US4429954A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Spatial light modulator and process of modulation
Assignee: Baybank Middlesex
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Filing: 1980-11-05
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Granted: 1984-02-07
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Expires: 2000-11-05
Abstract
Abstract Coherent light such as a laser beam is spatially modulated by causing it to interact at a photosensitive material such as a crystal with a focussed image of non-coherent light. An electric potential is applied to the crystal either transversely to the direction of the light or in line with the direction of the light according to either the Kerr effect or the Pockels effect. Typical crystals include Bismuth-silicon-oxide and strontium-barium-niobate.
Inventors
- 👤 H. John Caulfield
- 👤 W. Thomas Cathey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:19
CPC Classifications
G; G03; G03H; G03H1/00; G03H1/04; G03H1/06; G02; G02F; G02F1/00; G02F1/01; G02F1/03; G02F1/0338; G02F1/05; G02F1/0541; Y; Y10; Y10S; Y10S359/00; Y10S359/90
Claims Analysis
Total Claims: 41
Claim 1
Independent Claim
71 words
A method of spatial light modulation to impart information to a beam of coherent radiation from an input of non-coherent radiation, comprising imaging information-containing non-coherent radiation on a photosensitive crystal while applying an electric potential to said crystal to generate a pattern of electric charge within said crystal, and directing to said crystal at least one beam of coherent radiation, thus bringing about patternwise modification of refraction of said coherent beam.
Claim 2
Independent Claim
71 words
A method of spatial light modulation to impart information to a beam of coherent radiation from an input of non-coherent radiation, comprising imaging information-containing non-coherent radiation on a photosensitive crystal while applying an electric potential to said crystal to generate a pattern of electric charge within said crystal, and directing to said crystal at least one beam of coherent radiation, thus bringing about patternwise modification of refraction of said coherent beam.
Claim 3
Dependent Claim
10 words
The method of claim 1, wherein said crystal is bismuth-silicon-oxide.
Claim 4
Dependent Claim
10 words
The method of claim 1, wherein said crystal is barium-strontium-niobate.
Claim 5
Dependent Claim
22 words
The method of claim 1, wherein the potential applied to the crystal is transverse to the direction of radiation at said crystal.
Claim 6
Dependent Claim
23 words
The method of claim 1, wherein the potential applied to the crystal is in line with the direction of radiation at said crystal.
Claim 7
Independent Claim
80 words
A method of spatial light modulation to impart information to a beam of coherent radiation from an input of non-coherent radiation, comprising forming a hologram of coherent radiation beams in a photosensitive crystal, imaging a beam of information-containing non-coherent radiation in said crystal in at least a portion of said hologram while applying an electric potential to said crystal, thereby modulating said hologram, and generating a coherent beam from said hologram modulated by the information of said information-containing non-coherent radiation.
Claim 8
Independent Claim
80 words
A method of spatial light modulation to impart information to a beam of coherent radiation from an input of non-coherent radiation, comprising forming a hologram of coherent radiation beams in a photosensitive crystal, imaging a beam of information-containing non-coherent radiation in said crystal in at least a portion of said hologram while applying an electric potential to said crystal, thereby modulating said hologram, and generating a coherent beam from said hologram modulated by the information of said information-containing non-coherent radiation.
Claim 9
Dependent Claim
10 words
The method of claim 6, wherein said crystal is bismuth-silicon-oxide.
Claim 10
Dependent Claim
22 words
The method of claim 6, wherein the potential applied to the crystal is transverse to the direction of radiation at said crystal.
Claim 11
Dependent Claim
23 words
The method of claim 6, wherein the potential applied to the crystal is in line with the direction of radiation at said crystal.
Claim 12
Dependent Claim
10 words
The method of claim 6, wherein said crystal is barium-strontium-niobate.
