Fluorescence of a highly collimated atomic cesium beam: theory and experiment

We describe our system for producing a dense well collimated atomic cesium beam. Our motivation for constructing this system is to perform high resolution laser induced spectroscopy. The two stage oven system consists of a nozzle and reservoir. An array of stainless steel capillary tubes forms the exit port of the nozzle. Additional collimation of the atomic beam is achieved with a stack of microscope cover slips and spacers, giving a maximum beam divergence of 13.6 mrad. The heterodyne beat note between two diode lasers provides the frequency calibration for high resolution fluorescence spectra. Fluorescence spectra with high signal to noise ratio are accurately described by a simple theoretical model that gives a residual Doppler width of 2.3(1) MHz in agreement with the geometrical constraints of the collimator. (C) 2003 Elsevier Science B.V. All rights reserved.