Oxide-Confined, Surface-Grating 1060nm Edge-Emitting Semiconductor Laser with Low Threshold and Narrow Divergence

In this paper, we present the design and fabrication of a 1060-nm single-mode edge-emitting semiconductor laser based on an oxide-confined, surface-grating architecture that simultaneously enables lateral fundamental-mode control, robust longitudinal single-mode operation, and high efficiency with a regrowth-free process flow. Simulations confirm strong overlap of the fundamental mode with the oxide aperture and effective suppression of higher-order lateral modes, consistent with the measured narrow far-field. Under CW operation at room temperature, the device exhibits a low threshold current of 19 mA and a maximum slope efficiency of 0.7 W/A, and it maintains stable lasing at 85℃ with a slope efficiency of 0.64 W/A. A low lateral divergence of 4.2°(FWHM) and a side-mode suppression ratio of 38 dB further demonstrate excellent beam quality and spectral purity.