MEASUREMENT DEVICE AND MEASUREMENT METHOD
In the present invention, light from a low coherence light source (10) is divided by an optical coupler (20). One light divided by the optical coupler (20) irradiates a sample medium (40). The other light separated by the optical coupler (20) is phase modulated by a reference mirror (50) and an oscillator element (52). The light that has been phase modulated (reference light) and light scattered by the sample medium (40) are analyzed for each wavelength by a diffraction grating (62), and optical spectra of the interference light for the reference light and scattered light are detected by a light detecting unit (70). In a computation processing unit (80) an intensity signal is found for each position of a scattering point in the sample medium (40) on the basis of the optical spectrum that is detected, and the power spectrum is found for each position of the scattering points on the basis of temporal changes in the intensity signal at each position for the scattering points. A particle scattering coefficient is found at the same time for each position of the scattering points on the basis of the power spectrum that has been found.