We propose the use of subwavelength structures in a waveguide grating to achieve polarization-independent coupling of light between an optical fiber and a silicon-on-insulator (SOI) optical waveguide. The subwavelength structure allows the mode effective indices of the TE and TM modes in the grating section to be precisely engineered. We calculate that coupling efficiency of over 64% is possible using the proposed design for polarization-independent coupling between single-mode optical fibers and SOI nanophotonic waveguides.
© 2011 Optical Society of America
Diffraction and Gratings
Original Manuscript: December 10, 2010
Revised Manuscript: January 20, 2011
Manuscript Accepted: January 29, 2011
Published: March 7, 2011
Xia Chen and Hon K. Tsang, "Polarization-independent grating couplers for silicon-on-insulator nanophotonic waveguides," Opt. Lett. 36, 796-798 (2011)