Enhanced Transmission of Light and Particle Waves through Subwavelength Nanoapertures by Far-Field Interference

TL;DR

This paper introduces a novel far-field interference mechanism that enhances light and particle wave transmission through subwavelength apertures, independent of surface wave excitation, explaining Wood anomalies and resembling superradiance phenomena.

Contribution

The study proposes a new interference-based mechanism for transmission enhancement that does not rely on surface plasmon or matter wave resonances, broadening understanding of aperture array optics.

Findings

Demonstrates a nonresonant transmission enhancement via far-field interference.

Explains Wood anomalies through interference properties of the model.

Predicts Wood anomaly in a classical two-source system.

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 or matter waves on the metal surface. We show a new mechanism that could provide a great resonant and nonresonant transmission enhancement of the light or de Broglie 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. In contrast to other models, the mechanism depends neither on the nature (light or matter) of the beams (continuous waves or pulses) nor on material and shape of the multiple-beam source (arrays of 1-D and 2-D subwavelength apertures, fibers, dipoles or atoms). The Wood anomalies in transmission spectra of gratings, a long standing problem in optics, follow naturally from the interference properties of our model. The new point is the prediction of the Wood anomaly in a classical Young-type two-source system. The new 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.