Polarization characteristics of shallow-etched SOI ridge waveguide with non-rectangular cross section
College of Sciences, Zhejiang University of Technology, 310023, Hangzhou, China
2 College of Optical Science and Engineering, Zhejiang University, 310027, Hangzhou, China
Accepted: 11 October 2021
Published online: 9 November 2021
To control the polarization of shallow etched ridge waveguide made of crystalline silicon on insulator (SOI), a non-rectangular section SOI waveguide is proposed. The transmittivity formulas of TE0 and TM0 in the proposed waveguide are deduced, and the finite difference time domain method is used for analysis. It is found that the transmittivity of TE0 and TM0 modes shows great deviation in some parameter range; however, the difference is less than 0.03% in some other parameters, which could be regarded as polarization independent. At the same time, the sensitivity to structure parameters of modes in the non-rectangular waveguide is lower than that of the rectangular. Therefore, the proposed non-rectangular SOI ridge waveguide is expected to improve the polarization independence of the waveguide.
© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2021