High-power low-beam divergence edge-emitting semiconductor lasers with 1- and 2-D photonic bandgap crystal waveguide (Invited paper)

We report on edge-emitting lasers based on the land 2-D longitudinal photonic bandgap crystal concept. The longitudinal photonic bandgap crystal (PBC) design allows a robust and controllable extension of the fundamental mode over a thick multilayer waveguide to obtain a very large vertical mode spot size and a narrow vertical beam divergence. We focus on high-performance PBC lasers in different material systems. Ridge 658 nm GaInP-AlGaInP single-mode PBC lasers demonstrate vertical beam divergence of 8 degrees and continuous-wave (CW) output power above 115 mW. Multimode CW power of 500 mW is achieved at 635 nm in 50-mu m-wide lasers. GaAs/AlGaAs PBC lasers emitting at 850 nm show a vertical far-field divergence of 9 degrees, differential quantum efficiency of 95%, and maximum CW single mode power of 270 mW. InGaAs/AlGaAs PBC lasers emitting at 980 nm show a vertical far field of 4 degrees and single-mode output power of 1.2 W. Two-dimensional PBC lasers based on field-coupled multiridge arrays show stable single lateral mode operation with narrow lateral far field of 0.6 degrees and output power in pulsed mode of 20 W. Maximal CW output power in single lateral mode operation is 2.7 W.