US3731231A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Acousto-optical modulator systems
Assignee: THOMASON CSF
•
Filing: 1971-04-20
•
Granted: 1973-05-01
•
Expires: 1991-04-20
Abstract
Abstract The present invention relates to acousto-optical modulators systems which enable the luminous intensity of a beam of parallel coherent monochromatic light to be spatially modulated. The modulator comprises a block of birefringent material and means for exciting therein a plurality of ultrasonic parallel pencils capable of selectively reflecting the refracted portion of an incident light beam.
Inventors
- 👤 R Torguet
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:48
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/29; G02F1/33; G02F1/332
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
153 words
Acousto-optical modulator system for spatially modulating a parallel beam of coherent energy under the control of electrical modulating signals, said system comprising : a block of birefringent material, having at least one reflective face, a plurality of ultrasonic transducers positioned on said face, electrical means for causing said transducers to selectively radiate within said block and under the control of said signals parallel pencils of ultrasonic energy along a direction perpendicular to said face, refracting means for causing said parallel beam to propagate within said block along a direction opposite to said direction and for receiving upon reflection on said face scattered radiant energy portions resulting from the interaction of said parallel beam with said pencils of ultrasonic energy ; the respective wave numbers ki, kd and K of the waves corresponding to said parallel beam scattered energy portions and ultrasonic energy, satisfying substantially the vector relation ki kd + OR - K.
Claim 2
Dependent Claim
153 words
Acousto-optical modulator system for spatially modulating a parallel beam of coherent energy under the control of electrical modulating signals, said system comprising : a block of birefringent material, having at least one reflective face, a plurality of ultrasonic transducers positioned on said face, electrical means for causing said transducers to selectively radiate within said block and under the control of said signals parallel pencils of ultrasonic energy along a direction perpendicular to said face, refracting means for causing said parallel beam to propagate within said block along a direction opposite to said direction and for receiving upon reflection on said face scattered radiant energy portions resulting from the interaction of said parallel beam with said pencils of ultrasonic energy ; the respective wave numbers ki, kd and K of the waves corresponding to said parallel beam scattered energy portions and ultrasonic energy, satisfying substantially the vector relation ki kd + OR - K.
Claim 3
Dependent Claim
43 words
Modulator system as claimed in claim 1, wherein said refracting means comprise a further face of said block receiving said parallel beam at oblique incidence ; said block having an exit face transmitting the scattered radiant energy portions emerging from said further face.
Claim 4
Dependent Claim
20 words
Modulator system as claimed in claim 2, wherein said parallel beam impinges onto said further face at the Brewster incidence.
Claim 5
Dependent Claim
32 words
Modulator system as claimed in claim 2, wherein said parallel beam impinges onto said further face at a grazing incidence lying between the limiting incidences for total reflection upon said birefringent material.
Claim 6
Dependent Claim
15 words
Modulator system as claimed in claim 1, wherein said ultrasonic transducers are shear wave transducers.
Claim 7
Dependent Claim
15 words
Modulator system as claimed in claim 1, further comprising means for absorbing said ultrasonic energy.
Claim 8
Dependent Claim
43 words
Modulator system as claimed in claim 1, wherein said electrical means comprise an ultrasonic A.C. generator having an electrical output, and switching means coupling said transducers to said electrical output : said switching means having control inputs for receiving said electrical modulating signals.
Claim 9
Dependent Claim
26 words
Modulator system as claimed in claim 1, wherein said transducers build up a mosaic capable of selectively displaying characters in response to said electrical modulating signals.
Claim 10
Dependent Claim
15 words
Modulator system as claImed in claim 7, wherein said switching means are unipolar semiconductor devices.
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) | 1976-04-30 | 1976-10-30 | 1977-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-30 | 1980-10-30 | 1981-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-30 | 1984-10-30 | 1985-05-01 | $7700.00 | Window Closed / Lapsed |