Two-dimensional birefringence measurement technique using a polarization camera.

A two-dimensional birefringence measurement method is described. In this procedure, we send light through a rotatable linear polarizer and subsequently through a transparent and birefringent specimen. A polarization camera measures the state of linear polarization from which the relative position of the refractive index axes and the relative phase difference is determined. The measurement range of the phase difference is up to π rad, which corresponds to an optical retardation of half the wavelength of the light. The imaging system can measure a large sample area within one measurement cycle. Measurement performance is demonstrated with a quarter-wave plate, and an exemplary test case is shown.