Enhanced transmission of light and matter through subwavelength nanoapertures by far-field multiple-beam interference

Research output: Chapter in Book/Report/Conference proceedingChapter

Abstract

Subwavelength aperture arrays in thin metal films can enable enhanced transmission of light and matter (atom) waves. The phenomenon relies on resonant excitation and interference of the plasmon-polariton or matter waves on the metal surface. We show a mechanism that could provide a great resonant and nonresonant transmission enhancement of the light or de Broglie's particle waves passed through the apertures not by the surface waves, but by the constructive interference of diffracted waves (beams generated by the apertures) at the detector placed in the far-field zone. According to the model, the light beams generated by multiple, subwavelength apertures can have similar phases and can add coherently. If the spacing of the apertures is smaller than the optical wavelength, then the phases of the multiple beams at the detector are nearly the same and beams add coherently (the light power and energy scales as the number of light-sources squared, regardless of periodicity). If the spacing is larger, then the addition is not so efficient, but still leads to enhancements and resonances (versus wavelength) in the total energy transmitted (radiated). We stress that the plasmon-polaritons do not affect the principle of the enhancement based on the constructive interference of diffracted waves (beams) generated by the subwavelength apertures at the detector placed in the far-field zone. Naturally, the plasmonpolaritons could provide additional enhancement by increasing the power and energy of each beam. The Wood anomalies in transmission spectra of gratings, a long standing problem in optics, follow naturally from the interference properties of our model. The point is the prediction of the Wood anomaly in a classical Young-type two-source system. Our analysis is based on calculation of the energy flux (intensity) of a beamarray by using Maxwell's equations for classical, non-quantum electromagnetic fields. Therefore the mechanism could be interpreted as a non-quantum analog of the superradiance emission of a subwavelength ensemble of atoms (the light power and energy scales as the number of light-sources squared, regardless of periodicity) predicted by the well-known Dicke quantum model. In contrast to other models, the enhancement mechanism depends on neither the nature (non-quantum electromagnetic waves, quantum light or matter) of beams (continuous waves or pulses) nor material and shape of the multiple-beam source (arrays of one- and two-dimensional subwavelength apertures, fibers, dipoles, and atoms). The quantum reformulation of our model is also presented. The Hamiltonian describing the phenomenon of interference-induced enhancement and suppression of both the intensity and energy of a quantum optical field is derived. The basic properties of the field energy determining by the Hamiltonian are analyzed. Normally, the interference of two or more waves causes enhancement or suppression of the light intensity, but not the light energy. The model shows that the phenomenon could be observed experimentally, for instance, by using a subwavelength array of the coherent quantum light-sources (one- and two-dimensional subwavelength apertures, fibers, dipoles, and atoms).

Original languageEnglish
Title of host publicationPlasmons
Subtitle of host publicationTheory and Applications
PublisherNova Science Publishers, Inc.
Pages267-287
Number of pages21
ISBN (Print)9781617613067
Publication statusPublished - Feb 1 2011

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Keywords

  • Enhanced transmission
  • Multiple-beam interference
  • Quantum electromagnetic fields
  • Subwavelength nanoapertures
  • Superradiance

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Kukhlevsky, S. V. (2011). Enhanced transmission of light and matter through subwavelength nanoapertures by far-field multiple-beam interference. In Plasmons: Theory and Applications (pp. 267-287). Nova Science Publishers, Inc..