Optical Repeater Control for Phase Conjugation and Dispersion Compensation

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Solution Overview

Problem

Existing optical network systems face signal quality degradation due to nonlinear distortion in optical transmission, particularly in multi-span networks, which is not adequately addressed by current chromatic dispersion compensation methods.

Innovation Solution

An optical network system with a control device that manages wavelength and transmission line information to determine optimal chromatic dispersion compensation and phase conjugation processing in optical repeaters, using digital signal processing to invert distortion and minimize signal degradation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If chromatic dispersion compensation is performed in optical transmission, then signal quality is improved, but nonlinear distortion degradation is not adequately suppressed

Engineering Contradiction:

Improvesignal qualityVSAvoidnonlinear distortion

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies phase conjugation to convert nonlinear distortion, which is normally harmful, into a beneficial effect. By generating a phase-conjugated signal that contains inverted nonlinear distortion, the system enables cancellation of distortion when the conjugated signal is combined with the original signal at the receiver, thereby suppressing harmful nonlinear effects while maintaining chromatic dispersion compensation

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent implements preliminary anti-action by pre-compensating for chromatic dispersion and generating phase-conjugated signals before transmission. The phase conjugation process creates a signal with inverted phase characteristics that will counteract nonlinear distortion accumulated during transmission, effectively preparing an opposing force against the harmful distortion before it fully develops

Inventive Principle:

Principle #9Preliminary anti-action

2Reliability

If phase conjugation processing is applied, then nonlinear distortion cancellation is improved, but device complexity increases

Engineering Contradiction:

Improvenonlinear distortion cancellationVSAvoidoptical repeater complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges chromatic dispersion compensation and phase conjugation processing into a single integrated optical repeater unit. By combining these functions in one device rather than using separate components, the system achieves effective nonlinear distortion cancellation while minimizing the increase in overall device complexity through functional integration

Inventive Principle:

Principle #5Merging (Combining)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Maximizes the cancellation effect of nonlinear distortion in multi-span optical transmission, effectively reducing signal quality degradation at the receiving end by employing phase conjugation and chromatic dispersion compensation in each optical relay unit.

Implementation Method 1

determines phase conjugation processing in the optical repeater based on the wavelength information and the transmission line information... performs phase conjugation processing on an electrical signal according to a received optical signal based on the acquired phase conjugation processing information

Methodology Applied

Scientific EffectPhase conjugation:

Implementation Method 2

determines a chromatic dispersion compensation amount for compensation in the optical repeater based on the wavelength information and the transmission line information... performs chromatic dispersion compensation processing on an electrical signal according to a received optical signal based on the acquired chromatic dispersion compensation amount

Methodology Applied

Scientific EffectChromatic dispersion compensation:

Data Source

PatentUS12574119B2Optical network system, control method, and control device

Publication Date: 2026.03.10 NEC CORP

AI summary

An optical network system includes an optical repeater and a control device controlling the optical repeater. The control device: manages wavelength information of optical signals transmitted and received by the optical repeater in a path of the optical network and transmission line information of optical transmission lines connected to the optical repeater; determines a chromatic dispersion compensation amount for compensation in the optical repeater based on the wavelength information and the transmission line information; and determines phase conjugation processing in the optical repeater based on the wavelength information and the transmission line information. The optical repeater: acquires the chromatic dispersion compensation amount and phase conjugation processing information from the control device; performs chromatic dispersion compensation processing on an electrical signal based on the chromatic dispersion compensation amount; and performs phase conjugation processing on an electrical signal based on the phase conjugation processing information.