ABSTRACT
A novel subwavelength surface plasmon polaritons optical filter based on an incompletely directional coupler is proposed and numerically simulated by using the finite difference time domain method with perfectly matched layer absorbing boundary condition. An analytical solution for the resonant condition of the structure is derived by means of the cavity theory. Both analytical and simulative results reveal that the resonant wavelengths are proportional to the length of the slit segment, inversely proportional to the antinode number of a standing wave in the segment, and are related to the slit width and the gap between the two slits. The analytical solution being consistent with the numerical simulation verifies the feasibility of the concept of the new filter structure.
Subject(s)
Filtration/instrumentation , Optical Devices , Refractometry/instrumentation , Surface Plasmon Resonance/instrumentation , Computer-Aided Design , Equipment Design , Equipment Failure Analysis , Reproducibility of Results , Scattering, Radiation , Sensitivity and SpecificityABSTRACT
A novel nanometeric plasmonic filter in a tooth-shaped metal-insulator-metal waveguide is proposed and demonstrated numerically. An analytic model based on the scattering matrix method is given. The result reveals that the single tooth-shaped filter has a wavelength-filtering characteristic and an ultracompact size in the length of a few hundred nanometers, compared to gratinglike surface plasmon polariton (SPP) filters. Both analytic and simulation results show that the wavelength of the trough of the transmission has linear and nonlinear relationships with the tooth depth and the tooth width, respectively. The waveguide filter could be utilized to develop ultracompact photonic filters for high integration.
