The Impact of Connector Qualityon Network Elements

Many thanks to Sherlon Kauffman of US Conec Ltd. and the Team at Fiber Instrument Sales

Presented by Jim Fasano, Director of Strategic Accounts

Training Objectives

• Identify the sources for poor connector performance such as various common contaminants that are in the environment

• Discuss and understand the impact that Optical Return Loss has on overall system performance (video signal degradation)

• Learn techniques and technologies developed to eliminate performance issues

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Connector end face cleanliness effects performance:• What is it?• Where does it come from?• Is it really that bad?

Look familiar??

You are not alone…

Fiber Optic Cleanliness, a Basic understanding of effects

Dust Particles Hand Lotion

Skin Oil and Dead Skin Flakes

Alcohol Residue

• Debris generated from normal wear in mating and de-mating

• Dry wall dust• Saw dust• Residues from end caps

(outgassing)• Skin oil• Suntan lotion• Alcohol residue• Water residue• Vegetable oil• Hand lotion• Dryer lint• Saltwater residue• Graphite

Common Contaminants

Common Sources of Contamination

1. Mishandling• Accidental touching transfers skin oil, hand lotion and vegetable oil • Lint generated from organic wipe materials (i.e. T Shirt, Jeans)

2. Environmental sources• Saw dust, sheet rock and paint fumes from construction• Particle debris from cardboard boxes• Dust in the air from HVAC systems• Condensation

3. Poor technique and use of inferior grade cleaning products• Oil droplets from canned propellant and outgassing of the rubber in the seals• Cleaning solvent residues that are not completely wiped away• Exposed containers of alcohol• Fabric deposited (i.e. left behind) from cleaning cloths

4. Normal Wear By-Products• Ferrule materials• Adapter material (i.e. sleeve, guide pin wear on MT connectors)• Connector components (i.e. springs, housing)• Endcap abrasion or mold residue

Causes of Network Failure

• The chart above is a summary of a study from NTT-Advanced Technology that polled network owner and cable installers on the sources of network failures

• 98% of cable installers and 80% of network owners answered “Yes” to having contamination be the root cause of a network failure.

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

Contamination of the connector end face

Poor polishing of the ferrule

Mistakes in attaching labels to the cable

Damage to the optical connector

Damage to ferrule end face

Defective splicing

Macrobend loss from poor routing

Cable Installer Network Owner

Impact of Dust Contamination

Dust particles can cause problems in three ways:

1. Dust on the core region will block the signal path

2. Dust may prevent proper physical contact

3. Dust can cause scratches and pitting defects

Lasting Effects of Contamination

Initial Clean EndfaceContaminated Endface

Mated 5 times dirty then cleaned results in severe permanent damage

Residue Contamination

• Liquid residues have different refractive indices than the fiber which can create problems during physical contact.

• Residue contamination commonly contributes to optical back reflectance.

Examples of liquid and oil

residues

Example of dried alcohol residue

Residue Cross Contamination

Connector ABefore Mating

Connector BBefore Mating

Connector AAfter Mating

Connector BAfter Mating

What should a clean fiber look like?

Zone A

Zone B

Zone C

Zone D

Notes:• All the data assumes a 125µm cladding fiber• Multimode uses 65µm to accommodate

62.5µm and 50µm• Defect is defined as existing entirely within

the inner-most zone which it touches• Source: IEC 61300-3-35• Alternate source: IPC-8497-1

Signal Degradation on an MT Fiber

BEST PRACTICES

Inspect. Clean. Inspect.

1. Always inspect both connectors before mating.

2. Mating dirty connectors may:– Cross contaminate both connectors – Scratch and pit the ferrule end face

3. Inspecting and cleaning before mating will:– Prevent permanent damage to connectors– Reduce trouble shooting time– Reduce material costs– Improve signal quality

4. Make keeping fiber optic connectors clean a priority.

– Develop inspection and cleaning procedures– Train your team regularly on how to inspect

and clean your connectors

Inspect connector

Clean?

Mate

Clean

Yes

No

Fiber Optic Cleaning Tools1990’s & early 2000’s

Application: (2) SC connectors (TX & RX)

Typical Cleaners: Wipes, Swabs, CLETOP,

“Other”

Dry Wipes

Fabric-based and paper wipes that provide a mechanical action to absorb residues and trap dust particulates

Examples include: Tissues, field cards, etc.

