Realtime birefringence mapping by polarization camera

Recently, there is a requirement to visualize birefringence distribution by an internal stress and an orientation of the polymer materials in the field of materials and biomedical engineering. A real time measurement of two dimensional birefringence distribution has been proposed by the polarization camera whose adjacent 4 pixels of the image sensor have 45°of increment azimuthal of linear polarizer. There is a limitation of dynamic range of retardance up to 90° because of circular polarization for incident light. This report proposes to expand to measurement range of retardation up to 180° by two shot intensities which are captured in case of 0° and 45° of azimuthal direction of a quarter wave plate installed before a polarization camera.