Electrostrictive fluid pressure from a laser beam

TL;DR

This paper derives analytical expressions for the local pressure variation in a dielectric fluid caused by a laser beam with a Gaussian profile, considering different temporal switching scenarios, advancing understanding of electrostrictive effects in fluid optics.

Contribution

It provides the first general analytical solutions for electrostrictive pressure distribution in fluids under Gaussian laser beams with arbitrary time dependence.

Findings

Analytical expressions for pressure distribution under sudden beam application.

Analytical expressions for pressure distribution under gradual beam switching.

Demonstration of pressure behavior for different temporal profiles.

Abstract

Recent times have seen surge of research activity on systems combining fluid mechanics and electromagnetic fields. In radiation optics, whenever information about the distribution of pressure in a dielectric fluid is required, the contribution from electrostriction becomes important. In the present paper we calculate how the local pressure varies with position and time when a laser beam is imposed in a uniform fluid. A Gaussian intensity profile of arbitrary time dependence is assumed for the beam, and general results are derived in this case. For demonstration we analyze two different cases: first, that the beam is imposed suddenly (mathematically in the form of a step function); secondly, that the beam is switched on in a soft way. In both cases, simple analytical expressions for the pressure distribution are found.