Sensor and an imaging system for remotely detecting an object

摘要

A sensor for remotely detecting an object, the sensor comprising: a light source having a coherence length that is short relative to the distance between the sensor and the object; a splitter splitting the emitted light beam into an incident beam and a reference beam; a photorefractive crystal recording a hologram on interfering reception of the reference beam and of the reflected beam reflected by an object illuminated by the incident beam, and playing back the hologram in a diffracted beam that is re-emitted by the crystal by anisotropic diffraction under the effect of the reference beam; a detector recording information on receiving the diffracted beam; and a polarizing filter that eliminates the major fraction of the reflected beam as transmitted by the crystal on receiving the reflected beam; such that the detector receives only the diffracted beam from the crystal. Both the sensor and imaging systems incorporating the sensor enable measurements to be made through diffusing media.