Review of Scientific Instruments
Note: Generation of Raman laser beams based on a sideband injection-locking technique using a fiber electro-optical modulator
Hongbo Xue, Yanying Feng, X. J. Wang, Songtao Chen, Zheng Zhou
Abstract
Two phase-coherent Raman laser beams with a frequency offset of 6.835 GHz were generated by sideband injection-locking technique. A master diode laser was phase-modulated at 6.835 GHz by a fiber electro-optic modulator. A slave diode was injection-locked to the -1 sideband of the phase-modulated beam, and another diode was locked to the master laser carrier. This method produced stable and spatially separated Raman lasers with a large frequency shift range (>180 MHz). The relative linewidth of these two beams was ∼1 Hz, and the unwanted carrier mode was suppressed down to -24 dB. Stimulated Raman transitions and Ramsey fringes were driven by Raman lasers in a cold atomic beam.