»Light-Light« Modulator in the Lens Focus

In coherent optical data processing one comes across some difficulties associated with the formation and alignment of the spatial filters, When space light modulators (SLM) or optically-controlled transparencies operating in self-consistent filtration regime are used as the filters, then the mentioned difficulties can be partially eliminatedo Here the filter is produced automatically, in accordance with the optical signal, and no alignment is needed when the light beam incidence angle at the input of the optical system is changed.