Optical path difference determination method

摘要

The method involves splitting a coherent ray of light (2) into two preferably relatively perpendicularly polarized partial beams (5,6) with identical beams. The partial beams are passed separately through the path to be measured and are subsequently combined to form a combined beam (13) to be evaluated. The polarization of the combined beam is measured. The optical path difference is determined using a vector calculation in response to the phases of two signals.