It works by gently bending the fiber to detect the light passing through, showing if it's active and which way the signal is moving and this makes troubleshooting faster, safe and more reliable in real-world jobs. Before using a fiber identifier, preparation is key to making. Optical Fiber Identifiers - Identify optical fibers without the need to disconnect or cut the fiber. more the video tell you how to operate fiber identifier. These non-intrusive instruments help technicians verify fiber connections, locate faults, and prevent costly network downtime.