US3864020A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light controlled light modulator
Assignee: International Business Machines Corp
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Filing: 1973-12-28
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Granted: 1975-02-04
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Expires: 1993-12-28
Abstract
Abstract A light controlled light modulator is disclosed wherein a low intensity, circularly polarized driving light beam can be used to modulate or switch a linearly polarized main light beam. The main beam can be as much as three orders of magnitude more powerful than the driving beam, yet the response time is measured in picoseconds. The modulator itself comprises a coherent rotator and a polarizer, and modulation is accomplished by rotating the plane of polarization of the main beam under the control of the driving beam. The coherent rotator is a completely passive device and is a light cell containing an alkali metallic vapor such as rubidium or potassium.
Inventors
- 👤 John A Armstrong
- 👤 Daniel R Grischowsky
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:14
CPC Classifications
G; G01; G01N; G01N24/00; G01N24/006; G02; G02F; G02F1/00; G02F1/01; G02F1/0126
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
88 words
A light controlled light modulator comprising: a. a coherent rotator containing a material exhibiting Zeeman splitting of the optical spectra of radiations emitted by atomic transitions wherein the population densities of atoms in the Zeeman magnetic sublevels of the ground and excited states are controlled by a circularly polarized driving light beam, and b. a polarizer oriented to variably transmit a main beam of linearly polarized light as a function of the rotation of the plane of polarization of the main beam by passage through said coherent rotator.
Claim 2
Dependent Claim
88 words
A light controlled light modulator comprising: a. a coherent rotator containing a material exhibiting Zeeman splitting of the optical spectra of radiations emitted by atomic transitions wherein the population densities of atoms in the Zeeman magnetic sublevels of the ground and excited states are controlled by a circularly polarized driving light beam, and b. a polarizer oriented to variably transmit a main beam of linearly polarized light as a function of the rotation of the plane of polarization of the main beam by passage through said coherent rotator.
Claim 3
Dependent Claim
27 words
A light controlled light modulator as recited in claim 1 wherein the coherent rotator material in said coherent rotator is selected from the class of alkali metals.
Claim 4
Dependent Claim
17 words
A light controlled light modulator as recited in claim 2 wherein the coherent rotator material is rubidium.
Claim 5
Dependent Claim
16 words
A light controlled light modulator as recited in claim 2 wherein the coherent rotator is potassium.
Claim 6
Dependent Claim
68 words
A light controlled light modulator as recited in claim 1 wherein the frequency Nu d of the driving beam is resonant or nearly resonant with the frequency separation Nu o between two working levels of the atomic states of the atoms in said coherent rotator material and the frequency Nu m of the main beam is far from the frequency separation Nu o between said two working levels.
Claim 7
Dependent Claim
26 words
A light controlled light modulator as recited in claim 5 wherein Nu d < Nu o and a pulse of the driving beam is applied adiabatically.
Claim 8
Dependent Claim
18 words
A light controlled light modulator as recited in claim 6 wherein the coherent rotator material is rubidium vapor.
Claim 9
Dependent Claim
25 words
A light controlled light modulator as recited in claim 5 wherein Nu d Nu o and a pulse of the driving beam is applied non-adiabatically.
Claim 10
Dependent Claim
18 words
A light controlled light modulator as recited in claim 8 wherein the coherent rotator material is potassium vapor.
References Cited (Backward Citations)
US3671747A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-03 | 1978-08-05 | 1979-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-03 | 1982-08-05 | 1983-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-03 | 1986-08-05 | 1987-02-04 | $7700.00 | Window Closed / Lapsed |