title: Infrared surface polaritons on antimony.
abstract: The semimetal antimony, with a plasma frequency ~80 times less than that of gold, is potentially useful as a host for infrared surface polaritons (SPs). Relevant IR SP properties, including the frequency-dependent propagation length and penetration depths for fields into the media on either side of the interface, were determined from optical constants measured on optically-thick thermally-evaporated Sb films over the wavelength range 1 to 40 μm. Plasma and carrier relaxation frequencies were determined from Drude-model fits to these data. The real part of the permittivity is negative for wavelengths beyond 11 μm. Distinct resonant decreases in specular reflected intensity were observed for Sb lamellar gratings in the wavelength range of 6 to 11 μm, where the real part of the permittivity is positive. Both resonance angles and the angular reflectance spectral line shapes are in agreement with theory for excitation of bound surface electromagnetic waves (SPs). Finite element method (FEM) electrodynamic simulations indicate the existence of SP modes under conditions matching the experiments. FEM results also show that such waves depend on having a significant imaginary part of the permittivity, as has been noted earlier for the case of surface exciton polaritons.
authors.affiliation: Sensors Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433, USA. Justin.Cleary@WPAFB.af.mil
authors.forename: Justin W
authors.initials: JW
authors.lastname: Cleary
authors.forename: Gautam
authors.initials: G
authors.lastname: Medhi
authors.forename: Monas
authors.initials: M
authors.lastname: Shahzad
authors.forename: Imen
authors.initials: I
authors.lastname: Rezadad
authors.forename: Doug
authors.initials: D
authors.lastname: Maukonen
authors.forename: Robert E
authors.initials: RE
authors.lastname: Peale
authors.forename: Glenn D
authors.initials: GD
authors.lastname: Boreman
authors.forename: Sandy
authors.initials: S
authors.lastname: Wentzell
authors.forename: Walter R
authors.initials: WR
authors.lastname: Buchwald
mesh_terms: D000965:Antimony / Q000737:chemistry*; D003198:Computer Simulation; D007259:Infrared Rays; D008027:Light; D008956:Models, Chemical; D012542:Scattering, Radiation; D020349:Surface Plasmon Resonance / Q000379:methods*; D013499:Surface Properties
chemical_list: D000965:Antimony