Nonlinear optical dispersion and higher-order effects in bulk and wavelength-ordered photonic materials

Abstract

The dispersion of the nonlinear optical coefficients and the optical nonlinearities in bulk and wavelength-ordered materials are investigated using numerical simulations and compared with the experimental evidence. The dispersion of nonlinear absorption over a wide spectral region is investigated for materials such as Cadmium Sulfide (CdS) and Reduced Graphene Oxide (rGO) using Kramers-Kronig (KK) integral, invoking two-parabolic model which demonstrates the dominant mechanism for broadband ultrafast optical limiting behavior due to the strong two- and multi-photon absorption processes. The optical nonlinearity in the wavelength-ordered photonic structures ( metal-dielectric and dielectric-dielectric) are investigated by the transfer matrix method (TMM) incorporating the Gaussian single beam nonlinear pulse propagation technique. The optical field is deposited differently at different penetration depths inside the structure. Thus, the nonlinear contributions from individual layers also vary accordingly. In such photonic structures, the nonlinearities are considered to be layer-by-layer contributions and/or an average of the dominant nonlinear layers. The present study can be more effective as compared to the usual analysis of optical nonlinearities in practical applications.