A new series of linear, asymmetrical diphenylaminofluorene-based chromophores (AFX) with various strong π-electron acceptors were synthesized and evaluated for two-photon absorptivity. These chromophores were studied to determine a suitable replacement for 2-(4-vinyl)pyridine, the π acceptor for our previously reported AFX series, which contains a photochemically and thermo-oxidatively unstable olefinic unit. In addition to the benzoyl group (AF-370), these π-electron acceptors include 2-benzothiazolyl (AF-240), 2-benzoxazolyl (AF-390), 2-(N-phenyl)benzimidazolyl (AF-386), and 2-(3,4-diphenyl)imidazolyl (AF-385) moieties (five-membered heterocycles) and the 2-quinoxalinyl (AF-260) group (six-membered heterocycle). From nanosecond nonlinear transmission measurements, these new chromophores have effective two-photon cross sections (σ2‘) at 800 nm, spanning from 3.87 × 10-48 cm4 s/(photon molecule) for AF-385 to 97.46 × 10-48 cm4 s/(photon molecule) for AF-240. Two of them, 2-benzothiazolyl-end-capped AF-240...