Laser bars and single emitters in the 9xx emission range optimized for high output powers at reduced far field angles

Abstract

High-power single emitters and laser bars are used as light sources in many industrial applications such as materials processing or as pump sources for solid state or fiber lasers. Those applications require laser devices with high optical power, high efficiency and high brightness. To fulfill the requirements the laser design in both directions, vertical and lateral, is continuously improved. We have realized a new generation epitaxial structure, emitting at 940 nm, for a reduced vertical carrier leakage, lower thermal and electrical resistance resulting in high electro-optical efficiency up to high currents. Furthermore the fast axis divergence angle containing 95% power was reduced to 40°. 280 W CW-power with the wall-plug efficiency greater than 60% was reached from the new generation laser design when processed as high fill-factor laser bars. The epitaxial design was adapted to wavelengths 915 nm, 955 nm and 976 nm allowing for fabrication of powerful and high brightness single emitters, laser arrays an laser bars emitting in this wavelength range.