Robust single-sideband-modulated Raman light generation for atom interferometry by FBG-based optical rectangular filtration

Abstract

Low-phase-noise and pure-spectrum Raman light is vital for high-precision atom interferometry by two-photon Raman transition. A preferred and prevalent solution for Raman light generation is electro-optic phase modulation. However, phase modulation inherently brings in double sidebands, resulting in residual sideband effects of multiple laser pairs beside Raman light in atom interferometry. Based on a well-designed rectangular fiber Bragg grating and a plain electro-optic modulator, optical single-sideband modulation has been realized at 1560 nm with a stable suppression ratio better than −25 dB despite of intense temperature variations. After optical filtration and frequency doubling, a robust phase-coherent Raman light at 780 nm is generated with a stable SNR of better than −19 dB and facilitates measuring the local gravity successfully. This FBG-based all-fiber single-sideband-modulated Raman light source, proposed for the first time and characterized as robust, compact and low-priced, is practical and potential for field applications of portable atom interferometry.

Generation of visible Raman operation laser by a fiber electro-optical modulator feedback loop

“…Phase-coherent multi-tone lasers play a crucial role in the fields of modern information technology, e.g., optical microwave generation [1][2][3][4] , and atomic physics, e.g. atomic clocks [5][6][7] , quantum precision measurement [8][9][10][11][12][13] , and qubits manipulation [14][15][16][17][18] . Among them, the stimulated Raman transition is widely used to manipulate atomic hyperfine qubits [19,20] , and the Raman operation laser typically requires optical fields with gigahertz-level frequency difference to match the atomic energy levels.…”

Optical single-sideband (OSSB) Raman laser based on atomic filter for atom gravimeters

“…Q. Luo et al predict and set the magic time intervals to further eliminate the effect of the ASB which is suppressed over 20 dB but less than 30 dB, reducing the uncertainty that is induced by ASBs to 0.5 μGal [19]. G. Wang et al proposed a single sideband modulation method based on FBG-based optical rectangular filtration with SNR better than 19 dB [20].…”

Optical single-sideband (OSSB) Raman laser based on atomic filter for atom gravimeters

“…Q. Luo et al predict and set the magic time intervals to further eliminate the effect of the ASB which is suppressed over 20 dB but less than 30 dB, reducing the uncertainty that is induced by ASBs to 0.5 μGal [19]. G. Wang et al proposed a single sideband modulation method based on FBG-based optical rectangular filtration with SNR better than 19 dB [20].…”