Twist-tunable moir\'e optical resonances

TL;DR

This paper demonstrates that moiré patterns in bilayer dielectric photonic crystal slabs can produce ultra-narrow, twist-tunable optical resonances with high quality factors, advancing chiral nanophotonics applications.

Contribution

It introduces the concept of twist-tunable moiré optical resonances in multilayer photonic structures, showing their potential for highly sensitive and tunable photonic devices.

Findings

Moiré-periodicity induces ultra-narrow optical resonances.

Resonance wavelength can be tuned from 300 to 600 nm.

Quality factor varies from 10^2 to 10^5.

Abstract

Multilayer stacks of twisted optical metasurfaces are considered as a prospective platform for chiral nanophotonic devices. Such structures are primarily used for the realization of circularly polarized light sources, artificial optical rotation, and circular dichroism. At the same time, the behavior of their hybrid photonic modes is strongly affected by the moir\'e-pattern of superimposed periodic constituents. In this work, we show that moir\'e-periodicity in bilayer dielectric photonic crystal slabs leads to an arise of unlimitedly narrow optical resonances, which are very sensitive to the relative twist and gap width between the sublayers. We demonstrate the structure providing twist-tuning of the hybrid mode wavelength in the range of 300--600~nm with quality factor varying from~$10^2$~up~to~$10^5$ correspondingly. The obtained results pave the wave for the utilization of moir\'e-assisted effects in multilayer photonic crystal slabs.