Optimum modulator bias systems and methods in coherent optical transmitters
US9059805B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 11, 2013 |
| Grant date | Jun 16, 2015 |
| Priority date | — |
| Expiry date | Jul 19, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B10/5561
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A modulator bias selection method, a coherent optical transmitter, and optical modulator solve the problem of generating a correct constellation using the bias points with the minimum phase adjustment range. The optimum modulator bias systems and methods include a coherent optical transmitter with control of four (XI, XQ, YI, YQ) quadrature data signals via a transmitter (Tx) application specific integrated circuit (ASIC), with a modulator bias controller which implements an algorithm to find the optimum bias points. The optimum bias points yield a correct constellation with minimum phase/bias adjustment. An algorithm is used to find the optimum bias solution using fast, simple method, adjusting only one quadrature at a time and exploiting a control feature of the Tx ASIC. This algorithm is significantly simpler than a generalized search, is a local algorithm, and uses only DC power measurement at the transmitter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.