Detection scheme for white-light interferometric sensors.

Static interferometers whose optical path difference is not constant over the field of interferences are well adapted to demodulate sensing interferometers in the coherence multiplexing method. In this configuration the correlation peak can be spatially recorded on a linear detector array. However, the determination of the position of the peak maximum amplitude is often difficult because of the spatial sine amplitude modulation. This drawback can be eliminated by using a grating interferometer as a demodulator. In this case it is possible to record, on the detector, only the envelope of the correlation peak.