Dynamics of light propagation in spatiotemporal dielectric structures

TL;DR

This paper analyzes how light propagates through one-dimensional dielectric media with time-varying properties, revealing new effects like pulse manipulation and dynamic bandgap control using a unified analytical and numerical approach.

Contribution

It introduces a novel, exact method to study electromagnetic wave behavior in spatiotemporal dielectric structures without slow amplitude approximations, uncovering new physical phenomena.

Findings

Pulse compression, broadening, and spectral manipulation by spatiotemporal lenses

Closure and opening of frequency and wavenumber bandgaps in dynamic structures

Explicit transfer matrices for nonstationary interfaces

Abstract

Propagation, transmission and reflection properties of linearly polarized plane waves and arbitrarily short electromagnetic pulses in one-dimensional dispersionless dielectric media possessing an arbitrary space-time dependence of the refractive index are studied by using a two-component, highly symmetric version of Maxwell's equations. The use of any slow varying amplitude approximation is avoided. Transfer matrices of sharp nonstationary interfaces are calculated explicitly, together with the amplitudes of all secondary waves produced in the scattering. Time-varying multilayer structures and spatiotemporal lenses in various configurations are investigated analytically and numerically in a unified approach. Several new effects are reported, such as pulse compression, broadening and spectral manipulation of pulses by a spatiotemporal lens, and the closure of the forbidden frequency gaps with the subsequent opening of wavenumber bandgaps in a generalized Bragg reflector.