Observation of slow light in glide-symmetric photonic-crystal waveguides

We report optical transmission measurements on suspended silicon photonic-crystal waveguides, where one side of the photonic lattice is shifted by half a period along the waveguide axis. The combination of this glide symmetry and slow light leads to a strongly enhanced chiral light-matter interactio...

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Bibliographic Details
Authors: Patil, Chirag Murendranath, Arregui Bravo, Guillermo|||0000-0002-6458-5277, Mechlenborg, Morten, Zhou, Xiaoyan|||0000-0003-0833-0330, Alaeian, Hadiseh, García Fernández, Pedro David|||0000-0002-3422-178X, Stobbe, Søren|||0000-0002-0991-041X
Format: article
Publication Date:2022
Country:España
Institution:Universitat Autònoma de Barcelona
Repository:Dipòsit Digital de Documents de la UAB
Language:English
OAI Identifier:oai:ddd.uab.cat:266344
Online Access:https://ddd.uab.cat/record/266344
https://dx.doi.org/urn:doi:10.1364/OE.449221
Access Level:Open access
Keyword:Dispersion relations
Evanescent coupling
Group index
Light-matter interactions
Optical transmission measurements
Photonic crystal resonators
Symmetric waveguides
Symmetrics
Transmission measurements
Waveguide axis
Description
Summary:We report optical transmission measurements on suspended silicon photonic-crystal waveguides, where one side of the photonic lattice is shifted by half a period along the waveguide axis. The combination of this glide symmetry and slow light leads to a strongly enhanced chiral light-matter interaction but the interplay between slow light and backscattering has not been investigated experimentally in such waveguides. We build photonic-crystal resonators consisting of glide-symmetric waveguides terminated by reflectors and use transmission measurements as well as evanescent coupling to map out the dispersion relation. We find excellent agreement with theory and measure group indices exceeding 90, implying significant potential for applications in slow-light devices and chiral quantum optics. By measuring resonators of different length, we assess the role of backscattering induced by fabrication imperfections and its intimate connection to the group index.