Efficient diffraction-limited beam combining of semiconductor laserdiode arrays using photorefractive BaTiO3

Beam combining of 820-nm-wavelength laser diodes using two-wave mixing in BaTiO₃ is reported. Energy transfer efficiencies up to 80% were obtained with an index-guided diode. Efficient beam combining of two injection-locked laser arrays was demonstrated. Nearly 100 mW power in a diffraction-limited beam was obtained on the combined beam. Crystal response time of the order of a few seconds was measured