Divergence of the fundamental mode of a cavity apertured by a Gaussian, a super-Gaussian and a hard aperture

摘要

We model the fundamental mode of a circularly symmetric planoconcave resonator where one mirror has infinite aperture and the other is either a hard-apertured mirror or a variable reflectivity mirror (VRM). The VRM may have Gaussian or super-Gaussian reflectivity profile. We show that, depending on the VRM profile and resonator geometry, the far-field divergence can be increased or reduced with respect to that of the non-perturbed Gaussian beam.