There is herein, disclosed a dye laser including a container for a dye solution and a pumping energy source coupled thereto, said dye solution containing a perimidone dye formula (I): ##STR1## wherein R.sup.1 is a hydrogen atom, an alkyl group, a trifluoromethyl group, an alkoxycarbonyl group, an alkoxycarbonylalkyl group, an aralkyl group or a phenyl group; R.sup.2 is an optionally substituted alkoxycarbonyl group, a cyclohexyloxycarbonyl group, tetrahydrofurfuryloxycarbonyl group, an aryloxycarbonyl group, a benzyloxycarbonyl group, an acyl group, a cyano group or an optionally substituted carbamoyl group; R.sup.3 and R.sup.4 which may be the same or different are each a hydrogen atom, an alkyl group, an alkoxyalkyl group, an aralkyl group or an aryl group.