Patent ID: 8830460

Claim:
An optical measurement apparatus that measures a property of a scatterer by using a low-coherence enhanced backscattering technique, the optical measurement apparatus comprising: a light source configured to supply, as illumination light, incoherent light having a short spatial coherence length and at least one spectral component; an illumination fiber configured to propagate, to a distal end of the illumination fiber, light supplied from a proximal end of the illumination fiber by the light source and illuminates light onto the scatterer from the distal end; a first light detection fiber configured to output, from a proximal end of the first light detection fiber, a first returned light from the scatterer at a first scattering angle that is substantially the same as an angle of the light illuminated from the illumination fiber; a second detection fiber having a distal end configured to protrude towards the scatterer in a longitudinal direction more than the distal end of the first light detection fiber, the second detection fiber being configured to output, from a proximal end of the second detection fiber, a second returned light from the scatterer at a second scattering angle greater than the first scattering angle; a detection unit configured to detect: (1) the first returned light that is output from the proximal end of the first light detection fiber to obtain a peak value of an interference component of the illumination light, and (2) the second returned light output from the proximal end of the second light detection fiber to obtain a base value of a baseline; and a measurement unit configured to measure a property of the scatterer based on the peak value and the base value obtained by the detection unit.