Optical Nonlinear Proreties and Optical Limiting Effect of Metanil Yellow

Problem statement: The third order nonlinear optical properties of organic polymers are used in high speed telecommunication, optical limiters and optical computers. The purpose of the study was to determine the third order nonlinear characteristics and optical limiting effect of the organic dye, metanil yellow in liquid and solid medium. Approach: The samples were prepared by dissolving the dye in acetonitrile (liquid medium) at different concentration and thin film was prepared by bulk polymerization method. The nonlinear optical responses of the samples were studied by using single-beam Z-scan technique. The optical limiting effects of the samples were studied by using a CW, Nd: YAG laser at 532 nm. Results: The open aperture Z-scan of the solution and solid samples displayed reversible saturable absorption. The closed aperture Z-scan of the samples exhibited negative nonlinearity, which was larger in magnitude in solid film compared to that in solution. The third order nonlinear susceptibility was found to be 2.00 and 2.34×10^-6 (e.s.u) for the dye in solution and film at 0.05 mM concentration. The saturated output power for the dye in solution and film was found to be 1.2 and 0.8 mW respectively at 1.0 mM concentration. Conclusion: The dye doped in polymer can be utilized in optical limiting, low-power degenerate four wave mixing, data storage and grating applications.