The laser irradiation of the thin films of solid solution of eosin in gelatinous matrix in the first and some upper dyes absorption bands leads to decrease of films optical density due to reaction of photoreduction. In the paper the kinetic of photoreduction of the dye eosin K in polymeric matrix in three cases of irradiation was experimentally investigated: a) irradiation by N2 laser (λ=337nm, second band of absorption, π=2 nsec, repetition rate-100 Hz, average power-2,2 mW), b) irradiation by Ar-laser (λ=488 nm, first band of absorption, 6,5-12 mW), c) under a simultaneous action of both Ar and N2-lasers. It was demonstrated that the most effective reaction of photoreduction took place in case of direct populating of upper singlet states with probable following nonradiative transition into equienergetic triplet states (energy ranges 35000-45000 sm-1).
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