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Topic Name: More flexibility for lasers
Category: Optical imaging
Research persons: Dr.-Ing. Thomas Himmer
Location: Fraunhofer-Institut für Werkstoff- und Strahltechnik,IWS,Winterbergstraße 28, Germany
Details
Lasers
have become a standard feature of surgical interventions, be it to alleviate the
breathing difficulties of snorers or to treat prostate problems. A new diode
laser is ideally suited for use in soft tissue surgery. It has the advantage of
being compact and inexpensiveSnoring
is not only inconvenient but also strenuous. The only solution for many
sufferers is to undergo medical treatment that involves surgically removing part
of the palate and the uvula. The instruments used to perform this operation
often rely on a relatively cheap CO2 laser. But its light cannot be directed
along a waveguide, and so an articulated arm has to be used to direct the beam
to the correct position inside the patient’s mouth – not a very convenient
way of working.
Researchers at the Fraunhofer
Institutes for Laser Technology ILT in Aachen and for Applied Solid State
Physics IAF in Freiburg have now developed a diode laser of a suitable
wavelength that allows this problem to be overcome. “The laser output can be
routed through a very fine light-conducting fiber,” says ILT project manager
Dr. Konstantin Boucke. “Instead of laboriously positioning a mirror at the
correct angle, the surgeon merely has to introduce a flexible optical fiber into
the patient’s mouth.” It is more economical, too: A typical diode laser
costs less than a third of the price of other types of laser. What makes this
particular diode laser so special is that it has a wavelength of two
micrometers. “Light at this wavelength is readily absorbed by biological
tissue, and the laser beam doesn’t penetrate far. Surgical incisions can be
controlled much better with this laser. It can also be switched to a second
operating mode in which it emits radiation at 800 to 980 nanometers, the ideal
wavelength for arresting bleeding. This makes the new laser highly suitable for
any type of soft tissue surgery – including prostate resection, which involves
inserting an optical fiber in the urethra,” says Boucke. In order to produce a
diode laser operating at this wavelength, the researchers had to work with an
unconventional material – gallium antimonide – and adapt the optical setup
accordingly. The cameras normally used to calibrate the laser beam were not
sufficiently sensitive for a wavelength of two micrometers.
The new laser will also allow
workpieces made of transparent plastic to be processed. A plastic material that
appears transparent to the human eye allows conventional types of laser beam to
pass through without obstruction, and without producing any melting effect.
Until now, in order to weld transparent plastics with a laser, it was necessary
to add colored pigments to the material, which added to the cost, changed the
properties, and tainted the color of the resulting product. “The new laser
permits transparent plastics to be joined without having to add pigments,”
says Boucke. The prototype will be presented for the first time at the Laser
trade show in Munich from June 18 to 21.
About
Researcher:
Contact:
Dr. rer. nat. Konstantin Boucke
Phone: +49 241 8906-132
Fax: 0241/8906-121
Send
an e-mail
Fraunhofer-Institut für Lasertechnik (ILT)
ILT
Steinbachstr. 15
52074 Aachen
Funded:
Fraunhofer
Institutes for Laser Technology ILT in Aachen and for Applied
Solid State Physics IAF in Freiburg
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