Abstract

We present an air-cladding apodized focusing subwavelength grating that can effectively couple two polarizations into a single waveguide. For the transverse magnetic mode, $-3.2\mathrm{dB}$ maximum coupling efficiency with $\sim 28\mathrm{nm}$ 1 dB bandwidth is achieved. With the same grating, $-4.3\mathrm{dB}$ maximum coupling efficiency with $\sim 58\mathrm{nm}$ 1 dB bandwidth is achieved for the transverse electric mode. The minimum difference between two polarizations’ coupling peaks is demonstrated to be $\sim 32\mathrm{nm}$. At the 1525 nm wavelength range, the polarization-insensitive grating is demonstrated with $-6.5\mathrm{dB}$ coupling efficiency. The polarization-insensitive coupling wavelength can be controlled experimentally.

© 2014 Optical Society of America

Polarization-independent grating couplers for silicon-on-insulator nanophotonic waveguides

Xia Chen and Hon K. Tsang
Opt. Lett. 36(6) 796-798 (2011)

Broadband focusing grating couplers for suspended-membrane waveguides

Zhenzhou Cheng, Xia Chen, Chi Yan Wong, Ke Xu, and Hon Ki Tsang
Opt. Lett. 37(24) 5181-5183 (2012)

Focusing subwavelength grating coupler for mid-infrared suspended membrane waveguide

Zhenzhou Cheng, Xia Chen, C. Y. Wong, Ke Xu, Christy K. Y. Fung, Y. M. Chen, and Hon Ki Tsang
Opt. Lett. 37(7) 1217-1219 (2012)

Focusing subwavelength grating coupler for mid-infrared suspended membrane germanium waveguides

Jian Kang, Zhenzhou Cheng, Wen Zhou, Ting-Hui Xiao, Kimmy-Laure Gopalakrisna, Mitsuru Takenaka, Hon Ki Tsang, and Keisuke Goda
Opt. Lett. 42(11) 2094-2097 (2017)

Ultra-thin mid-infrared silicon grating coupler

Rongxiang Guo, Haoran Gao, Tiegen Liu, and Zhenzhou Cheng
Opt. Lett. 47(5) 1226-1229 (2022)