COHERENCE GROWTH OF LASER-RADIATION IN GAUSSIAN CAVITIES

The beam quality and coherence growth of the laser radiation in stable and unstable cavities equipped with a Gaussian reflectivity mirror as output coupler has been investigated, An experimental analysis of the time evolution of the near- and far-field beam quality factor and spo t size in dependence on the cavity configuration has been carried out. A theoretical analysis of the time evolution of a Schell-Gauss model beam propagating through Gaussian cavities is seen to provide a satisf actory description of the process in agreement with the experimental m easurements for all the tested resonators.