Shiyoshi Yokoyama, Akira Otomo, and Shinro Mashiko We prepared high-gain media for laser emission by using a conventional laser-dye (DCM) and dendrimer. A dendrimer can encapsulate the laser dye, and therefore increase its concentration up to 9.0 mM with limited self-aggregation and intermolecular quenching. The optical confinement is attributed to gain guiding under optical excitation. The la ser spectrum clearly indicated periodic resonant modes though the laser feedback was caused in an unusual way. Above the lasing threshold, the spectral linewidth became less than 0.1 nm. The laser-dye-doped dendrimer showed a particular ability to decrease the lasing threshold intensity by increasing the dye concentration. DOI:10.1063/1.1431400 |