Open AccessUltra-compact broadband mode converter and optical diode based on linear rod-type photonic crystal waveguide
Author(s) -
Han Ye,
Donglin Wang,
Zhongyuan Yu,
Jinqiannan Zhang,
Zhihui Chen
Publication year - 2015
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.23.009673
Subject(s) - optics , broadband , photonic crystal , diode , photonic integrated circuit , bandwidth (computing) , waveguide , photonics , materials science , optoelectronics , physics , computer science , telecommunications
In this paper, we present extremely compact designs of both broadband mode converter and optical diode in linear rod-type photonic crystal (PhC) waveguide with functional region consisting of only 4 × 1 unit cells of perfect PhC. The dielectric distribution inside functional region are optimized by combining geometry projection method and method of moving asymptotes. Bidirectional mode converter realizes above 60% transmission efficiency within bandwidth 0.02c/a, where c and a represent light velocity and PhC lattice constant respectively. Optical diode achieves above 19 dB unidirectionality for even mode within bandwidth 0.01c/a. Moreover, the proposed designs have reasonable tolerance of rod boundary fluctuation. We expect the results will help developing recipes for future PhC devices in all-optical integrated circuits.