Infrared optics instead of fiber in the data center: an original project of engineers from the USA

A US development team has proposed replacing fiber optics in the data center with infrared transceivers. According to them, too expensive elements are not needed for this, and such systems will take up a little space in the data center. In modern data centers, more and more wires are used, which combine both individual servers and entire network systems. A lot of wires often cause inconvenience, although some data center operators deal with this problem very well.

So, a group of engineers from the USA, many of whom work at the University of Pennsylvania (USA) created a system of transmitters and receivers of infrared waves specifically for data centers. In principle, this is not the first attempt to get rid of wires in the data center, but previous development projects did not receive due to a number of problems. One of the main ones is defocusing while increasing the distance between the receiver and the transmitter. Data centers are now quite large, so solving this problem was not easy. But the team of the current project did it.

Representatives of the University of Pennsylvania announced the results of their work at the Photonics West 2017 conference. They used optical systems (lenses) with a low price. Nevertheless, the authors of the work learned how to obtain infrared rays with a practically zero level of interference even with the help of such equipment. The throughput of the "heat network", according to representatives of the project team, is high, although they have not announced the exact parameters. There are no restrictions on the number of compounds.

The novelty is called Free-space optical Inter-Rack nEtwork with high FLexibilitY (Firefly). It has a unique architecture, which is based on the results of previous projects, both by scientists from the University of Pennsylvania and specialists from Carnegie Mellon University and New York University.



To ensure the operation of Firefly, it is necessary to install special modules in the upper part of the server racks: infrared lasers and receivers. The configuration of the modules can be quickly changed, as well as aimed at any of the racks of the data center. The receiver, receiving an infrared signal, directs it already into the fiber optic cable. And already by cable, the data is sent to the desired server or network device. According to the developers, Firefly almost does not require service and is able to work in automatic mode for a long time.



The receivers and emitters are positioned using miniature servos. Also, if necessary, you can change the direction of the mirrors of microelectromechanical systems. The diameter of such mirrors is only 2 mm. The power consumption of the microelectromechanical system is less than 1 mW.

The system in question is not artisanal at all; it can work inside the data center with tens or even hundreds of thousands of servers. The more servers in the data center, the more cables are required. Features of the data center infrastructure lead to bottlenecks with reduced bandwidth. If you use an infrared data transmission system, problems of this kind do not arise. In any case, so say the developers.



As for the tests in the "field", Firefly has not yet been tested in working with a large number of servers. So far, there is only a prototype of a small-scale system that works without any problems. As part of this system, engineers demonstrated the transmission of a bi-directional data stream at a speed of 10 Gbit / s. The level of errors is low and does not exceed the norm. As for the laser wavelength, it is 1550 nanometers - this is exactly the radiation wavelength in most fiber optic systems.