# Fano Resonances in a Photonic Crystal Covered with a Perforated Gold Film and its Application to Biosensing

## TL;DR

This paper investigates Fano resonances in a photonic crystal with a perforated gold film, demonstrating their origin from interactions between optical Tamm states and waveguide modes, and proposes a biosensing application.

## Contribution

It reveals the origin of Fano resonances in this structure and introduces a novel sensor design based on these resonances for environmental refractive index detection.

## Key findings

- Fano resonances originate from interaction between optical Tamm states and waveguide modes.
- A narrow dip in transmission spectrum indicates Fano resonance presence.
- Proposed sensor design shows sensitivity to environmental refractive index changes.

## Abstract

Optical properties of the photonic crystal covered with a perforated metal film were investigated and the existence of the Fano-type resonances was shown. The Fano resonances originate from the interaction between the optical Tamm state and the waveguide modes of the photonic crystal. It manifests itself as a narrow dip in a broad peak in the transmission spectrum related to the optical Tamm state. The design of a sensor based on this Fano resonance that is sensitive to the change of the environment refractive index is suggested.

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Source: https://tomesphere.com/paper/1701.08090