Second-harmonic generation with Ga1−xAlxAs lasers and KNbO3 crystals

Abstract
Efficient second‐harmonic generation from pulsed Ga1−xAlxAs injection lasers operating at room temperature has been observed in KNbO3 crystals. The Al concentration x of the laser was chosen such that the output corresponds to the room‐temperature noncritical 90° phase‐matching wavelength λpm=860 nm for the nonlinear optical coefficient d32 of KNbO3. Up to 0.35‐mW peak harmonic power was obtained with a pulsed fundamental peak power of 785 mW incident on a 5.74‐mm‐long crystal.