Production of Raman laser beams using injection-locking technique

We produced two Raman-laser beams with a frequency offset of 9.2 GHz by injection-locking of a master diode-laser to a slave diode-laser. The master laser was phase-modulated at 9.2 GHz while the laser beam passed through an electrooptic modulator. The phase-modulated beam was injected into the slave laser that was oscillating around one of the side-bands of the master laser. The relative linewidth of the two lasers was less than 10 Hz. Using these laser beams, coherent population trapping resonance of cesium atoms was observed for the purpose of testing the phase-coherence of the laser beams.