Four-Photon Transition in Semiconductors

Abstract

Based on a simple spherical energy-band model for the conduction and valence bands in cubic crystal, the transition probability for four-photon absorption is calculated theoretically by use of the Hartree-Fock and Hartree approximations for wave functions. These results are compared with those by Keldysh's high-frequency-limit time-dependent tunneling theory in a numerical example by applying the calculations to a ZnS crystal.