A whole-field polariscope using a liquid crystal polarization rotator.

A novel polariscope using a liquid crystal (LC) polarization rotator is proposed for full-field subfringe photoelastic stress analysis. The system uses a light-emitting diode-based modified Senarmont polariscope with an added liquid crystal polarization rotator to generate phase shifts by applying suitable voltages to the LC element. Four phase shift polariscope images are captured and analyzed to get the stress distribution. A comparative study with the gray-field polariscope method which uses a rotating analyzer shows good agreement.