Patent EP0379932B1 successfully refreshed from Google Patents.
US3792379A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Millimeter wave devices utilizing electrically polarized media
Assignee: AT&T Inc
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Filing: 1972-03-07
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Granted: 1974-02-12
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Expires: 1992-03-07
Abstract
Abstract Radiative signals, e.g., pulses of duration as short as one picosecond or CW energy with frequencies as high as 10,000 GHz are radiated from pyroelectric media. Pump energy is in the form of electromagnetic radiation of wavelength within the range of one millimeter and shorter. The effect of such devices is to replicate the form of intensity variations of pump radiation whereby such variations take the form of pulses, modulation signals, difference frequencies, etc. Rapid response is, in a preferred instance, due to direct absorption of pump radiation at or below a low frequency absorption edge of a crystalline medium so that the energy is pumped directly into the lattice of the pyroelectric medium. An alternative arrangement takes advantage of the thermalization accompanying relaxation of an excited electron state. In the latter case the excited state may be that of a dopant material having an absorption within a normal transparency bandwidth of the pyroelectric medium.
Inventors
- 👤 D Auston
- 👤 A Glass
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 05:22
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/35
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
179 words
Apparatus comprising a transducer for altering incoming electromagnetic radiation into outgoing electromagnetic radiation provided with first means for receiving radiation and second means for emitting the altered radiation, said incoming radiation having a maximum wavelength of about one millimeter, and manifesting a variation in input radiation intensity on a time scale of from about 1010 Hz to about 1013 Hz, said transducer being so adapted as to emit an electrical signal replicating said variation characterized in that said transducer consists essentially of a body which may manifest net electrical polarization and which manifests a maximum absorption length of about 0.2 millimeter for radiation of a wavelength within the said range, substantially the entirety of the altered radiation being due to a pyroelectric response resulting primarily from thermalization of that portion of the said incoming electromagnetic radiation which is absorbed, in which the said body has a polarization of at least 0.1 microcoulombs per centimeter2 whereby the thermalization results in a change in dipolar moment corresponding with a net electrical signal responsive to the said variation of incoming electromagnetic radiation.
Claim 2
Dependent Claim
179 words
Apparatus comprising a transducer for altering incoming electromagnetic radiation into outgoing electromagnetic radiation provided with first means for receiving radiation and second means for emitting the altered radiation, said incoming radiation having a maximum wavelength of about one millimeter, and manifesting a variation in input radiation intensity on a time scale of from about 1010 Hz to about 1013 Hz, said transducer being so adapted as to emit an electrical signal replicating said variation characterized in that said transducer consists essentially of a body which may manifest net electrical polarization and which manifests a maximum absorption length of about 0.2 millimeter for radiation of a wavelength within the said range, substantially the entirety of the altered radiation being due to a pyroelectric response resulting primarily from thermalization of that portion of the said incoming electromagnetic radiation which is absorbed, in which the said body has a polarization of at least 0.1 microcoulombs per centimeter2 whereby the thermalization results in a change in dipolar moment corresponding with a net electrical signal responsive to the said variation of incoming electromagnetic radiation.
Claim 3
Dependent Claim
14 words
Apparatus of claim 1 in which the said incoming radiation includes a pulsed component.
Claim 4
Dependent Claim
16 words
Apparatus of claim 2 in which the incoming radiation consists essentially of the said pulsed component.
Claim 5
Dependent Claim
34 words
Apparatus of claim 3 in which a pulse is of duration of a maximum of about 100 picoseconds (such pulses containing spectral components of a frequency of up to at least about 10 GHz).
Claim 6
Dependent Claim
30 words
Apparatus of claim 1 in which at least a component of the said incoming radiation is at least quasi continuous, i.e., is CW for a period corresponding with many cycles.
Claim 7
Dependent Claim
13 words
Apparatus of claim 5 in which the said incoming radiation includes two frequencies.
Claim 8
Dependent Claim
32 words
Apparatus of claim 6 in which at least a part of the said variation in radiation intensity is the result of the difference signal developed from beating of the two said frequencies.
Claim 9
Dependent Claim
22 words
Apparatus of claim 7 in which the two said frequencies are separated by a frequency difference of a minimum of 10 GHz.
Claim 10
Dependent Claim
20 words
Apparatus of claim 1 in which the said electrical polarization is induced by a field external to the said body.
Claim 11
Dependent Claim
15 words
Apparatus of claim 1 in which the said polar environment is due to spontaneous polarization.
Claim 12
Dependent Claim
22 words
Apparatus of claim 10 in which the absorption is by an absorbing species which is a dopant contained within the said body.
Claim 13
Dependent Claim
14 words
Apparatus of claim 1 in which the said second means includes a transmission line.
Claim 14
Dependent Claim
13 words
Apparatus of claim 12 in which the said transmission line is essentially nondispersive.
Claim 15
Dependent Claim
25 words
Apparatus of claim 12 in which the said transmission line is provided with separated conductive elements so as to cause propagation of a TEM mode.
Claim 16
Dependent Claim
12 words
Apparatus of claim 14 in which the said transmission line is electro-optic.
Claim 17
Dependent Claim
94 words
Apparatus of claim 15 in which the said second means includes means for irradiating the said transmission line with radiation within the transparency bandwidth of the said transmission line in a direction orthogonal to the said electrical signal for at least a portion of the period of traversal of the altered energy within the said line so that the transmission properties of the said transmission line for the irrAdiating radiation are altered during the period of coincidence between the said altered energy and radiation incident on the transmission line due to the said irradiation.
Claim 18
Dependent Claim
22 words
Apparatus of claim 16 in which the said altered energy is detected as a response to the said change in transmission properties.
Claim 19
Dependent Claim
13 words
Apparatus of claim 12 in which the said transmission line is a waveguide.
Claim 20
Dependent Claim
30 words
Apparatus of claim 1 in which the electrical signal includes a carrier with an imposed modulation signal corresponding with at least a component of the said variation in radiation intensity.
Claim 21
Dependent Claim
16 words
Apparatus of claim 1 in which the said body is crystalline and exhibits spontaneous electrical polarization.
Claim 22
Dependent Claim
34 words
Apparatus of claim 20 in which the said first means is so arranged as to receive radiation of a wavelength within the absorption band lying below a lower absorption edge of the said body.
Claim 23
Dependent Claim
66 words
Apparatus of claim 20 in which the said body is doped with atomic species having an absorption falling within the natural transparency band of the said body, in which the outgoing radiation is primarily due to thermalization accompanying electronic relaxation from an excited electronic state associated with the absorption of the species and in which the said relaxation time is a maximum of 10 10 seconds.
Claim 24
Dependent Claim
70 words
Apparatus of claim 20 in which the said first means provides for incoming radiation of a wavelength within the band lying above the upper absorption edge of the said body and in which the outgoing radiation is primarily due to thermalization accompanying electronic relaxation from an excited electronic state associated with the absorption of the species and in which the said relaxation time is a maximum of 10 10 seconds.
References Cited (Backward Citations)
US3453432A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-11 | 1977-08-13 | 1978-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-11 | 1981-08-13 | 1982-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-11 | 1985-08-13 | 1986-02-12 | $7700.00 | Window Closed / Lapsed |