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.

Palladium Germanides for Mid- and Long-Wave Infrared Plasmonics

“…Strictly speaking, this spectral range should not be called "plasmonic" as SPPs are generally said to be excited when ε'<0. However, it has been shown that bound electromagnetic surface waves can exist when the the real part of the permittivity is positive provided that ε'<<ε'' [15,16]. After a 500°C anneal, the PdGe film has the strongest mode confinement which extends the spectral range well beyond the LWIR, although propogation loss around the ε'=0 point limits the lower end of the useful spectral range.…”

Morphology and photoresponse of crystalline antimony film grown on mica by physical vapor deposition

“…Antimony is a semimetal with sp 3 hybridization whose rhombohedral crystal structures are stable at room temperature [11]. It exhibits 80 times lower plasma frequency than gold, therefore can be potentially used as a host for surface polarization [12]. In addition, the antimony thin films have also been regarded as one of the constituent materials used in electronic devices [13].…”

Investigation of plasmon resonance tunneling through subwavelength hole arrays in highly doped conductive ZnO films

“…The investigation of alternative plasmonic materials has recently been accelerated 7,[14][15][16][17][18][19][20][21][22][23][24][25][26] due to the push to the infrared where noble metals are not as useful due to weak mode confinement and lack of CMOS compatibility. Two promising candidates, aluminum and gallium doped ZnO, have been proposed as possible plasmonic materials in the near- 17,19 and mid-IR 26 as these materials typically demonstrate plasma wavelengths $1 lm.…”