Figure 1.

Basic principles of 3D-PLI. (A) Schemes of the large-area rotating polarimeter with a tilting stage and of the polarizing microscope (PM) from Taorad GmbH (Germany). (B) The signal intensity profile depending on the rotation angle ρ of the filters for a single pixel measured with a polarimeter. To obtain the fiber orientation, the measured light intensities are studied pixel-wise as a function of discrete rotation angles. The derived physical model provides (continuous black line) and relates the sine phase to the direction φ and the amplitude to the inclination angle α.