Optical Power Measurement in Passive Optical Networks

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional power meters in passive optical networks (PONs) struggle to distinguish and measure optical power in multiple-wavelength systems, particularly in next-generation PON2, where multiple downstream signals propagate at different wavelengths, and are not well-suited for coexistence with legacy architectures, requiring manual reconfiguration for each measurement.

Innovation Solution

A device and method for optical power measurement that includes an upstream wavelength analyzer to determine the upstream spectral characteristic, a downstream optical power meter assembly to measure downstream signal power, and a processing unit to identify the pass/fail thresholds based on the spectral characteristics, allowing for auto-adaptation to different network standards and operation modes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional power meters are used to measure optical power in PON systems, then measurement capability is provided, but the ability to distinguish and measure multiple downstream signals at different wavelengths is lost

Engineering Contradiction:

Improveoptical power measurement accuracyVSAvoidmulti-wavelength signal discrimination

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The device segments the measurement function by separating upstream wavelength analysis from downstream power measurement. The upstream wavelength analyzer independently determines the upstream wavelength, which then guides the downstream optical power meter assembly to measure only the specific downstream signal of interest among multiple WDM channels, enabling precise multi-wavelength measurement.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The processing unit acts as an intermediary that receives the upstream wavelength information from the upstream wavelength analyzer and uses it to control the downstream optical power meter assembly. This intermediary coordinates the two measurement functions, enabling the system to adaptively measure the correct downstream signal based on upstream spectral characteristics.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If manual reconfiguration is performed for each network standard, then measurement compatibility is improved, but measurement time and operational complexity increase

Engineering Contradiction:

Improvenetwork standard compatibilityVSAvoidmeasurement setup time

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The device performs self-configuration by automatically determining the upstream wavelength using the upstream wavelength analyzer. Based on this measured upstream wavelength, the processing unit automatically identifies the corresponding downstream signal of interest and configures the downstream optical power meter assembly without requiring manual intervention, enabling adaptive measurement across different network standards.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The upstream wavelength analyzer performs preliminary measurement of the upstream wavelength before the downstream power measurement takes place. This preliminary action provides the necessary information for the processing unit to pre-configure the downstream measurement settings, ensuring the correct downstream signal is measured without time-consuming manual reconfiguration.

Inventive Principle:

Principle #10Preliminary action

3Ease of operation

If total optical power of all downstream signals is measured, then measurement simplicity is maintained, but the ability to identify specific WDM channel power is lost

Engineering Contradiction:

Improvemeasurement simplicityVSAvoidspecific WDM channel power identification

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

Instead of measuring the total power of all downstream signals uniformly, the device applies local quality measurement by focusing the downstream optical power meter assembly on measuring only the specific downstream signal of interest at the wavelength determined from upstream analysis. This provides precise power measurement for the specific WDM channel while maintaining operational simplicity through automatic wavelength identification.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS10574378B2Optical power measurement in a passive optical network

Publication Date: 2020.02.25 EXFO

AI summary

A device and method for optical power measurement in an optical network supporting upstream and downstream signal propagation along an optical transmission path. An upstream wavelength analyzer receives upstream light extracted from the optical transmission path and is configured to determine an upstream spectral characteristic of the extracted upstream light. A downstream optical power meter assembly receives downstream light extracted from the optical transmission path and is configured to measure an optical power parameter of a downstream signal. A processing unit is configured to determine, based on the upstream spectral characteristic, at least one pass/fail threshold associated with the measured optical power parameter of the downstream signal.