Inverse Opal Optical Tamm State for Sensing Applications

TL;DR

This paper demonstrates the existence of optical Tamm states in inverse opal photonic crystals on metal substrates, showing their potential for sensitive chemical sensing through observable spectral shifts.

Contribution

It introduces a simple fabrication method for inverse opal-based Tamm states and validates their sensing capabilities with experimental and numerical results.

Findings

Optical Tamm states observed in inverse opal structures.

Sensitivity of ~110 nm/RIU demonstrated for solvent infiltration.

Spectral shifts consistent with simulations confirm sensing potential.

Abstract

We report the existence of optical Tamm states (OTS) in inverse opal (IO) - based three-dimensional photonic crystal on a flat metal substrate, validated through both numerical simulations and experimental observations. Our fabrication approach for the Tamm inverse opal (Tamm-IO) structure is notably straightforward and does not involve corrosive chemicals. Upon infiltration of non-reactive solvents such as methanol and ethanol into the IO, a noticeable shift of the OTS, consistent with our simulations is observed, and the temporal dynamics of the same have been investigated. The experimentally obtained sensitivity is ~ 110 nm/RIU which is of the same order as the computed value, making the IO OTS to be an attractive sensing tool.