STUDY OF PHOTOREACTION IN DICHROMATED GELATIN BY LASER PHOTOACOUSTIC TECHNIQUE

An experimental method to study the photochemical reaction in solid-st ate dichromated gelatin during exposure is proposed, in which two lase r sources with different wavelengths are used to induce photoreaction and to excite photoacoustic signal, respectively. This method is to ob tain the real-time characteristics during the formation of the photore action product. The curve is fitted using the Rosencwaig-Gersho (R-G) theory and chemical kinetics. The reaction order and the rate of react ion may be obtained by fitting the parameters. The results show that p hotochemical reaction in dichromated gelatin conforms to the mechanism suggested by Watanable-Westheimer, and the photosensitivity of the sa mples, prepared under different conditions, is dependent on the initia l concentration of photoactive ions.