Optical characterization method for birefringent fluids using a polarization camera
Connor Lane, David Rode, Thomas Rösgen
Abstract
Various techniques exist for characterizing a birefringent fluid by means of extinction angle and birefringence. We summarize these techniques and present a new procedure. The approach derives the first three Stokes parameters from images of a polarization camera and uses them to calculate the corresponding streaming birefringence by applying the Mueller matrix calculus. The required theory and a suitable experimental set-up are described. We apply the new measurement procedure to two Xanthan gum solutions and characterize their optical properties. The results agree with published data. Advantages of the new measurement technique are ease of handling, high robustness against optical imperfections and the possibility to measure a continuous response to shear in a single test series.