Two-Photon and Cooperative Excitation of an Infinite Chromophore Chain

V. A. Markel

Optoelectronics, Instrumentation and Data Processing 1993, No.6, 3-12 Received February 4, 1993

Translated from:

Автометрия 1993, № 6, стр. 3-13

The paper deals with two channels of optical excitation of an infinite chromophore chain: two-photon (step-wise) excitation and cooperative excitation (summation of energy of two closest neighbors in one of them). Steady-state populations of the first and second excited electronic states of the chromophores have been found The cooperative processes result in correlation of chromophore electronic level populations in a chain. It is taken into account accurately. To calculate the populations, the distribution function of state occupation numbers for an infinite chain is found and an analogy with the one-dimensional Ising model is used. It is shown that the cooperative processes can lead either to increase or to decrease in the population of the higher electronic levels, depending on the excitation conditions. The theoretical results are verified by numerical calculations.

REFERENCES 1. J. B. Birks, Photophysics of Aromatic Molecules (Wiley, N.Y., 1970). 2. J. B. Birks, ed., Organic Molecular Photophysics, v. 1 (Wiley, London, 1973). 3. S. Haroche, ed., Laser Spectroscopy, v. 2 (Springer, N.Y., 1975). 4. F. H. Zewail, ed., Advances in Laser Chamistry (Springer, N.Y., 1978). 5. F. Fromhertz, Chem. Phys. Lett. 109, 5650 (1984). 6. E. Sahar, S. Latt, Proc. Natl. Acad. Sci. USA 75, 5650 (1978). 7. L. Z. Benimetskaya, N. V. Bulychev, A. L. Kozionov et al., FEBS Lett. 163, 144 (1983). 8. K. H. Drexhage, Dye Lasers (Mir, Moscow, 1976). 9. V. A. Markel, M. I. Stockman, Optika i Spektroskopiya 165, 1231 (1988). 10. V. A. Markel, M. I. Stockman, Optika i Spectoscopiya 165, 1258 (1988). 11. R. M. Hochstrasser, in: Advances in Laser Chemistry (Springer, N.Y., 1978). 12. M. I. Stockman, Phys. Lett. 76A, 191 (1980). 13. M. I. Stockman, ZhTF 87, 84 (1984). 14. S. G. W. Colborn, J. Phys. A 23, 4013 (1990). 15. E. Ising, Z. Phys. 31, 253 (1925). 16. T. L. Hill, Statistical Mechanics, ch.7 (IL, Moscow, 1960)