Patent ID: 11892330
Assignee: YOKOGAWA ELECTRIC CORPORATION
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 10:
11. An optical fiber characteristics measuring device comprising:
a first optical splitter that splits modulation light, for which frequency modulation has been performed, into pump light and reference light;
a second optical splitter that causes the pump light to be incident from one end of an optical fiber under test and outputs Brillouin scattering light generated inside the optical fiber;
a first detector that detects interference light between the reference light and the Brillouin scattering light output from the second optical splitter;
an analyzer that acquires a Brillouin gain spectrum that is a spectrum of the Brillouin scattering light from a detection signal output from the first detector;
a second detector that detects a second harmonic component having a frequency that is twice a modulation frequency of the modulation light in the acquired Brillouin gain spectrum; and
a measurer that measures characteristics of the optical fiber based on the acquired Brillouin gain spectrum and the detected second harmonic component, wherein
the second detector comprises the signal detecting device according to claim 1 to which the acquired Brillouin gain spectrum is input as the measurement signal and that detects the second harmonic component using the reference signal having the frequency that is twice the modulation frequency of the modulation light.