Optical Module Power Feedback to Prevent Receiver Saturation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In passive DWDM systems, the lack of active components like optical fiber amplifiers leads to potential receive optical power exceeding saturation points, affecting receiving performance and potentially damaging receivers due to insertion loss.

Innovation Solution

Implementing an optical power adjustment method through out-of-band communication between optical modules using pilot tone signals to dynamically adjust transmit power based on receive power feedback, ensuring it does not exceed saturation points.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If optical power regulation is performed using existing switching devices and control methods, then optical power can be controlled, but insertion loss increases and optical power regulation precision deteriorates

Engineering Contradiction:
Improveoptical power regulation precisionVSAvoidinsertion loss
Core Design Contradiction:
Measurement precisionVSLoss of energy

Solution Approach 1:

The patent replaces mechanical/optical switching methods with an all-electrical control system. The optical switch is controlled by voltage signals generated through electrical feedback loops, eliminating the need for mechanical movement and associated losses. The control circuitry uses electrical fields to regulate optical power, substituting traditional mechanical switching with electrical control mechanisms.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the control parameter from mechanical switch position to voltage signal amplitude. By regulating the voltage applied to the optical switch through feedback control, the system achieves precise optical power regulation. The control circuit adjusts voltage parameters dynamically to maintain optimal optical power levels, improving precision while reducing insertion loss compared to fixed mechanical switching positions.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If complex control circuits are used to improve optical power regulation precision, then regulation accuracy improves, but device complexity increases

Engineering Contradiction:
Improveoptical power regulation precisionVSAvoidcontrol circuit complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The control circuit is designed to perform multiple functions: it generates voltage signals for the optical switch, processes feedback optical power information, and regulates output optical power. By making the control circuit multi-functional, the patent reduces the need for separate dedicated components for each function, thereby improving precision without proportionally increasing complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent implements a feedback control mechanism where the optical power regulation circuit receives feedback about the actual optical power output and adjusts its operation accordingly. This feedback loop enables precise regulation by continuously monitoring and correcting deviations, achieving high accuracy while keeping the control logic relatively simple through iterative adjustment rather than complex predetermined control algorithms.

Inventive Principle:
Principle #23Feedback

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

Ensures receiving performance by preventing optical power saturation, thereby protecting receivers and maintaining system integrity.

Implementation Method 1

an optical switch that transforms electrical signals to optical signals in response to an applied voltage

Methodology Applied
Scientific EffectElectro-optic effect: Electro-Optic Effects

Data Source

PatentEP3982562B1Optical power regulation method and device
Publication Date: 2026.04.29 HUAWEI TECH CO LTD
  • EP3982562B1 patent drawingFigure 1~2
  • EP3982562B1 patent drawingFigure 3~4
  • EP3982562B1 patent drawingFigure 5~6

AI summary

Embodiments of this application provide an optical power adjustment method and an apparatus, to adjust optical power of an optical signal sent by a transmit end, so that the optical power does not exceed an optical over-saturation point of a receive end and therefore receiving performance of the receive end is ensured. A specific technical solution in the embodiments of this application is as follows: A first optical module obtains a receive optical power value of a peer second optical module. Then, the first optical module adjusts transmit optical power of the first optical module based on the receive optical power value, and sends a next optical signal based on adjusted transmit optical power.