OVERVIEW OF SWITCHING SUBSYSTEM MODELS FOR DIGITAL PHOTONIC COMPUTING DEVICES

Abstract

This article examines options for organizing the switching subsystem of digital photonic computing devices, whose main task is to enable efficient computations in various problem domains. According to the authors, digital photonic computers should process information within a structural computing paradigm. This paradigm fundamentally differs from the classical von Neumann paradigm, as data transfer between functional elements is inseparable from processing. Therefore, developing a switching subsystem in digital photonic computing devices is a critical challenge. This subsystem must handle data dependencies between operations not only in time but also in space. Only under these conditions can data processing in photonic computing systems achieve performance that exceeds the performance of the most advanced electronic computing systems by two or more decimal orders. The article addresses issues of streaming data exchange between functional devices in a digital photonic computer. The authors developed and analyzed switching device models and methods for organizing the switching subsystem for sequential data processing, using a basis of photonic logic. The research established that structural organization of computations in digital photonic computers is feasible when data exchange is achieved through spatial switching of input and output channels of functional devices. In implementing digital photonic computers as universal devices aimed at a wide range of tasks, hierarchical and hierarchical-ring variants of the switching subsystem organization are most suitable for forming computational structures. However, these variants are characterized by high overhead for constructing switches. Therefore, in problem-oriented photonic computers designed for solving highly interconnected tasks with high specific performance, the use of orthogonal or toroidal switching subsystems is preferred. In this case, direct spatial switching between functional devices within a group, as well as between groups, should be ensured. These variants have higher requirements for the quality of physical channels formed between switches and functional devices, as well as between the switches themselves.