中国物理B ›› 2022, Vol. 31 ›› Issue (11): 114208-114208.doi: 10.1088/1674-1056/ac5c30

• • 上一篇    下一篇

Coupling characteristics of laterally coupled gratings with slots

Kun Tian(田锟), Yonggang Zou(邹永刚), Linlin Shi(石琳琳), He Zhang(张贺), Yingtian Xu(徐英添), Jie Fan(范杰), Hui Tang(唐慧), and Xiaohui Ma(马晓辉)   

  1. State Key Laboratory on High Power Semiconductor Lasers, Changchun University of Science and Technology, Changchun 130022, China
  • 收稿日期:2021-11-01 修回日期:2022-02-21 接受日期:2022-03-10 出版日期:2022-10-17 发布日期:2022-10-17
  • 通讯作者: Yonggang Zou E-mail:zouyg@cust.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 61804013, 61804014, and 61805023) and Department of Science and Technology of Jilin Province, China (Grant Nos. 20190302052GX and 20210201030GX).

Coupling characteristics of laterally coupled gratings with slots

Kun Tian(田锟), Yonggang Zou(邹永刚), Linlin Shi(石琳琳), He Zhang(张贺), Yingtian Xu(徐英添), Jie Fan(范杰), Hui Tang(唐慧), and Xiaohui Ma(马晓辉)   

  1. State Key Laboratory on High Power Semiconductor Lasers, Changchun University of Science and Technology, Changchun 130022, China
  • Received:2021-11-01 Revised:2022-02-21 Accepted:2022-03-10 Online:2022-10-17 Published:2022-10-17
  • Contact: Yonggang Zou E-mail:zouyg@cust.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 61804013, 61804014, and 61805023) and Department of Science and Technology of Jilin Province, China (Grant Nos. 20190302052GX and 20210201030GX).

摘要: Laterally-coupled ridge-waveguide distributed feedback lasers fabricated without epitaxial regrowth steps have the advantages of process simplification and low cost. We present a laterally coupled grating with slots. The slots etched between the ridge and grating area are designed to suppress the lateral diffusion of carriers and to reduce the influence of the aspect-ratio-dependent-etching effect on the grating morphology in the etching process. Moreover, the grating height in this structure can be decreased to lower the aspect ratio significantly, which is advantageous over the conventional laterally coupled ridge waveguide gratings. The effects of five main structural parameters on the coupling characteristics of gratings are studied by MODE Solutions. It is found that varying the lateral width of the grating can be used as an effective way to tune the coupling strength; narrow slots (100 nm and 300 nm) and wide ridge (2 μm-4 μm) promote the stability of grating coupling coefficient and device performance. It is important to note that the grating bottom should be fabricated precisely. The comparative study of carrier distribution and mode field distribution shows that the introduction of narrow slots can strengthen the competitive advantage and stability of the fundamental mode.

关键词: Bragg gratings, distributed feedback (DFB) lasers, coupling coefficient, mode field distribution

Abstract: Laterally-coupled ridge-waveguide distributed feedback lasers fabricated without epitaxial regrowth steps have the advantages of process simplification and low cost. We present a laterally coupled grating with slots. The slots etched between the ridge and grating area are designed to suppress the lateral diffusion of carriers and to reduce the influence of the aspect-ratio-dependent-etching effect on the grating morphology in the etching process. Moreover, the grating height in this structure can be decreased to lower the aspect ratio significantly, which is advantageous over the conventional laterally coupled ridge waveguide gratings. The effects of five main structural parameters on the coupling characteristics of gratings are studied by MODE Solutions. It is found that varying the lateral width of the grating can be used as an effective way to tune the coupling strength; narrow slots (100 nm and 300 nm) and wide ridge (2 μm-4 μm) promote the stability of grating coupling coefficient and device performance. It is important to note that the grating bottom should be fabricated precisely. The comparative study of carrier distribution and mode field distribution shows that the introduction of narrow slots can strengthen the competitive advantage and stability of the fundamental mode.

Key words: Bragg gratings, distributed feedback (DFB) lasers, coupling coefficient, mode field distribution

中图分类号:  (Semiconductor lasers; laser diodes)

  • 42.55.Px