Enhancing single-mode stability and optical power of AlGaN-based DUV lasers by 1/4λ phase-shifted surface DFB gratings
Abstract
AlGaN-based distributed-feedback (DFB) laser diodes (LDs) operating at 280 nm and incorporating surface gratings with different phase shifts were designed and investigated. Compared to Fabry–Pérot (FP) and other phase-shifted designs, the DFB LD with a 1/4 phase shift exhibits the best performance, achieving a threshold current of 17.39 mA (25.4% lower than FP), a slope efficiency of 1.254 W/A (411.1% of FP), and a side-mode suppression ratio of 25 dB at 0.10 A. Systematic analysis reveals that the 1/4 phase shift introduces a localized defect mode at the stop band center, thereby lifting Bragg-mode degeneracy and strengthening longitudinal-mode selectivity, leading to a significant improvement in slope efficiency. Furthermore, scattering-loss analysis indicates that the design can tolerate a dislocation density of up to 2.2 × 109 cm−2, highlighting fabrication feasibility on AlN/sapphire substrates. This design outlines a promising route toward low-threshold, high-power, single-mode, and cost-effective AlGaN Deep-ultraviolet DFB LDs.
Article Details
Journal Info
Applied Physics Letters
American Institute of Physics
Authors (10)
Ganwei Zhou
State Key Laboratory of Luminescence Science and Technology, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences 1 , Changchun 130033,
Shunpeng Lu
State Key Laboratory of Luminescence Science and Technology, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences 1 , Changchun 130033,
Ruojia Zhang
State Key Laboratory of Luminescence Science and Technology, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences 1 , Changchun 130033,
Zhongxu Liu
State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Department of Chemistry, College of Chemistry and Chemical Engineering
Baofeng Yu
State Key Laboratory of Luminescence Science and Technology, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences 1 , Changchun 130033,
Ke Jiang
International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology of Ministry of Education, Institute of Microscale Optoelectronics
Shanli Zhang
State Key Laboratory of Luminescence Science and Technology, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences 1 , Changchun 130033,
Zihui Zhang
Xiaojuan Sun
Dabing Li