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

χ

3

of metanil yellow were determined by the Z-scan technique. The nonlinear refractive index

n

2

and the nonlinear absorption coefficient

β

of the azo dye doped polymer films were calculated respectively. The real part of the third-order susceptibility

χ

3

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.