Characteristics of BENZOPYRAN Laser Dyes in Annealed Silica XEROGEL.

The spectroscopic and laser characteristics of two benzopyrane derivatives for 600-670 nm spectrum region of lasing in preliminarily annealed silica xerogel matrices in non-selective cavity under laser pumping at 551 nm have been measured and analysed. The influence of molecular structure of the dyes on their non-radiating losses has been revealed. The specific output laser energy of the studied matrices was approximately equal to the ones for corresponding methanol solutions under the same pumping conditions. The laser spectra of the matrices were displaced to the red region from the fluorescence maximum by about 1000-1500 cm-1 in a nonselective cavity. Such spectral displacement may improve the characteristics of biosensors made on the basis of these matrices because it shifts their emission spectrum to the range of deeper penetration into biological tissues.