Optical fiber characteristic measurement device and optical fiber characteristic measurement method

An optical fiber characteristic measurement method, comprising:

• emitting, by a light source, laser light modulated at a prescribed modulation frequency;
• making, by incident parts, the laser light, in the form of continuous light and pulsed light, incident on each of one end and the other end of an optical fiber;
• detecting, by a photodetection unit having a photoelectric conversion element, a current source connected to the photoelectric conversion element, and an amplifier circuit connected to a connection point between the photoelectric conversion element and the current source, light emitted from the optical fiber;
• measuring, by a measurement unit, characteristics of the optical fiber using detection signals output from the photodetection unit;
• and
• controlling, by a current-source control unit, the current source on the basis of detection results of the photodetection unit in a non-containing period that is a period during which the optical fiber emits light which includes the continuous light but does not include Brillouin scattered light.