Feeds

Off-the-shelf optics kit tweaked for bonkers performance

Radio tricks applied to light

Boost IT visibility and business value

A couple of Australian optics labs have joined up with vendor Finisar to demonstrate an energy-efficient optical system transmitting 10 Tbps over 850 km.

On its own, 10 Tbps isn't anything to crow about: terabit systems are, after all, routine in the long-haul market. However, doing it on one fibre and cutting down the energy – and achieving the result with off-the-shelf kit – is another matter.

By way of comparison, back in 2011 ZTE indulged in a certain amount of chest-beating that it had sent 10 Tbps down 640 Km of single fibre – and to do that, it needed 112 power-hungry lasers and patented carrier generation technology. The CUDOS / Monash University demonstration achieved its result using just one laser; even though it's pulsed at higher power, it yields an overall power saving to get the same performance over a greater distance.

Conventional WDM systems need a guard band between wavelengths, and since today's photonic systems occupy the 1530–1565 nanometre band, gaps between bands represent wasted capacity, Monash University's professor Arthur Lowery told The Register, the need for that band gap is eliminated.

Optical OFDM is a popular research angle at the moment, Professor Lowery noted: both Melbourne University and Monash submitted papers on the topic to last week's Optical Fiber Communications conference in California (the CUDOS / Monash work was accepted as a post-deadline paper).

Getting performance at this level, said Jochen Schroeder of Sydney University's CUDOS facility, was a three step process: broaden the pulsed laser spectrally (to increase its bandwidth); split the resulting pulse into multiple pulses; and then modulate each of the resulting pulses.

At the heart of the experiment was the use of standard equipment – a Finisair Wavelength Selective Switch (WSS) – doing something that might have been unexpected for its manufacturer.

“We use the WSS to perform a special filter function, equivalent to a discrete fourier transform. It's a switching device used for WDM to switch different WDM channels to different fibre outputs – we've adjusted this to work for OFDM,” explained Schroeder.

He likened the use of the WSS to how FPGAs are used in the world of electronics: it provides a reprogrammable platform. “We can create optical reconfigurable optical circuits, creating an optical circuit that emulates the functionality of a discrete fourier transform,” he said.

There's one more energy saving worth mentioning, Schroeder added: the OFDM is carried out entirely in the optical domain. In most current optical OFDM work, the modulation is carried out in electrical circuits and the result encoded onto the optical carrier, but in the CUDOS / Monash experiment, “the fourier transform, the parallel-serial conversion, cyclic prefix insertion – we do all this in optics”. ®

Secure remote control for conventional and virtual desktops

More from The Register

next story
6 Obvious Reasons Why Facebook Will Ban This Article (Thank God)
Clampdown on clickbait ... and El Reg is OK with this
So, Apple won't sell cheap kit? Prepare the iOS garden wall WRECKING BALL
It can throw the low cost race if it looks to the cloud
Time Warner Cable customers SQUEAL as US network goes offline
A rude awakening: North Americans greeted with outage drama
Shoot-em-up: Sony Online Entertainment hit by 'large scale DDoS attack'
Games disrupted as firm struggles to control network
BT customers face broadband and landline price hikes
Poor punters won't be affected, telecoms giant claims
Netflix swallows yet another bitter pill, inks peering deal with TWC
Net neutrality crusader once again pays up for priority access
prev story

Whitepapers

Top 10 endpoint backup mistakes
Avoid the ten endpoint backup mistakes to ensure that your critical corporate data is protected and end user productivity is improved.
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.
Backing up distributed data
Eliminating the redundant use of bandwidth and storage capacity and application consolidation in the modern data center.
The essential guide to IT transformation
ServiceNow discusses three IT transformations that can help CIOs automate IT services to transform IT and the enterprise
Next gen security for virtualised datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.