Inverse-designed photonics for semiconductor foundries

TL;DR

This paper demonstrates the successful fabrication and testing of four inverse-designed silicon photonic devices in a commercial foundry, showing their efficiency, robustness, and compactness, thus advancing practical applications of inverse design in photonics.

Contribution

It presents the first experimental realization of multiple inverse-designed photonic components in a commercial foundry, overcoming fabrication scalability challenges.

Findings

Devices are efficient and robust to fabrication variability.

Devices are compact, occupying only a few micrometers.

Successful fabrication in a commercial silicon photonics foundry.

Abstract

Silicon photonics is becoming a leading technology in photonics, displacing traditional fiber optic transceivers in long-haul and intra-data-center links and enabling new applications such as solid-state LiDAR (Light Detection and Ranging) and optical machine learning. Further improving the density and performance of silicon photonics, however, has been challenging, due to the large size and limited performance of traditional semi-analytically designed components. Automated optimization of photonic devices using inverse design is a promising path forward but has until now faced difficulties in producing designs that can be fabricated reliably at scale. Here we experimentally demonstrate four inverse-designed devices - a spatial mode multiplexer, wavelength demultiplexer, 50-50 directional coupler, and 3-way power splitter - made successfully in a commercial silicon photonics foundry. These devices are efficient, robust to fabrication variability, and compact, with footprints only a few micrometers across. They pave the way forward for the widespread practical use of inverse design.