Facile Z-scan determination of nonlinear refractive index and absorption coefficient of dye-doped polymer film

Herein, we report the nonlinear refractive index and nonlinear absorption coefficient of anthraquinone dye (disperse blue 14)-doped polymer film using a facile Z-scan technique. The Z-scan studies were carried out using a semiconductor diode laser with a constant power output of 5 mW at a wavelength of 635 nm as the source of excitation. The Z-scan technique consists of closed and open aperture methods, which revealed the self-defocusing and reverse saturable absorption mechanisms based optical nonlinearity. The third-order nonlinear optical susceptibility (chi(3)) of dye-doped polymer film was estimated to be in the order of 10-5 esu. Optical limiting (OL) behaviour of the polymer film with different dye concentrations was performed under the same experimental conditions and found to be a low OL threshold of 1.45 x 102 W cm-2 at 0.04 mM dye concentration. Self-diffraction ring pattern of the polymer film was also noticed in the far field. The overall results found that the dye-doped polymer film is a potential material for photonics and optoelectronics applications.