Geometry-Invariant Resonant Cavities

TL;DR

This paper introduces a new class of geometry-invariant resonant cavities that maintain their eigenfrequency despite shape changes, enabled by zero-index metamaterials, potentially leading to deformable resonant devices.

Contribution

The paper demonstrates theoretically that zero-index metamaterials can create resonant cavities with eigenfrequencies unaffected by geometrical deformations, a novel concept in resonator design.

Findings

Eigenfrequencies are invariant under shape changes.

Zero-index metamaterials enable decoupling of time and spatial field variations.

Potential for deformable resonant devices.

Abstract

Resonant cavities are one of the basic building blocks in various disciplines of science and technology, with numerous applications ranging from abstract theoretical modeling to everyday life devices. The eigenfrequencies of conventional cavities are a function of its geometry, and, thus, the size and shape of a resonant cavity is selected in order to operate at a specific frequency. Here, we demonstrate theoretically the existence of geometry-invariant resonant cavities, i.e., resonators whose eigenfrequency is invariant with respect to geometrical deformations. This effect is obtained by exploiting the unusual properties of zero-index metamaterials, which enable decoupling of the time and spatial field variations. This new class of resonators may inspire alternative design concepts, and it might lead to the first generation of deformable resonant devices.