| abstract |
Dyestuff laser consisting of a reservoir, with a laser dyestuff solution contained therein, and a pumped light source associated therewith, which is capable of exciting the dyestuff solution to produce an emission, characterized in that the dyestuff solution contains, in a solvent which does not interfere with the emission, a dyestuff which, in the form of the free acid, corresponds to the general formula ##STR1## wherein R 1 to R 4 independently of one another represent hydrogen, alkyl, trifluormethyl, alkoxy, aralkoxy, alkenyloxy, halogen or the carboxyl, cyano, alkylsulphone, aryl-sulphone, carboxamide, sulphonamide or carboxylic acid ester group, n R 1 and R 4 can additionally denote a fused-on benzene ring, n n represents a number 2 to 6 and n o, p, q and r independently of one another represent 0, 1 or 2, n in a concentration, preferably of 10 -2 to 10 -5 mol/1, which emits laser radiation. |