Enhanced photostability of dye molecules trapped in solid xerogel matrices

A quantitative study of the photostability of dye molecules, trapped in transparent solid matrices synthesized by the sol-gel technique and diluted in solutions, was carried out by measuring the average number B of photons that the dye molecules can absorb before getting bleached. The investigated dye molecules were: Perylene Red, Perylene Orange, Pyrromethenes 567 and 597, Rhodamines 6G and B, DMC, a xanthylium salt and Neon Red. Values of B from 103 to 109 were measured. We show that the photostability was largely enhanced when the molecules were trapped in solid matrices. The dye-doped matrices were used as gain media in pulsed lasers to see the influence of the photostability of the molecules on their degradation in this common application: other bleaching processes were then revealed.