Multiphonon absorption coefficients in solids: a universal curve

Abstract

A universal curve for the frequency dependence of the multiphoton absorption coefficient is proposed based on a 'non-perturbative' approach. Specific applications have been made to obtain two-, three-, four- and five-photon absorption coefficients in different materials. Proper scaling of the two-photon absorption coefficient and the use of the universal curve yields results for the higher-order absorption coefficients in good agreement with the experimental data.