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Australian breakthrough
could deliver 1000 times the bandwidth
Sydney: Presentation at 11.45
Tuesday, 25 October 2005, Hilton Sydney, level 4, room 3.
A small ‘smart’
scratch in a piece of glass is set to replace the electronic components in
global fibre optics networks, letting us reach data speeds up to one thousand
times greater than currently possible.
Researchers at
CUDOS, the Sydney-based Centre for Ultrahigh Bandwidth Devices for Optical
Systems, announced their breakthrough today at an international optics
conference - LEOS - in Sydney. They also announced a suite of other developments
towards their ultimate goal – light-powered switching transistors and
light-powered computers.
Light in
fibre-optic cables carries data at speeds and quantities far greater than the
old copper phone lines – that’s why fibre-optics are the backbone of Australian
communications and of the global internet. But every so often the light signals
need to be cleaned up, amplified and retransmitted. Currently, we do that with
electronic circuits which are much slower than light. These amplifiers are
becoming a bottleneck on the internet.
“Our discovery
will clear this bottleneck” says Ben Eggleton, Director of CUDOS.
“To get more
bandwidth, we need new technology that’s faster than electrons – and light’s the
fastest. We just need to build the components that can handle it. And now we’ve
got one of the first problems solved,” he says.
CUDOS have
developed a small plate of glass with a carefully engineered scratch in it that
can regenerate a new clean signal from an old noisy one. The glass is just
placed in the light flow. The “smart” scratch first separates out the signal
from the noise as the light is guided along it. The light then passes through a
series of finely etched channels that recognise which bits are the separated
signal and which bits are noise, and allow only the signal pulses past. Any
noise is trapped by the channels.
CUDOS have
tested this device at speeds over ten times higher than the fastest cables in
use in Australia.
“We hope to see
the technology implemented over the next decade by the major data carriers as
new ultrahigh bandwidth communications systems are rolled out,” says Ben.
With this
looming traffic jam cleared, the next challenge for CUDOS is to build an optical
switch - the light equivalent of the transistor switch. The invention of the
transistor in 1947 triggered the electronic age – an Intel Pentium 4 computer
chip can have up to one hundred million transistors.
During the LEOS
conference, CUDOS team members from the University of Sydney; Australia National
University; Macquarie University; Swinburne University and the University of
Technology, Sydney, will also be announcing some of the steps they’ve made
towards a light switching ‘transistor’ and a photonic chip – the building block
of ultra-fast light powered computers. LEOS is Lasers and Electro-Optics
Society of the IEEE ((the worldwide Institute for Electrical and Electronic
Engineers)
Background
information on CUDOS and conference abstracts are available online at
www.scienceinpublic.com.
For further
information and interviews contact Ben Eggleton on 0413 385 715, Jacob
O'Shaughnessy, Media Officer, University of Sydney, Tel: +61 (2) 9351 4312,
mobile: 0421 617 861,
jacob@media.usyd.edu.au
or Niall Byrne on 0417 131 977,
niall@scienceinpublic.com
Background
Who’s
in CUDOS? (and what’s in a name)
CUDOS = the Centre for Ultrahigh
Bandwidth Devices for Optical Systems.
CUDOS is a research consortium between
five Australian Universities: The University of Sydney, Macquarie University,
University of Technology Sydney, Australian National University and Swinburne
University of Technology.
Funding comes from the Australian
Research Council under the Centres of Excellence program, the five universities
and from the NSW State Government.
The Research Director is Professor Ben
Eggleton, with Professor Yuri Kivshar as Deputy Director. In 2004 the Prime
Minister awarded Ben Eggleton the Malcolm McIntosh Prize for Physical Scientist
of the Year (link to media releases and background below).
Current issues with optical
communications
Most of our telecommunications
backbones now run on fibre optics. Fibre optics carrying photons of light give
us much greater speed and carrying capacity than electron-based transmission.
The signal processing though is still done with electronics components, that
clean and regenerate signals, reamplify and retransmit them, buffer data, and
monitor the network for problems and faults. The electronics components are made
with transistors, which we won’t be able to make much smaller or faster. But our
demands for high speed transmission of data are still going up. So these signal
processing components are becoming bottlenecks on the network. If we could go
all-optical it would solve our current speed limitations.
