Photochemical formation of an image with second-order nonlinear optical properties in a polymer layer

Exposure of a light-sensitive donor-acceptor layer composed of the donor po lyhydroxyaminoether and the acceptor carbon tetrabromide leads to the forma tion of a chromophore in the polymer main chain, which exhibits the second- order nonlinear molecular susceptibility. As a result, exposed areas genera te the second harmonic (lambda = 532 nm) under the action of coherent laser radiation of lambda = 1064 nm. The square root of the second-harmonic inte nsity, I(-2 omega)(0.5), which is proportional to the second-order suscepti bility chi((2)), linearly increases with an exposure dose. This effect make s it possible to realize a new type of recording an optical image which is visualized (second harmonic) by exposing the layer containing the recorded image to coherent IR radiation.