Feeds

Caltech sends light on a one-way trip

Optical computing gets a small step closer

High performance access to file storage

A group of Caltech researchers is claiming what it describes as a key breakthrough in photonic computing: an optical diode using linear, rather than non-linear, materials.

The diode – or rather, components that mimic the function of the diode in the optical domain – is important to optical computing, because it helps isolate signals from each other. For example, it protects signals from interference from backscattered noise.

According to PhD scholar Liang Feng, the optical isolator – a device that allows light to travel in one direction only – is “something that scientists have been pursuing for 20 years”.

One way to isolate light is with magnets, but this isn’t feasible at the microscopic scale needed to build integrated optical chips capable of carrying out computing functions: the magnets need to be too big. The other is to use non-linear optical materials. This works well, but the researchers say non-linear materials are difficult to integrate with traditional silicon-based fabrication methods.

In their proof-of-concept paper, Non-reciprocal light propagation in a silicon photonic circuit, published in Science, the researchers say they have transmitted light in a symmetric mode in one direction, but in the other direction, the light changes to asymmetric mode. The paper is outlined here.

This isn’t actually “blocking” the light in the return direction – not in the way that a diode blocks an electrical signal in the “wrong” direction – but it means that the two optical signals don’t interact with each other.

The Caltech group built an 800nm x 200nm waveguide, and added materials with different reflective and refractive properties to break the symmetry of the light passing through the waveguide.

The next step for the researchers will be to take the proof-of-concept and create optical isolators suitable for integration onto integrated circuits. ®

High performance access to file storage

More from The Register

next story
IBM Hursley Park: Where Big Blue buries the past, polishes family jewels
How the internet of things has deep roots in the English countryside
Video games make you NASTY AND VIOLENT
Especially if you are bad at them and keep losing
Russian deputy PM: 'We are coming to the Moon FOREVER'
Plans to annex Earth's satellite with permanent base by 2030
Solar-powered aircraft unveiled for round-the-world flight
It's going to be a slow and sleepy flight for the pilots
LOHAN's Punch and Judy show relaunches Thursday
Weather looking good for second pop at test flights
Honeybee boffin STINGS OWN WEDDING TACKLE... for SCIENCE
Not the worst place to be stung, says one man
India's GPS alternative launches second satellite
Closed satnav system due to have all seven birds aloft by 2016
Curiosity finds not-very-Australian-shaped rock on Mars
File under 'messianic pastries' and move on, people
prev story

Whitepapers

Mainstay ROI - Does application security pay?
In this whitepaper learn how you and your enterprise might benefit from better software security.
Five 3D headsets to be won!
We were so impressed by the Durovis Dive headset we’ve asked the company to give some away to Reg readers.
3 Big data security analytics techniques
Applying these Big Data security analytics techniques can help you make your business safer by detecting attacks early, before significant damage is done.
The benefits of software based PBX
Why you should break free from your proprietary PBX and how to leverage your existing server hardware.
Mobile application security study
Download this report to see the alarming realities regarding the sheer number of applications vulnerable to attack, as well as the most common and easily addressable vulnerability errors.