Suppression of optical field leakage in GaN-based green laser diode using graded-indium n-InxGa1-xN lower waveguide
Authors: Liang, F; Zhao, DG; Jiang, DS; Liu, ZS; Zhu, JJ; Chen, P; Yang, J; Liu, ST; Xing, Y; Zhang, LQ
SUPERLATTICES AND MICROSTRUCTURES
Volume: 132 Published: AUG 2019 Language: English Document type: Article
Optical field leakage to the GaN substrate in GaN-based green laser diodes (LDs) can reduce the peak optical gain and weaken the output performance of LDs. In this study, a graded-indium composition n-InxGa1-xN lower waveguide (LWG) structure is proposed which should be more feasible to grow with high material quality and at the same time can effectively reduce the optical field leakage in GaN-based green LD, avoiding to use thick n-type Al0.08Ga0.92N cladding layer or thick n-InxGa1-xN LWG with high indium content. According to the optical and electrical characteristics of LDs calculated by LASTIP, it is found that the optical field has been concentrated around the active area and the optical field leakage has been eliminated effectively using graded-indium composition LWG in green LDs, which results in an obvious improvement of optical and electrical performance.