Diode pumping of a solid-state laser rod by a two-dimensional CPC–elliptical cavity with intervening optics

The pump radiation from a large area two-dimensional diode stack is concentrated into a cylindrical intervening optics by a first-stage 2D-CPC concentrator. The compressed radiation from the intervening optics is then efficiently coupled into a laser rod by a second-stage 2D-elliptical pump cavity. Depending on the width of the pump source, optimized rod mounting position is found through a non-sequential ray-tracing analysis. By comparing with the performance of a 2D-CPC–CPC cavity, significant improvements in both absorption efficiency and absorption distribution are achieved by a 2D-CPC–EL cavity. This asymmetric pumping scheme constitutes also an effective alternative to conventional symmetric pumping approaches.