Resonance modes of a metal-semiconductor-metal multilayer mediated by electric charge

Abstract

Electromagnetic fields around metal–semiconductor–metal (MSM) multilayers with square island top layers were numerically simulated to elucidate the difference in physics between the circuit resonance and Fabry–Pérot interference mediated by the surface plasmon polaritons (SPP). In the current study, the top and bottom metal layers were made of gold, and the intermediate semiconductor layer was a gallium antimony (GaSb). The lumped-element and Fabry–Pérot interference models showed less accuracy when the island width of the MSM multilayer was comparatively smaller. Since the capacitor and SPP could not be supported between the top and bottom gold layers, the anti-reflection mode of the gold–GaSb bilayer mainly affected the absorptance. However, when the width of the island was sufficiently large, the time-lapse development of the electromagnetic fields at resonant wavelengths showed strong electric and magnetic responses relating to the circuit resonance. Simultaneously, the electric fields depicted the movement of the electric charge, which coupled to the short-range surface plasmon polariton (SRSP) existing at the thin GaSb layer sandwiched by two gold layers. The wavelength of the SRSP approximately corresponded to that of the Fabry–Pérot interference. It was revealed that the lumped-element and Fabry–Pérot interference models indicated the same resonant mode from two different perspectives in physics.

Radiative energy transfer via surface plasmon polaritons around metal–insulator grating: For better understanding of magnetic polariton

“…A finite length of the waveguide gives a strict coupling requirement between the incident wave and SRSPs because the terminus of waveguide functioning as an end-fire coupler slightly reflects the SRSPs (Bozhevolnyi and Søndergaard, 2007). The incident and reflected SRSPs exhibit Fabry-Pérot-like interference using the MIM waveguide as a resonator (Barnard et al, 2008;Bozhevolnyi, 2009;Bozhevolnyi and Søndergaard, 2007;Isobe and Hanamura, 2022;Liu and Takahara, 2017). SRSPs are excited in the finite waveguide when the grating height corresponds to the integer multiples of the half wavelength; however, the actual resonance point is corrected by the phase shift at the terminus of the waveguide.…”

“…An earlier research study investigated the resonance frequencies and electromagnetic fields for SPPs excited as a short-range surface plasmon (SRSP) mode inside an MIM waveguide. The study showed that the Fabry-Pérot-like interference for SRSPs in a MIM multilayer with a square island top layer denotes similar resonance frequency as circuit resonance (Isobe and Hanamura, 2022). However, the results contained slight deviations of models from simulation results because two metal layers sandwiching the insulator layer had different shapes; one metal layer was a smooth plane while another was a square island structure.…”