High power with high efficiency in a narrow single-lobed beam from a diode laser array in an external cavity

Abstract
High output power (700 mW) in a nearly diffraction-limited (0.7°) single-lobed nonsteering output beam is obtained from a gain-guided diode laser array in a novel, easily fabricated external cavity configuration. The laser output beam is collimated in both lateral and vertical directions. Differential quantum efficiency as high as 70% has been measured along with excellent linearity of the optical power versus current characteristic. The power and efficiency are the highest reported for a coupled-stripe laser array emitting a narrow single-lobed beam.