High-power distributed feedback lasers with high-order surface curved gratings

Abstract

A novel, to the best of our knowledge, broad-area distributed feedback laser with high-order surface curved gratings has been fabricated based on standard near ultraviolet lithography. The characteristics of increasing output power and mode selection are achieved simultaneously by using a broad-area ridge as well as an unstable cavity structure composed of curved gratings and a high-reflectivity coated rear facet. Suppression of high-order lateral modes is realized by setting current injection/non-injection regions and asymmetric waveguides. This DFB laser emitting around 1070 nm has achieved a spectral width of 0.138 nm and a maximum output power of 915 mW kink-free optical power. The threshold current and side-mode suppression ratio of the device are 370 mA and 33 dB, respectively. The simple manufacturing process and stable performance give this high-power laser broad application prospects in the fields of light detection and ranging, laser pumps, optical disk access, etc.