity-frequency-doubled (IFD) is proposed to describe the output characteristics of continuous-wave IFD-SRO. The analytical solution is also given. The theoretical calculation results are in good agreement with the experimental results. According to these results, the output characteristics of the 532 nm green laser pumped IFD-SRO with resonant signal at 780 nm and the 1064 nm infrared laser pumped IFD-SRO with resonant signal at 1560 nm are predicted. The model is simple and easy to calculate. It provides a guideline for optimizing the design of continuous-wave IFD-SRO.