PHOTOSTABILITY AND LOSS MECHANISM OF SOLID-STATE RED PERYLIMIDE DYE-LASERS

The lasing photostability of the red perylimide dye (RPD) in various s olid matrices was measured under frequency-doubled Nd:YAG laser excita tion. The RPD: composite glass laser intensity decayed to 50% of its i nitial value after approximately 20,000 pump pulses of 13 mJ/pulse. Th e output of RPD:ormosil glass and RPD:PMMA glass lasers decayed to 50% of their initial value after 1,200 and 1,000 pump pulses of the same energy, respectively. For rhodamine-6G:silica-gel and rhodamine-6G:orm osil glass lasers, the 50% decay occurred already after 1,000 and 300 pulses, respectively. The decay was non-exponential, suggesting that t he dye bleaching was not a single-photon process. The average laser ou tput decay rates increased linearly with the pump energy. Singlet-sing let excited state absorption of the RPD dye in the solid matrices was also measured between 550 and 730 nm. At approximately 600 nm the cros s section was approximately 2 x 10(-16) cm2/molecule. The excited-stat e absorption competes with the lasing, and is a main factor that limit s the laser efficiency.