Investigation of thickness and concentration effects on the nonlinear optical properties of yellow disperse doped PMMA

Nonlinear optical properties of yellow disperse 211 doped polymethyl-methacrylate (pmma) solution in acetone isstudied experimentally employing different optical techniques. the effects of thickness of sample as well as its concentrationeffects are investigated in detail. experiments are performed using the second harmonic of a continuousnd-yag laser beam at 532 nm wavelength and 20 mw power. the effect of nonlinear refractive index of liquid filmsis obtained by measuring the profile of propagated beam through the samples and their nonlinear refractive index isfound to be negative. the optical limiting behavior of samples is investigated by measuring the samples transmission.the third order nonlinearity (chi)^3 is measured using z-scan data. the nonlinear absorption coefficient is calculatedusing open aperture z-scan data while its nonlinear refractive index is measured using the closed aperture zscandata. real and imaginary parts of the third-order nonlinear optical susceptibility (chi)^3 are changed significantly with thickness and concentration.