Multi-Fiber Array Optical Loss Testing Calibration

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Solution Overview

Problem

Existing optical loss testing methods for multi-fiber array cables face uncertainty due to varying polarity arrangements, leading to measurement inaccuracies of up to +/-0.3 dB, which is unacceptable for some applications.

Innovation Solution

A calibration step is introduced to characterize the relative optical power response of multiple power meters, allowing for the correction of optical loss measurements by calculating and applying a relative optical power response factor to each power meter, thereby eliminating measurement uncertainty.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple power meters are used for optical loss testing of multi-fiber array cables, then testing capability and coverage are improved, but measurement precision deteriorates due to multi-powermeter uncertainty reaching +/-0.3 dB

Engineering Contradiction:

Improvetesting capabilityVSAvoidmeasurement precision

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The patent applies preliminary action by performing a calibration step before actual optical loss testing. A reference measurement is taken using a known good cable to establish baseline power levels for each power meter. This preliminary calibration data is then used to correct subsequent measurements, eliminating the multi-powermeter uncertainty while maintaining the ability to test multiple fibers simultaneously.

Inventive Principle:

Principle #10Preliminary action

2Adaptability or versatility

If polarity arrangement of multi-fiber array cable is not known a priori, then adaptability to different cable types is improved, but measurement precision deteriorates due to correspondence mismatch between light sources and power meters

Engineering Contradiction:

ImproveadaptabilityVSAvoidmeasurement precision

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent uses feedback by measuring the actual optical power received at each power meter and comparing it against expected reference values. Based on this feedback, the system can identify the correct polarity arrangement and adjust the correspondence between light sources and power meters accordingly. This feedback mechanism enables the system to adapt to different cable types while maintaining measurement precision.

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

This approach significantly reduces measurement uncertainty, providing more accurate optical loss testing across varying polarity arrangements, enhancing the reliability of multi-fiber array cable testing.

Implementation Method 1

a second test instrument comprises an array of power meters (PM_i)

Methodology Applied

Scientific EffectOptical power detection: Photoelectric Effect

Data Source

PatentUS11067478B2Optical loss testing of multi-fiber array cables

Publication Date: 2021.07.20 EXFO

AI summary

There is provided an optical loss testing system for multi-fiber array cables an optical loss test method and a reference method therefor which overcomes at least part of the multi-powermeter uncertainty. A prior calibration step serves to characterize the relative difference in optical power response of the multiple power meters. This relative difference can then be used to correct the optical loss measurement so as to eliminate its effect.