This is an internationally collaborative project between the Institute for Lasers, Photonics and Biophotonics at the State University of New York at Buffalo (UB) and the Center for Advanced Molecular Materials (CAMM) in Sweden. Project goals are to develop efficient 3-photon absorb-ing materials for photonic applications. The Swedish group will conduct theoretical modeling to provide design criteria that will be used in Buffalo to synthesize novel 3-photon chromophores, characterize them and explore applications. Using their expertise in synchrotron research, the Swedish collaborator will also conduct synchrotron-based spectroscopic studies of these materials. The aim is to achieve greater understanding of structure property relations so as to identify those features of molecular structures that lead to enhanced 3-photon absorption. Recent suc-cesses in reaching a substantial enhancement of 2-photon absorption (2PA) in new molecular structures have created interest in exploring 3-photon (3PA) based applications. For the 3PA process, a longer excitation wavelength such as those for optical communications can be used. Also its cubic dependence on the input light intensity provides a stronger spatial confinement so that a higher contrast in imaging can be obtained. Recently UB reported observation of a highly directional and up-converted stimulated emission, produced by a strong simultaneous 3-photon absorption at 1.3 um in a new organic chromophore solution. Two convergent approaches will be used. First, experimental studies will investigate the 3-photon properties of a group of systematically derivatized promising structures. Second is the molecular design guided by theoretical stud-ies of the structure-property relationship by using quantum chemical models of 3-photon absorp-tion (e.g. the few-state model) as proposed by the Swedish collaborators. Anticipated project outputs include new materials with strong 3-photon absorption wavelengths of 1.3-1.55-um and exploration of their practical application for (1) optical fiber communication, (2) optical power limiting and stabilization, (3) up-converted stimulated emission and lasing, and (4) 3-photon ab-sorption based imaging and data storage. %%% The project addresses fundamental research issues associated with electronic and photonic mate-rials having technological relevance. An important feature of the project is the strong emphasis on education, with emphasis on integration of research and education, including minorities, and an international collaboration providing both scientific and educational benefits. Short and long-term staff and student exchanges will supplement electronic communications between the groups. The outcome of this research is expected to stimulate rational development of materials, which utilizes 3-photon processes for frequency up-conversion lasing; short pulse optical com-munications; optical power limiting and stabilization; and bioimaging and biophotonics. This NSF project is co-funded by the Office of Multidisciplinary Activities, the Division of Materials Research (Electronic Materials), and the International Office (Western Europe) as a Cooperative Activity in Materials Research between the NSF and Europe (NSF 02-135). This project is being carried out in collaboration with the Center for Advanced Molecular Materials (CAMM) in Swe-den. ***
