Synthesis of Amphiphilic Dye-Self-Assembled Mesostructured Powder Silica with Enhanced Emission for Directional Random Laser

In this paper, we report a laser device application of dye-self-assembled mesostructured powder. Dye-assembled submicrometer-sized mesostrucutred silica with high luminescence was first synthesized at room temperature from a mixed-surfactant system comprising laboratory synthesized hemicyanine dye and cetyltrimethylammounium bromide (CTAB) as structure-directing agents. The fluorescence emission of the dye molecules was greatly enhanced when self-assembled into the mesostructred powder even though the dye concentration is very high. The highly luminescent powder was further used as gain media to fabricate a laser device. The laser device is a combination of planar microcavity with mesostructured powder random gain layer. Investigation of the laser performance employing the mesostructured powder with enhanced emission as gain media shows a directional output and a much lower threshold, which is 85 times lower than counterpart device using a mixture of silica sphere and dye molecules as gain media.