Optical receiver for input to optronic device

摘要

A phase shift element is used to reduce the back reflection of light. The optical receiver comprises a focussing lens (L) and an object made of reflective material (D) placed in the focal plane (F) of the lens (L). There is also a phase element (EP) placed between the lens and the object, near to the focal plane. The phase element has a phase function with symmetry of revolution, with the axis of symmetry coincident with the axis (2) of the lens (L). The phase shift introduced to the beam is such as to reduce substantially the flux of light which is back reflected by the device.