Patent ID: 6697161
Filing Date: 2004-02-24
Classification: G01N

Abstract:
A method of optically characterizing the retardation and eigenpolarization of an unknown retarding device, comprising the steps of:a) generating an optical probe beam with a pre-determined polarization; b) splitting the probe beam into two components, with constant dynamic phase difference; c) passing each of the two probe beam components through the retarding device in opposite directions so that the polarization of each probe beam component is retarded by an equal degree; d) passing the retarded probe beam components together through a polarizing analyzer with a pre-determined polarization axis to resolve the polarization of each retarded probe beam component along said axis; e) receiving the polarization resolved beams on an optical detector so that said beams maintain the same dynamic phase and interfere coherently depending on the geometric phase between the two interfering polarization resolved beams; and f) using the detector to measure the interference between the two interfering polarization resolved beams; wherein the angle of the polarization axis of the analyzer is rotated to resolve the polarization of each of the polarization resolved beams along said rotating axis, in order to vary the geometric phase and hence the measured interference from the detector, the measured varying interference being used to calculate the retardation and eigenpolarisation of the unknown retarding device.