ADVANTAGES:•Cleans end face while disconnected from mating adapter•Common technique in the industry•Allows both dry & wet cleaning

DISADVANTAGES:•Cannot clean end face through mating adapter•Untrained operators can damage fiber end face•Must be protected from contamination until just prior to use•Some wipes can deposit fabric on the end face (self-contamination)

Solvents / Wet Clean

Solvents provide a chemical action to clean fiber optic connector end faces.

Examples include: Water, alcohol, HFE, etc.

ADVANTAGES:•Provides more aggressive cleaning of contamination•Very effective against oils and dried-on contamination

DISADVANTAGES:•Untrained operators can leave behind residue, which can be more difficult to remove than the original contamination•A dry clean is always required after a wet clean (i.e. two sets of tools for the operator)•May not be portable enough for some applications•May violate some customer MSDS requirements•Some solvents are flammable•Some solvents have storage and/or shipping limitations

Isopropyl Alcohol Residue

Sticks & Swabs

Swabs may be beneficial for cleaning connector end faces installed in adapters

ADVANTAGES:•Cleans the ferrule end face while installed in mating adapters•Allows cleaning of some specialty connectors without requiring disassembly of the connectors

DISADVANTAGES:•Cannot clean end face while disconnected from mating adapter•Can be more costly than other methods•Limited cleaning effectiveness due to the physical constraints of the adapter•Some swabs can deposit fabric on the end face (self-contamination)

Cleaning Cassettes

Relatively mature cleaning technology using a reel of specialty fabric

Examples include: OPTIPOP, CLETOP & NEOCLEAN

ADVANTAGES:•Low cost per clean•Faster cleaning times•Better consistency in cleaning performance•Refill packs for even lower cost per clean

DISADVANTAGES:•Cannot clean end face through mating adapter

NEXT GENERATION TOOLS

Refillable / Mechanical Cleaning Tools

NEW technology with optional refill cartridges

Examples include: NEOCLEAN-E Series tools

ADVANTAGES:•More eco-friendly•Cleans end faces in both mated (with adapter) and unmated conditions•Simple, One-hand operation•Faster cleaning times•Consistent cleaning performance

DISADVANTAGES:•Some tools have limited cleaning region•Some tools do not have a good method for keeping material on the track

Mechanical Cleaning Tools

Relatively new technology that advances a cleaning cloth across the end face in a controlled fashion

Examples include: IBC™ Brand Cleaning tools

ADVANTAGES:•Cleans end faces in both mated (with adapter) and unmated conditions•Simple, One-hand operation•Faster cleaning times•Consistent cleaning performance•Custom tools can be developed for specialty connectors

DISADVANTAGES:•Some tools have limited cleaning region•Some tools do not have a good method for keeping material on the track

Selecting a Cleaning Methodology

• What connector types will need to be cleaned?

• What type of contaminates will my technicians encounter?

• Where are the connectors physically located in the network?

• How many connector ends will need to be cleaned for this project?

• What type of environment have the connectors been exposed to?

• What type of environment will my technicians be cleaning in?

Optical Return Loss and Reflection impact on Systems

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• What is Optical Return Loss?

• What is Reflection?

• What is the impact on Systems?

• Why are connectors/splices of concern?

Overview

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• Optical Return Loss is the Total % of Power reflected back from points along an optical path.

• Optical Return Loss and Back Reflection impacts:- Transmission Systems with Laser Transmitters- Any Analog transmission system (video)- Any system where there is a high concentration of interconnecting

points• Effects!

- Increased receiver noise and an increase in Transmitter noise - Poor video clarity in Analog systems, Pixilation in Digital video - Overall loss of optical power, increasing cost and complexity of active

optical components as well as minimizing distances between points.

Minimizing Optical Return Loss

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• Minimize reflective points by:

- Maintain clean and contaminant free optical connector ends

- Eliminate mechanical splicing of any fiber (Connector terminations, field splices, etc.)

- Minimize connection points and unnecessary splices

- Educate all technicians of the importance of “Optical Return Loss” and potential effects.

Any Questions?

Thank you