Current network speeds can reach up to
40 gigabits per second. CUDOS expect to develop components that will work at
160 gigabits per second and beyond. The physics of photonic interactions
compared to electronic interactions means that light starts reaching its
carrying capacity at a data speed about 10,000 times greater than electrons can
manage.
Some optical components have been
built and demonstrated previously but they don’t offer the same advantages of
size and manufacturability that a silicon integrated circuit chip does.
CUDOS have built an effective signal
regenerator that compares in size to a silicon chip, and are continuing to
research other components to replace electronic network devices. They plan over
five years to develop these concepts and miniaturise them into an integrated
photonic chip that can replace the electronic silicon chips being used in our
networks.
Structure of the device
A signal regenerator needs to have
some way of distinguishing the signal from the noise and then separating out the
noise so that only the signal is passed on.
The idea of a Mamyshev regenerator
(what CUDOS have built) is that it uses a non-linear material to distinguish
signal and noise. Non-linear because the stronger (more powerful) that a light
pulse passing through is, the more its frequency is changed by the material. So
as long as your signal is still louder than the noise, its frequency will be
changed more. Put a band-pass filter on the end of this material to allow only
your highly-changed frequencies through, and you get a clean signal with none of
the noise.
CUDOS found that chalcogenide glass –
glass doped with sulphur, selenium and tellurium – worked as a non-linear
separator. Signal pulses passing through an optical waveguide in the glass
separated to a different, broader frequency range than the noise did. That gave
them the first half of the regenerator. To create the band-pass filter, they
etched a frequency-selective diffraction grating into the waveguide that would
filter out any of the noise. The results showed a clean, accurate signal with
the noise removed.
The LEOS Conference
Being held 23 - 27 October 2005
Hilton Sydney, Sydney, Australia
www.ieee.org/organizations/society/leos/LEOSCONF/LEOS2005/LEOS05.htm
LEOS is the IEEE Lasers and
Electro-Optics Society (IEEE is the Institute for Electrical and Electronic
Engineers, worldwide)
The papers CUDOS are presenting at
LEOS are:
-
an invited paper covering everything they’re
doing and their overall progress;
-
a over a dozen papers covering different
aspects of the technology they’ve developed and different problems they’ve
solved;
-
and apaper that presents the first
experimentally-demonstrated integrated pulse regenerator with terabit capacity
(using discoveries/developments/results from the other technical papers).
That paper’s conclusions: CUDOS has
demonstrated experimentally the first integrated pulse regenerator using a
non-linear waveguide followed by linear filtering through a double Bragg grating
band-pass filter. They achieve good agreement between their theory and
experimental results. Session details:
Integrated All-Optical Chalcogenide
Waveguide Pulse Regenerator: Experiment and Modeling
V. G. Ta'eed, M. Shokooh-Saremi,
CUDOS, University of Sydney, Sydney, NSW, Australia, L. Fu, D. Moss, M. Rochette,
I. C. M. Littler, University of Sydney, Sydney, NSW, Australia, B. J. Eggleton,
CUDOS, University of Sydney, NSW, Australia, Y. Ruan and B. Luther-Davies,
Australian National University, Canberra, ACT, Australia
We present an integrated,
all-optical, chalcogenide waveguide pulse regenerator based on linear filtering
of self phase modulated pulses. We demonstrate a nonlinear transfer function
with 1.5 ps optical pulses and find good agreement with theory.
Further reading:
CUDOS
http://www.cudos.org.au/cudos/
What CUDOS does (from annual report
2004 menu)
http://www.cudos.org.au/cudos/annualreport2004.php
Ben Eggleston wins the 2004 Malcolm
McIntosh Prize for Physical Scientist of the Year
http://www.scienceinpublic.com/scienceprize/2004/bensummary1.htm
Lighting up Australia’s future, by
Steven Keeping
http://www.ferret.com.au/articles/b7/0c02e0b7.asp
Abstracts
TuF1 08.30 - 09.00
(Invited)
Optically-Induced Lattices as Tunable Nonlinear Photonic Crystals, D. N. Neshev,
C. R. Rosberg, R. Fischer, A. A. Sukhorukov, A. S.
Desyatnikov, E. A. Ostrovskaya, T. Alexander, W. Z. Krolikowski and Y. S.
