Multiple core optical waveguide for secure transmission
US4436368A · kind A · utility
40Cited by
9References
21Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jul 31, 1981 |
| Grant date | Mar 13, 1984 |
| Priority date | — |
| Expiry date | Jul 31, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/4469
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A glass optical fiber has multiple cores and a cladding. The index of refraction of all cores is greater than the index of refraction of the cladding and the index of refraction of a first core is greater then the index of refraction of a second core. The change in the ratio of light loss from the first and second cores is detected to identify perturbations of the optical fiber before it reaches a level sufficient for a secure signal to be tapped.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.