利用光学注入锁定制备的拉曼激光可以用于原子干涉仪。为解决原子干涉条纹的相位受相位噪声的极大影响的问题,研究了不同实验条件下的拉曼激光相位噪声。采用光纤电光调制(EOM)和注入锁定相结合的方法得到两束频差为6.834 GHz的相位锁定拉曼激光,将主激光通过光纤EOM移频 6.834 GHz后作为种子光注入到从外腔半导体激光器,调节从激光器,获得-1级移频光的初步放大激光。结果显示,拉曼激光的拍频线宽不大于3 Hz,频率可调范围为300 MHz,主激光锁频下相位噪声在10 Hz~100 kHz范围内低于-60 dBc/Hz。

Raman lasers generated by optical injection locking can be used in atom interferometers. However, phase noise significantly affects the phase of atom interference fringe; thus, we experimentally study the phase noise of the Raman laser under varying conditions. Two phase-locked Raman lasers exhibiting a frequency difference of 6.834 GHz are obtained by modulation of optical fiber electro-optic modulation (EOM) and injection locking. In the experimental system, the master laser is modulated using a 6.834-GHz fiber EOM, and its output is emitted as seed light. By adjusting the slave laser, the first amplification output beam of -1 level frequency-shifted laser can be obtained. The result demonstrates that the Raman laser beat linewidth is not wider than 3 Hz, the frequency is adjustable to 300 MHz, and the phase noise is less than -60 dBc/Hz from 10 Hz to 100 kHz when the master laser is frequency-locked.