Measurement and imaging of birefringence and optic axis orientation by phase resolved polarization sensitive optical coherence tomography

Abstract

We present an improved method of polarization sensitive optical coherence tomography that enables measurement and imaging of backscattered intensity, birefringence, and fast optic axis orientation simultaneously with only one single A-scan per transverse measurement location. While intensity and birefringence data are obtained in a conventional way, the optic axis orientation is determined from the phase difference recorded in two orthogonal polarization channels. We report on accuracy and precision of the method by measuring birefringence and optic axis orientation of well defined polarization states in a technical object and present maps of birefringence and, what we believe for the first time, of optic axis orientation in biological tissue.

A review of some recent developments in polarization-sensitive optical imaging techniques for the study of articular cartilage

“…The simplest such system uses a circularly polarized input light beam 29 , which has the disadvantage however that it cannot easily be combined with fiber-optics because birefringence in the fiber itself will distort the circularly polarized light beam thus illuminating the sample with an arbitrary elliptical polarization state and thus invalidating the data analysis algorithms. However when used in a bulk-optics system the approach is a simple of way of determining R(x,z) and δ(x,z) and also the local fast axis orientation 30 . More sophisticated schemes, in which more than one incident polarization state is used, have also been implemented 31,32,33 .…”

Optical coherence tomography—current technology and applications in clinical and biomedical research

“…Tissue can change the polarization state of the light by several mechanisms: birefringence [69], diattenuation [70], or polarization scrambling [71]. While early implementations of PS-OCT measured only reflectivity and phase retardation between the polarization axes [67,68], improved techniques developed in recent years can extract and image more information, such as Stokes vectors of the backscattered light [72], Müller and Jones matrix distribution [73,74], axis orientation [75], and diattenuation [70]. If diattenuation is neglected-it is very low in most biological tissues-the three most important parameters, reflectivity, retardation, and axis orientation ( Fig.…”

“…If diattenuation is neglected-it is very low in most biological tissues-the three most important parameters, reflectivity, retardation, and axis orientation ( Fig. 6 a-c) can be determined by a phase sensitive twochannel method that requires only a single measurement per sample location [75]. Other quantities can be derived from the acquired data, e. g. the degree of polarization uniformity (Fig.…”

Polarization-Sensitive Optical Coherence Tomography in Cardiology

“…The amplitudes A i (z) and phases φ i (z) of the interference signals at different depths (z) were determined using the Hilbert transform; i = P and S represent the P and S polarization states, respectively. Three parameters-the backscatter intensity R(z), phase retardation ) (z Φ , and fast-axis angle β(z) of a specimen-were calculated using the amplitude and phase of the interference signal (Hitzenberger et al, 2001):…”