Fiber Optic Testing

Fiber optics cabling is the core of today's datacom networks. Optical fiber is the predominant media type for mission-critical datacenter links, backbone within buildings, and longer distances for campus networks. As network speeds and bandwidth demands increase, distance and loss limitations have decreased, making fiber optic cabling certification testing more important than ever.

Inspecting Fiber Optic Cable for Light Loss

For decades, fiber optics have been inspected and cleaned to ensure the proper passage of light. While fiber optics inspection and cleaning fiber connectors is not new, it is growing in importance as links with increasingly higher data rates are driving decreasingly small loss budgets. With less tolerance for overall light loss, the attenuation through adapters must be lower than ever before. This can be achieved by properly inspecting and cleaning fiber optic cables when they are installed or while making moves, or changes.

There are two types of problems that will cause loss as light leaves one end-face and enters another inside an adapter: contamination and damage.

Dust, oils and water blocking gel are common forms of fiber connector end-face contamination. Simply touching the ferrule will immediately deposit body oil on the end-face, and cause unacceptable attenuation once connection are made. Dust and small static-charged particles float through the air and can land on any exposed termination. This can be especially true in facilities undergoing construction or renovation. In new installations, buffer gel and pulling lube can easily find its way onto an end-face.

Fiber optic cable damage appears as a scratch, pit, crack, or chip. These end-face surface defects could be the result of poor termination or mated contamination. Deciding to mate every connection first and then inspecting only those that fail is a risky approach as the physical contact of mated contaminants can cause permanent damage. This permanent damage would require more costly and time consuming re-termination or replacement of pre-terminated links.

Cleaning Fiber Optic Cables

Because cleaning has been part of fiber optic cable maintenance for years, most people have their own approaches for cleaning end-faces, including some suboptimal approaches such as blasting the fiber optic cable with canned air, or using Isopropyl alcohol (IPA).  Fiber-specific solvents are superior at dissolving virtually any contaminate lurking on a fiber end-face and have tailored evaporation rates that give them time to work yet disappear before mating. The most basic tools used are wipes and swabs used to clean patch cords and inside ports, respectively.