The optical-limiting behavior of a series of trans-α, ω-diphenyl polyene compounds was observed in solutions of chloroform. The influence of planarity, the substitution of donor and acceptor groups, and the extent of π-electron delocalization on the nonlinear thresholds of the diphenyl polyenes in an optical-limiting geometry were examined. A saturation effect of optical-limiting nonlinear thresholds, consistent with the theoretical work, was observed at 10–11 π-electron bonds. The temporal profiles of the transmitted laser pulses and the power dependence of the nonlinear thresholds as a function of spot size and wavelength were examined. These examinations led to the conclusion that the predominant nonlinear mechanism was quasi-steady-state self-focusing. Nonlinear thresholds an order of magnitude lower, and thus effective n2 and χ3 values an order of magnitude higher, than the well-known self-focusing medium CS2 were observed. Our studies demonstrate that this series of polyenes consists of efficient broadband nonresonant optical-limiting materials.
© 1991 Optical Society of AmericaFull Article | PDF Article
J. W. Wu, J. R. Heflin, R. A. Norwood, K. Y. Wong, O. Zamani-Khamiri, A. F. Garito, P. Kalyanaraman, and J. Sounik
J. Opt. Soc. Am. B 6(4) 707-720 (1989)
J. R. Heflin, Y. M. Cai, and A. F. Garito
J. Opt. Soc. Am. B 8(10) 2132-2147 (1991)
W. M. K. P. Wijekoon, Y. Zhang, S. P. Karna, P. N. Prasad, A. C. Griffin, and A. M. Bhatti
J. Opt. Soc. Am. B 9(10) 1832-1842 (1992)