Frequency stabilization of DBR diode laser against Cs absorption lines at 852 nm using the modulation transfer method

Preliminary results on absolute frequency stabilization of Distributed Bragg Reflector (DBR) diode-lasers with emission wavelength at 852 nm will be reported. Saturated absorption D2 lines of cesium atom have been adopted as a frequency reference and the nonlinear spectroscopy method of Modulation Transfer has been used to lock the laser frequency against the resonance. From the preliminary results on the beat signal between two independent laser systems a relative frequency stability of 10-11 has been reached at an integration time of 0.1 s. The analysis on the obtained signal to noise ratio shows a frequency noise floor in the order of approximately 10-12 which should be achieved in an integration time of 1 s.