A device to make your computers faster

Here comes an optical device that may lead to new and more powerful computers that run faster and cooler. 

Researchers at Washington University in St Louis have developed an essential component of new computers that would run on light.

"We believe that our discovery would benefit many other fields involving electronics, acoustics, plasmonics and meta-materials," said Lan Yang, an associate professor of electrical and systems engineering at Washington University.

The team created an optical diode by coupling tiny doughnut-shaped optical resonators - one with gain and the other with loss - on a silicon chip.

This diode is capable of completely eliminating light transmission in one direction and greatly enhancing light transmission in the other nonreciprocal light transmission, explained lead author Bo Peng from Yang's team.

"Coupling of so-called loss and gain devices using PT (parity-time)-symmetry could enable such advances as cloaking devices, stronger lasers that need less input power, and perhaps detectors that could 'see' a single atom," Yang added.

To make the optical diode, the researchers used two micro-resonators positioned so that light can flow from one to the other.

One device is the "lossy" silica resonator. The other incorporates the chemical element erbium into the silica structure for gain.

When the rate of gain in one resonator exactly equals that of loss in the other, the "phase transition" occurs at a critical coupling distance between the resonators.

Simply put, when a "lossy" system is coupled with a "gain" system such that loss of energy exactly equals gain at an equilibrium point, a "phase transition" occurs.

"Our resonators are small enough to use in computers and future optical information processors," Peng noted.

According to Yang, we built our optical diodes from silica which has very little material loss at the telecommunication wavelength. The concept can be extended to resonators made from other materials for better performances.

The PT symmetry concept can be extended to electronics, acoustics and other fields to create one-way channels, and photonic devices with advanced functionalities, said the paper, published in the journal Nature Physics.

Robot ‘soldier’ to help develop protective gear

A state-of-the-art robotic 'mannequin' that can run, sit and even mimic the movement of a soldier has been created by Britain's ministry of defence.

The "Porton Man" has more than 100 sensors on its body to record data during tests and will help defence scientists create the next generation of protective equipment.

The $1.8m robot has been developed using Formula One technology. The robot was based on data collected from 2,500 soldiers. It has been made for UK's Defence Science and Technology Laboratory (DSTL), where clothing systems for soldiers are tested against chemical warfare agents.

The UK's MoD said, "Built using advanced lightweight materials developed for Formula One cars, Porton Man is able to walk, march, run, sit, kneel and can even lift his arms to sight a weapon like an infantry soldier." The data from the sensors enables scientists to "carry out real-time analysis on equipment such as chemical and biological suits in a realistic but secure environment," it added.

The mannequin was designed and built by I-Bodi Technology in Buckinghamshire. "Our brief was to produce a lightweight robotic mannequin that had a wide range of movement and was easy to handle," IBodi CEO Jez Gibson-Harris said. "There were a number of challenges associated with this and one way we looked to tackle these was through the use of Formula One technology. Using the same concepts as those used in racing cars, we were able to produce very light but highly durable carbon-composite body parts for the mannequin."

DSTL is the only laboratory in the world that uses chemical warfare agents to assess the effectiveness of complete clothing systems. Britain's defence minister Philip Dunne said, "This technology designed by a British company is enabling the UK to lead the way in this important testing."

At 14kg, Porton Man is much lighter than its predecessor, which weighed in at 80kg.