摘要 |
An angle-sensitive interferometer includes a first beam splitter for splitting a beam of coherent radiation into two portions and a second beam splitter for recombining the two beam portions to produce an interference pattern. It also includes reflecting mirrors and lenses for recombining the two beam segments in such a manner that an angle of deviation in the incident beam results in the recombined beams diverging from the interferometer axis to create a wedge angle. A corner cube reflector, cat's eye reflector, or a telescope with either convex lenses or concave mirrors are used for this purpose. The invention also includes a mirror in one of the beam portion paths to reflect it out of alignment with that beam portion path emerging from the first beam splitter so that the second beam splitter where the beam portions are recombined does not produce feed back into the radiation source. A quadrant diode is used to detect asymmetrical changes of intensity in the fringe pattern indicative of angle change of the incident beam. Apparatus for detecting, measuring, and controlling beam angles are also included.
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