Induced quasicrystallinity of solutions of organic compounds

Using the method of optical probing, we investigated the effect exerted by the concentration of the substance and the temperature of the solution on the spectral behavior of the difference in the refractive indices of ordinary and extraordinary waves Δn=n_o−n_e of excited solutions of Rhodamine 6G and 3,6-tetramethyldiaminophthalimide in glycerin. We established that laser-excitation-induced quasicrystallinity of the indicated solutions in probing in the fluorescence band, which is characterized by the magnitude of the difference between the refractive indices Δn, increases with increase in the concentration of the substance. This increase in the crystallinity of the system with increase in the concentration of the substance (the activator) is possible up to the instant of the appearance of intermolecular interaction of the molecules. To whom correspondence should be addressed. Reported at the Second International Scientific and Technical Conference on Quantum Electronics, Minsk, November 23–25, 1998. Institute of Molecular and Atomic Physics, National Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 5, pp. 672–674, September–October, 1999.