US3624402A
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Electromagnetic beam communication unit
Assignee: Georgetown University
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Filing: 1968-02-08
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Granted: 1971-11-30
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Expires: 1988-02-08
Abstract
Abstract A modulation cell which has two crystals side-by-side and oppositely oriented are driven by the same electromagnetic frequency modulated signal transmitter to form in the cell two parallel but similar moving periodic electro-optic diffraction gratings. An electromagnetic signal carrier producing source, such as a laser, has its beam pass through the sides of the cell and both electro-optic diffraction gratings. The zero diffraction order of the beam after it leaves the crystal has a frequency component which corresponds to the frequency modulated signal. The modulation cell may be a liquid or gas unit, with two sets of transmitters and absorbers, or the modulation cell may contain two oppositely oriented side-by-side optical crystals having an integral electromagnetic wave guide along which the frequency modulated signal is passed to the crystal.
Inventors
- 👤 William J Thaler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 04:06
CPC Classifications
H; H04; H04B; H04B10/00; H04B10/50; H04B10/501; H04B10/503; H04B10/505; G; G02; G02F; G02F1/00; G02F1/01; G02F1/11
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
172 words
An electromagnetic beam communication unit, comprising: a. means for generating a directional electromagnetic beam, b. modulation cell means disposed in the path of said electromagnetic beam, c. the modulation cell means including two oppositely oriented cell units disposed side by side each having a transducer at the receiving end and an absorber at the other end, d. electromagnetic frequency modulation generating means connected to the receiving end of each of the fluid cell units for imparting a travelling periodic wave diffraction pattern which travels along the length of each cell unit, resulting in two oppositely travelling parallel diffraction wave patterns within the modulation cell means, e. the directional electromagnetic beam being passed through the modulation cell orthogonally to the two oppositely travelling diffraction wave patterns and passing out of the modulation cell with the zero order diffraction pattern containing frequency components reflecting the frequency modulation signal of the frequency modulation means, f. detector means for detecting the frequency modulation components of the directional electromagnetic beam after it leaves the modulation cell means.
Claim 2
Dependent Claim
172 words
An electromagnetic beam communication unit, comprising: a. means for generating a directional electromagnetic beam, b. modulation cell means disposed in the path of said electromagnetic beam, c. the modulation cell means including two oppositely oriented cell units disposed side by side each having a transducer at the receiving end and an absorber at the other end, d. electromagnetic frequency modulation generating means connected to the receiving end of each of the fluid cell units for imparting a travelling periodic wave diffraction pattern which travels along the length of each cell unit, resulting in two oppositely travelling parallel diffraction wave patterns within the modulation cell means, e. the directional electromagnetic beam being passed through the modulation cell orthogonally to the two oppositely travelling diffraction wave patterns and passing out of the modulation cell with the zero order diffraction pattern containing frequency components reflecting the frequency modulation signal of the frequency modulation means, f. detector means for detecting the frequency modulation components of the directional electromagnetic beam after it leaves the modulation cell means.
Claim 3
Dependent Claim
30 words
The electromagnetic beam communication system as set forth in claim 1, wherein: a. said electromagnetic beam is a laser beam having a band width of from 1 to 2 giga-cycles.
Claim 4
Dependent Claim
46 words
The electromagnetic beam communication system as set forth in claim 1, wherein: a. said detector means is positioned directly in line with said directional electromagnetic beam to pick up only the zero diffraction order of said directional electromagnetic beam after it leaves said modulation cell means.
Claim 5
Dependent Claim
48 words
The electromagnetic beam communication system as set forth in claim 1, wherein: a. said modulation cell is an electro-optical crystal; b. said electromagnetic frequency modulation generating means is a traveling wave tube; and c. a wave guide is connected between said traveling wave tube and said electro-optic crystal.
Claim 6
Dependent Claim
32 words
The electromagnetic beam communication system as set forth in claim 1, wherein: a. blocking means is disposed adjacent said modulation cell means for allowing only the zero diffraction order to pass therethrough.
