A system, a structure, and a method for the generation of second harmonic
light are provided. A laser system comprises a seed laser that produces a
fundamental frequency light, and a nonresonant multiple pass nonlinear
structure generates a second harmonic light using the fundamental
frequency light. A second harmonic outcoupler outputs the second harmonic
light from the laser system and a reflecting structure reflects a
remaining portion of the fundamental frequency light back into the
nonresonant multiple pass nonlinear structure to generate additional
second harmonic light.