Rotatable shear plate interferometer
AssigneeThe United States of America as represented by the United States Department of Energy
InventorRichard C. Duffus
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Abstract
A rotatable shear plate interferometer comprises a transparent shear plate mounted obliquely in a tubular supporting member at 45.degree. with respect to its horizontal center axis. This tubular supporting member is supported rotatably around its center axis and a collimated laser beam is made incident on the shear plate along this center axis such that defocus in different directions can be easily measured.
Claims7
A rotatable shear plate interferometer comprising a tubular member which defines a central axis and is rotatably supported by a bracket means around said central axis, a transparent shear plate obliquely mounted in said tubular member at a fixed angle with respect to said axis, and a viewing screen rotatably attached to said tubular member so as to be able to assume a viewing position such that an interference pattern of a light beam made incident on said shear plate along said central axis can be observed on said viewing screen placed in said viewing position at any angular position of said tubular member around said central axis, whereby defocus, astigmatism and coma in said incident light beam can be measured in any direction.
Dependencies are inferred from the claim text.