ASCOT, England, Oct. 14 /CNW/ - Researchers at the Institute of
Photonics, University of Strathclyde, have started work on a 3.5 year project
to develop a novel solid-state laser design incorporating CVD (chemical vapour
deposition) diamond manufactured by Element Six Ltd. Element Six leads the
world in the field of CVD diamond synthesis and its application.
The development of a diamond Raman laser could open up a raft of new
application areas in, for example, underwater imaging, medical imaging,
ophthalmology, cancer therapy and multispectral imaging. The project will be
led by Dr. Alan Kemp at the Institute of Photonics, University of Strathclyde
supported by a grant of more than GBP600,000 from the UK government-funded
Engineering and Physical Sciences Research Council, EPSRC.
The use of diamond as a solid-state laser material opens up new
opportunities to design small, compact solid state lasers with greater power
handling capabilities and operating at currently unavailable wavelengths so
opening up new application areas. Diamond has a unique combination of optical
and thermal properties that make it suitable for this application and these
properties can be exploited through the latest single crystal CVD material
produced by Element Six. Raman lasers have already been developed using
materials such as silicon, for example, and are used in telecommunications,
but the use of diamond could move their capabilities to new power levels and
How Raman lasers work
Raman lasers make use of a phenomenon called Raman Scattering discovered
in 1922. When photons hit a substance, a tiny fraction of them interact by
causing the atoms of the substance to vibrate. In such 'inelastic' collisions,
the photons gain or lose specific amounts of energy, resulting in light of a
different wavelength. A Raman laser amplifies the secondary light by
oscillating it and pumping energy into the system to emit a coherent laser
The importance of this type of laser is that it can shift the wavelength.
As Dr. Kemp says the ability to shift the wavelengths "gives access to the
applications-rich, but currently source-poor, yellow-orange region of the
spectrum." Today, most commercial lasers operate in the near infrared region
of the spectrum between 0.8 microm to 1.1 microm with a particular
concentration around 1 microm (1.03 - 1.07 microm) where most of the high
performance laser work is done. "Perhaps the most important challenge in
modern solid-state laser engineering," says Dr. Kemp, "is to find ways to
generate new wavelengths but in doing so to retain as much as possible of the
convenience and performance of current lasers."
Potential of synthetic diamond
In addition, current generations of continuous wave solid state Raman
lasers have been limited to powers of only a few watts due to thermal
problems. Diamond has excellent thermal conductivity combined with a low
thermal coefficient of expansion allowing greater power handling capability.
"The least glamorous but most pervasive problem in laser engineering,
particularly when you want high performance in a small package, is how to deal
with heat," points out Dr. Kemp. "This is particularly problematic in high
power Raman lasers because crystals that are good Raman converters are
typically rather poor conductors of heat. This is where diamond comes in. With
a thermal conductivity that is two to three orders of magnitude better than
typical Raman active crystals, it should be an excellent Raman medium and
allow us to generate much higher output powers." In addition, diamond shifts
the wavelength slightly further than the Raman-active crystals that are
currently used which may extend its application potential. "The team at the
Institute of Physics has recognised that diamond has a high Raman gain
coefficient and a large Raman shift compared to conventional Raman media,"
adds Chris Wort, Technical Manager at Element Six.
A vital property of the diamond supplied by Element Six is that it
exhibits ultra-low birefringence. Birefringence is when the speed of light in
a medium varies if the polarisation of the light changes and this has to be
carefully controlled in a laser cavity in order to make the laser work well.
Dr. Kemp says, "The ultra-low birefringence single crystal CVD diamond that E6
produces is a real step forward for all photonics applications of diamond,
particularly laser applications. It allows us to exploit the exceptional
properties of diamond without compromising other aspects of the laser's
Element Six is to supply the research team with high quality single
crystal CVD diamond for the duration of the project. The Institute of
Photonics has a good working relationship with Element Six. The organisations
have previously worked together on the government supported MIDDI project
under which has led to the ability to carry out precision etching of single
crystal diamond micro-optics, for example.
About Element Six
Element Six is the world's leading supplier of high quality
supermaterials used throughout manufacturing industry for a wide range of
applications. It is the frontrunner in the development of synthetic diamond
and novel engineering materials that are being used in industrial applications
that span, for example optical, mechanical, thermal, electronic, automotive,
telecommunications and medical industries. With a turnover of more than
US$500m and almost 4,000 employees, Element Six has established production and
processing plants in China, Germany, Ireland, Sweden, South Africa, Ukraine
and the UK supported by a global distribution network.
About the Institute of Photonics
The Institute of Photonics, established in 1995, is a
commercially-oriented research unit, part of the University of Strathclyde.
Its key objective is to bridge the gap between academic research and
industrial applications and development in the area of photonics. The
Institute's research interests include semiconductor materials and devices,
practical, all solid state lasers, micro-LED arrays and a wide range of
applications particularly in biophotonics. The Institute of Photonics is based
in Strathclyde's Glasgow city centre campus. The IoP undertakes contract and
collaborative research with industry and offers consultancy. It has a large
number of PhD and EngD students, and licences technologies to companies.
For further information:
For further information: John Caldwell, Corporate Communications,
Element Six, Tel: +353-(0)61460015, Email: firstname.lastname@example.org; Institute of
Photonics, University of Strathclyde, Wolfson Centre, 106 Rottenrow, Glasgow
G4 0NW, Tel: +44-141-548-4120, Fax: +44-141-552-1575, Email: