High Brightness Nanosecond-Pulse Operation of 905 Nm Distributed Bragg Reflector Tapered-Ridge-waveguide Lasers with Multiple Active Regions

We present weakly tapered ridge waveguide distributed Bragg reflector lasers with three active regions epitaxially stacked in a common waveguide emitting nanosecond pulses around 905 nm for LIDAR. The vertical structure is optimized for pulsed operation and implementation of a surface Bragg grating for emission in the 2nd order vertical mode. 6 mm long diode lasers with a 25 mu m output aperture, integrated into an inhouse high pulse current electronic driver, provide a pulse power > 20 W, a beam propagation ratio of M-2 similar to 4.5, and a lateral brightness of approx. 16 W/(mm.mrad). The emission spectrum features a spectral width of < 0.3 nm and a temperature-related shift of < 70 pm/K.