Third-order nonlinearities and optical limiting properties of rose Bengal at 532 nm wavelength


The nonlinear refractive index n2 and nonlinear absorption coefficient  for aqueous solution of rose Bengal were obtained using closed aperture and open aperture Z-scan technique at the same wavelength. The nonlinear refractive index n2 shows negative nonlinearity of the sample and it is measured to be n2 = -5.6 x 10-8 cm2 /W. Moreover, a variation of nonlinear refractive index with intensity is observed. The nonlinear absorption coefficient is measured to be  = -8.3 x 10-3 cm/W. Also the optical limiting property of the sample has been investigated using frequency doubled Nd:YAG laser.