Progress toward high- Q perfect absorption: A Fano antilaser

Here we propose a route to the high-Q perfect absorption of light by introducing the concept of a Fano antilaser. 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 antilaser is confirmed using a photonic crystal platform, to demonstrate spatiospectrally 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 optothermal emitters.