Patent ID: 6240305
Filing Date: 2001-05-29
Classification: G01N

Abstract:
A method of measuring absorption information of a scattering medium, said method comprising:applying modulated light having a predetermined modulation frequency component to form a spot shape incident on a surface of a scattering medium comprising a measured object;acquiring respective measurement signals by receiving said modulated light having propagated inside said measured object at one or both of a plurality of different times and a plurality of positions on said surface of said scattering medium;detecting, from each of said respective measurement signals, respective signals of said modulation frequency component;obtaining, from said respective signals of said modulation frequency component, cosine components and sine component slopes against modulation angular frequency; andcalculating a difference between absorption coefficients of said measured object based upon a predetermined relation among said cosine components, said sine component slopes against modulation angular frequency, and a difference between absorption coefficients corresponding to different ones of said respective measurement signals.