Subwavelength grating couplers for an ultrathin silicon waveguide.

• Tác giả: Si Chen, Zhenzhou Cheng, Penghao Ding, Yu Du, Youfu Geng, Xu Li, Xuejin Li, Chuxian Tan, Hon Ki Tsang, Jiaqi Wang, Guoxian Wu, Hui Zhang, Zunyue Zhang
• Ngôn ngữ: eng
• Ký hiệu phân loại: 294.3823 Buddhism
• Thông tin xuất bản: United States : Optics letters , 2025
• Bộ sưu tập: NCBI
• ID: 707355

Tóm tắt

Subwavelength grating structures are widely used in integrated optical devices due to their compact footprints and flexible refractive index tailoring. In this paper, we present a subwavelength grating (SWG) coupler for a 70-nm-thick silicon waveguide without the upper cladding. The device was designed by using a particle swarm optimization algorithm in 3D finite-difference time-domain simulation. Experimental measurements show that the SWG coupler with a minimum feature size of ∼210 nm has a peak coupling efficiency of -7.0 dB with a 1-dB bandwidth of ∼40 nm and a backreflection of ∼-18.7 dB at 1550 nm wavelengths for transverse-electric polarized light. The ultrathin device structure is simple and reproducible, making it well suited for sensing and optoelectronic integration applications at low cost.