Researchers demonstrate ultrafast optical circuit switching

Researchers are working hard around the world to try and improve the speed available for data sharing. Microsoft Research and EPFL recently demonstrated ultrafast optical switching utilizing a chip-based soliton comb laser and a passive diffraction grating device. Project researchers believe the architecture may enable the transition to optical data centers that are energy efficient and can better meet the ever-increasing need for bandwidth around the world.

The faster data centers can share data, the better the performance for all users trying to connect to that data for work, education, and entertainment. Modern data center networks today use electrical packet switches that are connected using fiberoptics. The systems rely on electrical to optical conversion, which the researchers say increases power overhead requirements and costs.

One of the biggest challenges for modern data centers is increasing bandwidth to support increasing data rates resulting from modern applications like artificial intelligence and data analytics. It's becoming difficult to scale network architectures that rely on electrical chips to continue to meet Moore's Law.

Optical circuit switches have become an option to overcome bandwidth and scaling issues that data centers worldwide are currently experiencing. One of the most appealing optical circuit switching architectures is wavelength switching relying on different servers that connect using different wavelengths (colors) of light. That architecture allows a flatter network architecture that limits the need for logical switches and optical transceivers.

That technique relies on a switching element, a glass prism, and the different wavelengths of light are separated by dispersion. Researchers note that optical circuit switches are currently available commercially, but they are slowly making them unsuited for data center applications. Researchers on this project have integrated optical microcombs to act as a multi-wavelength source for coherent carriers.

The system utilizes optical amplifiers and arrayed waveguide gratings made from the same material as semiconductors to perform the switching while separating or combining different light colors as needed. The team has a proof of concept system-level demonstration that delivers packet-by-packet switching with the potential to meet requirements for data center applications.