Optical power meter derived from common-mode voltage of optical transimpedance amplifier
US6528777B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 16, 2001 |
| Grant date | Mar 4, 2003 |
| Priority date | — |
| Expiry date | Apr 21, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B10/6911
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An optical transceiver with a transimpedance amplifier generates a dynamic common mode voltage of the peak-to-peak output current of the photodetector for use as an in-situ optical power meter. Peak-to-peak voltage signal are imposed on the common mode voltage so optical power measurements are obtained using preexisting electrical contacts. An nfet and a capacitor of the transimpedance amplifier smooths the peak-to-peak voltage to create the control signal for the common mode voltage. The common mode current is mirrored into a bank of pfets at the output stage to create a current sink. Depending upon the potential of the common mode voltage, more or less current will be drawn from the peak-to-peak voltage signals output from a final differential amplifier stage of the transimpedance amplifier.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.