High-pressure mercury are lamp excited cw alexandrite lasers

Continuous laser operation is readily achieved from alexandrite when it is pumped by ac or de driven mercury lamps.1 In recent experiments output in excess of 50 W is obtained from a 10-cm×3-mm diam rod with both modes of excitation. Slope efficiencies of 2.5 % and overall efficiencies of 1 % have been observed when a single-lamp el­liptical enclosure is used. This performance is superior to that obtained with conventional de xenon arc lamps having arc diameters ~3X larger. The differences are probably due to the spectral power distribution in the lamp and the arc diameter. The output also depends on rod diameter and Cr3+concentration, and these influences will be briefly described.