Temporal multilayer structures for designing higher-order transfer functions using time-varying metamaterials

TL;DR

This paper introduces a method to design higher-order transfer functions using temporal multilayer structures in metamaterials, enabling novel electromagnetic device functionalities by manipulating properties over time rather than space.

Contribution

It proposes a synthesis approach for temporal multilayer structures to realize higher-order transfer functions, extending spatial multilayer design principles into the time domain.

Findings

Derived scattering coefficients for temporal multilayer media.

Demonstrated control of frequency-dependent scattering response.

Enabled design of novel time-varying electromagnetic devices.

Abstract

Temporal metamaterials are artificial materials whose electromagnetic properties change over time. In analogy with spatial media and metamaterials, where their properties change smoothly or abruptly over space, temporal metamaterials can exhibit a smooth variation over time, realizing a temporal non-homogeneous medium, or a stepwise transition, realizing the temporal version of dielectric slabs or multilayer structures. In this Letter, we focus our attention on temporal multilayer structures, and we propose the synthesis of higher-order transfer functions by modeling the wave propagation through a generalized temporal multilayer structure, consisting of a cascade over time of different media. The tailoring of the scattering response of temporal structure as a function of frequency is presented, deriving the corresponding scattering coefficients for a properly designed set of medium properties, i.e., permittivity and permeability, and application time, in analogy with what is typically done in optical and electromagnetic spatial multilayered structures. This allows us to design novel electromagnetic and optical devices with higher-order transfer functions by exploiting the temporal dimension instead of the spatial one.