Abstract: The present invention relates to an optical laser analog-to-digital (A/D) converter and the use of such a converter as a transducer. In a first embodiment of the invention, the converter consists of a source which produces a coherent beam of light that is passed through a lens system to produce a line or bar of light. The bar of light passes through a coded optical mask which is made of a thin transparent material with a binary or gray code printed thereon. The mask is mounted to an object whose movement is to be detected. The mask may also be configured in the form of a circle and mounted to a motor shaft to sense motor rotational displacement, RPM or velocity. As the mask moves, the imprinted pattern changes according to the coding on the mask. The portion of the light that passes through the mask strikes the target of a moving recording media.