The procedures in this document describe basic inspection techniques and processes of cleaning for fiber optic cables, bulkheads, and adapters used in fiber optic connections. What Is Fiber Optic Cable? Fiber optic cable contains one or more glass or plastic fibers that transmit data as light. These cables are thinner than a human hair and deliver faster transmission, longer. Once optical fiber systems are installed, ongoing maintenance and regular inspections are essential to ensure long-term performance, prevent outages, and maximize return on investment. But to ensure optimal performance, you should maintain their integrity by testing them regularly. That process, thankfully, is a simple one.