Patent ID: 8542356

Claim:
A measurement system for measuring birefringence of an optical measurement object comprising: a beam generating unit configured to generate a measurement beam having a defined input polarization state, the measurement beam being directed onto the measurement object; a detector unit configured to detect polarization properties of the measurement beam after interaction with the measurement object and to generate polarization measurement values representing an output polarization state of the measurement beam; and an evaluation unit configured to evaluate the polarization measurement values and to determine at least one birefringence parameter representing the birefringence of the measurement object, wherein the beam generating unit is further configured to modulate the input polarization state of the measurement beam into at least four different measurement states in accordance with a periodic modulation function of an angle parameter α; and wherein the evaluation unit is further configured to process the polarization measurement values associated with the at least four measurement states, to form a measurement function dependent on the angle parameter α, to determine a two-wave portion of the measurement function and to analyze the two-wave portion, in order to derive the at least one birefringence parameter.