Measurement of the gain and refraction effects in a solid state laser

The gain and propagation constants, characterizing a lenslike medium, are calculated on the basis of some experimental results on the parameters which determine the Gaussian beam in its fundamental mode. The experiments were carried out with a ruby and a glass neodymium laser. The amplification and refraction effects are more important in the ruby as they are in the neodymium case. If the length of the optical cavity s large with respect to the length of the rod amplifier, an apparent change is observed in the characteristic parameters of the lenslike medium.