Optical force density and surface displacements in transparent dielectrics due to non-ionizing sub-picosecond laser excitation

TL;DR

This paper theoretically analyzes optical force densities in transparent dielectrics under short laser pulses, showing significant optomechanical effects and surface displacements, with potential applications in optomechanics and fundamental physics.

Contribution

It provides a detailed theoretical analysis and simulations of optical force densities and surface displacements due to sub-picosecond laser pulses, highlighting the dominance of momentum components and proposing measurement methods.

Findings

Surface displacements of 50 pm in fused silica with 100 fs pulses.

Momentum component of optical force can be comparable to stress component.

Dispersive and nonlinear effects can be suppressed in simulations.

Abstract

The optical force density acting in transparent dielectric media due to short laser excitation is theoretically analyzed. For typical laser pulses with picosecond duration, the momentum component of the optical force becomes of the same order of magnitude as the stress component, enhancing the overall optomechanical effects. Simulations of the optically-induced surface displacements in fused silica glass are also presented. With careful choice of realistic simulation parameters, dispersive and nonlinear effects were shown to be suppressed and displacements of 50 pm were found for single-pulse excitation with 100 fs duration, where the momentum component of the force is dominant. A possibility of measuring these displacements with piezo-electric detection is also discussed, providing a way to attain spatiotemporal characterization of the optical momentum force in continuum media. Such a description would significantly advance our current knowledge on the behavior of optical forces, potentially contributing to more versatile optomechanical applications, while also clarifying the ongoing Abraham-Minkowski fundamental problem on the momentum transferred by light.