Optical limiting in solutions of diphenyl polyenes

• Published in: Applied optics (2004) Vol. 30; no. 30; p. 4341
• Main Authors: Bunning, T J, Natarajan, L V, Schmitt, M G, Epling, B L, Crane, R L
• Format: Journal Article
• Language: English
• Published: United States 20.10.1991
• ISSN: 1559-128X
• DOI: 10.1364/AO.30.004341

The optical-limiting behavior of a series of trans-alpha, omega-diphenyl polyene compounds was observed in solutions of chloroform. The influence of planarity, the substitution of donor and acceptor groups, and the extent of pi-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 pi-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 n(2) and X(3) values an order of magnitude higher, than the well-known self-focusing medium CS(2) were observed. Our studies demonstrate that this series of polyenes consists of efficient broadband nonresonant optical-limiting materials.