Two-Photon (TP) excitation followed by Resonance Energy Transfer (RET) is a potentially useful mechanism for multi-photon microscopy in biological research, multi-photon three-dimensional micro-fabrication and it can also give rise to enhanced nonlinear absorption. In this work we use a TP fluorophore as a donor (D) and a photo-chromic (PC) molecule as an acceptor (A). The molecules were chosen so as to display efficient RET to the photo-chromic acceptor following two-photon excitation of the donor. The spectroscopic behavior of each molecule was studied separately and in mixtures. The RET process following the TP excitation from the TP fluorophore to the photo-chromic molecule was studied using short pulse (2 ps) laser excitation at the TP peak absorption. The fluorescence decay indicates a modified Förster type energy transfer. The system should exhibit enhanced nonlinear absorption beyond the square law of TP absorption as expected in presence of donor itself.
|Number of pages||8|
|Journal||Proceedings of SPIE - The International Society for Optical Engineering|
|State||Published - 2005|
|Event||Organic Photonic Materials and Devices VII - San Jose, CA, United States|
Duration: 24 Jan 2005 → 26 Jan 2005
- Photo-chromic materials