Patent US4973169A successfully refreshed from Google Patents.
US4973169A
Expired / Lapsed
US
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Method and apparatus for securing information communicated through optical fibers
Assignee: Lockheed Martin Corp
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Filing: 1989-06-07
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Granted: 1990-11-27
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Expires: 2009-06-07
Abstract
Abstract This invention relates to a technique for protecting information from intrusion that is transmitted through optical fiber. The new method relates to transmitting energy at multiple wavelengths along a single mode optical fiber. The wavelengths can be propagated in single mode or alternatively n single mode or in high order modes. Energy at one or more wavelengths constitutes guard channels which have an enhanced power loss effect by selection of an appropriate cut-off wavelength of the single mode optical fiber. These guard channels can be monitored for power loss to detect intrusion. An apparatus is also described.
Inventors
- 👤 Mark H. Slonecker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 04:32
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/24; G02B6/26; G02B6/27; G02B6/2726; G02B6/274; H; H04; H04B; H04B10/00; H04B10/25
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
53 words
A method for wavelength division multiplexing in single-mode optical fibers comprising: transmitting optical energy simultaneously at multiple wavelengths through a single core, single mode optical fiber having a cut-off wavelength; and selecting the cut-off wavelength to enhance optical energy power loss of one of said wavelengths with respect to others of said wavelengths.
Claim 2
Independent Claim
53 words
A method for wavelength division multiplexing in single-mode optical fibers comprising: transmitting optical energy simultaneously at multiple wavelengths through a single core, single mode optical fiber having a cut-off wavelength; and selecting the cut-off wavelength to enhance optical energy power loss of one of said wavelengths with respect to others of said wavelengths.
Claim 3
Dependent Claim
23 words
The method according to claim 1, further comprising monitoring the optical power energy of at least one wavelength of the transmitted multiple wavelengths.
Claim 4
Dependent Claim
22 words
The method according to claim 2, further comprising interrupting transmission of substantially unattenuated energy at at least one of the multiple wavelengths.
Claim 5
Dependent Claim
15 words
The method according to claim 1, wherein energy at at least two wavelengths is propagated.
Claim 6
Dependent Claim
18 words
The method according to claim 1, further comprising discerning optical power loss by disturbance to the optical fiber.
Claim 7
Dependent Claim
15 words
The method according to claim 5, wherein the disturbance results from bending the optical fiber.
Claim 8
Dependent Claim
21 words
The method according to claim 1, wherein a first wavelength of the multiple wavelengths is longer than a second shorter wavelength.
Claim 9
Dependent Claim
22 words
The method according to claim 7, wherein the long wavelength is about 1300 nm and the short wavelength is about 850 nm.
Claim 10
Dependent Claim
22 words
The method according to claim 8, wherein the cut-off wavelength of the optical fiber is between about 1000 nm and 1100 nm.
Claim 11
Dependent Claim
22 words
The method according to claim 8, wherein the cut-off wavelength of the optical fiber is between about 600 nm and 850 nm.
Claim 12
Dependent Claim
25 words
The method according to claim 8, wherein the cut-off wavelength of the optical fiber is between about greater than 1300 nm and about 1550 nm.
Claim 13
Dependent Claim
25 words
The method according to claim 8, wherein the cut-off wavelength of the optical fiber is between about 1200 nm and less than about 1300 nm.
Claim 14
Dependent Claim
20 words
The method according to claim 7, wherein the cut-off wavelength of the optical fiber is less than the short wavelength.
Claim 15
Dependent Claim
20 words
The method according to claim 7, wherein the cut-off wavelength of the optical fiber is greater than the short wavelength.
Claim 16
Dependent Claim
86 words
An intrusion resistant optical communication method using wavelength division multiplexing in single core, single-mode optical fiber comprising: transmitting optical energy simultaneously at multiple wavelengths through a single core, single mode optical fiber having a cut-off wavelength; propagating first and second wavelengths in single mode, the first wavelength being greater than the second wavelength; and selecting the cut-off wavelength of the optical fiber to be less than the second wavelength and to enhance optical energy power loss of the first wavelength with respect to the second wavelength.
