Abstract: A dye laser employing a solution of: ##STR1## wherein R and R.sub.1 independently of one another represent hydrogen, alkyl, cycloalkyl or aralkyl or can form, with R.sub.2 or R.sub.3, or with R.sub.4 or R.sub.5, a partially hydrogenated 5-membered or 6-membered heterocyclic ring, R.sub.2 - R.sub.5 independently of one another represent hydrogen, alkyl, alkoxy or halogen or can form, with R or R.sub.1, a partially hydrogenated 5-membered or 6-membered heterocyclic ring,Me represents hydrogen, a monovalent or divalent metal cation, or the ammonium, monoalkylammonium, dialkylammonium or trialkylammonium radical, and m and n denote a number between 1 and 4,And whereinThe rings, A, B and C as well as the aliphatic or aromatic radicals present in the formula can also be substituted further,In a concentration which emits laser beams, preferably of 10.sup.-2 to 10.sup.-5 mol litre.

Abstract: A dyestuff laser which consists of a reservoir for the dyestuff solution and an energy source, coupled thereto, which is capable of exciting the dyestuff solution to produce an emission, the radiation generated lying in the wavelength range of 550 to 680 nm. The dyestuff is a sulforhodamine.