A new method for simultaneously measuring the phase retardation and optic axis of a uniaxial compensation film is demonstrated using an axially-symmetric sheared polymer network liquid crystal (SPNLC). By overlaying a tested compensation film with a calibrated SPNLC cell between crossed polarizers, two dark spots are clearly observed in a CCD image. From the orientation direction and distance of these two spots, the optic axis and phase retardation value of the compensation film can be determined. This method is particularly useful for those optical systems whose optic axis and phase retardation are dynamically changing.
© 2005 Optical Society of AmericaPDF Article