Plasmonic nanoantennas as integrated coherent perfect absorbers on SOI waveguides for modulators and all-optical switches

TL;DR

This paper investigates plasmonic nanoantennas on SOI waveguides as coherent perfect absorbers, demonstrating their potential for ultracompact optical modulation, switching, sensing, and nonlinear enhancement with high extinction ratios.

Contribution

It introduces a novel integration of plasmonic nanoantennas on SOI waveguides as efficient coherent perfect absorbers for optical switching and modulation.

Findings

Achieved ~1% losses and >25 dB extinction ratios.

Observed strong field enhancement and localization.

Demonstrated potential for ultracompact optical devices.

Abstract

The performance of plasmonic nanoantenna structures on top of SOI wire waveguides as coherent perfect absorbers for modulators and all-optical switches is explored. The absorption, scattering, reflection and transmission spectra of gold and aluminum nanoantenna-loaded waveguides were calculated by means of 3D finite-difference time-domain simulations for single waves propagating along the waveguide, as well as for standing wave scenarios composed from two counterpropagating waves. The investigated configurations showed losses of roughly 1% and extinction ratios greater than 25 dB for modulator and switching applications, as well as plasmon effects such as strong field enhancement and localization in the nanoantenna region. The proposed plasmonic coherent perfect absorbers can be utilized for ultracompact all-optical switches in coherent networks as well as modulators and can find applications in sensing or in increasing nonlinear effects.