Bremsstrahlung radiation from the interaction of short laser pulses with dielectrics

TL;DR

This paper develops a theoretical model for bremsstrahlung radiation emitted when intense short laser pulses interact with dielectrics, analyzing how various parameters influence the radiation's characteristics and efficiency.

Contribution

It introduces a comprehensive theory for bremsstrahlung emission in laser-dielectric interactions and simulates its properties across different conditions.

Findings

Radiation power, energy, and spectra depend on electron collision frequency and radiation frequency ratios.

Conversion efficiency saturates around 10^-5, influenced by laser pulse intensity and duration.

Emission origin (surface or bulk) varies with laser intensity relative to damage threshold.

Abstract

An intense, short laser pulse incident on a transparent dielectric can excite electrons from valence to the conduction band. As these electrons undergo scattering, both from phonons and ions, they emit bremsstrahlung radiation. Here we present a theory of bremsstrahlung emission appropriate for laser pulse-dielectric interactions. Simulations of the interaction, incorporating this theory, illustrate characteristics of the radiation (power, energy and spectra) for arbitrary ratios of electron collision frequency to radiation frequency. The conversion efficiency of laser pulse energy into bremsstrahlung radiation depends strongly on both the intensity and duration of the pulse, saturating at values of about 10e-5. Depending on whether the intensity is above or below the damage threshold of the material, the emission can originate either from the surface or the bulk of the dielectric respectively. The bremsstrahlung emission may provide a broadband light source for diagnostics.