Feeds

Caltech sends light on a one-way trip

Optical computing gets a small step closer

Secure remote control for conventional and virtual desktops

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. ®

Next gen security for virtualised datacentres

More from The Register

next story
Vulture 2 takes a battering in 100km/h test run
Still in one piece, but we're going to need MORE POWER
TRIANGULAR orbits will help Rosetta to get up close with Comet 67P
Probe will be just 10km from Space Duck in October
Boffins ID freakish spine-smothered prehistoric critter: The CLAW gave it away
Bizarre-looking creature actually related to velvet worms
CRR-CRRRK, beep, beep: Mars space truck backs out of slippery sand trap
Curiosity finds new drilling target after course correction
China to test recoverable moon orbiter
I'll have some rocks and a moon cheese pizza please, home delivery
What does a flashmob of 1,024 robots look like? Just like this
Sorry, Harvard, did you say kilobots or KILLER BOTS?
NASA's rock'n'roll shock: ROLLING STONE FOUND ON MARS
No sign of Ziggy Stardust and his band
Why your mum was WRONG about whiffy tattooed people
They're a future source of RENEWABLE ENERGY
Vulture 2 spaceplane autopilot brain surgery a total success
LOHAN slips into some sexy bespoke mission parameters
prev story

Whitepapers

5 things you didn’t know about cloud backup
IT departments are embracing cloud backup, but there’s a lot you need to know before choosing a service provider. Learn all the critical things you need to know.
Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Build a business case: developing custom apps
Learn how to maximize the value of custom applications by accelerating and simplifying their development.
Rethinking backup and recovery in the modern data center
Combining intelligence, operational analytics, and automation to enable efficient, data-driven IT organizations using the HP ABR approach.
Next gen security for virtualised datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.