Nonlinear Electromagnetic Interactions in Energetic Materials

TL;DR

This paper investigates nonlinear electromagnetic interactions in energetic materials, demonstrating how specific optical effects can be used for remote explosive detection without chemical decomposition.

Contribution

It introduces a molecular dynamics simulation approach to analyze nonlinear light-matter interactions in energetic materials for explosive identification.

Findings

Identification of frequency-conversion and polarization changes in energetic materials.

Simulation of Raman spectra in the terahertz range for PETN and ammonium nitrate.

Potential for remote explosive detection using spectral features.

Abstract

We study the scattering of electromagnetic waves in anisotropic energetic materials. Nonlinear light-matter interactions in molecular crystals result in frequency-conversion and polarization changes. Applied electromagnetic fields of moderate intensity can induce these nonlinear effects without triggering chemical decomposition, offering a mechanism for non-ionizing identification of explosives. We use molecular dynamics simulations to compute such two-dimensional Raman spectra in the terahertz range for planar slabs made of PETN and ammonium nitrate. We discuss third-harmonic generation and polarization-conversion processes in such materials. These observed far-field spectral features of the reflected or transmitted light may serve as an alternative tool for stand-off explosive detection.