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. Fiber-optic sensors are useful for industrial appli-cations in perturbed environments. One of the main advantages of these devices, as a result of the use of fiber optics, is that the information (modulation of the optic signal) about the measurand can be transmitted over long distances. However, the method used to encode the parameter to be measured and to decode it must be carefully chosen to preserve this advantage. Thus it is necessar