US3614754A
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Ferroelectric gadolinium molybdate compensation type bistable light gate and logic cell having memory
Assignee: STEWART E CUMMINS
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Filing: 1969-03-17
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Granted: 1971-10-19
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Expires: 1989-03-17
Abstract
Abstract Two, electroded, birefringent, bistable crystals of ferroelectric gadolinium molybdate are aligned along their crystallographic c axis between crossed optical polarizers. When the two crystals have their respective spontaneous polarization switched by an electrical pulse so that the directions of their a and b axes respectively coincide, the retardations add, and when they are switched so that the a direction of one crystal aligns with the b direction of the other crystal the retardations subtract. In the former instance light is passed, in the latter no light is transmitted through the crystals and crossed polarizers. Each bistable ferroelectric gadolinium molybdate crystal has memory in that only an electrical pulse is required to bring about a change of state which is retained until the crystal is conversely pulsed.
Inventors
- 👤 Stewart E Cummins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 13:45
CPC Classifications
G; G11; G11C; G11C13/00; G11C13/04; G11C13/047; G02; G02F; G02F1/00; G02F1/01; G02F1/03; G02F1/05; G02F3/00; G02F3/02; G02F3/022
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
145 words
An electrically controlled light gate device comprising: a. a first crystal element and a second crystal element having the same electrical and optical characteristics cut along the crystallographic axes from a single ferroelectric birefringent crystal of a molybdate of a rare-earth element, each having parallel faces normal to the crystallographic c axis; b. first and second light polarizers having polarization directions at right angles; c. means for passing light through the first polarizer, the first crystal element, the second crystal element, and the second polarizer in succession in a direction normal to the parallel faces of the first and second crystal elements; d. transparent electrodes on the parallel surfaces of the first and second crystal elements for selectively applying an electric pulse of either polarity therebetween for gating the said light; and e. means for sensing the light that has passed through the second polarizer.
Claim 2
Dependent Claim
145 words
An electrically controlled light gate device comprising: a. a first crystal element and a second crystal element having the same electrical and optical characteristics cut along the crystallographic axes from a single ferroelectric birefringent crystal of a molybdate of a rare-earth element, each having parallel faces normal to the crystallographic c axis; b. first and second light polarizers having polarization directions at right angles; c. means for passing light through the first polarizer, the first crystal element, the second crystal element, and the second polarizer in succession in a direction normal to the parallel faces of the first and second crystal elements; d. transparent electrodes on the parallel surfaces of the first and second crystal elements for selectively applying an electric pulse of either polarity therebetween for gating the said light; and e. means for sensing the light that has passed through the second polarizer.
Claim 3
Dependent Claim
20 words
The light gate as claimed in claim 1 wherein the said single crystal is a single crystal of gadolinium molybdate.
Claim 4
Dependent Claim
194 words
A dual electrically controlled light gate device having memory comprising: a. a first crystal element and a second crystal element having the same electrical and optical characteristics cut from a single crystal of the ferroelectric material GD2(MoO4)3 along the crystallographic axes of the crystal providing parallel crystal faces normal to the crystallographic c axis; b. the said first and second crystal elements positioned in axial spaced apart parallel planar relationship along their respective c axis with their respective a and b axes in parallel relationship; c. first and second light polarizers having polarization directions at right angle; d. means for passing light through the first polarizer, the first crystal element, the second crystal element and the second polarizer in succession in a direction parallel to the c axis of the crystal elements; e. transparent electrodes on the parallel faces normal to the crystallographic c axis of the first crystal element and the second crystal element for selectively applying independently to each crystal element an electric pulse of either polarity for changing the state of the spontaneous polarization of the element; and f. means for sensing the light that has passed through the second polarizer.
