Progress toward high-Q perfect absorption: A Fano antilaser

TL;DR

This paper introduces the concept of a Fano anti-laser for achieving high-Q perfect light absorption with minimal material loss, using spectral phase variation in Fano-resonant systems to enable new absorption-based device applications.

Contribution

It proposes a novel Fano anti-laser concept that leverages spectral phase variation for high-Q perfect absorption with reduced material loss, confirmed through photonic crystal platform simulations.

Findings

Achieved spectral singularity for perfect absorption with lower material loss.

Demonstrated spatio-spectral selective heating using a photonic crystal platform.

Revealed phase-dependent control of device bandwidths for high-Q light absorption.

Abstract

Here we propose a route to the high-Q perfect absorption of light by introducing the concept of a Fano anti-laser. Based on the drastic spectral variation of the optical phase in a Fano-resonant system, a spectral singularity for scatter-free perfect absorption can be achieved with an order of magnitude smaller material loss. By applying temporal coupled mode theory to a Fano-resonant waveguide platform, we reveal that the required material loss and following absorption Q-factor are ultimately determined by the degree of Fano spectral asymmetry. The feasibility of the Fano anti-laser is confirmed using a photonic crystal platform, to demonstrate spatio-spectrally selective heating. Our results utilizing the phase-dependent control of device bandwidths derive a counterintuitive realization of high-Q perfect conversion of light into internal energy, and thus pave the way for a new regime of absorption-based devices, including switches, sensors, thermal imaging, and opto-thermal emitters.