The sol-gel process is a solution synthesis technique which provides a low temperature chemical route for the preparation of rigid transparent matrices. A number of laser dyes have been incorporated in different sol-gel matrices and tunable laser action has been demonstrated with these materials. This paper extends the sol-gel laser field into two significant areas, infrared dyes and pyrromethenes. The work with the tricarbocyanine dyes shows the versatility of sol-gel chemistry as organic modifications produce a favorable environment for the dye molecules. The results with the pyrromethene system show a considerable increase in output energy and offer the promise of longer laser lifetimes.

Photoresistant laser dyes were trapped in silica based xerogel host matrices to obtain solid state tunable lasers. For this purpose very dense xerogel samples with improved chemical and physical properties were prepared at room temperature by the sol-gel technology. The as-prepared materials were polished to obtain optical quality surfaces and were used as new lasing media.

Lasing action of such different dyes as rhodamine, perylene and pyrromethene doping dense sol-gel matrices was demonstrated. Efficiencies of 30 % or lifetimes of more than 100,000 shots were achieved with different new ≤dye dopant/host matrix≥ couples. Their different performances are reviewed and discussed.

Compounds of europium(III) and ruthenium(II) are of interest for potential optical source applications in the red portion of the visible spectrum. Our previous work showed that the organo-europium complex tris(4,4,4-trifluoro-l-(2′-thienyl)-l,3-butanedionato-O, O′)europium( III), Eu(ttfa)3, demonstrated superior fluorescence properties to salts like europium(III) chloride when doped into sol-gel materials. The ruthenium complex tris(2,2′- bipyridyl)ruthenium(II) chloride, ‘Ru(bpy)3’Cl2, also shows strong fluorescence when doped into sol-gel materials.

Luminescence behavior of the ‘;Ru(bpy)3’Cl2 complex has been investigated as a function of matrix composition using three sol-gel-derived hosts: silica, an acrylate ORMOSIL, and an epoxide ORMOSIL. Luminescence characteristics have also been studied as a function of fluorophore concentration. Fluorescence lifetime, excitation and emission spectra, and quantum efficiency values have been determined.

Four pyrromethene-BF2 visible laser dyes, dissolved in a MIL-STD tested high temperature polymer matrix and pumped with a doubled Nd:YAG laser produced 61 % slope efficiency and retained 78% of the initial lasing efficiency after 95,000 pulses.