Patent ID: 11879803
Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 1:
2. The optical fiber testing method according to claim 1, wherein when the change amount is measured, the method comprises:
allowing probe light and pump light having a given wave number to enter the optical fiber to be measured for each of the propagation modes, thereby obtaining a Brillouin Frequency Shift amount;
allowing probe light and pump light having a different wave number different from the given wave number to enter the optical fiber to be measured for each of the propagation modes, thereby obtaining a Brillouin Frequency Shift amount; and
determining a difference between the Brillouin Frequency Shift amount for the given wave number and the Brillouin Frequency Shift amount for the different wave number for each of the propagation modes, as the change amount.