Study optical properties of R6G dye doped in polymer PVA

Abstract

The linear and nonlinear optical properties for laser dye R6G is investigated in solvent methanol at different concentrations (5x10-4, 1x10-4, 1x10-5, 5x10-6 and 1x10-6 Ml) at thickness (2µm). The nonlinear optical properties as refractive index (n2) and the nonlinear absorption coefficient (β) were studied by using Z-Scan technique in two parts; one part by putting aperture in front of the detector (close aperture) to find the nonlinear refractive index, however in second part is by removing the aperture (open aperture) to find nonlinear absorption coefficient, these by using two wavelengths 532, 1064 nm. The results show the effects of self – focusing in 532 nm and other concentrations in 1064 nm and the change of the saturation absorption effect in open aperture in both wavelengths. The higher nonlinear refractive index is found (n2=29.93cm2/mw) in the concentration (1*10-4 Ml), while the higher nonlinear absorption coefficient is (β=8.88cm/mw) in the concentration (5*10-4Ml) at the wavelength 532 nm.