Study the Linear and Nonlinear Optical Properties for Laser Dye Rhodamine B

In this study different concentrations (10-2, 10-3, 10-4) mol./l were prepared for Rhodamine B dye in solvent water at room temperature, then the optical linear properties for example transmission and absorption spectrum were calculated by employ UV-visible Spectrophotometer to find the linear index of refraction, the linear coefficient of absorption, the coefficient of extinction, and. reflectivity, the results showed an increase in the coefficient of extinction and index of refraction. values with the increase in the concentrations. The properties of nonlinear optical of the samples for example non-linear index of refraction, and non-linear coefficient of absorbance were measured by using a new technical method called the Z-Scan technique, in two parts; The first one was a closed aperture placed ahead of the detector to calculate the index of nonlinear refractive. While the second part; the aperture ahead the detector was taken away (open manhole) to calculate the coefficient of nonlinear absorption. The two cases were performed using diode laser of a continuous wave (CW) with 650 nm wavelength and input power of 50 mW. The result shows that the samples exhibit negative refractive index (-n2) self-defocusing for all concentrations and two-photon absorption for open aperture Ž-Scan so that the laser dye at this study can be applied in nonlinear optics application and it is useful in the optical limiter applications.