学術雑誌論文

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

eng

Hindawi Publishing Corporation

1

6

2010-07-16

Version of Record

Article ID 867271

A TM-pass/TE-stop polarizer consisting of a metal film sandwiched between dielectric gratings is investigated using the finitedifferencetime-domain method. At normal incidence with respect to the grating plane, a transmissivity of more than 94% anda reflectivity of more than 98% are obtained at λ = 1.55 μm for the TM and TE waves, respectively. The extinction ratio is morethan 17 dB over a wavelength range of 1.50 μm to 1.75μm. A high extinction ratio is maintained at oblique incidence, although thewavelength range shifts towards longer wavelengths. The TM-pass/TE-stop operation is also achieved with a modified structure,in which a dielectric grating is sandwiched between metal films.1. IntroductionThere are a great number of papers devoted to the studyof light propagation in periodic structures [1]. One ofthe important applications of the periodic structures is toconstruct a polarizer, which is used in optical communicationsand sensing devices. Recently, high transmission of thetransverse magnetic (TM) wave through a thin metal filmhas been suggested and discussed [2?4]. The transmission isclosely related to a surface plasmon (SP) resonance [5]. TheSP resonance is realized using a thin metal film sandwichedbetween dielectric gratings. We should also note that recentinterest has been directed toward plasmon waveguidesoperating at λ = 1.55 μm (optical communication band)[6, 7].In this paper, the SP-based enhanced transmissionthrough a thin metal film is investigated in more detail inthe optical communication band. The finite-difference timedomain(FDTD) method is used for the analysis. To obtaina high.

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