The quantum yields of the photochemical reactions of 9,9-didecyl-2,7-bis(N,N-diphenylamino)fluorene have been determined in hexane and CH2Cl2 under one-photon (linear) and near-IR two-photon (nonlinear) absorption conditions. The photochemical decomposition proceeds by a first-order reaction and is independent of the type of excitation (one- or two-photon). In hexane solution, the quantum yields of the photoreactions are in the range (2-5) x 10(-4) and increase dramatically to 10(-2) in CH2Cl2. The predominant mechanisms of the photoreactions and the photoproducts products which result were investigated via UV-visible absorption, fluorescence, and excitation anisotropy spectral methods.