TheUniversity of Bathis experimenting
with a new type of material that could increase data transfer
speeds and reduce part of the cost of installingbroadband networks.
Internet service providers (ISPs) say the cost of installing a
super-fast broadband network throughout the UK is expensive because
of the cost of laying the
fibre cable connections, which are necessary to deliver higher
speeds.
Businesses based in areas where demand for high speed broadband
might not justify an operator investing in installing fibre could
be left with second rate connections, according to analysts.
But a new approach to manufacturing "hollow core fibre" - a type
of fibre which uses air rather than conventional glass fibre to
transmit data as light - could make installations cheaper in the
future. To understand why hollow core fibre is better than
conventional fibre, a science lesson is needed.
Conventional
fibre optic connections carry data using light through shafts
of cylindrical glass, which look a bit like plastic straws.
But because the light has to travel through glass, the speed of
data transfers can be slowed. For example, the glass can be damaged
if there is too much light. Glass also causes light to spread out
in a blurring effect, which could disrupt or slow the flow of
data.
In hollow core designed fibre, light travels down a hollow core
and is guided by tiny air holes rather than glass, overcoming the
limitations. These fibres - which can be a kilometre in length and
the width of a human hair - can trap light so that it does not
become absorbed by matter or lose its power. It does this by the
structure of the tiny round holes running the length of the
photonic crystal fibre, arranged in a honeycomb shape.
Jonathan Knight, a professor at the University of Bath, said
that the problem in developing hollow-core fibres is that only a
special sort of optical fibre can guide light down an air hole.
Knight said that the detailed nature of these fibres means that
they have been difficult to produce and they can only work for a
limited range.
The new procedure developed by the Bath photonics group, shows
how a tiny change to these fibres - narrowing the wall of glass
around the large central hole by just a hundred nanometres (a
10-millionth of a metre) broadens the range of wavelengths that can
be transmitted.
The procedure omits some of the most difficult steps in the
fabrication procedure, reducing the time required to make the
fibres from around a week to a single day.
The superior performance of the fibre means that it could have a
significant impact in a range of fields such as laser design and
pulsed beam delivery, spectroscopy, biomedical and surgical optics,
laser machining, the automotive industry and space science, said
Knight
"The consequences of being able to use light rather than
electrical circuits to carry information will be fundamental," said
Knight. "It will make optical fibres many times more powerful and
brings the day when information technology will consist of optical
devices rather than less efficient electronic circuits much
closer."
For biomedical research, the fibres could be used to deliver
light for diagnosis or surgery anywhere - even deep inside the
body.
"The most immediate use of these types of fibre will be in
manufacturing, though," said Tim Birks, a professor in the project
team.
A manufactuer of laser equipment is trialling the fibre for fine
laser cutting in its manufacturing process.
"The fibre is of particular use in delivering highly focused and
concentrated pulses of light - so any application in biomedical or
manufacturing operations will be relevent. Birks said that the
application for broadband was still some way off, but that the
first steps had been paved for greater innovation.