Based upon the purely coherent radiation-exciton interaction and using the time dependent perturbation theory, an independent analytical investigation of the third order susceptibility ?(3) has been made for a semiconductor in the band-edge region. The possibility of a change in sign of ?(3) is noted when the pump energy is increased from below the renormalized band gap energy to exceed it. Numerical estimates are made for InSb, GaAs, GaSb and InAs when the energy difference is of the order of crystal exciton Rydberg in the true continum. © 1982.
|Number of pages||6|
|Journal||Solid State Communications|
|Publication status||Published - Jul 1982|