US3928822A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermal differential compensator
Assignee: United States Department of the Air Force
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Filing: 1974-07-09
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Granted: 1975-12-23
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Expires: 1994-07-09
Abstract
Abstract Lithium tantalate modulation crystals inside a boron nitride oven core are optically compensated by providing a temperature differential between the crystals. This is done by controlling the heater current flowing through the heaters on the core.
Inventors
- 👤 Amos J Chenoweth
- 👤 William E Heafner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 00:23
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/03; G02F1/0327
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
118 words
In a laser modulator having two modulation crystals contained in an oven core having two heater elements, one element substantially controlling the temperature of one crystal element of the modulator and the other heater element substantially controlling the temperature of the other crystal element of the modulator, the improvement for providing a determined thermal differential between the two crystal elements, comprising: a. controlled source of electrical energy for energizing the said heater elements to provide a determined amount of heat energy to the said oven core; and b. means cooperating with the said source of electrical energy and the said heater elements for providing a variable controlled thermal difference in temperature between the said two crystal modulating elements.
Claim 2
Dependent Claim
118 words
In a laser modulator having two modulation crystals contained in an oven core having two heater elements, one element substantially controlling the temperature of one crystal element of the modulator and the other heater element substantially controlling the temperature of the other crystal element of the modulator, the improvement for providing a determined thermal differential between the two crystal elements, comprising: a. controlled source of electrical energy for energizing the said heater elements to provide a determined amount of heat energy to the said oven core; and b. means cooperating with the said source of electrical energy and the said heater elements for providing a variable controlled thermal difference in temperature between the said two crystal modulating elements.
Claim 3
Dependent Claim
180 words
The improvement in a laser modulation system having a crystal modulator element with two crystal elements contained in an oven core, the said core having a first electrical heating element primarily associated with controlling the temperature of one of the said crystal modulation elements and a second electrical heating element primarily associated with controlling the temperature of the other of the said crystal modulation elements, each of the said heating elements having associated therewith two electrical terminal connections, and the said laser modulation system having a controlled source of electrical energy for energizing the said heating elements, the said source of electrical energy being electrically connected across the serially connected heater elements, the said improvement comprising a manually controllable variable resistance connected in parallel across one of the said heating elements for slightly lowering the electrical energy going into the said heating element and providing a controlled thermal differential between the two said crystal elements whereby the birefringence of the said crystals may be adjusted to provide substantially a zero field optical operating point for the said crystal modulator element.
Claim 4
Dependent Claim
180 words
The improvement in a laser modulation system having a crystal modulator element with two crystal elements contained in an oven core, the said core having a first electrical heating element primarily associated with controlling the temperature of one of the said crystal modulation elements and a second electrical heating element primarily associated with controlling the temperature of the other of the said crystal modulation elements, each of the said heating elements having associated therewith two electrical terminal connections, and the said laser modulation system having a controlled source of electrical energy for energizing the said heating elements, the said source of electrical energy being electrically connected across the serially connected heater elements, the said improvement comprising a manually controllable variable resistance connected in parallel across one of the said heating elements for slightly lowering the electrical energy going into the said heating element and providing a controlled thermal differential between the two said crystal elements whereby the birefringence of the said crystals may be adjusted to provide substantially a zero field optical operating point for the said crystal modulator element.
References Cited (Backward Citations)
US3875400A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-22 | 1979-06-23 | 1979-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-22 | 1983-06-23 | 1983-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-22 | 1987-06-23 | 1987-12-23 | $7700.00 | Window Closed / Lapsed |