Static deflector device for an infrared beam

A static deflector device for deflecting a polarized infrared beam, said device being for use with a source of a polarized infrared beam, and comprising:

• deflector means for deflecting said beam, said deflector means comprising a liquid crystal layer and modulator means for modulating said liquid crystal layer;
• and
• control signal generator means for generating a control signal and applying said control signal to control said modulator means, thereby creating local variations of refractive index in said layer in such a manner as to form a beam diffraction grating of adjustable spacing in said liquid crystal layer;
• said control signal being periodic in space having a staircase waveform varying from a minimum value to a maximum value in a continuous progression of N steps per period in such a manner that the maximum value causes an incident beam to be phase-shifted by 2.pi.;
• said modulator means for modulating said liquid crystal layer comprising electrodes disposed on both faces of said layer, the electrodes on the incident face of the layer being transparent, electrically isolated, and disposed in zones that are equidistant from one another and which are separated by interelectrode spaces which, at least in one direction, range in size between 1 and 10 micrometers, a common electrode being disposed on the other face of said liquid crystal layer.