Laser-Interferometer with Phase Compensation,

In the light path of a double-beam interferometer operated with continuous laser light a compensator is located. This is an electrically controllable, artificial phase object, which instantly compensates for any variations in path length caused by the object under observation. To achieve this, the change in voltage on the compensator is proportional to the change of the optical path length due to the event. The result of this is an analog signal of the event, which also follows optical path changes over several wavelengths, thus opening up new possibilities in laser-interferometry applications. The first measurements with this method are being described, and the capabilities of a new kind of Doppler-interferometer are being discussed.