The Fiber Optic Association, Inc. (FOA)

FOA 1-Page Standard On Fiber Optic Connector Inspection and Cleaning The latest FOA 1-Page Standard is FOA-8, Inspection and Cleaning of Fiber Optic Connectors https://lnkd.in/gTBGzR4F. The one international standard on inspection is ISO/IEC-61300-3-35 which is actually aimed at automatic inspection using a video microscope. The FOA standard covers both visual and automated inspection as well as guidelines for cleaning. And we added links to the FOA Guide page on inspection and cleaning for additional information https://lnkd.in/gczm-GU8. Here are all the current FOA 1-Page Standards FOA Standards   Understandable versions of industry standards (overview) https://lnkd.in/ggu2EVeH  FOA Standard FOA-1: Testing Loss of Installed Fiber Optic Cable Plant https://lnkd.in/g6Vn-bgX FOA Standard FOA-2: Testing Loss of Fiber Optic Cables, Single Ended https://lnkd.in/gPqHzYmW FOA Standard FOA-3: Measuring Optical Power https://lnkd.in/ge-BQaMF FOA Standard FOA-4: OTDR Testing of Fiber Optic Cable Plant https://lnkd.in/gDvj-Gph FOA Standard FOA-5 Fiber Optic Datalinks   https://lnkd.in/gF-SMQRD FOA Standard FOA-6: Fiber Optic Cable Plant    https://lnkd.in/gScTkrN7 FOA Standard FOA-7: Mode Conditioning For Testing Multimode Fiber Optic Cables https://lnkd.in/gP2wbUFu FOA Standard FOA-8: Inspection and Cleaning of Fiber Optic Connectors https://lnkd.in/gAS6tGCw

The Evolution Of Cleaning Connectors Cleaning properly has evolved with the development of special cleaning products. In the beginning, cleaning was done primarily with 99% isopropyl alcohol as a cleaning agent, using clean, lint-free wipes. The proper process was to wet a wipe with alcohol and wipe the connector ferrule end several times, then dry it with a dry wipe. Without the drying process, the alcohol would evaporate and leave a residue. Alcohol had another problem; it was flammable. A more convenient cleaning could be done with packaged wipes saturated in alcohol. When ready to clean connectors, you opened the package and exposed the wipe. A quick wipe or two did a good job of cleaning the connector. After the pad started to dry out, you could do a proper wet/dry cleaning. Medical wipes were not useful since they contained alcohol diluted with water. Chemical cleaner suppliers soon came up with better cleaners, many derived from those used in electronic component manufacturing. Most supply packaged wipes like this cube with a roll of wipes. There are numerous suppliers of cleaning solutions and kits designed especially for fiber optics. Dry cleaning products were developed that required no solvents. The connector end was wiped along a special fabric tape in a cassette that would clean the connector. Special small swabs were developed to clean a single connector or reach inside mating adapters or transceiver ports to clean hidden connectors. Connectors other than the normal ferrule connectors like the SC or LC require special cleaning tools and procedures. Manufacturers offer special cleaners for array connectors like the MPO, expanded beam and some multi-fiber military connectors. Clean Just The Ferrule End? Dirty connector bodies like the one shown above can be cleaned by the swabs used to clean the insides of connector mating adapters. Insert the swab and wipe around the ferrule and connector body. Inspect-Clean-Inspect The goal of cleaning is to have a perfectly clean connector, so the process is to inspect and if necessary clean the connector. After cleaning, it is necessary to inspect it again to ensure the cleaning was properly completed. Repeat as necessary until the connector is acceptable. More information on Cleaning: FOA Guide: Visual Inspection And Cleaning Of Connectors https://lnkd.in/gczm-GU8 Clearfield: Inspect Then Connect https://lnkd.in/geBxy3Uj Chemtronics: How To Clean And How NOT To Clean Fiber Optic Connectors https://lnkd.in/gfT48N_j AFL: Cleaning and Inspecting Resources https://lnkd.in/gDzJpnMT

