Optical fiber leakage loss measurement method

摘要

The present embodiment relates to a method for directly measuring leakage loss from the outer core of an MCF having a coating to the coating. In the measurement method, the first transmission power of the measurement light propagating through the outer edge core of the MCF is measured in a high refractive index state where the coating exists on the outer peripheral surface of the common cladding, while the common transmission is performed on the outer periphery of the common cladding. The second transmission power of the measurement light propagating through the outer edge core of the MCF is measured in a low refractive index state in which a low refractive index layer having a lower refractive index than that of the cladding is provided. The leakage loss LL from the outer edge core to the coating is calculated as the difference between the first transmission power and the second transmission power.