一种内腔式He-Ne激光器频率稳定方法的实验研究

实现了用微型风扇冷却的方法替代常见的加热方式完成对He-Ne内腔激光器的频率稳定.研究了微型风扇驱动电压与转速的响应特性和内腔式He-Ne激光器的热膨胀特性.采用风冷方式对激光器的腔长进行调节和控制,并通过双纵模功率平衡原理完成了激光频率的稳定.稳定后的激光器管壁平均温度低于50℃.与高精度碘稳定激光的拍频实验结果表明,其频率在20h内的波动范围小于1.4 MHz (τ=1 s),4个月内激光频率的相对标准不确定度为U=4.7×10-9.

Experimental study on frequency stabilization method of internal-mirror He-Ne laser

Frequency of an internal-mirror He-Ne laser is stabilized by using a micro cooling fan, instead of traditional heating method. Both the relationship between driving voltage and rotating speed and the thermal expansion of the intermal-mirror laser are discussed. The cavity length of the laser is controlled and adjusted by air cooling. The frequency stabilization is based on a theory of power balance between two longitudinal modes. The average temperature of the laser tube is less than 50 ℃ when the frequency is stabilized. A frequency fluctuation of less than 1.4 MHz in 20 h and a frequency relative standard uncertainty of U=4.7×10^-9 in 4 months are evaluated by measuring the beat signal with a high-precision laser stabilized by iodine.