Investigation of optical inhomogeneities which appear in an active medium of a photodissociation laser during coherent emission

An experimental investigation was made of the optical inhomogeneities which appeared in the active medium of a photodissociation laser during coherent emission. The transverse gradient of the refractive index could reach 10^–4 cm^–1. The experimental results indicated that the inhomogeneities were mainly due to gas-dynamic displacements of the working medium and not due to changes in the polarizability of the molecules as a result of photodissociation. Inhomogeneity waves appeared at the walls of a laser cell because of the adsorption of the active gas on the walls. The change in the polarizability of the C₃F₇I molecules in the photodissociation process was estimated. A photodissociation laser with a divergence of the output radiation close to the diffraction limit was built.