Optical privacy communication system in two-way optical transmission system
US4933990A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 21, 1988 |
| Grant date | Jun 12, 1990 |
| Priority date | — |
| Expiry date | Jul 21, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B10/27
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An optical privacy communication system in optical fiber communications between many points is disclosed in which, each station is provided with a privacy circuit. Each privacy circuit comprises a first optical branch for connecting the station to first and second optical branches, a second optical branch for connecting the first and second optical branches to the optical fiber transmission line, an optical isolator inserted in the first optical branch, for passing only a signal of a direction from the first optical branch to the second optical branch, and an optical filter inserted in the second optical branch, for passing only an optical signal of a frequency assigned to the station, so that an optical privacy communication is carried out between the stations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.