Claim 13
Dependent Claim
126 words
Apparatus for spatial modulation of coherent radiation comprising a source of information intended for input into coherent radiation, a photosensitive member adapted to exhibit modified refraction of radiation at areas of electric charge therein, means to focus an optical image of said source of information into said photosensitive member, said means including a source of non-coherent radiation directed to said source of information to receive such information and means to focus said non-coherent radiation at said photosensitive member, means to apply an electric potential across said photosensitive member, and means to direct to said photosensitive member a beam of coherent radiation to which spatial modulation is to be imparted, said coherent beam being directed at least in part at the position of said focussed non-coherent radiation.
Claim 14
Dependent Claim
126 words
Apparatus for spatial modulation of coherent radiation comprising a source of information intended for input into coherent radiation, a photosensitive member adapted to exhibit modified refraction of radiation at areas of electric charge therein, means to focus an optical image of said source of information into said photosensitive member, said means including a source of non-coherent radiation directed to said source of information to receive such information and means to focus said non-coherent radiation at said photosensitive member, means to apply an electric potential across said photosensitive member, and means to direct to said photosensitive member a beam of coherent radiation to which spatial modulation is to be imparted, said coherent beam being directed at least in part at the position of said focussed non-coherent radiation.
Claim 15
Dependent Claim
12 words
The apparatus of claim 11, wherein said photosensitive member is a crystal.
Claim 16
Dependent Claim
10 words
The apparatus of claim 12, wherein said crystal is bismuth-silicon-oxide.
Claim 17
Dependent Claim
10 words
The apparatus of claim 12, wherein said crystal is strontium-barium-niobate.
Claim 18
Dependent Claim
25 words
The apparatus of claim 11, wherein said electric potential is applied in a direction transverse to the direction of said radiation at the photosensitive member.
Claim 19
Dependent Claim
26 words
The apparatus of claim 11, wherein said electric potential is applied in a direction in line with the direction of said radiation at the photosensitive member.
Claim 20
Dependent Claim
11 words
The apparatus of claim 11, wherein sight radiation is visible light.
Claim 21
Dependent Claim
11 words
The apparatus of claim 11, wherein said radiation is non-visible light.
Claim 22
Dependent Claim
160 words
Apparatus for spatial modulation of coherent radiation comprising a source of information for input into coherent radiation, an optical grating, a source of non-coherent radiation directed to said source of information to receive such information as modulation of said radiation, means to focus said non-coherent radiation containing said information at said grating to form therein an image of said source of information, a photosensitive member adapted to exhibit modified refraction of radiation at areas of electric charge therein, means to focus at said photosensitive member an image of said grating including the imaged information to form in said photosensitive member a focal-plane hologram equivalent of said source of information, means to apply an electric foeld to said photosensitive member, and a source of coherent radiation and means to direct said coherent radiation to said photosensitive member in hologram configuration with respect to said focal-plane hologram equivalent, whereby information corresponding to said source of information is imparted to said coherent radiation.
Claim 23
Dependent Claim
160 words
Apparatus for spatial modulation of coherent radiation comprising a source of information for input into coherent radiation, an optical grating, a source of non-coherent radiation directed to said source of information to receive such information as modulation of said radiation, means to focus said non-coherent radiation containing said information at said grating to form therein an image of said source of information, a photosensitive member adapted to exhibit modified refraction of radiation at areas of electric charge therein, means to focus at said photosensitive member an image of said grating including the imaged information to form in said photosensitive member a focal-plane hologram equivalent of said source of information, means to apply an electric foeld to said photosensitive member, and a source of coherent radiation and means to direct said coherent radiation to said photosensitive member in hologram configuration with respect to said focal-plane hologram equivalent, whereby information corresponding to said source of information is imparted to said coherent radiation.
Claim 24
Dependent Claim
12 words
The apparatus of claim 19, wherein said non-coherent radiation is visible light.
Claim 25
Dependent Claim
12 words
The apparatus of claim 19, wherein said non-coherent radiation is non-visible light.
Claim 26
Dependent Claim
14 words
The apparatus of claim 21, wherein said photosensitive member is a crystal of bismuth-silicon-oxide.
Claim 27
Dependent Claim
14 words
The apparatus of claim 21, wherein said photosensitive member is a crystal of strontium-barium-niobate.
