Edge-emitting diode lasers with narrow circular beam output

We report near circular beam output from 808 nm edge-emitting diode lasers based on Bragg reflection waveguide design. Increasing quantum well number combined with reducing defect layer index and thickness was used to achieve high power output and extremely low vertical far field divergence. The TQW-BRLs achieve the lowest vertical divergence of 4.91° (full width at half maximum) and 9.8° (95% power). The maximum power of 4.6 W was achieved in the mounted DQW-BRL device under continuous-wave operation, being limited by thermal rollover.