腔外多普勒频率调制激光稳频方法的研究

Study of laser frequency stabilization with external Doppler frequency modulation

利用腔外气体吸收池内的SF_6分子饱和吸收线作为参考频率,并通过振动腔外反射镜使进入吸收池的激光的频率受到多普勒调制,实现了对CO_2激光10P(16)和10P(18)支线频率的闭环锁定,最大频率漂移约为7kHz.该法得到的稳频激光输出不仅无寄生频率调制和幅度调制,并且可将激光频率锁定在独立的分子吸收线中心.

By utilizing an external Doppler dither modulation scheme, the frequency of the CO2 laser 10P(16) and 10P(18) lines are locked at the centers of the saturated absorption lines of SF6 molecules in an external absorption cell. The locked laser has a frequency fluctuations of some 7 kHz. The looked laser output has neither parasitic frequency modulation nor parasitic amplitude modulation. The stabilized frquency is independent of laser operating characteristics.