Linear and Nonlinear optical properties of Rhodamine 6G

Abstract

In this study, the linear and nonlinear optical properties of laser dye R6G in methanol solvent were investigated with various concentrations (1×10−4, 5×10−4, 1×10−5, 1×10−6 and 5×10−6 mole/liter) at thickness (1mm). To study the non-linear optical properties like refractive index and absorption coefficient (β) Z-Scan technique was used in two modes, the first is the close aperture which can be done by putting the aperture in front of the detector to find the non-linear refractive index. While the second mode is the open aperture which can be obtained by removing the aperture to find non-linear absorption coefficient, using two-wavelength 532 and 1064 nm. The results show that all R6G dye concentrations exhibited self – focusing in closed aperture Z-scan in 532 nm except the (1x10−4 mol/liter) in 1064 nm which shown a self-defocusing and the change of the effect of saturation absorption in an open aperture in both wavelength.