GASP: Gallium Arsenide (III-V) photonic integrated circuits built like Silicon Photonics

There are very few exponential trends in technology that stay exponential for long. Moore's law is probably the best example, where an exponential (the doubling of the number of transistors in modern microprocessors every 18-24 months) has persisted for almost four decades, with great benefit to modern society. On the other hand, in recent years, there has been another slightly more worrying exponential. This is the total amount of data that we as a society have been consuming. It has been growing exponentially for the past decade and shows no signs of slowing down. It is probably best illustrated by modern data centers that have grown in size scale and number all around the globe to the point where by 2030, they are expected to consume ~ 20% of the world's total electricity supply and even today, they emit more CO2 than the global airline industry. If you look at a data center more carefully, most of the energy is dissipated not in computing, but in sending bits around at very high data rates over variable distances, and this is predominantly done in the optical domain.

If we can build a more efficient photonic integrated circuit for handling this optical communication, we can address this energy problem in principle. The work done as part of this project is aimed towards developing the underlying platform and a scalable manufacturing process for building these efficient photonic devices. Our approach is to apply the best manufacturing processes (derived from silicon photonics and silicon MEMS foundries) to the best available optical materials (compound semiconductors). We believe this is a natural route towards building the most energy efficient integrated photonic devices. In addition to data center transceivers, the platform developed here will also be applicable to other areas ranging from photonic devices for satellite communication to cryogenic photonics platforms for quantum information.