Two novel two-photon polymerization initiators, 10-etliyl-3-E-(4-(N,N'-di-n-butylamino)styryl)phenothiazine 5 and 10-ethyl-3,7-E,E-bis(4-(N,N'-di-n-butyl amino)styryl)phenothiazine 6, have been efficiently synthesized with room temperature solid phase Wittig reaction. Two initiators were found to exhibit good single-photon fluorescence emission and their quantum yields, lifetimes and solvent effects have been studied in detail. Two-photonfluorescence spectra were investigated under 800 nm fs laser pulse and two-photon absorption (TPA) cross-sections of the initiators have been evaluated by theoretical calculation. Two-photon initiating polymerization microfabrication experiments have been carried out and artificial defects were made and polymerization mechanism was also discussed. (C) 2004 Elsevier B.V. All rights reserved.