High-power CW oscillation of 1.3-µm wavelength InP-based photonic-crystal surface-emitting lasers

We demonstrate high-power continuous-wave (CW) lasing oscillation of 1.3-µm wavelength InP-based photonic-crystal surface-emitting lasers (PCSELs). Single-mode operation with an output power of over 100 mW, a side-mode suppression ratio (SMSR) of over 50 dB, and a narrow single-lobe beam with a divergence angle of below 1.2° are successfully achieved by using a double-lattice photonic crystal structure consisting of high-aspect-ratio deep air holes. The double lattice is designed to enhance both the in-plane optical feedback and the surface radiation effects in the photonic crystal. The coupling coefficients for 180 ^∘, +90 ^∘, and -90 ^∘ diffractions are estimated from the measurements of the photonic band structure as κ_1D = 417 cm^-1, κ_2D+ = 135 cm^-1, and κ_2D- = 65 cm^-1, respectively. The stable single-mode, high-beam-quality operation is attributed to these large coupling coefficients introduced by the asymmetric double-lattice structure.