Optical-fiber-characteristic measuring apparatus and optical-fiber-characteristic measuring method

An optical-fiber-characteristic measuring apparatus comprising:

• a light source unit which outputs an oscillation light that has undergone frequency modulation;
• probe light generating means for performing frequency shifting on an output light from the light source unit, and inputting that light as a probe light into one end of a measurement-target optical fiber, said probe light generating means including a second optical intensity modulation unit that performs intensity modulation on the probe light;
• pump light generating means for inputting an output light from the light source as a pump light into an other end of the measurement-target optical fiber, said pump light generating means including a first optical intensity modulation unit that performs intensity modulation on the pump light at a different frequency from the probe light;
• detection means for separating only a change in the probe light originating from stimulated Brillouin scattering from an outgoing light from the measurement-target optical fiber, using the two intensity modulations performed by the first and the second optical intensity modulation units;
• and
• measurement means for measuring a characteristic feature of the measurement-target optical fiber based on data on the change in the probe light, acquired by the detection means.