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 D-2 lines of cesium atom have been adopted as a frequency reference and the non-linear 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 approximate to 10(-12) which should be achieved in an integration time of I s.