Claim 17
Dependent Claim
86 words
An intrusion resistant optical communication method using wavelength division multiplexing in single core, single-mode optical fiber comprising: transmitting optical energy simultaneously at multiple wavelengths through a single core, single mode optical fiber having a cut-off wavelength; propagating first and second wavelengths in single mode, the first wavelength being greater than the second wavelength; and selecting the cut-off wavelength of the optical fiber to be less than the second wavelength and to enhance optical energy power loss of the first wavelength with respect to the second wavelength.
Claim 18
Dependent Claim
92 words
An intrusion resistant optical communicator method using wavelength division multiplexing in single core, single-mode optical fiber comprising: transmitting optical energy simultaneously at multiple wavelengths through a single core, single mode optical fiber having a cut-off wavelength; propagating a first wavelength in single mode and second wavelength in higher order mode, the first wavelength being greater than the second wavelength; and selecting the cut-off wavelength of the optical fiber to be greater than the second wavelength and to enhance optical energy power loss of the first wavelength with respect to the second wavelength.
Claim 19
Dependent Claim
92 words
An intrusion resistant optical communicator method using wavelength division multiplexing in single core, single-mode optical fiber comprising: transmitting optical energy simultaneously at multiple wavelengths through a single core, single mode optical fiber having a cut-off wavelength; propagating a first wavelength in single mode and second wavelength in higher order mode, the first wavelength being greater than the second wavelength; and selecting the cut-off wavelength of the optical fiber to be greater than the second wavelength and to enhance optical energy power loss of the first wavelength with respect to the second wavelength.
Claim 20
Independent Claim
63 words
An apparatus for wavelength division multiplexing in single core, single-mode optical fiber comprising: means for simultaneously propagating optical energy as multiple wavelengths; means for propagating at least one wavelength in single-mode and wavelengths in higher order modes; and means for enhancing the optical energy power loss of one of the wavelengths by selection of the single-mode optical fiber having a predetermined cut-off wavelength.
Claim 21
Independent Claim
63 words
An apparatus for wavelength division multiplexing in single core, single-mode optical fiber comprising: means for simultaneously propagating optical energy as multiple wavelengths; means for propagating at least one wavelength in single-mode and wavelengths in higher order modes; and means for enhancing the optical energy power loss of one of the wavelengths by selection of the single-mode optical fiber having a predetermined cut-off wavelength.
Claim 22
Dependent Claim
17 words
The apparatus according to claim 17, further comprising means for monitoring the optical power of each wavelength.
Claim 23
Dependent Claim
16 words
The apparatus according to claim 18, further comprising means for interrupting transmission of an unattenuated wavelength.
Claim 24
Independent Claim
51 words
A method for wavelength division multiplexing in a single-mode optical fiber comprising: selecting the single-mode optical fiber having a desired cut-off wavelength to enhance optical energy power loss of one wavelength with respect to other wavelengths; and transmitting optical energy substantially simultaneously at multiple wavelengths through said selected single-mode optical fiber.
Claim 25
Independent Claim
51 words
A method for wavelength division multiplexing in a single-mode optical fiber comprising: selecting the single-mode optical fiber having a desired cut-off wavelength to enhance optical energy power loss of one wavelength with respect to other wavelengths; and transmitting optical energy substantially simultaneously at multiple wavelengths through said selected single-mode optical fiber.
References Cited (Backward Citations)
US4070091A
Cited
US4436368A
Cited
US4237550A
Cited
US4616898A
Cited
US4566754A
Cited
US4412722A
Cited
US4435850A
Cited
US4530078A
Cited
US4630255A
Cited
US4749248A
Cited
US4770492A
Cited
US4912523A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-11-26 | 1994-05-28 | 1994-11-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-11-26 | 1998-05-28 | 1998-11-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-11-26 | 2002-05-28 | 2002-11-27 | $7700.00 | Window Closed / Lapsed |