Abstract

It is well known that open-sided laser resonators have nonorthogonal transverse eigenmodes, where these eigenmodes are defined as the Fox-Li modes of the resonator, i.e., the modes that reproduce themselves after one round trip in the resonator. We outline a class of resonator having nonorthogonal eigenmodes and then study in more detail the cases of unstable resonator lasers with variable reflectivity output mirrors or hard-edged output mirrors. We show analytically and numerically that lasers built with such resonators should exhibit very large excess noise factors for large magnification or large Fresnel number.

© 1988 Optical Society of America