Accession Number : ADA311109

Title :   Excitonic Nonlinear Optical Properties.

Descriptive Note : Final rept. 1 Sep 92-31 May 95,

Corporate Author : ALABAMA UNIV IN HUNTSVILLE CENTER FOR APPLIED OPTICS

Personal Author(s) : Klepfer, Robert O., III ; Madarasz, Frank L.

PDF Url : ADA311109

Report Date : 12 JUN 1996

Pagination or Media Count : 4

Abstract : Exciton and biexciton binding and excited state energies, and wave functions are calculated numerically via a finite element method in an effective mass approximation for GaAs quantum well disks and dots (including pyramid shaped structures) surrounded by an AlGaAs cladding. Moreover, the Al interdiffusion into the dot and the finite band offsets between the dot and the cladding have been included. For the range of dimensions studied, the inclusion of the Al interdiffusion had a pronounced effect on on the binding energies when compared to those obtained from the infinite barrier model. Using the results of the exciton and biexciton calculation, we calculate the third-order nonlinear optical susceptibility as a function of pump-probe frequencies in a range about the exciton absorption resonance. We restricted our calculation to the optical nonlinearity via the biexciton state arising from the population saturation of the exciton state. We expect, depending upon dot dimensions, broadening parameter(s) size, and the amount of pump detuning values of the imaginary parts of the susceptibilities to be on the order of -10 to -10(exp. -1) esu near resonance absorption due to biexciton formation.

Descriptors :   *QUANTUM WELLS, *GALLIUM ARSENIDES, *EXCITONS, FINITE ELEMENT ANALYSIS, NONLINEAR OPTICS, NUCLEAR BINDING ENERGY, BARRIERS, WAVE FUNCTIONS, RESONANCE ABSORPTION, ELECTROMAGNETIC SUSCEPTIBILITY, DETUNING.

Subject Categories : Electricity and Magnetism
      Quantum Theory and Relativity

Distribution Statement : APPROVED FOR PUBLIC RELEASE