Author(s)

Soma Venugopal Rao, Puliparambil Thilakan Anusha, Turaga Shuvan Prashant, Debasis Swain, Surya P. Tewari

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We have investigated the nonlinear optical properties, optical limiting thresholds, and figures of merits for five different phthalocyanine thin films, achieved through doping in PMMA polymer, using the Z-scan technique at 800 nm with 2 ps laser pulse excitation. From the open-aperture Z-scan data we derived that these molecules exhibit strong two photon absorption (2PA) with the nonlinear coefficients in the range of 15 - 200 cm/GW. We have also estimated the sign and magnitude of real part of third order nonlinearity through the closed aperture data. Preliminary femtosecond pump-probe data suggests that the lifetimes of excited states are in the sub-100 ps regime for all the molecules in film form. Our studies provide concrete evidence that these phthalocyanines are prospective candidates for multi-photon imaging and optical limiting applications.

Z-Scan, Phthalocyanines, Thin Films, Picosecond, Figures of Merit

S. Rao, P. Anusha, T. Prashant, D. Swain and S. Tewari, "Ultrafast Nonlinear Optical and Optical Limiting Properties of Phthalocyanine Thin Films Studied Using Z-Scan," Materials Sciences and Applications, Vol. 2 No. 5, 2011, pp. 299-306. doi: 10.4236/msa.2011.25039.