1. Brian Teague – Product Line Manager November 2016
Sources of End Face Contamination on Fiber Optical Interconnects and Recommended Best Practices for Removing the Contaminates
Brian Teague – Product Line Manager
November 2016

2. Program Agenda Do It Right The First Time Residues Contamination
Dust Contamination
Electrostatic Charge
Solve the Problem

3. Do It Right The First Time
A study of 300 reported failure causes of fiber cabling revealed:
57% (172) dig ups
7% (22) craft and workmanship failures
5% (16) unknown
4% (13) rodents
4% (11) fire
3% (8) defective cable
2% (6) flood
1% (4) lightning
If you don’t have time to do it right, when will you have time to do it over? - Albert Einstein
Source: Sumitomo Lightwave “Optical Fiber Cable Design & Reliability” P. VanVickle May 2014 for IEEE802

4. Industry Statics on Fiber Connector Cleaning
HTI Martin Technical Research Survey of 89 network owners and network contactors study on network failure.
80% of Network Owners and 98% of Network Contractors have experienced fiber failures during the installation process
82% of Network Owners and 92% of Network Contractors use IPA as the cleaning agent
12% of Network Owners and 30% of Network Contractors use compressed air for cleaning
Truck Roll Back Expense Stats:
“The average truck roll is ~ $150 NOT including labor. Labor $50/hour. The average PRISM truck roll results in a three hour visit.” Matt Olson, Principal Architect at CenturyLink at CONF 2014
National Association of Regulatory Utility Commissioners estimates a truck roll costs upwards of $275 in 2014 and that does not take into consideration the cost of parts.

5. Case Study on Installation Expenses
US National Association of Telecommunications Officers & Advisors
Installation of new fiber cables added to an existing community network
Adding 11KM of new fiber cables to connect to 9 buildings - schools, fire station and government buildings
Medium density suburban area outside of Washington, DC
Using 144F SM cable fiber for right of way

6. Case Study on Installation Expenses
80% of project expense was spent on labor
Understanding and avoiding problems reduces the variability installation labor expenses
An upfront investment in fiber cleaning consumables reduces initial upfront labor expenses and truck roll back expenses

7. Contamination Issues - Residues
Residues change the refractive index of the transmission medium
The higher the frequency of the light signal, the greater the refractive angle
Changes in the refractive angle causes a phenomenon called chromatic aberration
Light Refraction Through Glass & Water
Chromatic Aberration
60°
41°
Water
60°
35°
Glass

8. Cross Contaminated IPA
Sources of Residue Contamination
Outgassing of end caps
Plasticizers residues in components
Skin Oil, Vegetable Oil, & Hand Lotion
Cross contaminated cleaning alcohol
Humidity
Skin Oil
Source: Image taken with PROMET FiBO
Cross Contaminated IPA
Source: Image taken with PROMET FiBO

9. Isopropyl Alcohol Cross Contamination Issues
Alcohol is hygroscopic meaning it attracts water
Highly flammable and high vapor pressure
“Menda”-style bottles pull air in to dispense the alcohol
Pre-saturated wipes packaging breaks down over time and leeches into wipe

10. Contamination Issues – Fusion Splicing
Fiber Ø125μm
Fiber Core
Ø 9μm Singlemode
Ø 50μm for OM3/OM4
Dust from paper based wipe
Water residue from cross contaminated IPA
Dust from cross contaminated IPA
Dirty electrodes and dust in fiber grooves

11. Source: RSM using RSM1 scope
Dust Contamination is Common
Source: RSM using RSM1 scope

12. Contaminations Issues – Dust Particulates
Back Reflectance
Insertion Loss
Dust interferes with physical contact creating small air gaps and permanent end face defects
Residues in signal path change index of refraction between the connector pair causing signal loss
Absorption Loss

13. Source: NASA Electronics Parts & Packaging Program
Sources of Dust Contamination
Common Internal Contributors:
Dead skin, hair, and clothing lint
Packaging and construction materials
Foam based swabs and paper based wipes
Connector wear debris and dirty test assemblies
Zinc whiskers from electroplated surfaces
Protective end caps for connectors and adapters
Left: Dust from top of cabinet. Right: Paper Fiber(wood) from inside drawer
Source: Karen Brynjolf Pedersen & Morten Ryhl-Svendsen National Museum of Denmark
Zinc Whiskers
Source: NASA Electronics Parts & Packaging Program

