Artificial ‘life’ can be used to unlock photonic computing power

Manufacturers are designing smaller transistors to increase speed and power.


Cellular automata are computational models that simulate complex phenomena using basic rules and techniques. However, these principles are only encapsulated at the software level while utilizing traditional computers.

Modern digital electronic computers based on the von Neumann architecture have extremely high hardware complexity. They are made up of billions of transistors constructed in a hierarchical and highly structured manner.

Traditional silicon transistors can only become so small due to problems producing devices that are only a few dozen atoms broad in certain situations. As a result, researchers have begun to explore computing technologies that do not rely on silicon transistors, such as quantum computers.

Alireza Marandi, assistant professor of electrical engineering and applied physics at Caltech, has developed 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 distinct behaviors. These automata have been utilized to accomplish computer tasks, and Marandi believes they are well-suited to photonic technology.

Photonic computing, which uses light instead of electricity, is another study area, similar to how fiber optic connections have replaced copper wires in computer networks.

Alireza Marandi said, “If you compare an optical fiber with a copper cable, you can transfer information much faster with an optical fiber; 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 better-fit photonics than digital electronics.”

It is important to understand cellular automata and how they operate to appreciate the hardware that Marandi’s team created completely. Simulated cells called cellular automata adhere to a very simple set of laws. The Game of Life, one of the most well-known cellular automata, was created in 1970 by English mathematician John Conway.

 There are four rules:

1) Any living cell with less than two living neighbors dies.

2)Any living cell with more than three living neighbors dies.

3)Any cell with two or three neighbors lives to the next generation.

4)Any dead cell with exactly three living neighbors will come to life.

These rules are applied to the universe in which the cells reside by a computer playing the Game of Life repeatedly, with each repetition representing a generation. These basic principles cause the cells to arrange into intricate structures over a few generations, giving rise to names like loaf, beehive, toad, and heavyweight spaceship.

Researchers interested in the theory of mathematics and computer science are drawn to cellular automata like The Game of Life. However, they can also be used in real-world scenarios. While some fundamental cellular automata are computationally as capable as traditional computing systems, others can be utilized for random number generation, physics simulations, and cryptography.

Others are computationally as powerful as traditional computing designs, in theory. These task-oriented cellular automata resemble an ant colony in that the small activities of individual ants combine to do more significant collective actions, such as digging tunnels or gathering food and returning it to the nest.

More complex cellular automata with more complicated rules can be employed for computer applications like image object recognition.

He said, “While we are fascinated by the type of complex behaviors that we can simulate with relatively simple photonic hardware, we are excited about the potential of more advanced photonic cellular automata for practical computing applications.”

The researcher explains that cellular automata are well suited to photonic computing because information processing occurs at an extremely low level, removing the requirement for much of the gear that makes photonic computing difficult. Cellular automata may operate extremely rapidly because of the large bandwidth of photonic computing.

In traditional computing, cellular automata are designed in a computer language based on another “machine” language layer. The cellular automaton cells of Marandi’s photonic computing device are just ultrashort pulses of light, allowing operation up to three orders of magnitude faster than the fastest digital computers.

The researcher said, “The ultrafast nature of photonic operations and the possibility of on-chip realization of photonic cellular automata could lead to next-generation computers that can perform important tasks much more efficiently than digital electronic computers.”

The Army Research Office of the United States Army, the Air Force Office of Scientific Research, and the National Science Foundation funded the study.

Journal Reference:

  1. Li, G. H., Leefmans, C. R.,etal. Photonic elementary cellular automata for simulation of complex phenomena. Light: Science & Applications. DOI: 10.1038/s41377-023-01180-9