The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 20, 1994
Filed:
Mar. 29, 1991
Leland G Atkinson, Rochester, NY (US);
Kevin J Vent, Clifton Springs, NY (US);
Jeffrey P Wong, Rochester, NY (US);
Gradient Lens Corporation, Rochester, NY (US);
Abstract
An interferometer is provided which includes a source for generating a source beam of linearly polarized coherent light along a light path; a non-polarizing beam splitting, combining and resplitter disposed in the path of the source beam for splitting the source beam into a reference beam and a measuring beam and for recombining the reference and measuring beams into an interfering beam and resplitting the interfering beam into a first output beam and a second output beam; a reference reflector positioned in the reference beam for causing the reference beam to traverse a reference path and return to the non-polarizing beam splitting means; a measuring reflector spaced a distance to be measured from the non-polarizing beam splitter for causing the measuring beam to traverse a measured path and return to the non-polarizing beam splitter; a half wave plate in one of the reference and measuring beams for rotating the polarization of the measuring beam relative to the reference beam prior to recombining the measurement and reference beams in the non-polarizing beam splitter; a first polarizing beam splitter positioned in the first output beam for selecting like polarized components of the first output beam; a quarter wave plate in the second output beam for lengthening the optical path traversed by one polarization of the second output beam relative to the other polarization; a second polarizing beam splitter in the second output beam following the delay means for selecting like polarized components of the second output beam; and first and second detectors coupled to the first and second polarizing beam splitters respectively which detectors are responsive to the selected like polarized components of the first and second output beams respectively for providing first and second output signals proportional to the amplitudes of the combined like polarized components of the first and second output beams for determining changes in the length of the measurement path.