LASER HARMONIC GENERATION EMPLOYING LOW-LOSS EXTERNAL OPTICAL RESONATOR

摘要

TEM00q laser radiation derived from a diode-pumped ring laser (16) is directed into a faceted member (13) of nonlinear optical material (12) defining either a standing wave or ring monolithic optical resonator to generate harmonic laser radiation. The losses of the optical resonator, exclusive of the conversion loss to the harmonic, are made sufficiently low such that the dominant loss presented to the resonated mode of the optical resonator is the conversion loss to the generated harmonic. The reflectance of the input mirror (13) of the optical resonator is impedance matched to the losses of the resonator including the harmonic conversion loss for optimum conversion efficiency. The lenght of the nonlinear optical material (12) is shortened to the point where the bulk losses are less than ten times the sum of the surface and mirror losses, yielding conversion efficiencies of greater than 20 percent.