In situ probing and stabilizing the power ratio of electro-optic-modulated laser pairs based on VIPA etalon for quantum sensing.

Monitoring and stabilizing the power ratio of laser pairs is significant for high-precision atom interferometers, especially as the compact electro-optic-modulated all-fiber laser system prevails. In this Letter, we demonstrate a novel, to the best of our knowledge, method to in situ probe the relative power of laser pairs and to stabilize the power ratio of two Raman lasers using a high-dispersion virtually imaged phased array (VIPA) etalon. Sub-microsecond resolution on probing laser power transformation during the atom interferometer sequence is achieved and the power ratio of two Raman lasers (PRTR) is tightly locked with high bandwidth despite environmental disturbances, showing an Allan deviation of 4.39 × 10 at 1000 s averaging time. This method provides a novel way to stabilize the PRTR and diagnose multi-frequency laser systems for atom interferometers, and it could find potential applications in broad quantum sensing scenarios.