# Diffractive coupling for photonic networks: how big can we go?

## TL;DR

This paper investigates the scalability of diffractive coupling in photonic networks, demonstrating the potential to host over a million optical emitters, which could revolutionize large-scale photonic computing.

## Contribution

It provides a detailed characterization of the scalability limits of diffractive coupling in photonic networks through experiments, analysis, and simulations.

## Key findings

- Networks can host over a million optical emitters.
- Diffraction-based coupling offers a scalable approach for photonic networks.
- The study establishes bounds and practical considerations for large-scale implementation.

## Abstract

Photonic networks are considered a promising substrate for high-performance future computing systems. Compared to electronics, photonics has significant advantages for a fully parallel implementation of networks. A promising approach for parallel large-scale photonic networks is realizing the connections using diffraction. Here, we characterize the scalability of such diffractive coupling in great detail. Based on experiments, analytically obtained bounds and numerical simulations considering real-world optical imaging setups, we find that the concept in principle enables networks hosting over a million optical emitters. This would be a breakthrough in multiple areas, illustrating a clear path toward future, large scale photonic networks.