频率差可调的加力型频率分裂氦氖激光器具有广阔的应用前景，目前鲜有关于该激光器频率差热漂移的具体报道，但它是一个重要的应用指标，特别是在光刻机用干涉仪中需要重点关注。采用弹性加力法对双折射-塞曼氦氖双频激光器进行频率差赋值，详细观察了频率差在开机漂变阶段、过渡阶段及稳定阶段状态的变化过程， 给出了频率差对开机时间的曲线。实验表明稳频作用下的频率差的稳定性优于23 kHz/h，重复性优于130 kHz。此外还就不同结构或材料的弹性加力元件对频率差的影响进行了对比分析，实验表明系统温度分布的均匀性和稳定性对频率差热漂移起重要作用。

The force-exerting laser with tunable frequency difference has a broad application prospect, there are few reports on the thermal drift of frequency difference of this laser, but it is an important application index, especially for the interferometer of lithography machine. The frequency difference of birefringence Zeeman dual frequency laser was assigned through elastic force method, and its states of frequency difference in the drift stage, transition stage and stable stage were observed. The experiments prove that the stability of frequency difference is better than 23 kHz/h, and its repeatability is better than 130 kHz; In addition, this paper also comparatively analyzed the influences of elastic force-exerting elements with different structures or materials on frequency difference. The experiments indicate that the uniformity and stability of the temperature distribution play an important role in the frequency difference thermal drift.