Patent ID: 7016048

Claim:
An apparatus for phase-resolved functional optical coherence tomography of a sample characterized by optical birefringence comprising: an interferometer having a source arm, a reference arm, a sample arm and a detector arm; a source of at least partially coherent polarized light coupled to the source arm, the partially coherent polarized light being characterized by a well defined polarization state; a polarization modulator for providing modulated polarized light of selected linearly independent polarization states incident on the sample, wherein backscattered arbitrarily polarized modulated light is returned to the detector arm from the sample arm according to sample birefringence, the returned light from the reference arm and sample arm interfering in the detector arm to form polarization interference fringes; a phase modulator coupled to the interferometer for modulating an optical path length difference in the reference and sample arms of the interferometer at a predetermined phase modulation frequency; a scanner coupled to the interferometer for scanning the sample; a sensor coupled to the interferometer for detecting backscattered radiation received by the interferometer from the scanner to detect interference fringes within the interferometer; and a polarization demodulator to demodulate the polarization interference fringes; and a data processor coupled to the sensor for processing signals from the sensor corresponding to the interference fringes established by the backscattered radiation in the interferometer and for controlling the scanner to generate tomographic images to generate a complete polarization state description of the backscattered light from the sample by preserving phase relationships between orthogonal components of the polarization interference fringes formed from backscattered light from the sample and from the reference arm, and wherein the data processor simultaneously generates the Stokes vectors, and generates tomographic structure, blood flow velocity, standard deviation, and birefringence images at each pixel in the image.