Superposition in Optical Computing

The design of an optical computer must be based on the characteristics of optics and optical technology, and not on those of electronic technology. The property of optical superposition is considered and the implications it has in the design of computing systems is discussed. It can be exploited in the implementation of optical gates, interconnections, and shared memory. INTRODUCTION Fundamental differences in the properties of electrons and photons provide for expected differences in computational systems based on these elements. Some, such as the relative ease with which optics can implement regular, massively parallel interconnections are well known. In this paper we examine how the property of superposition of optical signals in a linear medium can be exploited in building an optical or hybrid optical/electronic computer. This property enables many optical signals to pass through the same point in space at the same time without causing mutual interference or crosstalk. Since electrons do not have this property, this helps to shed more light on the role that optics could play in computing. We will separately consider the use of this property in interconnections, gates, and memory.