Ultrafast optical circuit switching for data centers using integrated soliton microcombs

TL;DR

This paper demonstrates ultrafast optical circuit switching in data centers using integrated microcombs, enabling sub-nanosecond switching speeds and high-bandwidth transmission for scalable, energy-efficient photonic networks.

Contribution

It introduces a novel microcomb-based approach for ultrafast optical switching, achieving sub-ns switching and high data rates in integrated photonic circuits.

Findings

Achieved sub-500 ps switching of over 20 carriers.

Demonstrated 25-Gbps NRZ and 50-Gbps PAM-4 burst transmission.

Showed scalable, energy-efficient wavelength switching using integrated photonics.

Abstract

Networks inside current data centers comprise a hierarchy of power-hungry electronic packet switches interconnected via optical fibers and transceivers. As the scaling of such electrically-switched networks approaches a plateau, a power-efficient solution is to implement a flat network with optical circuit switching (OCS), without electronic switches and a reduced number of transceivers due to direct links among servers. One of the promising ways of implementing OCS is by using tunable lasers and arrayed waveguide grating routers. Such an OCS-network can offer high bandwidth and low network latency, and the possibility of photonic integration results in an energy-efficient, compact, and scalable photonic data center network. To support dynamic data center workloads efficiently, it is critical to switch between wavelengths in sub nanoseconds (ns). Here we demonstrate ultrafast photonic circuit switching based on a microcomb. Using a photonic integrated Si3N4 microcomb in conjunction with semiconductor optical amplifiers (SOAs), sub ns (< 500 ps) switching of more than 20 carriers is achieved. Moreover, the 25-Gbps non-return to zero (NRZ) and 50-Gbps four-level pulse amplitude modulation (PAM-4) burst mode transmission systems are shown. Further, on-chip Indium phosphide (InP) based SOAs and arrayed waveguide grating (AWG) are used to show sub-ns switching along with 25-Gbps NRZ burst mode transmission providing a path toward a more scalable and energy-efficient wavelength-switched network for future data centers.