Azo dye doped polymer films for nonlinear optical applications

Azo dye doped polymer films were prepared on glass substrates using spin-coating technique. FTIR, UV-Vis spectra and PL measurements were recorded to characterize the structure of the metanil yellow doped PVA films. Surface morphology and thickness of the films were studied using AFM and FESEM. The magnitude of both real and imaginary parts of third-order nonlinear susceptibility χ3 of metanil yellow were determined by the Z-scan technique. The nonlinear refractive index n2 and the nonlinear absorption coefficient β of the azo dye doped polymer films were calculated respectively. The real part of the third-order susceptibility χ3 is much larger than its imaginary part indicating that the third-order optical response of the metanil yellow doped PVA films is dominated by the optical nonlinear refractive behavior.