Two-dimensional polarization measurement by optical coherence tomography

In recent years, an optical coherence tomography (OCT) has attracted attention in the field of not only biology but also industry. It is because the structure of a living body organization and of industrial products, such as sur face profile, thickness, refractive index and birefringence, can be known by non-contact and non-destructive. The OCT system consists of Michelson interferometer with a low-coherent light source. A low-coherence interferogram can be observed in case an optical path difference (OPD) equal to zero. A phase shifting method (PSM) is utilized to determine a peak point of contrast variation. A contrast of interferogram is calculated by using four images with different phase at 90degrees. To overcome a measurement speed, a measurement of a high speed measurement is proposed using a two interferogram taken by two reference mirror. Moreover, an optical path of sample beam is changed by birefringence of sample. It is possible to measure a polarization state using OCT. In this paper, a surface topography and tomography image considered polarization state of sample is discussed and measured some sample.