Fig. 3

Numerical simulations for the antenna-assisted subwavelength Au–InSb–Au structure. a Localized surface plasmon polariton (SPP) intensity (E ²/E ₀ ²) of the structure as a function of incident power. b SPP intensity of the structure at different polarization angles for incident 0.151 meV photons. c SPP intensity of the air–InSb–air structure at different polarization angles for incident photons of 0.151 meV for comparison. d Normalized E ²/E _max ² as a function of incident photon energy. e Distribution of E ²/E ₀ ² along the half width line for devices with spacings s of 10, 30, 50, 70, 90, 110, and 130 µm. Inset: E ²/E ₀ ² as a function of s at the point (s/2, 0, 0)