Prism reflectors for high power lasers

A new type of laser reflector is described in which the laser beam is split by frustrated total internal reflection and the components combined again. It has the properties of high reflectivity, high damage resistance, wide bandwidth and variable reflectivity. The design of two particular reflectors is discussed and their performance evaluated. One of these reflectors has the property of lateral inversion of the reflected beam, which is found to aid transverse mode selection in a ruby laser. As an application of the reflectors, a damage free, single transverse mode, mode-locked ruby laser is described.