Abstract

We have built and tested a monolithic diffusion bonded quasi phase matched (DB-QPM) GaAs nonlinear crystal for second harmonic generation of 10.6 μm. This work was motivated by the need for nonlinear infrared materials with increased power handling capabilities and damage thresholds. These thermal related factors have limited the performance of other nonlinear infrared materials. Quasi phasematching extends the selection of nonlinear materials to include those that can not be phase matched by ordinary birefringent techniques. In this initial demonstration, we selected GaAs, which has a large nonlinear coefficient but is not birefringent. Diffusion bonding allows the construction of a monolithic structure retaining the excellent thermal and mechanical properties of bulk GaAs single crystals and significantly reduces losses at the multiple interfaces unavoidable in a stack of plates quasi phase matched structure.

© 1993 Optical Society of America