DYE LASER INTRACAVITY ABSORPTION AS AN OPTICAL PROBE IN CONDENSED PHASE AND BIOLOGICAL SYSTEMS

Abstract— A sensitive optical method to monitor local environmental changes in biological systems is described. It utilizes the high optical amplification typical to any dye laser cavity by installing the investigated system inside the laser resonator. Very small changes in the optical density of a probe dye can be detected and related to the dye's state of aggregation or in another demonstration to its adsorption on differently charged micelles and liposomes. When further developed, this technique can prove to be a very sensitive method to measure membrane potentials, changes in molecular environment and molecular dynamics. The pulsed laser used is advantageous to a continuous source used in fluorescence and absorption methods reducing photodynamic damage.