Optics: measuring and testing – By particle light scattering – With photocell detection
Patent
1987-11-12
1989-02-28
Willis, Davis L.
Optics: measuring and testing
By particle light scattering
With photocell detection
356363, G01B 902
Patent
active
048079979
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 rhomboid-shaped glass element (72 ) attached to the mechanical apparatus whose angular displacement is to be measured, located such that the third and fourth beams enter adjacent faces and are refracted to produce fifth and sixth beams which are reflected from the fixed plano mirror (70) back through the rhomboid-shaped glass element (72) 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: 4329055 (1982-05-01), Schaefer et al.
patent: 4688940 (1987-08-01), Sommargren et al.
patent: 4693605 (1987-09-01), Sommargren
patent: 4717250 (1988-01-01), Sommargren
Koren Matthew W.
Willis Davis L.
Zygo Corporation
LandOfFree
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.
Profile ID: LFUS-PAI-O-1362038