Angular displacement measuring interferometer

Optics: measuring and testing – By polarized light examination – With birefringent element

Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

G01B 902

Patent

active

050281372

ABSTRACT:
An angular displacement interferometer system capable of measuring accurately changes in angular displacement comprises a source (10) of a frequency stabilized input beam with two linear orthogonally polarized components; a tilted parallel plate or shear place (16) with regions of reflection, antireflection, and polarizing coatings for converting the input beam (12) into two separated, parallel, orthogonally polarized beams (30, 31); a half-wave retardation plate (29) located in one of the separated beams (31) for converting the two separated, parallel, orthogonally polarized beams (30, 31); into first and second beams which are spatially separated parallel, and have the same polarization (30, 33); a polarizing beamsplitter (40) and quarter-wave retardation plate (44) for transmitting the first and second beams (34, 35) to a fixed plano mirror (70) nominally perpendicular to the first and second beams for reflecting the first and second beams back into the quarter-wave retardation plate (44), polarizing beamsplitter (40), and retroreflector (48) for producing third and fourth beams (56, 67); a rotatable angle prism (72, 93) attached to the mechanical apparatus whose angular displacement is to be measured, located such that the third and fourth beams enter adjacent polygon faces of prism (72) or legs of prism (93) and are refracted to produce fifth and sixth beams which are reflected from the fixed plano mirror (70) back through the angle prism (72, 93) back through the quarter-wave retardation plate (44), beamsplitter (40), retardation plate (29) and shear plate (16) where the fifth and sixth beams are recombined into a single output beam (80) having two orthogonally polarized components in which the phase difference between the two components of the output beam (80) is related to the angular displacement; a polarizer (81) for mixing the orthogonal components of the output beam (80); a photoelectric detector (83) for producing an electrical measurement signal (85); and a phase meter/accumulator (90) for indicating the measured phase (92), the measured phase being related to the angular displacement.

REFERENCES:
patent: 4807997 (1989-02-01), Sommargren

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Angular displacement measuring interferometer does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Angular displacement measuring interferometer, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Angular displacement measuring interferometer will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-1242745

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.