Optical Spin Effects Induced by Phase Conjugation at a Space-Time Interface

TL;DR

This paper investigates how phase conjugation at a space-time interface induces optical spin effects, revealing novel spin-conversion dynamics and polarization control through temporal boundary interactions in dispersive media.

Contribution

It introduces a new analysis of spin-conversion phenomena at space-time interfaces with Lorentz-type dispersion, highlighting the role of rapid plasma frequency modulation in controlling polarization.

Findings

Phase conjugation at space-time interfaces causes spin conversion and polarization manipulation.

Resonant excitation at natural frequencies enables precise polarization control.

Superposition of incident and phase-conjugated waves results in unique electromagnetic field behaviors.

Abstract

Electromagnetic temporal boundaries, emerging when the constitutive parameters of a medium undergo abrupt temporal variations, have garnered significant interest for their role in facilitating unconventional wave phenomena and enabling sophisticated field manipulations. A key manifestation is temporal reflection in an unbounded spatial domain, where a sudden temporal discontinuity induces phase-conjugated backward waves alongside anomalous spin conversion. This study explores distinctive spin-conversion dynamics at a time-dependent spatial interface governed by Lorentz-type dispersion, in which the plasma frequency undergoes rapid modulation over time. The interaction of a circularly polarized wave with a space-time interface excites electromagnetic signals at the system's natural resonance, allowing precise control over polarization states. The scattered field stems from the combined influence of temporal and spatial boundaries, yielding a superposition of the original incident wave's polarization and its phase-conjugated counterpart.