Exploring the Potential of Cellular Automata for Photonic Computing Applications

Thursday - June 22 2023, 20:22 UTC - 1 year ago

Researchers at Caltech have created a new optical hardware utilizing photonic computing to realize cellular automata, a type of computer model consisting of cells that can live, die, reproduce, and evolve into multicellular creatures with their own unique behaviors. This technology could lead to computers that are smaller, faster and use less power than traditional silicon transistors.

The never-ending quest for faster, smaller computers that can do more has led manufacturers to design ever tinier transistors that are now packed into computer chips by the tens of billions.And so far, this tactic has worked. Computers have never been more powerful than they are now. But there are limits: Traditional silicon transistors can only get so small because of difficulties in manufacturing devices that are, in some cases, only a few dozen atoms wide. In response, researchers have begun developing computing technologies, like quantum computers, that do not rely on silicon transistors.

Another avenue of research is photonic computing, which uses light in place of electricity, similar to how fiber optic cables have replaced copper wires in computer networks. New research by Caltech's Alireza Marandi, assistant professor of electrical engineering and applied physics, uses optical hardware to realize cellular automata, a type of computer model consisting of a "world" (a gridded area) containing "cells" (each square of the grid) that can live, die, reproduce, and evolve into multicellular creatures with their own unique behaviors. These automata have been used to perform computing tasks and, according to Marandi, they are ideally suited to photonic technologies.

The paper describing the work, titled, "Photonic Elementary Cellular Automata for Simulation of Complex Phenomena," appears in the May 30 issue of the journal Light: Science & Applications.

"If you compare an optical fiber with a copper cable, you can transfer information much faster with an optical fiber," Marandi says. "The big question is can we utilize that information capacity of light for computing as opposed to just communication? To address this question, we are particularly interested in thinking about unconventional computing hardware architectures that are a better fit for photonics than digital electronics." .

Cellular automata .

To fully grasp the hardware Marandi's group designed, it is important to understand what cellular automata are and how they work. Technically speaking, they are computational models, but that term does little to help most people understand them. It is more helpful to think of them as simulated cells that follow a very basic set of rules (each type of automata has its own set of rules). From these simple rules can emerge incredibly complex behaviors. One of the best-known cellular automata, called The Game of Life or Conway's Game of Life, was developed by English mathematician John Conway in 1970. It has just four rules that are applied to a grid of "cells" that can either be alive or dead. Those rules are: .

Basic, or "elementary," cellular automata like The Game of Life appeal to researchers working in mathematics and computer science theory, but they can have practical applications too. Some of the elementary cellular automata can be used for random number generation, physics simulations, and cryptography. Others are computationally as powerful as conventional computing architectures—at least in principle. In a sense, these task-oriented cellular automata are akin to an ant colony in which the simple actions of individual ants produce remarkably complex collective behaviors.