An alternative solar pumping approach by a light guide assembly elliptical-cylindrical cavity

To improve solar laser output performance, what we believe to be a novel light guide assembly is proposed to pump a Nd:YAG laser rod within a two-dimensional elliptical-cylindrical (2D-EL-CYL) cavity with intervening optics. Based on refractive and total internal reflection principles, the concentrated solar radiation from a primary parabolic mirror is coupled through the square input face of a fused silica light guide assembly to its rectangular output end, located along the first focal line of the 2D-EL-CYL cavity. Optimized pumping conditions are found through ZEMAX™non-sequential ray-tracing software. By comparing with the laser performance of a two-dimensional dielectric compound parabolic concentrator (2D-DCPC) cavity, significant improvements in absorption distribution, TEM00 laser power and tracking error dependent output power stability are obtained by the proposed pumping approach.