1. A modulatable light signalling device comprising: a modulation signal source for producing a modulating signal; a light transmitter coupled to said source for emitting light in accordance with said modulating signal, said light transmitter including a light-emitting surface which tends to produce a light output which varies in phase over said surface; optical beamforming means responsive to said light transmitter for forming the light receiver means for receiving the transmitted light output thereof into a beam of light; and means, located in the optical path between said beam-forming means and receiver means having an input surface and an output surface, for randomly varying the orientation of the light received on said output surface so that the light emitted from said output surface is oriented differently from the light received on said input surface thereby phase averaging the phase of the light received by the receiver means.

4. In a system including a transmitter and a receiver for modulated light said receiver including a photomultiplier tube having a light responsive surface which tends to produce an output which varies in phase over said surface, the improvement comprising a multi-path light translator positioned between the transmitter and receiver, having an input surface for receiving light and an output surface for transmitting light to the light-responsive surface of the receiver, for randomly varying the orientation of the light transmitted from the transmitter to the input surface of the photomultiplier tube, thereby averaging the light received across the input surface of the photomultiplier tube so as to average the phase delays within the phototube at the output of said phototube the input surface.