<title>Nonlinear optical beam propagation method for describing optical limiter performance</title>

Abstract

In this paper, a method is described which may be applied to an experimental system used for characterization of nonlinear properties of a liquid limiter, the pinhole is placed in front of the detector to measure nonlinear refractive effects. To measure the nonlinear absorption, the pinhole is removed. The nonlinear wave propagation equation is solved using the finite difference method, assuming the beam incident on the nonlinear medium to be that appropriate for a small f-number, apertured system. Effects of both nonlinear absorption and nonlinear refraction are included. Results are provided for the case described and only for the case in which the nonlinear absorption mechanism is two- photon absorption and the nonlinear refractive mechanism is thermal.