Kivshar, Australian National University, Canberra, ACT, Australia By using
optically-induced photonic lattices as tunable periodic structures, we
demonstrate the key aspects of light propagation in periodic medium, as
selective excitation of eigenmodes, diffraction control, and nonlinear beam
focusing, shaping and interactions.
TuF3 09.30 - 09.45
Spatial Switching in Modulated Photonic Lattices I. L. Garanovich, A. A.
Sukhorukov and Y. S. Kivshar, Australian National University, Canberra, ACT,
Australia We discuss propagation and switching of discrete solitons in modulated
optically induced photonic lattices. We reveal novel dynamical regimes for
strongly localized solitons and show the possibility of binary spatial switching
realized by varying the amplitude of the modulating beam.
TuN5 11.45 - 12.15 (Invited)
High Nonlinearity Chalcogenide, Waveguide based All-Optical, Regeneration
Schemes, B. J. Eggleton, D. Moss, M. Rochette, V. G. Ta’eed, L. Fu, and I. C. M.
Littler, CUDOS, University of Sydney, NSW, Australia We review our recent
progress in demonstrating low-power, compact all-optical regeneration schemes
suitable for ultrahigh bit-rates (>100Gb/s) based on highly nonlinear
chalcogenide optical waveguides.
Self-phase modulation schemesare demonstrated in chalcogenide singlemode fibre
and integrated chalcogenide rib waveguides incorporating photosensitively
written Bragg gratings.
TuR2 14.00 - 14.15
Evanescent Coupling to Chalcogenide, Glass Photonic Crystal Waveguides via
Tapered Microstructured Optical Fibre Nanowires, C. Grillet, D. Moss, E. Magi,
University of Sydney, Sydney, NSW, Australia, D. Freeman, S. Madden, B.
Luther-Davies, Australian National University, Canberra, ACT, Australia and B.
J. Eggleton, CUDOS, University of Sydney, NSW, Australia We demonstrate coupling
to chalcogenide glass based photonic crystal waveguides via tapered
microstructured fibre nanowires.
TuZ1 15.30 - 16.00 (Invited)
Engineering Fano Resonances in Photonic Structures with Nonlinear Defects and
Cavities, Y. S. Kivshar and A. E. Miroshnichenko, Australian National
University, Canberra, ACT, Australia We study linear and nonlinear transmission
of photonic structures, such as photonic crystals, nonlinear waveguide arrays,
and ring resonators, based on directional waveguides coupled to defects or
microcavities. We demonstrate the basic principles of engineering Fano
resonances and discuss a novel type of photonic bandgap due to Fano resonances.
TuZ4 16.30 - 16.45
Modal Formulation for Plane Wave Scattering by a Photonic Crystal Slab:
Fano Resonances, L. C. Botten, University of Sydney, Sydney, NSW, Australia, M.
Byrne, University of Technology, Sydney, Sydney, NSW, Australia, A. A. Asatryan,
University of Sydney, Sydney, NSW, Australia, N. Nicorovici, A. Norton,
University of Technology, Sydney, Sydney, NSW, Australia and R. C. McPhedron,
University of Sydney, Sydney, NSW, Australia A modal theory of diffraction by
planar photonic crystal slabs, based on a multipole-scattering matrix approach,
is developed. The theory accurately describes the diffraction problem, providing
real insight into the scattering process of Fano resonances.
WA1 08.30 - 09.00 (Invited)
Confinement of Light in Left-Handed Periodic Structures, I. V. Shavidrov, A. A.
Sukhorukov and Y. S. Kivshar, Australian National University, Canberra, ACT,
Australia We discuss unusual features of wave propagation in periodic arrays of
slabs made of transparent left-handed metamaterials with simultaneously negative
dielectric permittivity and magnetic permeability, and demonstrate the
possibility of light confinement due to the appearance of complete photonic
bandgaps in such one-dimensional structures.
WF3 09.00 - 09.15
Slow Gap Soliton Propagation Excited by Microchip Q-Switched Pulses, J. T. Mok,
E. Tsoy, I. C. M. Littler, C. M. de Sterke, University of Sydney, Sydney, NSW,
Australia and B. J. Eggleton, CUDOS, University of Sydney, NSW, Australia We
demonstrate slowly propagating gap solitons excited by microchip Q-switched
laser pulses with kilowatts peak power in a 10 cm apodized fibre Bragg grating.
