Third order nonlinear optical properties and two photon absorption in newly synthesized phenyl sydnone doped polymer

We have investigated third order nonlinear optical properties of three newly synthesized 3-phenyl sydnones, doped into PMMA and determined both real and imaginary part of χ(3). The measurements were performed using nanosecond laser pulses at 532 nm wavelength by employing Z-Scan technique. The nonlinear refractive index is found to be of the order of 10−14 cm2/W. The magnitude of third order susceptibility is of the order of 10−13 esu. Their two photon absorption coefficient and absorption cross section have also been determined. The optical power limiting behavior of sydnone moieties doped PMMA was also investigated. The results suggest that among the three organic phenyl sydnone moieties, 2-benzylhydrazono-5-(3-p-tolylsydnone-4-yl)1,3,4,-thiadiazine doped PMMA is a promising class of nonlinear optical material due to its simple molecular structure with p-tolyl group. It also shows a very good optical limiting behaviour with a limiting threshold of 0.21 mJ/pulse. The nonlinear parameters obtained are comparable with the values obtained in stilbazolium like dye such as trans-4-[2-(pyrrl)vinyl]-1-methylpyridium iodide. Hence this material may be tailored suitably for applications such as optical power limiters, switches and modulators.