Measurement of the friction coefficient in 1D corkscrew optical molasses by stimulated Rayleigh spectroscopy

Abstract

The transmission spectrum of a probe interacting with one-dimensional cesium optical molasses made from two circularly cross-polarized cooling beams (corkscrew molasses) displays a narrow (≊30–70 kHz) Rayleigh resonance. From the width of this resonance we deduce the friction coefficient of the cooling force to be α=(5.8±0.4)ħ${\mathit{k}}^2$ for a detuning from resonance equal to 3Γ. This value is in quantitative agreement with theoretical predictions. We also show that the shape of the Rayleigh resonance depends dramatically on the efficiency of the sub-Doppler cooling mechanism.