Superfluorescence action from rhodamine-cored dendrimer

Shiyoshi Yokoyama, Tatsuo Nakahama, Akira Otomo, Shinro Mashiko

This paper describes preparation of the rhodamine B cored dendritic macromolecule, called Rh-dendrimer, and the radiative properties from the neat film due to the spontaneous emission and superfluorescence processes. An important concept investigated for material preparation is surrounding a fluorescent chromophore by the dendritic branches achieving a core|shell structure. Therefore, the dendrimer became emitting species with high fluorescence efficiency even in a high concentrated medium. Optical properties from the dendrimer were very different from that from the bared chromophore, which formed charge transferred complex and became less fluorescent. Under optical excitation, emission from the dendrimer was nonlinearly increased, giving relation of IN2 and с|1, where I is the emission intensity, N is the number of molecules, and is the life time. Results were discussed in terms of superfluorescence.