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

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, and 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 the 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.

Automated summary

Temporal metamaterials are artificial materials with electromagnetic properties that change over time, allowing for the realization of non-homogeneous temporal media or stepwise transitions. By modeling wave propagation through a generalized temporal multilayer structure, higher-order transfer functions can be synthesized, enabling the design of novel electromagnetic and optical devices with tailored scattering responses. This approach leverages the temporal dimension instead of the spatial dimension typically used in optical and electromagnetic multilayered structures.