Polarization mode hybridization and conversion in phononic wire waveguides
Abstract
Phononic wire waveguides of subwavelength cross sections support two orthogonal polarization modes: the out-of-plane motion dominated Rayleigh-like and the in-plane motion dominated Love-like modes, analogous to transverse-electric and transverse-magnetic modes in photonic waveguides. Due to the anisotropic elasticity of the substrate material, the polarization states of phonons propagating along certain crystallographic orientations can strongly hybridize. Here, we experimentally investigate the orientation-dependent mode hybridization in phononic wire waveguides patterned from GaN-on-sapphire thin films. Such mode hybridization allows efficient actuation of piezoelectrically inactive Love-like modes using common interdigital electrodes designed for Rayleigh-like modes and further enables on-chip polarization conversion between guided transverse modes. Both are important for on-chip implementation of complex phononic circuits.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Nov 11, 2019
- Source ID
- 10.1063/1.5120844
Entities
People
- Chang-Ling Zou
- Hendrick Townley
- Hong X Tang
- Risheng Cheng
- Wei Fu
- Zhen Shen
Organizations
- Air Force Office of Scientific Research
- Army Research Office
- Naval Information Warfare Systems Command
- Yale University