Singlet oxygen and dye-triplet-state quenching in solid-state dye lasers consisting of Pyrromethene 567-doped poly(methyl methacrylate)

Solid-state dye lasers based on poly(methyl methacrylate) (PMMA) doped with Pyrromethene 567 dye (P567) have been investigated The preparation techniq ues employed provided high photostability and laser damage threshold for P5 67 in pure PMMA with 270,000 pulses emitted before the conversion efficienc y fell to half its initial value for a pump fluence of 0.16 J cm(-2). When PMMA was modified with 1,4-diazobicyclo [2,2,2] octane singlet oxygen quenc her, the longevity increased to 550,000 pulses, corresponding to a normaliz ed photostability of 270 GJ mol(-1). Modification of PMMA with a triplet qu encher (perylene) yielded no improvement, but in ethanol solutions both add itives enhanced photostability. It is possible that in PMMA, stabilization by means of triplet quenching that depends on dye diffusion is prevented. b ut that stabilization by means of singlet oxygen quenching that depends on the faster oxygen diffusion rate will succeed. (C) 1999 Optical Society of America.