Polarization-sensitive optical coherence tomography using only linearly polarized light

This work presents polarization-sensitive optical coherence tomography (PS-OCT) using only linearly polarized light. The main characteristics of linear PS-OCT include the following. (1) In a turbid medium with linear birefringence, the degree of polarization (DOP) of backscattered linearly incident polarized light does not change significantly with the increase of birefringence value; (2) the phase retardation of the sample can be obtained from only the phase difference between the orthogonal polarization heterodyne signals, so a common phase noise rejection mode is introduced. These advantages may not only support the immunity of background phase noise and laser frequency noise, but also increase the sensitivity of phase retardation measurements; (3) the dynamic range of phase retardation in this system is between 0° and 180°.