Optical parallel logic gates using a shadow-casting system for optical digital computing

A new, simple method of optically implementing optical parallel logic gates has been described. Optical parallel logic gates can be implemented by using a lensless shadow-casting system with a light-emitting diode (LED) array as a light source. Pattern logic, i.e., parallel logic for two binary patterns (variables), is simply obtained with these gates; this logic describes a complete set of logical operations on a large array of binary variables in parallel. Coding methods for input images are considered. Applications of the method for a parallel shift operation and optical digital image processing, processing of gray-level images, and parallel operations of addition and subtraction for two binary variables are presented. Comparison of the operation of the proposed optical logic gate with that of array logic in digital electronics leads to a design concept for an optical parallel array logic system available for optical parallel digital computing.