Design of supporting structure of an optical resonator

Calculations are given of the instability of the frequency of a laser resonator due to vibrations of its supporting structure. The influence of longitudinal and transverse vibrations of the base is considered. Equations are obtained for the design of a structure which is equally strong in the longitudinal and transverse directions. It is concluded that the most desirable is a structure ensuring that instabilities of the resonator length due to longitudinal and transverse vibrations are equal. It is shown that the optic axis of the resonator should be made to coincide with the neutral axis of the supporting structure so as to minimize the instability of the resonator length and reduce the transverse dimensions of the structure.