Coherent Wavelength Switched Co-packaged Optics to Disrupt Datacenters/HPC

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Santa Barbara, California
Project Term:
08/25/2020 - 02/24/2023

Technology Description:

The UC Santa Barbara team aims to develop a networking solution based on coherent co-packaged optics (optics and switch silicon together in the same package), which enable the transport of much more information. Coherent link technology underpins all long-distance fiberoptic communications, but today is too complicated, power hungry, and bulky to be used within datacenters. This project aims to demonstrate a simplified, highly energy-efficient coherent link architecture based on electro-absorption modulators, semiconductors that can modulate the intensity of a laser beam, in a multi-micron silicon photonics platform and powered by energy efficient quantum dot (QD) lasers. The solution employs photonic circuits based on the Rockley Photonics platform to simultaneously enable high performance, high energy efficiency, high integration densities, and significant cost reductions for co-packaged input/output (I/O). Furthermore, the coherent link technology can accommodate much more signal loss, which will enable the augmentation of datacenter networks with photonic routing and switching capability to realize dramatic gains in server productivity and overall datacenter efficiency.

Potential Impact:

If successful, developments from ENLITENED projects will result in an overall doubling in datacenter energy efficiency in the next decade through deployment of new photonic network topologies.


The United States is home to much of the world’s datacenter infrastructure. Photonic networks add resilience that can bolster the energy security of this critical driver of economic activity.


Reducing the overall energy consumption of datacenters cuts energy-related emissions per bit of data processed or stored.


Photonic networks can lower the costs associated with operating datacenters, improving American economic competitiveness in this fast-developing area.


ARPA-E Program Director:
Dr. Olga Spahn
Project Contact:
Clint Schow
Press and General Inquiries Email:
Project Contact Email:


Rockley Photonics, Inc.

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