New processor computes at light speed

13:14 30 October 03

NewScientist.com news service

A superfast computing processor that uses light, not electrons, to perform calculations has gone on sale for the first time. Lenslet, the Israeli company that developed the processor, say its light speed calculations deliver the power of a supercomputer in a single device.

The device is called Enlight and can perform 8000 billion arithmetic operations per second, about 1000 times faster than a standard processor. Previously this type of processor was only available to highly financed government laboratories, says Lenslet's founder, Aviram Sariel.

He believes EnLight will be useful across a broad range of applications, from military projects to compressing high definition video images. Sariel acknowledges that Enlight "is not a general purpose processor like a Pentium". Instead, each processor will be custom-built to perform a specific set of tasks, and will not be programmable.

Much research has been done to try to exploit the much faster speed at which light travels compared to electronic signals, but most commercial work in this area has focused mainly on optical interfaces. These devices allow fibre optic and related systems to communicate with traditional electronic systems.

Hybrid device

Strictly speaking, EnLight is a hybrid device, housing both electronic and optical circuits, but it is the optical processing that make it so fast, Sariel told New Scientist: "It allows you to do a massive level of operations in parallel."

Derryck Reid, part of the Ultrafast Optics Group at Scotland's Heriot Watt University, says it may still be some time before we have fully optical devices: "Fully optical processors are still very much at the basic component level."

Reid says he has not heard of any other commercially available optical processors. But, he adds, with these kinds of hybrid devices there is a fine distinction between performing calculations like a processor and processing light signals like a telecommunication switching circuit. The latter are also being developed.

Matrix multiplication

The processing in the Enlight device is carried out using a process called vector matrix-multiplication, which allows calculations to be performed on 256 optical inputs.

The beams from 256 lasers are added or multiplied together when shone on a matrix device called a spatial light modulator. The outputs are then read by an array of light detectors.

Lenslet would not put a precise price on how much an EnLight processor would cost, because each will be made to order. But a spokeswoman did say that it would be in the region of tens of thousands of dollars.

Duncan Graham-Rowe

Sun more active than for a millennium

19:00 29 October 03

Exclusive from New Scientist Print Edition. Subscribe and get 4 free issues.


The Sun is more active now than it has been for a millennium. The realisation, which comes from a reconstruction of sunspots stretching back 1150 years, comes just as the Sun has thrown a tantrum. Over the last week, giant plumes of have material burst out from our star's surface and streamed into space, causing geomagnetic storms on Earth.

The dark patches on the surface of the Sun that we call sunspots are a symptom of fierce magnetic activity inside. Ilya Usoskin, a geophysicist who worked with colleagues from the University of Oulu in Finland and the Max Planck Institute for Aeronomy in Katlenburg-Lindau, Germany, has found that there have been more sunspots since the 1940s than for the past 1150 years.

Sunspot activity

Sunspot observations stretch back to the early 17th century, when the telescope was invented. To extend the data farther back in time, Usoskin's team used a physical model to calculate past sunspot numbers from levels of a radioactive isotope preserved in ice cores taken from Greenland and Antarctica.

Global warming

Ice cores provide a record of the concentration of beryllium-10 in the atmosphere. This is produced when high-energy particles from space bombard the atmosphere, but when the Sun is active its magnetic field protects the Earth from these particles and levels of beryllium-10 are lower.

There was already tantalising evidence that beryllium-10 is scarcer now than for a very long time, says Mike Lockwood, from the UK's Rutherford Appleton Laboratory near Oxford.

But he told New Scientist that when he saw the data converted to sunspot numbers he thought, "why the hell didn't I do this?" It makes the conclusion very stark, he says. "We are living with a very unusual sun at the moment."

The findings may stoke the controversy over the contribution of the Sun to global warming. Usoskin and his team are reluctant to be dragged into the debate, but their work will probably be seized upon by those who claim that temperature rises over the past century are the result of changes in the Sun's output (New Scientist, print edition, 12 April 2003). The link between the Sun's magnetic activity and the Earth's climate is, however, unclear.

Journal reference: Physical Review Letters (in press)

Jenny Hogan