A novel symmetrical charge transfer fluorene-based compound 2,7-bis (4-methoxystyryl)-9, 9-bis (2-ethylhexyl)-9H-fluorene (abbreviated as BMOSF) was synthesized and its nonlinear absorption was investigated using two different laser systems: a 140-fs, 800-nm Ti:sapphire laser operating at 1-kHz repetition rate and a 38-ps, 1064-nm Nd:YAG pulsed laser operating at 10-Hz repetition rate, respectively. Unique nonlinear absorption properties in this new compound were observed that rise from multiphoton absorption. The nonlinear absorption coefficients were measured to be 6.02*10^(-3) cm/GW (due to two-photon absorption, exciting wavelength is 800 nm) and 3.6*10^(-20) cm3/W2 (due to three-photon absorption, exciting wavelength is 1064 nm). This new compound possesses strong fluorescence induced by two-photon absorption and obvious three-photon absorption optical limiting effects.
© 2005 Chinese Optics Letters
(160.4330) Materials : Nonlinear optical materials
(190.4180) Nonlinear optics : Multiphoton processes
(320.2250) Ultrafast optics : Femtosecond phenomena
(320.5390) Ultrafast optics : Picosecond phenomena
Wenbo Ma, Yiqun Wu, Donghong Gu, and Fuxi Gan, "Two- and three-photon absorption in a novel fluorene-based compound," Chin. Opt. Lett. 3, 351-354 (2005)