Grating-coupled excitation of multiple surface plasmon-polariton waves

Abstract

The excitation of multiple surface-plasmon-polariton (SPP) waves of different linear polarization states and phase speeds by a surface-relief grating formed by a metal and a rugate filter, both of finite thickness, was studied theoretically, using rigorous coupled-wave-analysis. The incident plane wave can be either p or s polarized. The excitation of SPP waves is indicated by the presence of those peaks in the plots of absorbance vs. the incidence angle that are independent of the thickness of the rugate filter. The absorbance peaks representing the excitation of s-polarized SPP waves are narrower than those representing p-polarized SPP waves. Two incident plane waves propagating in different directions may excite the same SPP wave. A line source could excite several SPP waves simultaneously

Grating-coupled excitation of Tamm waves

“…The boundary-value problem was formulated using the rigorous coupled-wave approach (RCWA) [16,17] and was implemented using a stable algorithm [12,18]. The accuracy of the solution using RCWA depends on the value of N t , the number of terms of Floquet harmonics in the representation of field phasors being 2N t 1.…”

“…The electromagnetic field has to be expressed in terms of Floquet harmonics [12]. If the period of the surface-relief grating is appropriate, the incident light can couple to a Tamm wave at a certain angle of incidence when the component of the wavenumber of a Floquet harmonic parallel to the mean grating/rugate-filter interface matches that of the Tamm wave.…”

“…Since the theoretical formulation of the boundary-value problem solved in this paper is the same as has been provided in [12] for the grating-coupled excitation of SPP waves, only a brief description is provided in Section 2. Representative numerical results showing the excitation of Tamm waves in the grating-coupled configuration are provided in Subsections 3.A-3.C.…”

Grating-coupled excitation of the Uller–Zenneck surface wave in the optical regime

“…The wave vector of the incident plane wave lies wholly in the xz plane and is oriented at an angle θ with respect to the z axis. The electric field phasor in the half space z < 0 is adequately represented by [17,14] E(r) = (−û x cos θ +û z sin θ) exp [ik 0 n d (x sin θ + z cos θ)]…”

“…The rigorous coupled-wave approach [17,23,24,14] was used to compute the reflection and transmission amplitudes. As for the previous two sections, air was chosen as the nondissipative partnering material and crystalline silicon as the dissipative partnering material.…”