USH615H
Expired / Lapsed
US
⏱️ 0.0 years remaining
High speed/low light wavefront sensor system
Assignee: United States Department of the Air Force
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Filing: 1988-01-22
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Granted: 1989-04-04
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Expires: 2008-01-22
Abstract
Abstract A scalable, low light, high speed wavefront sensor system is disclosed for real time sensing of optical wavefronts using: a gateable image intensifier tube (GIIT), a monolithic lenslet array (MLM), a custom high speed switched silicon detector array, high speed analog/digital processing components, which are microprogrammed with signal processing algorithms. The incoming wavefront is reimaged by foreoptics, then divided into multiple subapertures by the use of the MLM. The MLM forms N×M target images which are intensified and transferred to a detector array in which the centroid of each target image on the pixels of the detector array define the local tilt aberration of the wavefront in each subaperture. This local tilt in each subaperture is calculated with microcoded implemented algorithms using real time processing electronics. By combining the local tilt in each subaperture with wavefront reconstruction techniques, the conjugate phase map of the original wavefront can be produced for adaptive optic applications. In order to sense a desired wavefront, the "time of arrival" and flux of the incoming beam can be controlled by the processor via the time and duration of the signal to the GIIT.
Inventors
- 👤 Julius M. Feinleib
- 👤 Lawrence E. Schmutz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:12
CPC Classifications
G; G01; G01J; G01J9/00; G01J9/02; G01J2009/0249
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
236 words
A wavefront sensing apparatus capable of sensing wavefront distortion and an angle of arrival of an incoming wavefront, said wavefront sensing apparatus comprising: a source which produces a reference beam; a means for combining said reference beam from said source with said incoming wavefront to produce a combined wavefront; a means for dividing said combined wavefront from said combining means into multiple subaperture wavefront images; an image intensifier which receives and intensifies said multiple subaperture wavefront images above a detection threshold level, to produce thereby intensified multiple subaperture wavefront images with a plurality of incoming wavefront spots and reference beam spots indicative of tilt angles of said incoming wavefront and said reference beam in each subaperture; a detector array which produces measurement signals which indicate an incoming beam centroid and a reference beam centroid for each subaperture by an optical detection of said intensified multiple subaperture wavefront images received from said image intensifier, said detector array being characterized by having a detection threshold which must be exceeded for optical signals to be detected by the detector array; and a means for calculating said angle of arrival and said wavefront distortion of said incoming wavefront from said incoming beam centroid and said reference beam centroid of said multiple subaperture wavefront images, said calculating means receiving and converting into digital said measurement signals from said detector array and calculating therefrom said wavefront distortion and said angle of arrival.
Claim 2
Dependent Claim
236 words
A wavefront sensing apparatus capable of sensing wavefront distortion and an angle of arrival of an incoming wavefront, said wavefront sensing apparatus comprising: a source which produces a reference beam; a means for combining said reference beam from said source with said incoming wavefront to produce a combined wavefront; a means for dividing said combined wavefront from said combining means into multiple subaperture wavefront images; an image intensifier which receives and intensifies said multiple subaperture wavefront images above a detection threshold level, to produce thereby intensified multiple subaperture wavefront images with a plurality of incoming wavefront spots and reference beam spots indicative of tilt angles of said incoming wavefront and said reference beam in each subaperture; a detector array which produces measurement signals which indicate an incoming beam centroid and a reference beam centroid for each subaperture by an optical detection of said intensified multiple subaperture wavefront images received from said image intensifier, said detector array being characterized by having a detection threshold which must be exceeded for optical signals to be detected by the detector array; and a means for calculating said angle of arrival and said wavefront distortion of said incoming wavefront from said incoming beam centroid and said reference beam centroid of said multiple subaperture wavefront images, said calculating means receiving and converting into digital said measurement signals from said detector array and calculating therefrom said wavefront distortion and said angle of arrival.
Claim 3
Dependent Claim
67 words
A wavefront sensing apparatus, as defined in claim 1, wherein said dividing means comprises a monolithic lenslet array containing N×M lenslets which receive and divide said combined wavefront from said combining means into N×M subaperture wavefront images, which are separately forwarded to said image intensifier, and wherein N and M are integers whose product is indicative of a total number of lenslets in said monolithic lenslet array.
Claim 4
Dependent Claim
56 words
A wavefront sensing apparatus, as combined in claim 2, wherein said image intensifier includes multiple gated image intensifier tubes which are optically connected together and which sequentially amplify said multiple subaperture wavefront images, said multiple gated image intensifier tubes thereby collectively providing sufficient photon gain to enable said wavefront sensing apparatus to detect low light emissions.
Claim 5
Dependent Claim
145 words
A wavefront sensing apparatus, as defined in claim 3, wherein said image intensifier comprises: a photocathode which receives said multiple subaperture wavefront images from said dividing means, and which outputs an electron stream; a focus gate electrode which conducts said electron stream from said photocathode; a first stage image intensifier which produces a first intensified image by amplifying said electron stream from said focus gate electrode; a second stage image intensifier, which produces a second intensified image by amplifying said first intensified image received from said first stage image intensifier; an output stage image intensifier which produces said intensified multiple subaperture wavefront images by amplifying said second intensified image received from said second stage image intensifier; a means for optically connecting said first, second and output stage image intensifiers; and a means for supplying electrical power to said first, second and output state image intensifiers.
Claim 6
Dependent Claim
64 words
A wavefront sensing apparatus, as defined in claim 4, wherein said optically connecting means comprises: a first fiber optic plug which is butted between said first and second stage image intensifier to optically conduct said first intensified image therebetween; and a second fiber optic plug which is butted between said second and said output stage image intensifier to conduct said second intensified image therebetween.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-04-03 | 1992-10-03 | 1993-04-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-03 | 1996-10-03 | 1997-04-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-04-03 | 2000-10-03 | 2001-04-04 | $7700.00 | Window Closed / Lapsed |