A Review on Organic Materials for Optical Phase Conjugation & All-Optical Switches

Abstract

Nonlinear optical materials with optimum properties are essential in the continuous development of photonic and electro-optical devices, used in optical communications, networking, optical computation for signal processing, and data storage equipment. The changing trend is to use organic materials/dyes that exhibit exceptional nonlinear optical properties instead of conventional materials which have comparatively low nonlinear properties. These organic materials/dyes are easy to prepare in solution or solid form. The resulting organic material has a low dielectric constant, eliminating the need for poling while maintaining the refractive index. However, these organic materials have few of the drawbacks inherent in the processing of comparable inorganic materials like of intense light-induced degradation or bleaching and aggregation at higher dye concentration. In order to overcome these drawbacks and for effective use of highly nonlinear dyes, the dye molecules are doped in polymer matrix. This idea of dye-doped polymer material matrix may increase the concentration of absorptive or fluorescence centers as well as the opto-chemical and opto-physical stability. In this paper, we have discussed the strategic advantages of dye-doped polymer nonlinear materials in comparison with organic and inorganic nonlinear materials for optical phase conjugation and all optical switches in future photonics technology. This was done by studying the linear optical properties and nonlinear optical Phase Conjugation properties of two azo dye-doped polymer films by considering organic dyes disperse orange (DO-25) and disperse yellow (DY-7) doped in a polymer matrix Polymethyl methacrylate methacrylic acid (PMMA-MA). The nonlinear optical phase conjugation properties are studied using Degenerate Four Wave Mixing set-up using 532 nm wavelength CW laser beam.The effect of dye concentration, intensity of backward, forward pump, and inter-beam angle between probe and forward pump beam on phase conjugation reflectivity are also studied and compared.

Keywords: Azo Dye-doped Polymer films, Degenerate Four Wave Mixing, Nonlinear Optical Properties, Optical Phase Conjugation.