Periodic Modulation of Extraordinary Optical Transmission through Subwavelength Hole Arrays using Surrounding Bragg Mirrors

TL;DR

This paper demonstrates how surrounding Bragg mirrors can significantly enhance and periodically modulate light transmission through subwavelength hole arrays by confining surface plasmons in a resonant cavity, verified by simulations.

Contribution

It introduces a method to control optical transmission using Bragg mirrors to form a surface resonant cavity, enabling periodic modulation of light transmission at specific wavelengths.

Findings

Transmission increased by over three times with Bragg mirrors.

Transmission can be periodically modulated by geometric parameters.

Simulations confirm the surface plasmon interference effect.

Abstract

The enhanced light transmission through an array of subwavelength holes surrounded by Bragg mirrors is studied, showing that the mirrors act to confine the surface plasmons associated with the Extraordinary Optical Transmission effect, forming a surface resonant cavity. The overall effect is increased light transmission intensity by more than a factor of three beyond the already enhanced transmission, independent of whether the Bragg mirrors are on the input or the output side of the incident light. The geometry of the Bragg mirror structures controls the enhancement, and can even reduce the transmission in half. By varying these geometric parameters, we were able to periodically modulate the transmission of light for specific wavelengths, consistent with the propagation and interference of surface plasmon waves in a resonant cavity. FDTD simulations and a wave propagation model verify this effect.