Properties of optical limitation of radiation in pi-conjugated organic systems doped with fullerenes (the COANP-C-70 system)

The effect of optical limitation of laser radiation in 2-cyclooctylamino-5- nitropyridine (COANP-C-70) doped with fullerene is experimentally studied. The energy density of the incident beam is measured to be similar to4-4.5 J cm(-2) and the attenuation coefficients and the absorption spectrum of a n ew structure are determined. The photoinduced variation of the refractive i ndex of the COANP-fullerene system and its influence on the optical limitat ion is studied in the visible range upon irradiation by nanosecond laser pu lses. The mechanisms of optical limitation of radiation in these structures are specified. The nonlinear optical coefficients n(2) and chi ((3)) of th e fullerene-doped pi -conjugated COANP system are measured for the first ti me by the methods of dynamic holography. (C) 2001 MAIK "Nauka/Interperiodic a".