PHOTOSTABILITY ENHANCEMENT OF PYRROMETHENE-567 AND PERYLENE-ORANGE INOXYGEN-FREE LIQUID AND SOLID DYE-LASERS

We investigated the effect of oxygen on the photostability of the lase r dyes Pyrromethene 567, Perylene Orange, and Rhodamine 590 by determi ning their longevity of laser operation when pumped by the second harm onic of a Q-switched Nd:YAG laser. In solution, dissolved oxygen accel erated the photodegradation of Pyrromethene 567 and Perylene Orange bu t not Rhodamine 590. The photostability of Pyrromethene 567 was also f ound to be dependent on the solvent and on the lifetime of singlet oxy gen. Deoxygenated Pyrromethene 567 doped polycom glass and modified po ly(methyl methacrylate) (MPMMA) samples were tested for longevity of l aser operation. A factor of 6 improvement in photostability was found for Pyrromethene 567 in MPMMA upon deoxygenation, and the total absorb ed energy per mole of dye molecules to one-half output pulse energy wa s 36 GJ mol(-1). (C) 1997 Optical Society of America.