Title :
Mode Control in Planar Waveguide Grating Couplers With Double Surface Corrugation
Author :
Xiao, Zhe ; Liow, Tsung-Yang ; Zhang, Jing ; Silalahi, Samson T H ; Shum, Ping ; Luan, Feng
Author_Institution :
OPTIMUS Photonics Centre of Excellence, Nanyang Technol. Univ., Singapore, Singapore
Abstract :
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.
Keywords :
diffraction gratings; light polarisation; optical couplers; optical losses; optical planar waveguides; TE modes; TM modes; double surface corrugation; double-channel grating coupler; mode control; planar waveguide grating couplers; polarization-dependent loss; polarization-independent grating coupler; wavelength 1.31 mum; wavelength 1.49 mum; wavelength 1.55 mum; Corrugated surfaces; Couplers; Couplings; Diffraction gratings; Gratings; Optical waveguides; Surface waves; Coupler; grating; integrated photonics; planar waveguide;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2012.2213300