14. Sources of Dust Contamination
Environmental Contributors:
Electricity generation & vehicle emissions
Aerial blown dirt and sands
Plant pollen and molds
Concrete dust
Flower Pollen
Source: Dartmouth College Electron Microscope Facility
Coal Ash
Source: University of Kentucky Center for Applied Energy Research

15. Electrostatic Charge – Contact Friction
Before material contact,
materials are not charged
At material separation,
materials are oppositely charged - + - + - + - + -
Material 2
-3 Electrons
+3 Protons
0 Net
Material 1
-2 Electrons
+3 Protons
+1 Net
Material 2
-4 Electrons
+3 Protons
-1 Net
Material 1
-3 Electrons
+3 Protons
0 Net

16. Electrostatic Charge - Attraction
The Role of Electrostatic Charge Effect on Contamination of Fiber Optic Connectors and Ways of Eliminating it
by T. Berdinskikh, A. Fisenko, J. Daniel, J.Bragg, D.Phillips of Celestica Applications of Photonics Technology 5, 420 (Feb 2003)
ST Connector is cleaned and image captured
ST placed 2mm above iron dust
ST placed 4mm above iron dust
ST placed 2mm above nickel dust
Conclusions:
The contact friction of the dry wipe created an electrostatic charge on the ceramic ferrule surface
The oppositely charged dust particles bonded on the ferrule surface quickly

17. Electrostatic Charge - Decay
Base line image of cleaned ST
7 Day Observation
14 day Observation
30 day Observation
Conclusions:
The electrostatic charge on the ferrule surface came after the contact friction from the dry wipes
The electrostatic charge remains and does not go away on its own

18. Sources of Electrostatic Charge
Dry wiping connectors with wipes that do not have dissipative properties
Cleaning only with compressed air
Inserting or removing a connector into the adapter during mating
Removing the protective end cap from the connector or adapter
Connecting to test equipment
Using foam based cleaning sticks to dry an end face

19. Installer Best Practice
Clean It NO
Is It Clean?
Inspect the end face
YES
Connect It!
Always clean just before mating.
Cleaning process takes < 10 secs (How much time does it take to trouble shoot a problem?

20. Best Practices for Removing Contamination
Wet-dry cleaning is most effective for removing all forms of contamination and eliminates electrostatic charge
Use optical grade cleaning fluids that are zero residue and fast evaporating
Use cleaning fluids in hermitically sealed packaging to prevent cross contamination
If you must use IPA, change it out frequently and thoroughly wash and dry (no water) the container
When using stick cleaners, one stick per end face to avoid cross contamination
When using sticks, rotate them in the same direction 6x to 8x times
Mechanical cleaners are good for light and medium levels of contamination levels
Boxes and tubs of optical grade wipes plus cleaning fluid are best for splicing pigtails to bulk cable
Clean your test assemblies and ports of the test gear
Always clean both ends of a mated connector pair just before mating

21. Cleaning Selection Guide
What kind of contamination have the connectors been exposed to?
What are the work conditions like at the work site?
Residues, Dust, Both
Light, Medium, Heavy Levels
Ventilation and Air Flow
Flammability Concerns
Operating and Storage Conditions
How do the cleaning fluids need to be transported ?
What are regulatory requirements?
Air Shipment Requirements
HAZMAT Restrictions
Spill and Leak Concerns
DOT Restrictions
RoHS, REACH, GHS Compliance
Substance

22. Final Thoughts Best Practices for Cleaning Fluid:
Use hermetically sealed containers to avoid cross contamination
Less is more – Dispense just enough to clean a connector
Best Practices for Sticks & Swabs:
Rotate stick at least 6X in a single direction
Limit force to about the same pressure you would use for a writing pen
Never excessively scrub the end face to prevent scratching with wear particulates
Best Practices for Wiping Connectors:
Wipe connectors in a single direction
Always wipe MT based connectors (i.e MPO) in a single direction vertical direction ↑↓ → ↕
Tilt end face for APC so the 8˚ angle is touching the wipe
General Best Practices:
Never look directly into a connector with the bare eye
Inspect, clean if necessary & re-inspect
Reusing wipes & sticks causes cross contamination

23. Thank You for your time. Questions?
Technical Support
Local Contact
Brian Teague
Product Line Manager C:
(US Based)
Jerald Chan
Asia Market Manager C:
(Singapore Based)