High transmission of system "dielectric grating thin metal film - dielectric grating"

Abstract

The analysis of transmission of system the dielectric grating-metal thin film-dielectric gratingsubstrate by the coupled wave method (CWM) is conducted. It is revealed that at certain parameters the system has the anomalous high transmittance and practically zero reflectance on defined wavelengths. For example, the silver film with thickness of 0.0385gm placed between two gratings with certain parameters transmit more than 0.86 and 0.83 corresponding to TE and TM polarizations on wavelength of 1.5gm. The silver film in vacuum with same thickness has the reflectance higher than 0.98 and transmittance less than 0.004. Transmission sharply drops at deviation of the wavelength from the defined value. The system the dielectric with high refraction coefficient-metallic thin film-dielectric with high refraction coefficient has the analogous spectrum characteristics.

A TM-Pass/TE-Stop Polarizer Based on a Surface Plasmon Resonance

“…where k 0 is the free-space wavenumber; Λ(=2w) is the periodicity; k sp is the propagation constant of the SP mode, which can be obtained by the eigenmode analysis. Note that in the eigenmode analysis the refractive index of the dielectric grating is approximately modeled as a homogeneous layer with second-order effective index for the TM wave (n (2) TM ), which is calculated by the effective medium theory [1]:…”

“…One of the important applications of the periodic structures is to construct a polarizer, which is used in optical communications and sensing devices. Recently, high transmission of the transverse magnetic (TM) wave through a thin metal film has been suggested and discussed [2][3][4]. The transmission is closely related to a surface plasmon (SP) resonance [5].…”

“…Figure 1 illustrates the periodic structure of the polarizer, in which a two-dimensional model is treated. The configuration is similar to that treated in [2,3]. We illuminate a uniform plane wave of either the TE or the TM wave from the input side and intend to extract the TE wave as a reflected field at the input side and the TM wave as a transmission field at the output side.…”