Gap solitons propagating at 0.19 c/n are observed.
WA3 09.30 - 09.45
Reduction of Spontaneous Emission in Tapered Photonic Crystal Fibres, J. M.
Dawes, S. Myers, Macquarie University, North Ryde, NSW, Australia, D. Fussell,
E. Magi, R. C. McPhedron, University of Sydney, Sydney, NSW, Australia, B. J.
Eggleton, CUDOS, University of Sydney, NSW, Australia and C. de Sterke,
University of Sydney, Sydney, NSW, Australia The spontaneous emission from dye
introduced into the centre of tapered hollow-core photonic crystal fibre was
characterized in the transverse direction.
Suppression of emission due to local density of state effects, which cannot be
understood from the bandstructure alone, were observed to be consistent with
theory.
High Performance Bragg Gratings in Chalcogenide Glass Rib Waveguides Written
with a Modified Sagnac Interferometer: Fabrication and Characterization, M.
Shokooh-Saremi, V. G. Ta’eed, N. J. Baker, CUDOS, University of Sydney, Sydney,
NSW, Australia, I. C. M. Littler, D. Moss, University of Sydney, Sydney, NSW,
Australia, B. J. Eggleton, CUDOS, University of Sydney, NSW, Australia, Y. Ruan
and B. Luther-Davies, Australian National University, Canberra, ACT, Australia
We report high performance Bragg gratings in As2S3 chalcogenide glass rib
waveguides, written with a modified Sagnac interferometer for the first time.
Grating growth dynamics obtained from an in-situ monitoring system are presented
and analyzed.
WR2 13.45 - 14.00
All-Optical Directional Coupler Switching in Chalcogenide Glass, Y. Ruan, B.
Luther-Davies, A. V. Rode, V. Kolev and W. Z. Krolikowski, Australian National
University, Canberra, ACT, Australia The waveguide-based directional couplers in
As2S3 glass were fabricated by using inductively coupled plasma (ICP) etching.
Their ultrafast all-optical switching operation was demonstrated at 1530 nm with
switching peak power of 55 W.
WBB2 15.45 - 16.00
Femtosecond Laser Writing of Symmetric, Low Loss Waveguides in Active Glasses,
M. Ams, Macquarie University, North Ryde, NSW, Australia Beam shaping techniques
are used to write symmetric, low transmission loss waveguides in bulk media
using fs-lasers. The characteristics of waveguides written in active glasses and
the implications for miniature waveguide lasers will be presented.
ThM4 11.30 - 11.45
Integrated All-Optical Chalcogenide Waveguide Pulse Regenerator: Experiment and
Modeling, V. G. Ta’eed, M. Shokooh-Saremi, CUDOS, University of Sydney, Sydney,
NSW, Australia, L. Fu, D. Moss, M. Rochette, I. C. M. Littler, University of
Sydney, Sydney, NSW, Australia, B. J. Eggleton, CUDOS, University of Sydney,
NSW, Australia, Y. Ruan and B. Luther-Davies, Australian National University,
Canberra, ACT, Australia We present an integrated, all-optical, chalcogenide
waveguide pulse regenerator based on linear filtering of self phase modulated
pulses. We demonstrate a nonlinear transfer function with 1.5 ps optical pulses
and find good agreement with theory.
ThM5 11.45 - 12.00
Low Power All-Optical Signal Regeneration in Single Mode As2Se3 Chalcogenide
Glass Fiber, L. Fu, M. Rochette, University of Sydney, Sydney, NSW, Australia,
V. G. Ta’eed, CUDOS, University of Sydney, Sydney, NSW, Australia, I. C. M.
Littler, D. Moss, University of Sydney, Sydney, NSW, Australia and B. J.
Eggleton, CUDOS, University of Sydney, NSW, Australia We report low power
all-optical signal regeneration in single mode As2Se3 chalcogenide fibre,
achieving a near optimum nonlinear power transfer curve with low pulse
distortion for 6ps pulses, at <10W peak power.
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