Low noise laser for optically pumped cesium standards

Abstract

An external cavity diode laser is developed for optical pumping and detection of a cesium atomic beam. The laser is about 2*4*5 cm in size, is tunable to any wavelength over a 40-nm range, and emits two collimated beams of light with power outputs to 6 mW each. The laser spectrum consists of a single longitudinal mode with every narrow linewidth. When locked to a single hyperfine transition in atomic cesium, the signal-to-noise ratio (SNR) for fluorescence detection of the transition far exceeds the SNR observed when an unmodified laser diode is used.<>