Optical modulation device and bias voltage control method
US9116368B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 21, 2012 |
| Grant date | Aug 25, 2015 |
| Priority date | — |
| Expiry date | Aug 21, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B10/548
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An optical modulation device including: bias power supplies that output a signal having a bias voltage corresponding to the null point of an optical modulation unit to the optical modulation unit; and synchronous detection circuits that determine whether an intensity of a QAM signal at a drift non-occurrence time where no drift occurs in the bias voltage becomes larger or smaller than the intensity of the QAM signal at a drift occurrence time where a drift occurs in the bias voltage, adjust the bias voltage to maximize the intensity of the QAM signal when determining that the intensity of the QAM signal at the drift non-occurrence time becomes larger than the intensity of the QAM signal at the drift occurrence time, and adjust the bias voltage to minimize the intensity of the QAM signal when determining that the intensity of the QAM signal at the drift non-occurrence time becomes smaller than the intensity of the QAM signal at the drift occurrence time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.