Electro-optic modulator with ultra-low residual amplitude modulation for frequency modulation and laser stabilization

摘要

The reduction of the residual amplitude modulation ( RAM) induced by electro-optic modulation is essential for many applications of frequency modulation spectroscopy requiring a lower system noise floor. Here, we demonstrate a simple passive approach employing an electro-optic modulator (EOM) cut at Brewster's angle. The proposed EOM exhibits a RAM of a few parts per million, which is comparable with that achieved by a common EOM under critical active temperature and bias voltage controls. The frequency instability of a 10 cm cavity-stabilized laser induced by the RAM effect of the proposed EOM is below 3 x 10(-17) for integration times from 1 to 1000 s, and below 4 x 10(-16) for comprehensive noise contributions for integration times from 1 to 100 s. (C) 2016 Optical Society of America