Mode control in planar waveguide grating couplers with double surface corrugation

• Main Authors: Xiao, Zhe, Liow, Tsung-Yang, Zhang, Jing, Silalahi, Samson T. H., Shum, Perry Ping, Luan, Feng
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering::Electrical and electronic engineering
• Online Access: https://hdl.handle.net/10356/102731; http://hdl.handle.net/10220/16419
• Institution: Nanyang Technological University

Grating couplers with double surface corrugation are proposed to adjust the resonance behavior of both TE and TM modes simultaneously. Through proper selection of parameters, we designed a polarization-independent grating coupler operating at 1.55-μm telecommunication wavelength. Efficiency is achieved at around 55% for both TE and TM modes, and the polarization-dependent loss is <; 0.05 dB within the spectral window from 1544 to 1561 nm. Furthermore, a double-channel grating coupler is proposed to excite the TE and TM modes at 1.31 and 1.49 μm, respectively. The achievable efficiency is around 60% for both channels with good uniformity.