SYSTEM AND METHOD FOR SEPARATION OF SIGNAL AND INPUT BEAMS UTILIZING WALK-OFF PHENOMENON

摘要

A frequency converter is configured from a phase-matched non-linear crystal portion which frequency-converts radiation of one or more input beams to the desired frequency of the signal beam. Due to birefringence of the phase-matched crystal portion, the input and signal beams propagate at a walk-off angle relative to one another along the entire length of the phase-matched portion. The frequency converter further includes a non-phase-matched non-linear crystal portion receiving the input and signal beams which continue to propagate at the walk-off angle so as to be spatially separated from one another at the desired distance after exiting the output of the non- phased portion. The desired distance is selected to provide unobstructed propagation of the signal beam to the target to be irradiated while the input beam(s) is incident on an optical component preventing the input beam from impinging upon the target.