Influence of Mutual Rotation of Polarizing Filters on Light Intensity Measured with Collagen Fibres

Abstract

The most common technique for observation of collagen fibres and evaluation of their directionality is polarized light microscopy. In the microscope, there are two polarizing filters, polarizer and analyzer, that can rotate individually. The default position of the polarizer is perpendicular to the analyzer. When the light passes through a birefringent specimen, the plane of the polarized light is rotated. This leads to a 90 ∘ periodic change in light intensity passing through the sample and both filters. If the orientation of the polarizer differs from the perpendicular direction to the analyzer, the period of light intensity changes to 180 ∘; one of the original maxima increases and the other decreases. This change is very useful for the determination of directions of collagen fibres by an automatic algorithm.