Chemical Additive Cascading System – A new Scheme for Enhancing Optical Nonlinearity

Abstract

Nanophotonics is an emerging area where nanotechnology is used to change the physical and
chemical properties of photonic materials or the effectiveness of photonic processes that have
major applications in optical communication and computation. Though many photonic devices
are developed using nonlinear optical materials, efforts are still going on to increase theirefficiency toward 100% and other device characteristics toward their optimum level. In orderto improve the efficiency of the third harmonic process further, we have a plan to use dyesensitized metal nanoparticles doped in PMMA films. It is expected that the ability ofnanotechnology in tailoring the physio-chemical properties of the materials will give rise to theoptimum nonlinear devices to be used in nanophotonics. A considerable improvement in bothnonlinear optical susceptibility and laser damage threshold is expected based on the resultspublished in the case of dye-sensitized metal nanoparticle doped solar cells. Such a researchmay contribute to the efficient nanophotonic devices such as all optical switches, which are thebasic building blocks of the final dream of realizing all optical computers. In this paper, atheoretical study is carried out on the effect of sensitization of some well-knownnanocomposites TiO2/Au and ZnS/PVA by nonlinear DASPB dye-doped PMMA-MA polymermatrix in order to change the dielectric and nonlinear susceptibility. This is achieved by thesystematic study of the size of nanoparticles used for the sensitization study, various donoracceptor combinations,andconcentration of dyes & nanoparticles in the sample films. Thenonlinear absorption coefficient for each case and the theoretical optical limiting properties areexpected to be modified based on cascaded nonlinear susceptibility for Type 1, Type 2, andType 3 Z-scan configurations.