Coherent signal composition and global phase determination in signal multiplexed polarization sensitive optical...

We present an analysis of the structural image information acquired with polarization sensitive optical coherence tomography (PS-OCT). In PS-OCT a total of four channels of data are acquired: two orthogonal polarization state components for each of two incident polarization states by which the sample is interrogated. Up to recently, the structural information of the sample was obtained by incoherent summation of these four channels. The four channels can be represented as a Jones matrix for each data point acquired from a sample. We show that the Signal to Noise ratio of the structural information can be improved by 2.3 dB by taking advantage of the structure of this Jones matrix, imposed by the propagation and scattering properties of the sample. We demonstrate that the Jones Matrices are all in the shape of an SU(2) matrix, which is key to understanding the coherent composition of the structural image in PS-OCT and the 2.3 dB SNR improvement. We also discuss a global phase of the Jones matrix in signal multiplexed PS-OCT.