1.5 µm wavelength NPN-type photonic-crystal surface-emitting laser exceeding 100 mW.

A 1.5 µm laser diode has applications in eye-safe light detection and ranging (LiDAR) and optical communications via photonic integrated circuits. Photonic-crystal surface-emitting lasers (PCSELs) have lens-free applications in compact optical systems because of narrow beam divergences (<1 degree). However, the output power has still been less than 1 mW for 1.5 µm PCSELs. For higher output power, one approach is suppression of p-dopant Zn diffusion in the photonic crystal layer. Therefore, n-type doping was used for the upper crystal layer. Moreover, an NPN-type PCSEL structure was proposed to reduce intervalence band absorption in the p-InP layer. Here, we demonstrate a 1.5 µm PCSEL with 100 mW output power, which exceeds previous reported values by two orders of magnitude.