通过铯原子D_1线超精细跃迁能级的偏振光谱获得鉴频曲线,利用电子伺服系统将鉴频曲线反馈到894.6nm外腔式半导体激光器的压电陶瓷上进行锁定。由于偏振光谱技术不需要对激光器进行调制,因此不会带来额外的噪声。激光器自由运转400s内频率起伏为2.35 MHz,采用偏振光谱锁定激光器后400s内频率起伏为0.95 MHz,有效抑制了激光器的频率起伏。 The frequency-discriminating curve is obtained by the polarization spectrum of the super-fine transition level of the C-atom atom D_1 line, and the frequency-matching curve is fed back to the piezoelectric ceramic of the 894.6 nm external-cavity semiconductor laser by the electronic servo system for locking. Because polarization spectroscopy does not require the laser to be modulated, it does not introduce additional noise. The frequency fluctuation of the laser in free running within 400s is 2.35 MHz, and the frequency fluctuation within 400s after using the polarization locked laser is 0.95 MHz, which effectively restrain the frequency fluctuation of the laser.