Gaussian Mirror for Improving Beam Quality

Unstable resonator can produce large volum of basic mode and has satisfactory space mode. But in solid Q setting laser, its output transverse mode is not smooth beause of the aperture diaphragm and heat deformation. The output beam quality can be improved by adopting Gaussian reflectivity coupling output mirror, using plano-convex unstable cacity, Nd: YAG, and electro-optic Q setting solid laser in the experiment. We achieved satisfactorily smooth distribution of far-field light intensity. Experiment result indicates that Gaussian reflectivity output mirror can improve the output beam quality of unstable cavity in solid laser.