Lasing of Some Red Laser Dyes in Annealed Silica Xerogel

The spectral and energy characteristics of generation in the red spectral region 650–720 nm were measured and analyzed for three laser dyes in preliminarily annealed SiO 2 xerogel matrices under laser excitation λ p = 588 nm in a nonselective cavity. The specific laser-energy output for two of them (LK678 and Ox170) in the matrices was 10–13% higher than in MeOH. NBA dye in the matrix generated two laser radiation bands in the 700–720 nm region with pumping E p ≥ 80 mJ whereas its generation threshold in MeOH exceeded the maximum pumping energy of 140 mJ so that NBA generation was not observed. Laser emission spectra of the studied matrices in a nonselective cavity were red-shifted by ~1000 cm –1 from the fluorescence maximum. Such a shift could improve the characteristics of biosensors based on these matrices.