A superposition test for the emergence of nonlinearities in a laser irradiated spherical absorber

TL;DR

This paper investigates the validity of linear superposition in a laser-irradiated spherical absorber, identifying the transition point from linear to nonlinear behavior through computational analysis.

Contribution

It introduces a method to detect the transition from linear to nonlinear regimes in a laser-irradiated system using superposition principles.

Findings

Superposition holds at low fluence levels.

Transition to nonlinearity occurs at higher fluence.

The method can quantify the onset of nonlinear behavior.

Abstract

The principal of linear superposition is investigated in the computational system of a solid spherical absorber immersed in a transparent aqueous medium and illuminated by a laser pulse. The absorber is exposed to a single top-hat pulse and to a fraction of the pulse from which a superimposed response is calculated. The results clearly show the transition of the system from a low fluence linear state where superposition is valid to a high fluence nonlinear state where the superposition is violated. The procedure described in the text can be used to find the transition to nonlinearity in a given excited system. This work can lead to better understanding and quantifying the transition from linear to non-linear regimes in complex systems.