Third-order nonlinear optical properties and two-photon absorption in polymers doped with p-phenyl sydnone

We report the measurements of the third-order susceptibilities and two-photon absorption in three different polymers doped with p-phenyl sydnone moiety viz., 2-benzylhydrazono-5-(3-p-tolylsydnone-4-yl)1,3,4,-thiadiazine, which is recently synthesized and characterized, with the prospective of reaching a good compromise between processability and high nonlinear optical properties. The measurements were done using nano second Z-scan at 532 nm. The Z-scan spectra reveal a large negative nonlinear refraction coefficient n(2) of the order 10(-14) cm(2)/W and a two-photon absorption 0, which is determined to be the order of cm/GW. The absorption cross section is 10(-46) cm(4) s/photon. The molecular second-order hyperpolarizability in PMMA matrix was calculated to be 1.47 x 10(-31) esu, comparable with stilbazolieum derivatives, a well-known class of optical materials for photonics and biophotonics applications. The chromophore shows its optical power limiting behavior in all the three polymer matrices. All these results suggest that this moiety has potential for the application of all-optical limiting and switching devices. (C) 2008 Wiley Periodicals, Inc.