Claim 5
Dependent Claim
194 words
A dual electrically controlled light gate device having memory comprising: a. a first crystal element and a second crystal element having the same electrical and optical characteristics cut from a single crystal of the ferroelectric material GD2(MoO4)3 along the crystallographic axes of the crystal providing parallel crystal faces normal to the crystallographic c axis; b. the said first and second crystal elements positioned in axial spaced apart parallel planar relationship along their respective c axis with their respective a and b axes in parallel relationship; c. first and second light polarizers having polarization directions at right angle; d. means for passing light through the first polarizer, the first crystal element, the second crystal element and the second polarizer in succession in a direction parallel to the c axis of the crystal elements; e. transparent electrodes on the parallel faces normal to the crystallographic c axis of the first crystal element and the second crystal element for selectively applying independently to each crystal element an electric pulse of either polarity for changing the state of the spontaneous polarization of the element; and f. means for sensing the light that has passed through the second polarizer.
Claim 6
Dependent Claim
240 words
A dual electrically controlled light gate device having memory for controlling the passage of light comprising: a. a first crystal element and second crystal element having the same electrical and optical characteristics cut from a single crystal of the ferroelectric material Gd2(MoO4)3 along the crystallographic a, b, and c axes of the crystal providing crystal plates having a predetermined thickness along the c axis determined by the wavelength of the said light; b. the said first and second crystal elements positioned in axial spaced apart parallel planar relationship along their respective c axis with their respective a and b axes in parallel relationship; c. first and second light polarizes having polarization directions at right angles positioned in parallel planar relationship with the first and second crystal elements, and having the said polarization directions at approximately an angle of 45* with the crystallographic a and b axes of the crystal elements; d. means for passing light through the first polarizer, the first crystal element, the second crystal element and the second polarizer in succession in a direction parallel to the c axis of the crystal elements; e. transparent electrodes on the first and second crystal elements for selectively applying independently an electric field of either polarity to each crystal along the c axis of the crystal for changing the state of spontaneous polarization of the crystal element; and f. means for sensing the light that has passed through the second polarizer.
Claim 7
Dependent Claim
240 words
A dual electrically controlled light gate device having memory for controlling the passage of light comprising: a. a first crystal element and second crystal element having the same electrical and optical characteristics cut from a single crystal of the ferroelectric material Gd2(MoO4)3 along the crystallographic a, b, and c axes of the crystal providing crystal plates having a predetermined thickness along the c axis determined by the wavelength of the said light; b. the said first and second crystal elements positioned in axial spaced apart parallel planar relationship along their respective c axis with their respective a and b axes in parallel relationship; c. first and second light polarizes having polarization directions at right angles positioned in parallel planar relationship with the first and second crystal elements, and having the said polarization directions at approximately an angle of 45* with the crystallographic a and b axes of the crystal elements; d. means for passing light through the first polarizer, the first crystal element, the second crystal element and the second polarizer in succession in a direction parallel to the c axis of the crystal elements; e. transparent electrodes on the first and second crystal elements for selectively applying independently an electric field of either polarity to each crystal along the c axis of the crystal for changing the state of spontaneous polarization of the crystal element; and f. means for sensing the light that has passed through the second polarizer.
Claim 8
Dependent Claim
245 words
An exclusive NOR gate having memory and nondestructive optical readout comprising: a. a first electrical element and a second crystal element having the same electrical and optical characteristics cut from a single crystal of the ferroelectric material Gd2(MoO4)3 along the crystallographic a, b, and c axes of the crystal providing parallel crystal faces normal to the c axis; b. transparent electrodes on the parallel faces normal to the c axis of each crystal element for selectively applying, independently, an electrical pulse of either positive or negative polarity for changing the direction of the state of spontaneous polarization parallel to the c axis of the crystal element; c. the first and second crystal elements positioned in parallel relationship along their c axes with their respective a and b axes in parallel relationship for like directions of spontaneous polarization; d. first and second light polarizers having polarization directions at right angles, positioned parallel to the said parallel crystal faces, and Having the said polarization directions at approximately an angle of 45* with the crystallographic a and b axes of the crystal elements; e. means for passing light through the first polarizer, the first crystal element, the second crystal element, and the second polarizer in succession in a direction parallel to the c axes of the crystal elements; and f. means for sensing the light that has passed through the second polarizer and providing an output responsive to the said directions of spontaneous polarization in the crystal elements.
