NEWLY SYNTHESIZED DYES AND THEIR POLYMER/GLASS COMPOSITES FOR ONE-PHOTON AND 2-PHOTON PUMPED SOLID-STATE CAVITY LASING

A newly synthesized laser dye, trans-4-[p-(N-ethyl-N-(hydroxyethyl)amino)styryl]-N-methylpyridinium tetraphenylborate (ASPT or dye I) has high thermal stability and photostability. To modify the solubility of dye I, a series of dyes has been synthesized. Using dye I doped polymer film with a refractive index less than that of the glass substrate, a leaky waveguide device has been investigated. Under pump conditions of 532 nm wavelength, 10 ns pulse width, and 5 Hz repetition rate, one-photon cavity lasing was obtained at 590 nm, with a lasing efficiency of 12%, and lasing lifetime >3 x 10(4) pulses. Utilizing dye I doped bulk polymer rods, two-photon pumped frequency up-converted cavity lasing has also been accomplished using a Q-switched Nd:YAG laser as the pump source. The new dyes possess a much greater two-photon-absorption cross section and much stronger up-converted fluorescence emission than that exhibited by common organic dyes (such as rhodamine). The cavity lasing wavelength and pulse duration were 600 nm and 3-6 ns obtained with a pump wavelength of 1.06 mu m and pump pulses of 10 ns. Lasing lifetime, in terms of pulse numbers, was more than 4 x 10(4) pulses at 2 Hz repetition rate. By impregnating these dyes into a sol-gel glass:poly(methyl methacrylate) (PMMA) and Vycor glass:PMMA composite glasses, two-photon pumped cavity lasing properties have also been studied.