Shearing interferometers for testing corner cubes and right angle prisms.
A wavefront reversing interferometer and an inverting interferometer are described for use in testing corner cubes and right angle prisms. Both the interferometers are stable, easy to adjust, and require comparatively simple setup. They have adequate sensitivity for measuring the divergence of the reflected wavefronts, but do not give directly the symmetrical errors of the prisms. With the inverting interferometer, the latter can be determined by changing the shear. Methods are suggested for testing the prisms during manufacture and correcting their defects by use of these interferometers.
Sen
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National Physical Laboratory, NewDelhi, India.
Puntambekar
P N
PN