Multiphoton absorption of solutions of polydiacetylene polyDCHD-HS measured using ps Z-scan at 1064 and 1500 nm
ABSTRACT The nonlinear absorption of benzene and toluene solutions of polydiacetylene polyDCHD-HS was measured at λ=1064 and 1500 nm by using Z-scan and picosecond pulses with a trimmed Airy beam configuration. In the data analysis, we took into account both the saturation of the open aperture Z-scan traces occurring for high values of nonlinear absorption and the possible occurrence of cross-talk effects between nonlinear refraction and multiphoton absorption. The polymer exhibits three-photon absorption at both 1064 and 1500 nm. The molecular three-photon absorption coefficient at 1064 nm was and in toluene and benzene, respectively, while at 1500 nm it was in toluene. On this basis, the optical limiting behavior of polyDCHD-HS in the near infrared range is also shown.
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ABSTRACT: Diacetylene monomer containing p-nitrophenyl azobenzene moiety (NADA) was synthesized. Silver nanoparticles with different concentrations were adulterated in the above polymerized NADA (PNADA) films and the third-order nonlinear optical properties were investigated in detail. UV–vis spectra and transmission electron microscopy were used to confirm the formation of PNADA/Ag nanocomposite films. The silver nanoparticles (average size of 10 nm) were well dispersed in the polymer films. The value of the nonlinear refractive index n 2 for PNADA films (8.48×10−15cm2/W) was much higher than that of pure polydiacetylene films. Further, the introduction of silver nanoparticles into the PNADA polymer films led to the further enhancement of nonlinear optical properties. The maximum value of n 2 for PNADA/Ag nanocomposite films could be 11.6×10−15cm2/W. This enhancement should be ascribed to the surface plasmon resonance of silver nanoparticles.Applied Physics A 04/2012; 100(1):223-230. · 1.55 Impact Factor