Calculation of Nonlinear Susceptibilities

G�nter Sauermann

Haider R. Zaidi

A new propagator approach for the calculation of nonlinear susceptibilities is proposed. In this approach a higher order susceptibility is generated by the functional derivative of a lower order susceptibility. The procedure is illustrated through a calculation of the third-order susceptibility. A diagram technique is employed to select and calculate the important contributions. The results are applied to the resonance fluorescence from a two-level atom in a gas. The existing results of the impact theory are generalized by taking proper account of the lower state interaction and by calculating the higher order collision corrections.

Monique Combescot, Odile Betbeder-Matibet, K. Cho +1 more

The calculation of the third order susceptibility still is a long standing fundamental problem of particular importance in nonlinear nanooptics: Indeed, cancellation of size-dependent terms coming from uncorrelated excitations is expected, but up to now shown for very simple Hamiltonians only. Using a many-body theory recently developed to handle interacting close-to-bosons, we prove it here for \emph{arbitrary} H. This new formalism actually provides the first clean way to calculate nonlinear susceptibilities, with results different from previous ones.

J. Collet

Odile Betbeder-Matibet, Kikuo Cho, Hiroshi Ajiki

The calculation of the third order susceptibility still is a long standing fundamental problem of particular importance in nonlinear nanooptics: Indeed, cancellation of size-dependent terms coming from uncorrelated excitations is expected, but up to now shown for very simple Hamiltonians only. Using a many-body theory recently developed to handle interacting close-to-bosons, we prove it here for \emph{arbitrary} H. This new formalism actually provides the first clean way to calculate nonlinear susceptibilities, with results different from previous ones.

L. Rosenfeld