Laser dyes III: Concepts to increase the photostability of laser dyes

Two approaches of increasing the photostability of the laser dye POPOP are reported. Desensibilisation against singlet oxygen was accomplished either by substitution with electron acceptor groups or by linking the dye molecule with a suitable quencher unit, e.g. tertiary amines. To test the efficiency of the modifications of the dye molecules the rate of their continuous UV-bleaching (λ = 366 nm) was investigated.