Strong two-photon-absorption (TPA) based nonlinear optical properties of a new chromophore, N, N-diphenyl-7-[2-(4-pyridinyl) ethenyl]-9, 9-di-n-decyl-fluoren-2-amine (AF-50) has been experimentally studied. Under excitation with 10-Hz, ∼8-ns, and ∼800-nm laser pulses, the TPA cross section and the TPA-induced frequency-upconverted emission spectra are measured for AF-50 solutions in various solvents. The most attractive feature of this chromophore is its remarkably high value of the molecular TPA cross section (∼78×10<sup>−20</sup> cm<sup>2</sup>/GW in benzene solution). Based on this feature, superior optical power limiting and stabilization performance has been demonstrated in a 1-cm-long AF-50 solution sample with concentration of d<sub>0</sub>=0.045 M/L. The nonlinear transmission of the measured sample decreased from ∼0.93 to ∼0.3 when the input-beam intensity increased from ∼10 MW/cm<sup>2</sup> to ∼360 MW/cm<sup>2</sup>; the relative intensity fluctuation of the output laser pulses was reduced to one third of that of the input laser beam.
© 1997 Optical Society of America
Guang S. He, Lixiang Yuan, Ning Cheng, Jayant D. Bhawalkar, Paras N. Prasad, Lawrence L. Brott, Stephen J. Clarson, and Bruce A. Reinhardt, "Nonlinear optical properties of a new chromophore," J. Opt. Soc. Am. B 14, 1079-1087 (1997)