设计了基于Nd∶YVO4/Nd∶GdVO4组合晶体的双波长激光器, 研究了双波长激光器的热效应以及双波长信号的频率差调谐特性.实验中固定抽运功率, 调节组合晶体的温控温度从5 ℃上升到40 ℃, 测得双波长信号的频率差从351.11 GHz下降到316.14 GHz, 频率差与温控温度呈负线性关系, 斜率为-0.95 GHz/℃.对于实验结果, 从掺钕晶体发射谱的温度漂移特性角度进行了分析, 发现激光波长漂移由晶体发射谱随温度的漂移引起, 双波长信号的频率差变化则由不同晶体的温度漂移速率不同引起; 分析结果与双波长激光器频率差实验结果符合较好.

A Dual-Wavelength Laser (DWL) based on the Nd∶YVO4/Nd∶GdVO4 combined crystal was presented. The thermal effect and the frequency-separation tuning mechnism of the DWL were investigated. In the experiments, with fixed pumping power, when the heat sink temperature of the combined crystal increased from 5 ℃ to 40 ℃, the frequency separation of the DWL signal decreased from 351.1 GHz to 316.1 GHz, the frequency separation decreasing rate was measured as -0.95 GHz/℃. For the experimental results, it was found that the wavelength shifting of the DWL signal is mainly caused by the Emission Cross Section (ECS) spectra shifting of the laser crystals with the temperature varying, and the change of the frequency separation is caused by different ECS spectral shifting rates of the crystals. The analysis results are in good agreement with the experimental results.