Patent ID: 6141369
Filing Date: 2000-10-31
Classification: H01S

Abstract:
A laser comprising:a laser resonator terminated by first and second resonator mirrors and having a longitudinal resonator axis;a gain-medium and an optically-nonlinear crystal located in said resonator serially disposed along said resonator axis with said optically-nonlinear crystal closest said second mirror;an optical-pump providing pump-light for pumping said gain-medium, thereby generating a primary laser-beam said primary laser-beam reciprocally propagating in said resonator along said resonator axis in first and second opposite directions, said primary laser-beam propagating in said first direction passing through said optically-nonlinear crystal, thereby generating a first frequency-multiplied beam and said primary laser-beam propagating in said second direction passing through said optically-nonlinear crystal, thereby generating a second frequency-multiplied beam;said second resonator mirror being transmissive for said frequency-multiplied radiation, thereby allowing said first frequency-multiplied beam to exit said resonator as output frequency-multiplied radiation;said optically-nonlinear crystal characterized by a walkoff-angle therein between said primary laser-beam passing therethrough and said frequency-multiplied beams generated thereby, and arranged such that said first and second frequency-multiplied beams outside of said optically-nonlinear crystal are laterally separated from said primary laser-beam and from each other by a distance sufficient to reduce interaction therebetween; anda component located in said resonator between said optically-nonlinear crystal and said gain-medium and arranged to impede passage of said second frequency-multiplied beam into said gain-medium.