Connectors Get Dirty (part 2 in series) Connectors can get dirty easily if the ferrule end is exposed to a dirty atmosphere or touched to a dirty surface (like a fingertip.) Here is a sample of connectors: See Image #1: A clean connector ferrule end and ones with dirt, oily contamination and scratches Connectors, even those on factory-made patchcords, can be dirty. The plastic protective caps on the connector ferrule can introduce dirt themselves (which is perhaps why they are called "dust caps.) All connectors should be inspected, cleaned if needed and inspected to ensure the cleaning was done thoroughly, before mating to another connector or inserting in a transceiver port. Image #2 These are a series of photos a the same clean connector ferrule on the top left and a dirty ferrule on the bottom left after repeated mating of the two. The final two photos show the dirt cleaned away but damage to the ferrules caused by the dirt. (Sticklers photo) Image #3 Inspection of connectors for dirt and contamination is generally limited to a small area around the fiber itself. The size of the area covered in the IEC 61300-3-35 standard for connector inspection is shown in the photo below. The area inside the red circle in the photo below shows the total area covered in this international standard for connector inspection used for automatic inspection by video microscopes. However there is a lot more area on the end of the connector ferrule, plus the sides of the ferrule which can get dirty from mating cycles, and the inside of the connector body which can transfer dirt to the connector ferrule. Note the connector on the right has a clean ferrule and a very dirty connector body. In a future FOA Newsletter we will cover connector inspection and elaborate on this issue.

Spring Cleaning (Fiber Optic Connector Cleaning), Part 1 By Jim Hayes As Spring approaches in the Northern Hemisphere, it brings a traditional activity, "Spring Cleaning." It's time to open doors and air the place out, while cleaning everything that has been ignored over the Winter. The idea of Spring Cleaning has been applied to fiber optics too, but not in an appropriate way. Occasionally an article will show up online suggesting that Springtime is a good time to do routine maintenance on a fiber optic network. The problem is that fiber optic networks do not require routine maintenance https://lnkd.in/gcb2Yii3. Cable plants should be installed properly and not touched except for moves/adds/changes or troubleshooting. Unmating a fiber optic connector for inspection and maintenance as suggested by one article just creates an opportunity for contaminating that connection, not to mention bringing down the link if the fiber is in use. "If it ain't broke, don't fix it" is good advice. However cleaning is very important in fiber optics. Dirty connectors are one of the major problems in fiber optics, causing high connector loss, high reflectance and contaminating transceivers and even other clean connectors if mated with them. Network operators claim that 15-50% of all network problems can be traced to dirty connectors causing connection problems. One of the first visits we made to a fiber optic network user's facilities many years ago, we watched as a technician showed us a Biconic connector and explained that the fiber was so small that it was very sensitive to dirt on the connector. Every connector needed cleaning before mating, he explained, and he demonstrated how he did it by wiping it on his shirt several times with a circular motion like this: While his intentions were good, his method, at least with our current knowledge, was not. The shirt was neither clean or lint free. It probably added more contamination to the connector than it removed (pizza sauce?).

The March FOA Newsletter is online now https://lnkd.in/gJx2Egu9 Features this month: • Cleaning Connectors • Broadband Communities Summit • OFC Turns 50 • ISE Expo • FOA News •What's New And Popular On FOA Website News: • End Of An Internet Era • Fiber: BEAD And AI • WiFi Predictions For 2025 Technical:  •TIA Documents Network Specifications • Problems With MPO Connections • What Technical Advisors Are Telling US Worth Reading Lots of interesting articles to read, watch or listen to. Q&A: Interesting questions from our readers Workforce Training/Fiber U: • Types Of Work Done By Fiber Techs • FOA-Approved School News • Fiber U MiniCourses Resources:  New FOA Technical Resources

