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US 2006/0215160 A1Published application
Optical alignment apparatus and method of correcting alignment errors in a segmented reflective surface
AssigneeOptical Physics Company
InventorRichard Hutchin
Life of this patent
Estimating the term…
Abstract
An optical alignment apparatus comprising a plurality of subapertures and a plurality of detectors. The subapertures are optically coupled to a reflective surface which formed by a plurality of adjustable reflective segments. Each subaperture falls within one of two subsets. The first subset includes those subapertures that are positioned to receive light reflected from a single reflective segment. The second subset includes those subapertures that are positioned to receive light reflected across the abutting edges of adjacent reflective segments. Each detector is disposed at a focal plane of one of the subapertures and receives light reflected from that subaperture.
Claims30
An optical alignment apparatus comprising:
- a plurality of subapertures optically coupled to a reflective surface, the reflective surface comprising a plurality of adjustable reflective segments, wherein a first subset of subapertures within the plurality of subapertures is positioned to receive light reflected from a single reflective segment and a second subset of subapertures within the plurality of subapertures is positioned to receive light reflected across abutting edges of adjacent reflective segments;
- a plurality of detectors, each detector being disposed at a focal plane of one of the plurality of subapertures;
- and
- a processor communicably coupled to the detectors and to a plurality of steering motors, wherein each reflective segment is coupled to one of the steering motors.
1 more element
An optical alignment apparatus comprising:
- a plurality of hexagonal subapertures optically coupled to a reflective surface, the reflective surface comprising a plurality of adjustable hexagonal reflective segments and each subaperture comprising at least one lens, wherein a first subset of subapertures within the plurality of subapertures is positioned to receive light reflected from a single reflective segment and a second subset of subapertures within the plurality of subapertures is positioned to receive light reflected across abutting edges of adjacent reflective segments;
- a plurality of detectors, each detector being disposed at a focal plane of one of the plurality of subapertures;
- and
- a processor communicably coupled to the detectors and to a plurality of steering motors, wherein each reflective segment is coupled to one of the steering motors.
1 more element
An optical alignment apparatus comprising:
- a plurality of subapertures optically coupled to a reflective surface, the reflective surface comprising a plurality of adjustable reflective segments, wherein a first subset of subapertures within the plurality of subapertures is positioned to receive light reflected from a single reflective segment and a second subset of subapertures within the plurality of subapertures is positioned to receive light reflected across abutting edges of adjacent reflective segments;
- a plurality of detectors, each detector being disposed at a focal plane of one of the plurality of subapertures;
- and
- a processor communicably coupled to the detectors and to a plurality of steering motors, wherein each reflective segment is coupled to one of the steering motors, wherein the processor is adapted to:
- compare a first intensity from a first subaperture within the first set of subapertures with a reference intensity from a second subaperture within the first set of subapertures and determine an error in a tilt alignment of the reflective segment associated with the first subaperture;
- and
- determine an error in piston alignment between an adjacent pair of reflective segments using intensity measurements of light received by a second subaperture within the second set of subapertures, the second subaperture receiving light from both of the adjacent pair of reflective segments.
4 more elements
A method of correcting alignment errors in a segmented reflective surface, the method comprising:
- receiving through a subaperture an image reflected across abutting edges of adjacent reflective segments of the reflective surface, the adjacent reflective segments having an unknown piston difference;
- deriving a phase plateau value using spatial frequencies of the image;
- resolving the unknown piston difference using the phase plateau value;
- and
- adjusting a piston position of at least one of the adjacent reflective segments.
2 more elements
A method of correcting alignment errors in a segmented reflective surface, the method comprising:
- receiving through a subaperture an image reflected across abutting edges of adjacent reflective segments of the reflective surface, the adjacent reflective segments having an unknown piston difference;
- determining optical path differences for select spatial frequencies of the image, wherein the select spatial frequencies are characterized by separations in a predetermined direction, the. separations being greater than d/2, where d represents a maximum width of the subaperture in the predetermined direction;
- deriving a phase plateau value using the optical path differences;
- resolving the unknown piston difference using the phase plateau value;
- and
- adjusting a piston position of at least one of the adjacent reflective segments.
3 more elements
A method of correcting alignment errors in a segmented reflective surface, the method comprising:
- receiving an image through a first subaperture following reflection of the image across abutting edges of adjacent reflective segments of the reflective surface, wherein the adjacent reflective segments have an unknown piston difference;
- measuring first subaperture intensities at select spatial frequencies of the image;
- calculating a first subaperture image Fourier Transform (FT) for each of the measured first subaperture intensities;
- determining a first subaperture Optical Transfer Function (OTF) at the select spatial frequencies;
- deriving a phase plateau value using each first subaperture image FT and each first subaperture OTF;
- resolving the unknown piston difference using the phase plateau value;
- and
- adjusting a piston position of at least one of the adjacent reflective segments.
5 more elements
Dependencies are inferred from the claim text.