Photoinduced tunability of the Reststrahlen band in 4H-SiC

Abstract

Materials with a negative dielectric permittivity (e.g. metals) display high reflectance and can be shaped into nanoscale optical-resonators exhibiting extreme mode confinement, a central theme of nanophotonics. However, the ability to $actively$ tune these effects remains elusive. By photoexciting free carriers in 4H-SiC, we induce dramatic changes in reflectance near the "Reststrahlen band" where the permittivity is negative due to charge oscillations of the polar optical phonons in the mid-infrared. We infer carrier-induced changes in the permittivity required for useful tunability (~ 40 cm${}^{-1}$) in nanoscale resonators, providing a direct avenue towards the realization of actively tunable nanophotonic devices in the mid-infrared to terahertz spectral range.

References in corpus (4)

• Gate-tuning of graphene plasmons revealed by infrared nano-imaging
• Optical nano-imaging of gate-tuneable graphene plasmons
• Sub-diffractional, volume-confined polaritons in a natural hyperbolic material: hexagonal boron nitride
• Phase-change chalcogenide glass metamaterial

Cited by in corpus (5)

• Ultra-low-loss Polaritons in Isotopically Pure Materials: A New Approach
• Active Tuning of Surface Phonon Polariton Resonances via Carrier Photoinjection
• Hybrid Longitudinal-Transverse Phonon Polaritons
• Theory of Optical Nonlocality in Polar Dielectrics
• Nonlocal Scattering Matrix Description of Anisotropic Polar Heterostructures