Impact of Relaxation Processes on Features of Laser Dyes

The spectroscopic, fluorescence, and lasing characteristics of series of laser dyes for red and near infrared (NIR) regions of laser emission in solutions and silica gel matrices are summarized and analyzed for the purpose to ascertain the influence of dye molecule structure and its nearest molecular surroundings on processes of nonradiative deactivation of this molecule in the exited S1 state. It has been shown for the dyes that have moderate quantum yield of fluorescence (Q≤ 0.5) the surroundings of the dye molecule in silica gel matrix reduce nonradiative losses essentially both at spontaneous transitions and induced ones.