Distinctive features of the lasing of organic dyes

An asymmetric decrease in the divergence and pulse length of the stimulated emission of organic dyes during longitudinal pumping by UV radiation from a pulsed nitrogen laser is described. A general trend is observed in a series of laser dyes belonging to a common class. This behavior can be used to find a long-wave boundary on the lasing region for dyes of this class. An expression for this boundary is offered. A method for assigning an unknown laser dye to a certain class is described. Data from a spectral and energy study of laser dyes of various classes are reported.