Fiber Optic Connector Cleaning

Clean fiber optic connectors help maintain a high-quality network. Contamination can significantly reduce signal strength and lead to test failures. Cleaning is a simple step that eliminates one of the leading causes of these problems.

These kits come with either a solvent pen or a cleaning cube. Both are lint free and made with a non-woven material. The solvent pen is spring-activated to dispense the proper amount of solution for the job.

Dry Cleaning

Cleaning fiber optic connectors regularly prevents poor signal quality and downtime. It fiber-optic-connector-cleaning also increases their lifespan and reduces maintenance costs. The key is to use the proper procedure and products to ensure clean, consistent results.

Lint-free wipes and cleaning sticks/swabs are essential for dry cleaning of fiber optic connectors. These specialized tools help to remove contaminants without damaging the end-face of the connector. To ensure the best results, choose a wipe or stick that is lint-free and of an appropriate size for the connector. The ideal cleaning solution is an isopropyl alcohol-based cleaner that evaporates quickly and leaves no residue.

The most important thing to remember when selecting a cleaning fluid is that the chemical properties of the fluid must enhance the mechanical action of the wiping material or tool. This is because the triboelectric charges created by the contact of the cleaner and end-face can cause abrasion or scratches on the fiber optical surface.

A combination wet-to-dry cleaning method is the recommended and preferred way to clean fiber optic connectors. The process is simple: Deposit a small amount of reagent grade isopropyl alcohol on a clean lint-free wipe or swab, then wipe the connector face from the wet area of the wipe across to the dry area. The wet-to-dry cleaning process keeps the amount of solvent to a minimum, avoiding flooding and cross-contamination.

Wet Cleaning

Wet cleaning is more aggressive than dry cleaning and will remove any airborne contamination as well as light oil residue from the connector. It is recommended that you use a solution specifically designed for fiber optics as other general purpose cleaners could cause smudges and scratching of the end face of the connector. To perform a wet cleaning, apply the alcohol to a lint free fiber optic cleaning cloth and then wipe the connector from the wet area towards the dry section of the cleaning cloth. Be sure to move the cleaning cloth straight across the connector and not in a figure 8. This will prevent any smudges from being left on the end face of the connector.

During the wet cleaning process, be sure to use powder-free gloves or finger cots to avoid scratching or damaging the surface of the connector. Also be sure to turn off any laser sources as these can damage the end face of the connector. It is recommended to pre-inspect the connector using a fiberscope or inspection scope at 200x magnification to identify any contamination.

When using either dry or wet cleaning, the quickest and most reliable method is to use a combination cleaning process. A combination cleaning uses a dry cloth to inspect the connector and then immediately cleans it with a small amount of reagent grade isopropyl alcohol or methanol on a proper lint-free fiber optic cleaning cloth. This process eliminates the problems with both dry and wet cleaning techniques while delivering a superior result.

Isopropyl Alcohol

Many fiber optic cleaning kits include a dry lint free pad and isopropyl alcohol. Always check the packaging for specific directions and inspect after each use. If you have to wet clean, start with a fresh lint free pad moistened with reagent grade isopropyl alcohol (91% or better). Do not use cotton swabs, they might leave threads behind or grind contaminates into the end face of the ferrule. Drag the lint free pad gently across the end face of the LC connector with medium pressure. This will remove any liquid and prevent the re-deposition of contaminates on the surface of the connector.

Isopropyl alcohol (IPA) is the solvent of choice for most fiber engineers and technicians. However, IPA is a poor solvent for the wide range of soils that can contaminate optical fiber connections. IPA is hygroscopic, which makes it prone to drawing water and other impurities into the mated surface of the connector (Blair, 2006). Moreover, IPA evaporates more slowly than the other common organic solvent cleaners and can leave a residue on the connector surface after it is mated (IPC-8497-1, 2005, p. 13).

In addition, IPA is a flammable substance that must be handled with care and used only in well-ventilated areas. Exposure to IPA vapors can cause dizziness, nausea, eye irritation, and respiratory depression. Inhalation can also result in drowsiness, ataxia, stupor, and coma.

Cleaning Tools

Using cleaning tools that are designed for fiber optic connectors will help you avoid contamination that can damage the sensitive components inside your devices. These Fiber Optic assemblies cleaners often include lint-free wipes, cleaning sticks and inspection scopes that remove debris without scratching the connector end faces. In addition, these tools are available in kits that include a variety of cleaners and solvents to address different types of contaminants found on fiber optic end faces.

Whether you’re using dry cleaning or wet cleaning, it’s important to always inspect the connector under magnification before and after the cleaning process. This will ensure the end face is clean and there are no remaining residues from previous cleaning attempts.

A combination of both dry and wet cleaning methods can offer the best results. For example, you can use a reel-based cassette cleaner like a Cletop or OptiPop to clean the connector with medium pressure, then wipe it with a lint free, non-woven polyester cloth to finish cleaning the surface.

Another option is to use a cleaning card that has 12 different cleaning zones on a small, easy-to-carry card. This card can be used with a cleaning solvent such as lint-free alcohol or IPA, and it will clean multiple end faces in one stroke. This is especially helpful for cleaning LC connectors in remote locations.