Coupling efficiencies and mode discrimination in coaxial waveguide laser resonators

Abstract

An approach of calculating coupling efficiencies of waveguide modes in a coaxial waveguide laser resonator is developed by which the computational time is considerably reduced. The coupling efficiency is expressed in terms of the structural parameters of the resonator, which indicates that there exist three special configurations to provide low coupling losses. Mode discrimination can be achieved by appropriately choosing resonator parameters. The influences of the ratio of the outer radius to the inner radius of the waveguide on coupling losses and mode properties are also discussed.