为了研究热致相位失配对中红外连续波单谐振光学参量振荡器(CW-SRO)输出效率的影响, 结合CW-SRO计算模型和热传导方程, 利用有限元分析方法, 重点对输出3.3 μm波长闲频光的CW-SRO进行了分析。计算了不同信号光输出耦合率及不同泵浦功率下CW-SRO晶体输出截面上热致相位失配量的分布。由计算结果可以看出：晶体吸收腔中振荡信号光是导致晶体热效应的主要因素；在相同的输入条件下, 泵浦功率在30 W以上时CW-SRO的热致相位失配将会大大降低其泵浦损耗率；通过增加信号光输出耦合率的方法, 可以减少热致相位失配对CW-SRO输出效率的影响, 但CW-SRO的振荡阈值会增加。

This work is devoted to the study of thermal-induced dephasing in mid-infrared continuous-wave singly resonant optical parametric oscillator(CW-SRO). The thermal-induced dephasing in crystal output section versus pump power and output coupling of signal is calculated. The simulation results indicate that the crystal thermal effect of CW-SRO with 3.3 μm idler output is mainly affected by the absorption of the circulating signal power. Under the same input conditions, the CW-SRO’s thermal-induced dephasing with pump power above 30 W will greatly reduce the pump depletion. The thermal-induced dephasing will reduce with increasing the signal output coupling, while the threshold of CW-SRO will increase.