Angle Measuring Interferometer

Abstract

A cube-corner angle-measuring interferometer has been developed which reproduces angles up to 30° with a precision of 0.01″. The angular dependence of the interference order rigorously follows a sine law and any angle in the range of the interferometer may be measured with an accuracy which is limited only by the error in the full scale calibration angle. Theory, construction details, and alignment and calibration procedures are given. The instrument is insensitive to both translation and tilting of the axis of rotation. As constructed the instrument had a range of ±15°, and suggested improvements should increase this to ±20° or more. The 0.01″ precision is not a limitation inherent in design, but was due both to imperfections in available optical parts and to building vibration.