Claim 9
Dependent Claim
245 words
An exclusive NOR gate having memory and nondestructive optical readout comprising: a. a first electrical element and a second crystal element having the same electrical and optical characteristics cut from a single crystal of the ferroelectric material Gd2(MoO4)3 along the crystallographic a, b, and c axes of the crystal providing parallel crystal faces normal to the c axis; b. transparent electrodes on the parallel faces normal to the c axis of each crystal element for selectively applying, independently, an electrical pulse of either positive or negative polarity for changing the direction of the state of spontaneous polarization parallel to the c axis of the crystal element; c. the first and second crystal elements positioned in parallel relationship along their c axes with their respective a and b axes in parallel relationship for like directions of spontaneous polarization; d. first and second light polarizers having polarization directions at right angles, positioned parallel to the said parallel crystal faces, and Having the said polarization directions at approximately an angle of 45* with the crystallographic a and b axes of the crystal elements; e. means for passing light through the first polarizer, the first crystal element, the second crystal element, and the second polarizer in succession in a direction parallel to the c axes of the crystal elements; and f. means for sensing the light that has passed through the second polarizer and providing an output responsive to the said directions of spontaneous polarization in the crystal elements.
Claim 10
Dependent Claim
258 words
An exclusive OR gate having memory and nondestructive optical readout comprising: a. a first crystal element and a second crystal element having the same electrical and optical characteristics cut from a single crystal of the ferroelectric material Gd2(MoO4)3 along the crystallographic a, b, and c axes of the crystal providing parallel crystal faces normal to the c axis; b. transparent electrodes on the parallel faces normal to the c axis of each crystal element for selectively applying, independently, an electrical pulse of either positive or negative polarity for changing the direction of the state of spontaneous polarization parallel to the c axis of the crystal element; c. the first and second crystal elements positioned in parallel relationship along their c axes with the a axis of the first crystal element aligned in parallel relationship with the b axis of the second crystal element for like directions of spontaneous polarization; d. first and second light polarizers having polarization directions at right angles, positioned parallel to the said parallel crystal faces, and having the said polarization directions at approximately an angle of 45* with the crystallographic a and b axes of the crystal elements; e. means for passing light through the first polarizer, the first crystal element, the second crystal element, and the second polarizer in succession in a direction parallel to the c axes of the crystal elements; and f. means for sensing the light that has passed through the second polarizer and providing an output responsive to the said directions of spontaneous polarization in the said crystal elements.
Claim 11
Dependent Claim
258 words
An exclusive OR gate having memory and nondestructive optical readout comprising: a. a first crystal element and a second crystal element having the same electrical and optical characteristics cut from a single crystal of the ferroelectric material Gd2(MoO4)3 along the crystallographic a, b, and c axes of the crystal providing parallel crystal faces normal to the c axis; b. transparent electrodes on the parallel faces normal to the c axis of each crystal element for selectively applying, independently, an electrical pulse of either positive or negative polarity for changing the direction of the state of spontaneous polarization parallel to the c axis of the crystal element; c. the first and second crystal elements positioned in parallel relationship along their c axes with the a axis of the first crystal element aligned in parallel relationship with the b axis of the second crystal element for like directions of spontaneous polarization; d. first and second light polarizers having polarization directions at right angles, positioned parallel to the said parallel crystal faces, and having the said polarization directions at approximately an angle of 45* with the crystallographic a and b axes of the crystal elements; e. means for passing light through the first polarizer, the first crystal element, the second crystal element, and the second polarizer in succession in a direction parallel to the c axes of the crystal elements; and f. means for sensing the light that has passed through the second polarizer and providing an output responsive to the said directions of spontaneous polarization in the said crystal elements.
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) | 1974-10-18 | 1975-04-19 | 1975-10-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-18 | 1979-04-19 | 1979-10-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-18 | 1983-04-19 | 1983-10-19 | $7700.00 | Window Closed / Lapsed |