Lumentum Inline Optical Tap Detectors (also known as EigenLight Inline Optical Tap Detectors) are used for the measurement of optical fiber power while preserving the continuity of the transmitted signal inside the core of the fiber. Unlike conventional tap detectors, the Lumentum inline tap detector does not use any lens or partial reflector and only a small fraction of the light is removed from the core. Insertion loss can be as low as 0.05 dB, including an extremely low polarization-dependent loss, which makes the device ideal for highly-sensitive applications.

Inline tap detectors are used in 100/400G long haul, metro, FTTX, and data center optical networks, as well as optical networking subsystems (ROADMs, EDFAs, WSS, etc.) where low insertion loss and low PDL optical components are required.