基于399 nm激光调制转移谱的频率锁定及频移测量

Frequency locking and frequency shift measurement based on 399 nm laser modulation transfer spectrum

为了获得高信噪比的激光检测光谱,激光光源的频率必须实现锁定,本研究仿真了不同调制频率下的调制转移谱信号,并在实验上利用空心阴极灯中的调制转移光谱技术实现了399 nm激光稳频,同时测量了镱原子同位素~1S_0-~1P_1跃迁频移。结果表明,调制频率的最佳选择值是0.8Γ;闭环锁定后,399 nm激光器的激光线宽小于±1.3 MHz,可以得到很好的谱线信噪比;利用调制转移谱还可以获得精确的~1S_0-~1P_1跃迁的同位素频移。

In order to obtain high signal to noise ratio laser spectroscopy,the frequency of laser source must be locked.The modulation transfer spectroscopy with different modulation frequency is simulated and the frequency of 399 nm laser is experimentally stabilized with modulation transfer spectroscopy in the hollow-cathode lamp.The ytterbium atomic isotope 1S 0-1P 1 transition frequency was also measured.The experiment results indicate that the optimum modulation frequency is 0.8Γand a high signal to noise spectroscopy ratio can be obtained when the 399 nm laser line width of the laser device is less than±1.3 MHz.The precise isotope frequency shift of 1S 0-1P 1 transition can also be obtained by using the modulation transfer spectrum.