Open AccessCompact high-performance adiabatic 3-dB coupler enabled by subwavelength grating slot in the silicon-on-insulator platform
Author(s) -
Luhua Xu,
Yun Wang,
Amar Kumar,
Eslam El-Fiky,
Mao Deng,
Heba Tamazin,
Maxime Jacques,
Zhenping Xing,
Md. Ghulam Saber,
David V. Plant
Publication year - 2018
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.26.029873
Subject(s) - electron beam lithography , optics , materials science , silicon on insulator , grating , adiabatic process , insertion loss , optoelectronics , lithography , beam propagation method , refractive index , wavelength , coupling loss , silicon , resist , optical fiber , physics , layer (electronics) , composite material , thermodynamics
We demonstrate a compact high-performance adiabatic 3-dB coupler for the silicon-on-insulator platform. The refractive index of the gap region between two coupling waveguides is effectively increased using subwavelength grating, which leads to high-performance operation and a compact design footprint, with a mode-evolution length of only 25 µm and an entire device length of 65 µm. The designed adiabatic 3-dB coupler has been fabricated using electron beam lithography and the feature size used in our design is CMOS compatible. The fabricated device is characterized in the wavelength range from 1500 nm to 1600 nm, with a measured power splitting ratio better than 3 ± 0.27 dB and an average insertion loss of 0.20 dB.