Ultra-narrow-band metamaterial perfect absorber based on surface lattice resonance in a WS2 nanodisk array

Metamaterial perfect absorbers (MPAs) are attractive platforms for the unique manipulation of electromagnetic waves from near-field to far-field. Narrow-band MPAs are particularly intriguing for their potential applications as thermal emitters or biosensors. In this work, we proposed ultra-narrow-band MPAs based on surface lattice resonance (SLR) modes of WS2 nanodisk arrays on gold films. The SLR modes stem from the coupling between the magnetic dipole modes of individual nanodisks and the Rayleigh anomaly of the array giving rise to high quality-factor resonances. With proper design of the nanodisk array, an ultra-narrow-band of 15 nm is achieved in the near infrared wavelength range. The underneath gold film provides the loss channel converting the incident light within the narrow band into heat in the gold film, effectively creating a perfect absorber. Systematic numerical simulations were performed to investigate the effects of the geometrical parameters on their optical properties, demonstrating the great tunability of this type of MPAs as well as their potential for engineering light-matter interactions. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Automated summary

This study proposes ultra-narrow-band MPAs based on WS2 nanodisk arrays on gold films, achieving a 15nm ultra-narrow band in the near infrared wavelength range. The design shows great potential for applications in thermal emitters or biosensors.