Experimental determination of the incremental gain for a transit in a neodymium laser

A method is described by which the power gain and axis intensity for a direct transit can be calculated on the basis of parameter measurements from the laser beam. The results obtained are used in the case of a neodymium laser. The measurements show that the power gain for a transit depends both on the diameter of the mode selector and the cavity length whereas the intensity gain depends only on the latter. The measured gains are smaller than the calculated ones on the basis of the plane wave approximation.