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Proceedings Paper

Shearing Interferometer Block As A Precision Angular Datum Reference
Author(s): C-C. Huang; J. R. Hodor; R. H. Anderson
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Paper Abstract

A shearing interferometer block consisting of a beamsplitter cube, a right angle prism and a corner cube is used in conjunction with a dual detector to measure when an input beam is normal to the cube to better than 0.001 arc seconds. The two arms of the interferometer have optical path differences of X/4. The wavefronts of the exit beams, one from the corner cube and the other from the right angle prism are tilted in opposite directions from a moving input beam. Zero-crossings of the detector pair output occur when they each receive the same optical power. The output maximum and minimum occur just before and after the zero-crossing associated with normal in-cidence of the input beam. Analysis shows the zero-crossing to be detectable to an accuracy of better than 0.0001 arc seconds for 2.5 cm optics, 1 mW optical power and 1 MHz electronic bandwith with a dual p-i-n photodetector. Laboratory tests confirm this result. The interferometer block has many precision measurement applications. Those discussed herein include: a precision angular reference point; a building block to define a precision reference beam; a sensing element for high precision active control to maintain alignment between two surfaces; a star tracker sensing element. All of the above instruments should have a precision better than 0.001 arc seconds.

Paper Details

Date Published: 31 December 1980
PDF: 6 pages
Proc. SPIE 0251, Optical Alignment I, (31 December 1980); doi: 10.1117/12.959451
Show Author Affiliations
C-C. Huang, Lockheed Missiles and Space Company, Incorporated (United States)
J. R. Hodor, Lockheed Missiles and Space Company, Incorporated (United States)
R. H. Anderson, Lockheed Missiles and Space Company, Incorporated (United States)

Published in SPIE Proceedings Vol. 0251:
Optical Alignment I
Richard N. Shagam; William C. Sweatt, Editor(s)

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