Equipment and method for characterizing bidirectional crosstalk

A method comprising:

• measuring first backscattered light from a first core included in an optical fiber under test when an optical pulse is injected into one end of the first core;
• measuring second backscattered light from a second core adjacent to the first core when an optical pulse is injected into one end of the second core;
• detecting a loss occurrence point of the optical fiber under test by using at least one of a loss distribution of the first backscattered light or a loss distribution of the second backscattered light;
• calculating a mode coupling matrix Ti at an i-th loss occurrence point of the optical fiber under test;
• calculating a fiber length Li of an i-th fiber section having a separation at the i-th loss occurrence point of the optical fiber under test;
• and
• calculating bidirectional crosstalk in the first core or the second core by using the calculated mode coupling matrix Ti and fiber length Li and using a fiber loss factor α and power coupling coefficient h of the optical fiber under test measured in advance.