Experimental model of a combined optical processing correlation system

The paper describes an experimental model of an optical correlator. Optical information processing systems became a new generation of very high speed processing units because of their natural parallelism and generally fast performance (A. Vanderlugt, 1992). Calculation of the correlation function is one of the most important mathematical tasks in the field of signal and image processing. Special problems such as identification, detection of weak signals below noise level etc. are frequently solved by using correlation units. The most important part of an optical processing system is a spatial modulator. A spatial modulator-a converter of an electrical signal into an optical image-can be based upon many physical principles. From them we have tested a combined setup consisting of an 18 line LCD modulator as a computer controlled reference and an acoustooptic unit as a signal modulator. The model has been used for a real time identification of codewords up to 18 bits long in a signal flow. Finally, some parameters of the experimental system model are summarized and future expectations of improvement are outlined.