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Common path point diffraction interferometer using liquid crystal phase shiftingA common path point diffraction interferometer uses dyed, parallel nematic liquid crystals which surround an optically transparent microsphere. Coherent, collimated and polarized light is focused on the microsphere at a diameter larger than that of the microsphere. A portion of the focused light passes through the microsphere to form a spherical wavefront reference beam and the rest of the light is attenuated by the dyed liquid crystals to form an object beam. The two beams form an interferogram which is imaged by a lens onto an electronic array sensor and into a computer which determines the wavefront of the object beam. The computer phase shifts the interferogram by stepping up an AC voltage applied across the liquid crystals without affecting the reference beam.
Document ID
20080004613
Acquisition Source
Headquarters
Document Type
Other - Patent
Authors
Mercer, Carolyn R.
Date Acquired
August 24, 2013
Publication Date
November 18, 1997
Subject Category
Instrumentation And Photography
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
Patent
US-PATENT-5,689,314
Patent Application
US-PATENT-APPL-SN-490250

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