Zeng Yong, Fu Zhuo, Liu Yang-Yang, He Xiao-Dong, Liu Min, Xu Peng, Sun Xiao-Hong, Wang Jin
Appl Opt. 2021 Feb 10;60(5):1159-1163. doi: 10.1364/AO.415011.
We develop and demonstrate a method of optical phase modulation in the Pound-Drever-Hall (PDH) technique. The phase modulation in this paper is realized by an acousto-optic modulator (AOM) operating in the Bragg diffraction regime. In this process, a light beam separated from a laser (780 nm) is sent through the AOM twice and coupled to a high finesse Fabry-Perot cavity. Then, the light power coupling into the cavity is stabilized by modulating the optical amplitude with this AOM. The coupling light power is stabilized to a level of 10. In the meantime, the PDH error signal is obtained by modulating the optical phase with the same AOM. After the error signal is fed back to the laser current, the laser linewidth is suppressed to approximately 907.91 Hz. This method of phase modulation is simple and convenient, and we believe it can be widely used in modulation transfer spectroscopy and frequency-modulation sideband spectroscopy.
我们开发并演示了一种在庞德-德瑞弗-霍尔（PDH）技术中进行光学相位调制的方法。本文中的相位调制是通过工作在布拉格衍射模式下的声光调制器（AOM）实现的。在此过程中，从激光器（780纳米）分离出的一束光两次通过AOM，并耦合到一个高精细度法布里-珀罗腔。然后，通过用该AOM调制光振幅来稳定耦合到腔内的光功率。耦合光功率稳定到10的水平。同时，通过用同一个AOM调制光学相位来获得PDH误差信号。在误差信号反馈到激光电流后，激光线宽被抑制到约907.91赫兹。这种相位调制方法简单方便，我们相信它可广泛应用于调制转移光谱和调频边带光谱。
