Transmission of light through slit apertures in metallic films
ABSTRACT Transmission of polarized light through sub-wavelength slit apertures is studied based on the electromagnetic field distributions obtained in computer simulations. The results show the existence of a cutoff for E|| and a strong transmission (with no cutoff) for E?; here || and ? refer to the direction of the incident E-field relative to the long axis of the slit. These observations are explained by the standard waveguide theory involving inhomogeneous plane waves that bounce back and forth between the interior walls of the slit aperture. We examine the roles played by the slit-width, by the film thickness, and by the real and imaginary parts of the host material's dielectric constant in determining the transmission efficiency. We also show that the slit's sharp edges can be rounded to eliminate highly-localized electric dipoles without significantly affecting the slit's throughput. Finally, interference among the surface charges and currents induced in the vicinity of two adjacent slits is shown to result in enhanced transmission through both slits when the slits are separated by about one half of one wavelength.
- SourceAvailable from: Yuya Ishii[Show abstract] [Hide abstract]
ABSTRACT: The monolithic integration of a silicon-based plasmonic detector with metal- oxide-semiconductor field-effect transistors (MOSFETs) was demonstrated. The plasmonic detector consisted of a gold film with a nanoslit grating on a silicon substrate and was operated at a free-space wavelength of 1550 nm. The structure of the nanoslit grating was optimized by using the finite-difference time-domain method. The output current from the plasmonic detector was amplified by ~14 000 times using the monolithically integrated MOSFETs. In addition, dynamic operation of the integrated circuit was demonstrated by modulation of the intensity of a beam that was incident to the plasmonic detector.IEEE Photonics Journal 08/2013; 5(4):6800609-6800609. DOI:10.1109/JPHOT.2013.2272779 · 2.33 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: Large-scale studies of biomolecular interactions required for proteome-level investigations can benefit from a new class of emerging surface plasmon resonance (SPR) sensors: nanohole arrays and surface plasmon (SP) enhanced optical transmission. In this paper we present a real-time, label-free multiplex SPR imaging sensor in a microarray format. The system presented is built around a low-cost microscope with laser illumination, integrated with microfluidics. The specific binding kinetics of biotin and streptavidin are measured from several sensing elements simultaneously, demonstrating the feasibility of using nanohole arrays as a high-throughput SPR microarray sensor.Proceedings of SPIE - The International Society for Optical Engineering 08/2008; DOI:10.1117/12.794299 · 0.20 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: We theoretically investigate second harmonic generation that originates from the nonlinear, magnetic Lorentz force term from single and multiple apertures carved on thick, opaque metal substrates. The linear transmission properties of apertures on metal substrates have been previously studied in the context of the extraordinary transmission of light. The transmission process is driven by a number of physical mechanisms, whose characteristics and relative importance depend on the thickness of the metallic substrate, slit size, and slit separation. In this work we show that a combination of cavity effects and surface plasmon generation gives rise to enhanced second harmonic generation in the regime of extraordinary transmittance of the pump field. We have studied both forward and backward second harmonic generation conversion efficiencies as functions of the geometrical parameters, and how they relate to pump transmission efficiency. The resonance phenomenon is evident in the generated second harmonic signal, as conversion efficiency depends on the duration of incident pump pulse, and hence its bandwidth. Our results show that the excitation of tightly confined modes as well as the combination of enhanced transmission and nonlinear processes can lead to several potential new applications such as photo-lithography, scanning microscopy, and high-density optical data storage devices. Comment: Keywords: Enhanced Transmission, Second Harmonic Generation, Surface Plasmon, Sub-wavelength SlitProceedings of SPIE - The International Society for Optical Engineering 03/2008; DOI:10.1117/12.779847 · 0.20 Impact Factor