title: Hybrid wide-band, low-phase-noise scheme for Raman lasers in atom interferometry by integrating an acousto-optic modulator and a feedback loop.
abstract: We report a hybrid scheme for phase-coherent Raman lasers with low phase noise in a wide frequency range. In this scheme, a pair of Raman lasers with a frequency difference of 3.04 GHz is generated by the ±1-order diffracted lights of an acousto-optic modulator (1.52 GHz), where a feedback loop is simultaneously applied for suppressing the phase noise. The beat width of the Raman lasers is narrower than 3 Hz. In the low-frequency range, the phase noise of the Raman lasers is suppressed by 35 dB with the feedback. The phase noise is less than -109  dBc/Hz in the high-frequency range. The sensitivity of an atom gyroscope employing the hybrid Raman lasers can be implicitly improved 10 times. Due to the better high-frequency response, the sensitivity is not limited by the durations of Raman pulses. This work is important for improving the performance of atom-interferometer-based measurements.
authors.forename: Kai
authors.initials: K
authors.lastname: Wang
authors.forename: Zhanwei
authors.initials: Z
authors.lastname: Yao
authors.forename: Runbing
authors.initials: R
authors.lastname: Li
authors.forename: Sibin
authors.initials: S
authors.lastname: Lu
authors.forename: Xi
authors.initials: X
authors.lastname: Chen
authors.forename: Jin
authors.initials: J
authors.lastname: Wang
authors.forename: Mingsheng
authors.initials: M
authors.lastname: Zhan