Universal branching unit
US6304351A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 28, 1998 |
| Grant date | Oct 16, 2001 |
| Priority date | — |
| Expiry date | Oct 28, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04Q2011/0075
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A branching unit is provided for directing individual wavelengths of a WDM optical communication signal among a transmitting terminal, a receiving terminal and a branch terminal. The branching unit includes first and second cross bar switches each having at least a first, second and third port such that in a first state the first cross bar directs an optical signal appearing on the first port to the second port and in a second state the first cross bar directs the optical signal from the first port to the third port. A reflective filter couples the third port of the first switch to the third port of the second switch. The reflective filter is configured to reflect a prescribed wavelength and to transmit therethrough all remaining wavelengths forming the WDM signal. An optical fiber couples the second port of the first switch to the second port of the second switch. First and second circulators are also provided, which each have an input, output and an intermediate port. The intermediate port of the first and second circulators are coupled to the first port of the first and second switches, respectively. The input port of the first circulator is adapted to receive the WDM signal fro…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.