Beam quality measurement of a static-cell cesium DPAL with a stable resonator.

We performed a measurement of the beam quality of an optimized moderate power cesium Diode Pumped Alkali Laser (DPAL). The DPAL used a stable resonator and operated in continuous wave mode using a static cell filled with metallic cesium and a mixture of methane and helium at 200 and 400 torr respectively. In this work, we characterized the spatial quality of the DPAL output beam. As a result of these experiments we determined the output beam quality was excellent (M < 1.2) in the whole range of pump power used (up to 11.5W) and pump intensities reaching 1.5 kW/cm. The optical conversion efficiency of this laser was 51% and the slope efficiency was 61%.