Second-harmonic generation in graded metal-dielectric films of anisotropic particles

We investigate theoretically the effective second-harmonic generation (SHG) susceptibility in graded films of metal-dielectric random composites with anisotropically shaped particles by invoking the local field effects. Using numerical examples, we demonstrate that in the presence of gradation profiles and/or shape effects, graded metal-dielectric films could be used as novel optical materials for producing a broad structure in both the linear and nonlinear (SHG) response and with an enhancement in the nonlinear response.