Open AccessSilicon subwavelength grating waveguides with high-index chalcogenide glass cladding
Author(s) -
Philippe Jean,
Alexandre Douaud,
Sophie LaRochelle,
Younès Messaddeq,
Wei Shi
Publication year - 2021
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.430204
Subject(s) - cladding (metalworking) , materials science , grating , optics , refractive index , chalcogenide , optoelectronics , photonics , waveguide , chalcogenide glass , resonator , silicon , silicon photonics , diffraction grating , metamaterial , physics , metallurgy
Silicon subwavelength grating waveguides enable flexible design in integrated photonics through nano-scale refractive index engineering. Here, we explore the possibility of combining silicon subwavelength gratings waveguides with a high-index chalcogenide glass as a top cladding, thus modifying the waveguiding behavior and opening a new design axis for these structures. A detailed investigation of the heterogeneous SWG waveguide with high-index cladding is presented based on analytical and numerical simulations. We design, fabricate and characterize silicon subwavelength grating waveguide microring resonators with an As 20 S 80 cladding. Thanks to As 20 S 80 negative thermo-optic coefficient, we achieve near athermal behavior with a measured minimum thermally induced resonance shift of -1.54 pm/K, highlighting the potential of subwavelength grating waveguides for modal confinement engineering and to control light-matter interaction. We also show that the chalcogenide glass can be thermally reflowed to remove air gaps inside the cladding, resulting in a highly conformal structure. These types of waveguides can find application in reconfigurable photonics, nonlinear optics, metamaterials or slow light.