title: Dispersion of nonresonant third-order nonlinearities in Silicon Carbide.
abstract: In this paper we present a physical discussion of the indirect two-photon absorption (TPA) occuring in silicon carbide with either cubic or wurtzite structure. Phonon-electron interaction is analyzed by finding the phonon features involved in the process as depending upon the crystal symmetry. Consistent physical assumptions about the phonon-electron scattering mechanisms are proposed in order to give a mathematical formulation to predict the wavelength dispersion of TPA and the Kerr nonlinear refractive index n2. The TPA spectrum is investigated including the effects of band nonparabolicity and the influence of the continuum exciton. Moreover, a parametric analysis is presented in order to fit the experimental measurements. Finally, we have estimated the n2in a large wavelength range spanning the visible to the mid-IR region.
authors.affiliation: Dipartimento di Ingegneria Elettrica e dell'Informazione, Politecnico di Bari Via Edoardo Orabona n. 4, 70125 Bari, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: De Leonardis
authors.affiliation: Department of Engineering, The University of Massachusetts, Boston, Massachusetts, 02125 USA.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Soref
authors.affiliation: Dipartimento di Ingegneria Elettrica e dell'Informazione, Politecnico di Bari Via Edoardo Orabona n. 4, 70125 Bari, Italy.
authors.forename: Vittorio M N
authors.initials: VM
authors.lastname: Passaro