Low-loss, infrared and terahertz nanophotonics using surface phonon polaritons

Abstract

Abstract:The excitation of surface-phonon-polariton (SPhP) modes in polar dielectric crystals and the associated new developments in the field of SPhPs are reviewed. The emphasis of this work is on providing an understanding of the general phenomenon, including the origin of the Reststrahlen band, the role that optical phonons in polar dielectric lattices play in supporting sub-diffraction-limited modes and how the relatively long optical phonon lifetimes can lead to the low optical losses observed within these materials. Based on this overview, the achievements attained to date and the potential technological advantages of these materials are discussed for localized modes in nanostructures, propagating modes on surfaces and in waveguides and novel metamaterial designs, with the goal of realizing low-loss nanophotonics and metamaterials in the mid-infrared to terahertz spectral ranges.

Second harmonic generation spectroscopy in the Reststrahl band of SiC using an infrared free-electron laser

“…In recent years, there has been considerable interest in the mid-infrared Reststrahl 1 spectral region of Silicon Carbide (SiC), [2][3][4][5][6] since it holds much promise for a novel approach to low-loss, mid-infrared (IR) nanophotonic applications based on surface phonon polaritons (SPhPs). 4,5 Similarly to surface plasmon polaritons in metals, these surface phonon waves in the Reststrahl band of polar dielectrics can be tailored using resonant optical nano-antennas 4,5 as the fundamental building block of future nanophotonic devices.…”

“…7,8 Most importantly, nanophotonics based on SPhPs could solve the intrinsic optical loss-problem of plasmonics, 9 making use of the much smaller damping rates of phonons as compared to plasmons. 6 The peculiar linear optical properties in the Reststrahl region responsible for SPhP formation are dominated by dielectric response of the optical phonons in polar dielectrics. 10 The polar bonding character leads to splitting of the transversal optical (TO) and longitudinal optical (LO) phonon branches at the Brillouin zone-center and IR activity of the zone-center TO phonon.…”

Surface bound waves and optical interactions in excitonic thin films

“…Several polar dielectric materials (such as SiC and hBN) have strong phonon resonances in the infrared region [20]. These materials can have sharp Lorentzian dispersions with the negative permittivity region and have been widely used in the studies of surface phonon polaritons.…”

Specialized directional beaming through a metalens and a typical application

“…Extra ordinary enhanced transmission through subwavelength metallic structures such as slits and holes have been reported by numerous researchers in the last decade [2][3][4][5][6][7][8][9][10][11][12][13][14][15]. One of the typical works is the presentation regard ing the control of beaming through the subwavelength metallic slits reported by Yu et al in Ref.…”