Electrical engineers are harnessing the polarity of light to expand the bandwidth of data transmissions in a breakthrough that promises to increase speed and cut costs in data center operations – all with the spin of a laser.
Teams from a pair of German universities and the University of Buffalo in New York have formalized the findings of their lab research into the field of what’s being called spintronics:Opens a new window  the study of the directional spin of electrons and their associated magnetic properties.
Spintronics, an offshoot of photonicOpens a new window technology, uses optical recognition to revolutionize the way information is passed and processed, foregoing intensity when coding the data into one-and-zero binaries that then is transferred in light beams.
By replacing the on-off pulses with right-left polarities, the researchers found they can reliably raise the volumes of data passing through a fiber optic network while at the same time dramatically reducing the amount of heat generated by the transmissions.
At present, the technology shows the most promise for data center applications, where transmissions between server nodes can be sent and received more reliably at higher throughput speeds that in wireless transmissions via connected devices.
According to a report published in the journal NatureOpens a new window , the teams led by researchers from Ruhr Universitat Bochum in the German state of North Rhine-Wesphalia, documented data transfer rates in excess of 240 gigabits per second using spintronic laser diodes that coded ones in a data binary with a leftward spiral beam and zeroes with a rightward spiral.
That represents a figure far above the standard rate of 25GB per second at which data is transmitted using modulations of on for one and off for zero in data center fiber optic communication.
While the researchers predict those speeds could double based on the elemental composition of laser diodes and the crystals used to focus the beams, the boon appears in the ability of spintronic coms to take place at room temperature.
Not only did the teams, which also featured researchers from the University of Ulm, increase the speed of transmission by nearly an order of magnitude, they did so using a fraction of the energy.
The current-driven model of intensity modulation consumes greater amounts of energy, both to create on-off pulses that represent data binaries and for cooling systems that permit systems to run without overheating.
Already a significant cost in data center operationOpens a new window , waste energy produced as heat only will grow with the increasing volumes of throughput that will result from the adoption of fifth-generation mobile communications technology. Hence, the sometimes-novel steps being taken independent of spintronic data transfer to cool server farms.
According to the research teams, spintronic transmission generated just 7% of the waste heat in shifting those greater volumes of data over the same distance as with current-driven modulation. Corkscrewing the light beams down fiber optic cables let researchers reduce surface temperatures of integrated copper circuits, while endowing the beams with different characteristics based on spin direction, either left or right.
The same sort of material anisotropy led the research teams to postulate that speeds of as much as 500GB per second might be achieved by polarizing lasers through gallium/adenine diodes.
In contrast, they say speeds of 100GB per second are achievable at room temperature with techniques such as quantum cascading that permit laser light to travel through aligned tunnels in silicon substrates.
But they add that going any faster with current-driven modulation requires cryogenic cooling of data center operations.
Moving the research beyond laboratory test success is dependent on several factors that include applying guidance to polarized waves of light and the arrival of storage drives with compatible interfaces capable of handling the read/write speeds necessary to cope with high-volume transmission.
Alongside the rising demand for servers and the desire of data center operators to reduce their carbon footprintsOpens a new window , rapid development of photonic semiconductor technology promises to close some of those gaps.
Recent refinements have seen researchers achieving longer life cycles for the crystals grown directly on substrates that are used to focus and direct beams of laser light across silicon chips.
Networking giant Cisco Systems, among others, is building photonic technologies into its data center switches and routers and pushing out transfer speeds. The technology is useful for alleviating Ethernet bottlenecks that arise in chip-to-chip communications as customers pursue rising international standards that will push out to a terabit and beyondOpens a new window over the coming decade with the arrival of 5G technology.