Spectral and emission characteristics of DCM and oxazine laser dyes in annealed silica xerogel

Abstract

The solid-state laser media based on preliminary annealed xerogel SiO 2 matrices doped with three laser dyes for 600-700 nm range of tuning actively used in biomedical diagnostics and sensory analysis, were developed and studied. The spectral, fluorescence, and laser characteristics of DCM and two oxazine dyes (Ox9 and Ox17) in the solutions and the matrices were measured and analyzed. It was revealed the influence of bulky fragments able to swing within the structure of the dye molecule and its nearest neighbor surroundings on nonradiative losses in the excited S 1 state of this molecule. The specific output laser energy of DCM and Ox9 laser dyes were found to appreciably rise in the matrix as compared with their methanol solution, whereas for Ox17, this value remained approximately the same. The studied matrices had lasing in a nonselective cavity with red shift with respect to the fluorescence maximum by value of 900-1700 cm −1 . This may extend the penetration depth of laser biosensor radiation into organic tissues.