Claim 7
Dependent Claim
167 words
An electromagnetic beam communication unit, comprising: a. electro-optical crystal difFraction modulation cell means through which an electromagnetic wave can be propagated from one end to another; b. said electro-optical crystal diffraction modulation cell comprising two oppositely oriented electro-optical diffraction cell units disposed side by side each cell unit responsive to frequency modulation wave transmitting means connected to one end of each of said cell units to produce two parallel oppositely traveling periodic waves which traverse said cell units from end to end to create a traveling diffraction grating effect in said crystal diffraction modulation cell means; c. electromagnetic coherent beam radiation means which passes through said electro-optical crystal modulation cell orthogonally to interact with said traveling diffraction grating; d. detector means adjacent said crystal for picking up the zero order diffraction pattern of said coherent electromagnetic beam and producing a signal responsive to said zero order diffraction pattern; and e. signal conversion means responsive to said signal from said detector means to produce the desired output information.
Claim 8
Dependent Claim
167 words
An electromagnetic beam communication unit, comprising: a. electro-optical crystal difFraction modulation cell means through which an electromagnetic wave can be propagated from one end to another; b. said electro-optical crystal diffraction modulation cell comprising two oppositely oriented electro-optical diffraction cell units disposed side by side each cell unit responsive to frequency modulation wave transmitting means connected to one end of each of said cell units to produce two parallel oppositely traveling periodic waves which traverse said cell units from end to end to create a traveling diffraction grating effect in said crystal diffraction modulation cell means; c. electromagnetic coherent beam radiation means which passes through said electro-optical crystal modulation cell orthogonally to interact with said traveling diffraction grating; d. detector means adjacent said crystal for picking up the zero order diffraction pattern of said coherent electromagnetic beam and producing a signal responsive to said zero order diffraction pattern; and e. signal conversion means responsive to said signal from said detector means to produce the desired output information.
Claim 9
Dependent Claim
43 words
The electromagnetic beam communication unit as set forth in claim 6, wherein: a. said frequency modulation wave transmitting means includes a traveling wave tube; and b. a wave guide is connected between said traveling wave tube and said electro-optical crystal diffraction modulation cell.
Claim 10
Dependent Claim
34 words
The electromagnetic beam communication unit as set forth in claim 6, wherein: a. said frequency modulation wave transmitting means includes a ridged wave guide between said crystal and said electromagnetic coherent beam radiation means.
Claim 11
Dependent Claim
26 words
The electromagnetic beam communication unit as set forth in claim 6, wherein: a. said electro-optical crystal diffraction modulation cell comprises a crystal of potassium deuterium phosphate.
Claim 12
Dependent Claim
26 words
The electromagnetic beam communication unit as set forth in claim 6, wherein: a. said electro-optical crystal diffraction modulation cell comprises a crystal of ammonium deuterium phosphate.
Claim 13
Dependent Claim
25 words
The electromagnetic beam communication unit as set forth in claim 6, wherein: a. said electro-optical crystal diffraction modulation cell comprises a crystal of lithium miobate.
Claim 14
Dependent Claim
27 words
The electromagnetic beam communication unit as set forth in claim 6, wherein: a. said crystal is approximately one inch long and one-quarter inch square in cross section.
Claim 15
Dependent Claim
23 words
The electromagnetic beam communication unit as set forth in claim 6, wherein: a. said frequency modulation wave transmitting means is a klystron tube.
Claim 16
Dependent Claim
59 words
The electromagnetic beam communication unit as set forth in claim 6, wherein: a. said electro-optical diffraction modulation cell means includes two solid, elongated crystals disposed side by side and having a simultaneous identical signal applied to an opposite end of each, whereby two traveling periodic waves each moving in opposite directions are produced to give oppositely traveling diffraction gratings.
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) | 1974-11-29 | 1975-05-31 | 1975-11-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-29 | 1979-05-31 | 1979-11-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-29 | 1983-05-31 | 1983-11-30 | $7700.00 | Window Closed / Lapsed |