Some Reader Questions Submitted to the FOA Online Newsletter: Reducing Attenuation: Q: What is the best way of reducing fiber optic attenuation A: In any cable plant, the loss comes from the loss of the optical fiber and loss at joints (splices or mated connectors) plus any stress losses caused by bad installation of the cable. For a give cable plant, the options are lower loss fiber or lower loss at joints. If you need lower loss, the fiber loss is a function of the attenuation coefficient (dB/km) times the length (km)., eg 0.4dB/km X 10 km = 4.0 dB. So if the length is fixed, you can try to find lower loss fiber. The loss at joints is a function of the methods of joining. Splices have very low loss - 0.1 dB or less on singlemode fiber. slightly more on multimode fiber. Connections can have loss from 0.1 dB to more than 0.5 dB, depending on the type of connector chosen. On SM fiber, if connectors are top quality fusion splice on connectors and are properly cleaned loss can be under 0.2 dB. Some connectors like the MPO multifiber array connector can have losses up to 0.75 dB or more. Replacing connectors with fusion splices is also a way to lower loss at joints. Here is a reference to loss budgets: https://lnkd.in/ghM66VAG Safe handling of fiber optics: Q: Is there a particular glove recommended for safe handling of FO's? I appreciate dexterity in handling may be important, but glass shards / splinters into the skin is a significant risk as well. There are vague references to using gloves, but looking for the preferred / recommended type of glove. A: Gloves are hard to use when dealing with bare fiber but thin surgical gloves work for some people. Regular gloves are too clumsy and some cannot stop fiber penetration. When working with cable, especially armored cable or large cables, work gloves are good protection. You can also get Kevlar gloves that resist cuts but are flexible and cooler. They are often advertised as kitchen gloves to prevent knife cuts. Fault Location: Q: How do you detect fault location of fiber optics in the field? How much time it takes to detect geo-location? A: The simple answer is an OTDR but the physical location depends on cable plant documentation and location data like GIS data. The time depends on the availability of data and equipment. Minutes to days?

More Variations/Problems In MPO Array Connector Connections At the latest TIA meetings a presentation pointed out a problem with MPO array connector connection mismatches. MPOs standards have created a complicated connection situation, now already around 40 pages, fully taking up half of the TIA-568 fiber standards. The problems are caused by the options of connecting 12, 16 or more fibers in a row to duplex or multifiber transceivers. MPOs are now being used for singlemode fiber, requiring angled (APC) ferrules to reduce reflectance at connections. Multimode is now using angled ferrules for some applications also to reduce reflectance. The problem arises because the standards allow two options for angles, up or down in relation to the connector key. To properly mate APC connectors, the angles must be properly aligned. Because the angle is not fixed in relation to the key and MPO hardware has mating adapter options for keys aligned or opposite, it is possible in some standard options to have connectors mated where the angles do not match, such as in the Type B cable connections shown above. Single fiber connectors like SCs or LCs do not have this kind of option if one follows the color codes since they do not have any options on the alignment of the angle. Now that this has been brought to the attention of the standards committee, it will have to be addressed in the standards to ensure users know the problem. Photo MPO APC mismatch problem, from presentation at TR-42.11 meeting presentation.

More on Submarine Cables: Back in January 2025, Sweden sixteen vessel after new cable breach in Baltic Sea Sweden is investigating damage to a submarine cable linked to Latvia, the latest breach in the Baltic Sea region where European authorities are on high alert. Swedish authorities have launched a preliminary investigation into suspected sabotage and detained a vessel in the Baltic Sea after damage was reported to an undersea data cable between Latvia and Sweden. Swedish officials said Monday that authorities had boarded the Malta-flagged Vezhen. The Swedish national police, coast guard and armed forces are taking part in the investigation, senior prosecutor Mats Ljungqvist said in a statement late Sunday. The Bulgarian shipping company that owns the detained ship denied any involvement in sabotage, describing the incident as an emergency situation that resulted from bad weather. The company said it was ready to cooperate with the investigation. This is the latest in a string of ruptures of undersea cables in a vast underwater network of conduits that carry gas, electricity and internet traffic to millions of people across Northern Europe. Four cases in the Baltic Sea since late last year have caused no major disruption to public life but have rattled European security officials. Washington Post January 27, 2025 https://lnkd.in/gssG8_CU

NYTimes, January 31, 2025 Norway Seizes Russian-Crewed Ship Suspected of Cutting an Undersea Cable https://lnkd.in/gzz2TXrf Crew members on a French Navy plane patrolling over the Baltic Sea last week as part of a NATO mission to protect undersea cables and pipelines.Credit...John Leicester/Associated Press The authorities in Norway have seized a Russian-crewed ship that is suspected of damaging an undersea cable in an act of sabotage in the Baltic Sea, the Norwegian police said on Friday. They were acting on a request from the Latvian authorities and on an order issued in Norwegian courts, the police said in a statement, after an undersea cable that runs between Sweden and Latvia was damaged this week. It is the latest in a growing number of acts of damage or sabotage to undersea infrastructure in the Baltic Sea, including to cables used for communication and for the distribution of electricity. In response to one such instance in December, NATO has stepped up its patrol and surveillance operation in the Baltic Sea.