Indexed by: Journal paper

Journal: Opt. Express

Affiliation of Author(s): 光电学院，国家光电研究中心

Place of Publication: 美国

Discipline: Engineering

Funded by: 自然科学基金

Document Type: J

Volume: 27

Issue: 13

Page Number: 17648-17657

Key Words: 无

DOI number: 10.1364/OE.27.017648

Date of Publication: 2019-02-13

Teaching and Research Group: c716

Abstract: In Hermitian photonic devices, S-parameters, i.e., the elements of a scattering matrix based on integrated power flux and Hermitian modal orthogonality, are used to account for the transmission or reflection of light from one port to another. The definition of S-parameters in Hermitian settings becomes inappropriate in the non-Hermitian optical environment. Here we revisit the fundamental problems associated with extracting the S-parameters of light in photonic 𝒫𝒯-symmetric devices, i.e., waveguides or coupled waveguide-cavity systems, wherein the waveguide ports themselves may also be non-Hermitian. We first use the bi-orthogonal inner product that restores the modal orthogonality on the waveguide ports containing balanced gain and losses to quantify the modal overlapping instead of Hermitian inner product. Secondly, a finite element implementation is proposed and realized to extract the S-parameters on non-Hermitian ports. Lastly, we illustrate our approach of calculating the S-parameters on non-Hermitian ports via two waveguide-lattice structures. The numerical results of S-parameters are validated against the constraints imposed by reciprocity and 𝒫𝒯-symmetry.

Note: 无

Links to published journals: https://doi.org/10.1364/OE.27.017648