Efficient second-harmonic generation of a CO_2 laser with a quasi-phase-matched GaAs crystal

Abstract
We report on the fabrication and characterization of 5-mm-long quasi-phase-matched diffusion-bonded GaAs crystals designed for frequency doubling of a CO2 laser. Second-harmonic generation of a pulsed laser yielded up to 24% peak power efficiency at 20 MW/cm2. Tunability and laser damage threshold are also investigated.