31 Jul 2008
IQE material helps push VCSEL performance beyond 10 Gbit/s
IQE plc (AIM: IQE, “IQE” or the “Group”), the leading global
supplier of advanced semiconductor wafer products and wafer
services to the semiconductor industry, is pleased to
announce that VCSEL optoelectronic materials produced at its
Cardiff manufacturing facility have enabled researchers to
produce potentially reliable devices capable of operating at
speeds greatly in excess of 10 Gbit/s.
In an article published in this month’s Electronics Letters,
Professor Anders Larsson of Sweden’s Chalmers University of
Technology said:
“The vertical cavity surface emitting laser (VCSEL) emitting
at 850 nm has become the laser of choice for short reach
data communication links in local and storage area networks
operating at single channel data rates up to 10 Gbit/s.
While there is a future need for even higher data rates it
has been commonly believed that VCSELs operating at rates
much higher than 10 Gbit/s will have to be scaled down in
size to achieve the modulation bandwidth needed, thus
operating at current densities too high for reliable
operation.”
Professor Larsson’s research group at the Photonics
Laboratory at the Department of Microtechnology and
Nanoscience, Chalmers University of Technology, in Göteborg,
Sweden, has recently shown that this is not necessarily the
case. By optimizing the VCSEL design with respect to
differential gain, capacitance, electrical resistance and
thermal impedance, it was demonstrated that 850 nm oxide
confined VCSELs with an aperture as large as 9 µm can
achieve low threshold current, high differential efficiency
and a modulation bandwidth as large as 21 GHz (Figs. 1 and
2). At a bias current of 6.5 mA, clear and open eyes could
be generated at bit rates up to 25 Gbit/s and an extinction
ratio of 6 dB (Fig. 3). This current corresponds to a
current density of 10 kA/cm2, which is at the level where
the present 10 Gbit/s VCSEL technology operates. This
clearly indicates the potential for reliable operation of
directly modulated 850 nm VCSELs at very high data rates for
future, high capacity data communication links.
Professor Larsson went on to say that the epitaxial material
for the work was provided by IQE and the project was
supported by the European project VISIT and the Swedish
Foundation for Strategic Research.
Contacts:
IQE plc (+44 29 2083 9400)
Chris Meadows
Andrew Joel
NOTE TO EDITORS
About IQE
www.iqep.com
IQE is the leading global supplier of advanced semiconductor
wafers with products that cover a diverse range of
applications, supported by an innovative outsourced foundry
services portfolio that allows the Group to provide a 'one
stop shop' for the wafer needs of the world's leading
semiconductor manufacturers.
IQE uses advanced crystal growth technology (epitaxy) to
manufacture and supply bespoke semiconductor wafers ('epi-wafers')
to the major chip manufacturing companies, who then use
these wafers to make the chips which form the key components
of virtually all high technology systems. IQE is unique in
being able to supply wafers using all of the leading crystal
growth technology platforms.
IQE's products are found in many leading-edge consumer,
communication, computing and industrial applications,
including a complete range of wafer products for the
wireless industry, such as mobile handsets and wireless
infrastructure, Wi-Fi, WiMAX, base stations, GPS, and
satellite communications; optical communications, optical
storage (CD, DVD), laser optical mouse, laser printers &
photocopiers, thermal imagers, leading-edge medical
products, barcode, high efficiency LEDs and a variety of
advanced silicon based systems.
The manufacturers of these chips are increasingly seeking to
outsource wafer production to specialist foundries such as
IQE in order to reduce overall wafer costs and accelerate
time to market.
IQE also provides bespoke R&D services to deliver customised
materials for specific applications and offers specialist
technical staff to manufacture to specification either at
its own facilities or on the customer's own sites. The Group
is also able to leverage its global purchasing volumes to
reduce the cost of raw materials. In this way IQE's
outsourced services, provide compelling benefits in terms of
flexibility and predictability of cost, thereby
significantly reducing operating risk.
IQE operates six manufacturing facilities located in Cardiff
(two) and Milton Keynes in the UK; in Bethlehem,
Pennsylvania and Somerset, New Jersey in the USA; and
Singapore. The Group also has 11 sales offices located in
major economic centres worldwide.
About Chalmers University of Technology
http://www.chalmers.se/en
Chalmers is a university of technology in which research and
teaching are conducted on a broad front within technology,
natural science and architecture. Our inspiration lies in
the joy of discovery and the desire to learn. Underlying
everything we do is a wish to contribute to sustainable
development both in Sweden and world-wide.
Our research work deals ultimately with improving people’s
conditions, and we often cross traditional boundaries in
order to solve the problems of the future. Chalmers has
become strong within several areas of science, and some of
our research leads its field internationally. We wish in
particular to develop and strengthen our research in the
fields of bioscience, information technology, environmental
science and nanotechnology.
Chalmers is a pioneer in Europe in the field of start-up
companies, and has built up an efficient system of
innovation in order to find applications in research into
the formation of companies.
Chalmers has great aspirations to develop continually by
opening doors to the outside world and by thinking
innovatively. We have a close and productive collaboration
with business and society at large. In this way we reinforce
our own development, at the same time as we contribute to
the growth of society.
Chalmers was founded in 1829 as a result of a donation from
the director of the Swedish East India Company, William
Chalmers.