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CPP: Chemische Physik und Polymerphysik

CPP 3: Light-induced Phenomena

CPP 3.2: Vortrag

Dienstag, 3. April 2001, 18:05–18:25, 110

Dynamic hologram limiting in C60 solutions. — •Anna Pyajt, Inna Belousova, and Victor Bespalov — Pyajt Anna, Stacheck Avenue 132-64, St-Petersburg, Russia, 198207

For improvement of limiting properties of fullerene solution the self-diffraction phenomenon on a grating is proposed. We performed numerical experiments describing optical limiting in C60 fullerene solutions taking into account the dynamic hologram recording using 10-ns pulses at 532 nm. Our study was based on the phenomenon of nonlinear optical absorption and on the solution of balanced equations system describing population moving in six-level energetic scheme of a fullerene and the equation for absorption from different levels in dependence on coordinate. We found the phase grating profile and estimated the dynamic holograms diffraction efficiency in different diffraction orders. We calculated absorption index of the medium for different concentrations of the fullerene and dependence of zero diffraction order intensity on input intensity.It was shown that during the recording the profile of phase thermal grating becomes nearly rectangular due to absorption on exited singlet and triplet sublevels. High self-diffraction orders appeared and the effect of optical limiting considerably increased. The results of numerical analysis showed that recording of dynamic hologram in fullerene solution is perspective for development of a limiter device.