Patent · US Active

Pre-distortion techniques for optical modulators to improve constellation point separation

US8948609B2 · kind B2 · utility

3Cited by

2References

27Claims

0Family size

Assignee

Cisco Technology, Inc. · US

Inventors

James Whiteaway · Sawbridgeworth, GB
Thomas Duthel · Nuremberg, DE
Jonas Geyer · Seukendorf, DE

Key dates

Filing date	Feb 24, 2012
Grant date	Feb 3, 2015
Priority date	—
Expiry date	Jun 30, 2032

Classification

Technology area (CPC H)Electricity
CPC primaryH04L27/368
WIPO fieldDigital communication
WIPO sectorElectrical engineering

Abstract

According to a first aspect, techniques are provided to optimize a Mach-Zehnder modulator drive waveform by distorting the outer modulation levels of the waveform, thereby equalizing eye openings of the received optical field, and in particular creating a wider and more defined central eye opening of the received optical field. According to a second aspect, techniques are provided to adjust in-phase (I) modulation levels based on the imperfect performance of a Mach-Zehnder modulator allocated to modulate quadrature-phase (Q) modulation levels, and conversely to adjust the Q modulation levels based on the imperfect performance of an MZ modulator allocated to modulate I modulation levels.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.