Fringe Pattern of an Oscillating Fabry-Perot Interferometer

The dependence of the frin ge pattern of an oscill ating Fabry-Pcrot intcrferomctcr upon the vibration a mplitude is discussed cxperimentall y a nd thcoret icall y. If t hc frin gcs of t he stationary interferomet er are wide, the frin gc pattcrn tends to di sappea r at certain valucs of the amplitude. If the stationary frin ges a re narrow, a splitting of frin ges occurs at ccrtain a mpli tudes. In both cases, the stationary pattcrn rcappears, with rcd uced co nt ras t, at intermediate amplitudes. The practicability of using thesc effects for t hc measu rement of vibration amplitudes is discussed .