Global efficiency, transverse mode discrimination, and the near- and far-field optical quality of unstable laser resonators are improved with variable reflectivity mirrors (VRMs). Analytical and numerical results are given for Gaussian and parabolic reflectivity mirrors. The VRM design is described, and experimental results obtained using different lasers with Cassegrain cavities are presented.
Correction to: Thrust measurements and evaluation of asymmetric infrared laser resonators for space propulsion