Patent US3572878A successfully refreshed from Google Patents.
US3572878A
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Complex spatial filter synthesis
Assignee: Texas Instruments Inc
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Filing: 1967-09-11
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Granted: 1971-03-30
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Expires: 1987-09-11
Abstract
Abstract An optical filter in the form of a synthetic hologram of an aggregation of point sources recorded on a photographic plate using a standard two-beam holographic system. The required filter function of the optical filter is established and generalized into a periodic function which is then synthesized by a finite number of harmonics in a spatial frequency domain. Where the filter function has a degree of symmetry, the synthesis process is comparatively simple with only the first several harmonics needed to construct the optical filter. Both the amplitude and phase of the desired function are recorded on the synthetically generated hologram.
Inventors
- 👤 Sun Lu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:01
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/42; G02B27/46; G02B5/00; G02B5/32; Y; Y10; Y10S; Y10S359/00; Y10S359/90
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
106 words
A system for generating a spatial filter by synthesizing a filter function with a plurality of interference patterns on an energy sensitive surface, comprising: means for generating an object beam; means for generating a reference beam to form the interference patterns with said object beam on said energy sensitive surface; electrooptic means for controlling the phase angle of one of said beams, said means comprising a quarter-wave plate in association with a half-wave plate; means for varying the angle of incidence between said beams at said energy sensitive surface; and means for varying the intensity of said object beam for each interference pattern between said beams.
Claim 2
Independent Claim
106 words
A system for generating a spatial filter by synthesizing a filter function with a plurality of interference patterns on an energy sensitive surface, comprising: means for generating an object beam; means for generating a reference beam to form the interference patterns with said object beam on said energy sensitive surface; electrooptic means for controlling the phase angle of one of said beams, said means comprising a quarter-wave plate in association with a half-wave plate; means for varying the angle of incidence between said beams at said energy sensitive surface; and means for varying the intensity of said object beam for each interference pattern between said beams.
Claim 3
Dependent Claim
141 words
Apparatus for generating a spatial filter by synthesizing a representative filter function with a plurality of interference patterns on a photosensitive surface, comprising: means for generating a beam of monochromatic polarized light; a beam splitter for dividing said beam into an object wave and a reference wave; means for directing said object wave to impinge on said photosensitive surface; means for directing said reference wave to impinge on said photosensitive surface to form the interference patterns with said object wave on said surface; means for varying the phase angle of one of said waves, said means comprising a quarter-wave plate and a half-wave plate positioned in said reference wave; means for varying the angle of incidence between said waves at said photosensitive surface; and means for varying the exposure time of said photosensitive surface for each interference pattern between said waves.
Claim 4
Dependent Claim
141 words
Apparatus for generating a spatial filter by synthesizing a representative filter function with a plurality of interference patterns on a photosensitive surface, comprising: means for generating a beam of monochromatic polarized light; a beam splitter for dividing said beam into an object wave and a reference wave; means for directing said object wave to impinge on said photosensitive surface; means for directing said reference wave to impinge on said photosensitive surface to form the interference patterns with said object wave on said surface; means for varying the phase angle of one of said waves, said means comprising a quarter-wave plate and a half-wave plate positioned in said reference wave; means for varying the angle of incidence between said waves at said photosensitive surface; and means for varying the exposure time of said photosensitive surface for each interference pattern between said waves.
Claim 5
Dependent Claim
44 words
Apparatus for generating a spatial filter as set forth in claim 2 wherein said means for directing said object wave is a reflective surface and said means for varying the angle of incidence is coupled to said reflective surface for controlling the position thereof.
Claim 6
Independent Claim
87 words
A method of generating a preselected complex spatial filter by synthesizing a predetermined filter function with a plurality of interference patterns on an energy sensitive surface comprising: generating sequentially a plurality of interference patterns between two plane waves from separate energy beams, discrete ones of said plurality of interference patterns corresponding to respective harmonics of said predetermined filter function; and exposing said energy sensitive surface to record each of said plurality of interference patterns to produce a multiple exposure hologram which synthesizes a preselected complex filter function.
Claim 7
Independent Claim
87 words
A method of generating a preselected complex spatial filter by synthesizing a predetermined filter function with a plurality of interference patterns on an energy sensitive surface comprising: generating sequentially a plurality of interference patterns between two plane waves from separate energy beams, discrete ones of said plurality of interference patterns corresponding to respective harmonics of said predetermined filter function; and exposing said energy sensitive surface to record each of said plurality of interference patterns to produce a multiple exposure hologram which synthesizes a preselected complex filter function.
Claim 8
Independent Claim
148 words
A method of generating a preselected complex spatial filter by synthesizing a predetermined filter function with a plurality of interference patterns recorded on a light sensitive surface comprising: generating an object beam to impinge on said light sensitive surface; generating a reference beam to impinge on said light sensitive surface to form the interference patterns thereon with said object beam; forming a plurality of discrete interference patterns, respectively corresponding to harmonics of said predetermined filter function, by varying the angle of incidence said object makes with said light sensitive surface and by varying the phase angle of said reference beam prior to impinging on said light sensitive surface; and exposing said light sensitive surface once for each interference pattern between said beams to record the interference pattern corresponding to one of said harmonics thereby to form a multiple exposure hologram that synthesizes a preselected complex spatial filter function.
Claim 9
Independent Claim
148 words
A method of generating a preselected complex spatial filter by synthesizing a predetermined filter function with a plurality of interference patterns recorded on a light sensitive surface comprising: generating an object beam to impinge on said light sensitive surface; generating a reference beam to impinge on said light sensitive surface to form the interference patterns thereon with said object beam; forming a plurality of discrete interference patterns, respectively corresponding to harmonics of said predetermined filter function, by varying the angle of incidence said object makes with said light sensitive surface and by varying the phase angle of said reference beam prior to impinging on said light sensitive surface; and exposing said light sensitive surface once for each interference pattern between said beams to record the interference pattern corresponding to one of said harmonics thereby to form a multiple exposure hologram that synthesizes a preselected complex spatial filter function.
Claim 10
Dependent Claim
28 words
A method of generating a spatial filter as set forth in claim 5 including varying the exposure time for each interference pattern recorded on said light sensitive surface.
References Cited (Backward Citations)
US3435244A
Cited
US3427629A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-03-29 | 1974-09-28 | 1975-03-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-29 | 1978-09-28 | 1979-03-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-29 | 1982-09-28 | 1983-03-30 | $7700.00 | Window Closed / Lapsed |