Digital optical receiver with instantaneous Josephson clock recovery circuit
US5963351A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 29, 1997 |
| Grant date | Oct 5, 1999 |
| Priority date | — |
| Expiry date | Apr 29, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03B15/00
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A digital optical receiver and clock recovery circuit for use in detecting and retiming optical data transmitted at rates up to and exceeding 40 Gb/s. The receiver is made, in part, of superconducting Josephson junctions. The receiver includes an optical signal detector, an SFQ (single flux quantum) transition detector for converting the signal from the photodetector into a stream of single flux quantum signals, and a clock recovery circuit. The clock recovery circuit includes a superconducting ring oscillator in which an SFQ pulse rotates and provides a clock signal at an output of the oscillator. When a pulse from the stream of single flux quantum pulses arrives from the transition detector, two pulses are generated in the ring oscillator. One of the pulses eliminates the rotating SFQ pulse and the second pulse replaces the rotating SFQ pulse, thereby recovering the phase of the clock signal in one bit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.