Study on the third-order NLO properties of trace metal ions in nitric acid solution by closed-aperture Z-scan technique

Abstract

Discovery of materials which exhibit large real third-order optical nonlinearities have recently become the topic of a broad scientific interest, due to its potential applications in many areas especially in the field of all-optical signal-processing. Here in this work, we report a preliminary investigation on the third-order nonlinear optical (NLO) response of different type of trace metal ions in nitric acid standard solution. A facile and rapid single beam z-scan technique incorporating 532nm diode pump solid state laser was employed to study the response of Lead (Pb), Cadmium (Cd), Mercury (Hg), Zinc (Zn), Aluminum (Al) ions towards NLO properties. Nonlinear refraction (NLR) response of the heavy metal samples were recorded from closed-aperture output and the maximum values of nonlinear refractive index, n 2 for all Pb, Cd, Hg, Zn, Al were recorded at 1.96355×10-9, 3.38228×10-9, 9.36907×10-9, 8.67559×10-10,3.28211×10-9 cm2W-1 respectively. Based on the experimental findings, the negative sign of the nonlinear refractive index values successfully indicates that the samples exhibit nonlinear self-defocusing effect, which is further expected to have potential applications in all-optical devices.