Patent ID: 7333212

Claim:
A method for measuring an absorption coefficient and a reduced scattering coefficient of a multiple scattering medium, comprising the steps of: outputting a source light beam using a two-frequency polarized laser, the source light beam including a mutually correlated and mutually orthogonal polarized photon pair; transforming the source light beam into a transformed light beam that includes a mutually parallel circularly polarized photon pair, the mutually parallel circularly polarized photon pair being one of a pair of R waves and a pair of L waves; splitting the transformed light beam into a signal beam and a reference beam; detecting and converting the reference beam into a reference heterodyne interference signal; focusing the signal beam and projecting the focused signal beam into the multiple scattering medium via an optical signal fiber to produce a diffused polarized photon pair density wave; detecting the diffused polarized photon pair density wave via an optical detection fiber that is spaced apart from the optical signal fiber; converting the diffused polarized photon pair density wave into a test heterodyne interference signal; obtaining amplitude attenuation and phase delay of the signal beam that has propagated through the multiple scattering medium based on the reference and test heterodyne interference signals; and inferring the absorption coefficient and the reduced scattering coefficient of the multiple scattering medium with reference to the amplitude attenuation and the phase delay thus obtained.