Coupled resonators; critical dependence of the mutual interaction on their separation.

The interaction of a scanning Fabry-Perot on the laser source is investigated. The system of the modematched laser resonator and the scanning interferometer is treated analytically as amulti-mirror resonator. The changes of the laser intensity and the oscillating frequency are numerically calculated for a special case of weak coupling. The calculations and the experiments show that the laser intensity is critically dependent on the separation of the two coupled resonators.