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Excitonic and phonon-mediated optical Stark effect in a conjugated polymer

J.P. Heritage, S. Etemad, and G.J. Blanchard

The last several years have been marked by steady progress in the understanding of optically induced non-linearity of reduced-dimension excitons. The two-dimensional excitons associated with GaAs-AlGaAs quantum wells have been extensively investigated. For nonresonant excitation, the nonlinear response is dominated by anharmonic interactions among virtual excitons and virtual carriers. Virtual particles exist only in the presence of an optical field; their influence on optical properties disappear with the passing of that field. One well known signature of this instantaneous nonlinear response is the optical Stark effect, i.e., a blue shift of the exciton transition for below resonance excitation.

Publish Date: 01 December 1989