GaN-based two-dimensional surface-emitting photonic crystal lasers with AlN/GaN distributed Bragg reflector

GaN-based two-dimensional (2D) surface-emitting photonic crystal (PC) lasers with AlN/GaN distributed Bragg reflectors are fabricated and demonstrated. The lasing threshold energy density is about 3.5 mJ/cm(2) per pulse under optical pumping at room temperature. Only one dominant emission wavelength of 424.3 nm with a narrow linewidth of 1.1 A above the threshold is observed. The laser emission covers whole circularly 2D PC patterns (50 mu m in diameter) with a small divergence angle. The lasing wavelength emitted from 2D PC lasers with different lattice constants occurs at the calculated band-edges provided by the PC patterns. The characteristics of large area, small divergence angle, and single mode emission from the GaN-based 2D surface-emitting PC lasers should be promising in high power blue-violet emitter applications.