Solid-state laser unstable resonators with tapered reflectivity mirrors: the super-Gaussian approach

A general procedure for treating solid-state laser unstable resonators with tapered reflectivity mirrors within the framework of geometrical optics is presented. A suitable choice of the analytical form of the reflectivity profile, which can simulate many experimental devices, makes possible the derivation of simple design equations for the resonator parameters. Experiments performed with a pulsed Nd:YAG laser containing a variable-reflectivity output coupler, implemented with vacuum evaporation techniques, are discussed.>