Laser dye mixtures

Properties necessary to obtain efficient laser action from laser dyes are reviewed. It is concluded that the dye added (booster dye) to a laser dye (active dye) solution to increase its efficiency need not necessarily be a laser dye. This is illustrated by considering different spectral locations of a triplet-triplet absorption band present in the booster dye relative to the location of the laser action region (part of the fluorescence spectrum) of the active laser dye. Conditions required for booster dyes to form efficient dye mixtures are given. These observations are used to explain why specific well known laser dye mixtures show efficient, little, or no laser action at all.