Stabilization of cavity and etalon of CW-dye-laser with respect to an atomic beam

In the measurement of differential cross sections with a laser excited atomic beam of Na one can use the transition between the F=2 level of the groundstate and the F=3 level of the 2Psub(3/2)-state. This requires a laser with single-mode operation and a bandwidth less than 30 MHz. These conditions are met by available dye-lasers. But in the special application considered here the stability of the center of the line for several hours is required. This problem has not been solved in commercial lasers. For a solution both the etalon and the cavity must be monitored in a closed-loop stabilization. In this work the authors have developed such a stabilization with a minicomputer. In this realization the problem has been split into two parts, the stabilization of the cavity and of the etalon, which by interrupt techniques work simultaneously. (Auth.)