Claim 28
Dependent Claim
100 words
Apparatus for spatial modulation of coherent radiation comprising an object containing optical information for input into coherent radiation, a crystal of a photosensitive material adapted to exhibit modified refraction of radiation at areas of electric charge therein, means to illuminate said object with non-coherent radiation and to image said object at said crystal, a hologram source comprising at least one laser, a beam splitter and reflection means to direct at least one split laser beam to said crystal in hologram configuration at the position of the image of said object, and means to apply an electric field to said crystal.
Claim 29
Dependent Claim
100 words
Apparatus for spatial modulation of coherent radiation comprising an object containing optical information for input into coherent radiation, a crystal of a photosensitive material adapted to exhibit modified refraction of radiation at areas of electric charge therein, means to illuminate said object with non-coherent radiation and to image said object at said crystal, a hologram source comprising at least one laser, a beam splitter and reflection means to direct at least one split laser beam to said crystal in hologram configuration at the position of the image of said object, and means to apply an electric field to said crystal.
Claim 30
Dependent Claim
11 words
The apparatus of claim 24, wherein said crystal is bismuth-silicon oxide.
Claim 31
Dependent Claim
10 words
The apparatus of claim 24, wherein said crystal is strontium-barium-niobate.
Claim 32
Dependent Claim
12 words
The apparatus of claim 24, wherein said laser is a neon-helium laser.
Claim 33
Dependent Claim
20 words
The apparatus of claim 24, wherein said electric field is applied transversely to th direction of radiation at said crystal.
Claim 34
Dependent Claim
24 words
Th apparatus of claim 24, wherein said electric field is applied in a direction in line with the direction of radiation at said crystal.
Claim 35
Dependent Claim
137 words
Apparatus for spatial modulation of coherent radiation by the interaction of non-coherent radiation therewith, comprising a source of information for input into coherent radiation, a source of non-coherent radiation directed to said source of information to produce non-coherent radiation containing information from said source of information, a photosensitive member adapted to exhibit modified refraction of radiation at areas of electric charge therein, means to establish an electric field at said photosensitive member, means to focus said information-containing non-coherent radiation at said photosensitive member, a source of coherent radiation to which spatial modulation is to be imparted, means to direct said coherent radiation to said photosensitive member at the location therein of said focussed information-containing non-coherent radiation and to form a focal-plane hologram at said location, whereby said coherent radiation is spatially modulated by said informatin-containing non-coherent radiation.
Claim 36
Dependent Claim
137 words
Apparatus for spatial modulation of coherent radiation by the interaction of non-coherent radiation therewith, comprising a source of information for input into coherent radiation, a source of non-coherent radiation directed to said source of information to produce non-coherent radiation containing information from said source of information, a photosensitive member adapted to exhibit modified refraction of radiation at areas of electric charge therein, means to establish an electric field at said photosensitive member, means to focus said information-containing non-coherent radiation at said photosensitive member, a source of coherent radiation to which spatial modulation is to be imparted, means to direct said coherent radiation to said photosensitive member at the location therein of said focussed information-containing non-coherent radiation and to form a focal-plane hologram at said location, whereby said coherent radiation is spatially modulated by said informatin-containing non-coherent radiation.
Claim 37
Dependent Claim
11 words
The apparatus of claim 30, wherein said photosensitive member is bismuth-silicon-oxide.
Claim 38
Dependent Claim
11 words
The apparatus of claim 30, wherein said photosensitive member is strontium-barium-niobate.
Claim 39
Dependent Claim
18 words
The apparatus of claim 30, wherein said electric field is transverse to the radiation at said photosensitive member.
Claim 40
Dependent Claim
22 words
The apparatus of claim 30, wherein said electric field is in line with the direction of said radiation at said photosensitive member.
Claim 41
Dependent Claim
12 words
The apparatus of claim 30, wherein said non-coherent radiation is visible light.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-02-06 | 1987-08-08 | 1988-02-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-02-06 | 1991-08-08 | 1992-02-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-02-06 | 1995-08-08 | 1996-02-07 | $7700.00 | Window Closed / Lapsed |