MIRSURG project develops table-top laser for minimally invasive
31 May 2012
The EU funded MIRSURG project has developed a table-top
solid-state laser system that can cut brain tissue with unprecedented
precision. The project involves partners from seven European countries.
The new laser emits short pulses exactly at 6.45 microns
with a repetition rate of 100-200 Hz which ensures the targeted
average power of over 1 Watt.
The greatly reduced collateral damage at this wavelength is due
to the combined absorption of water and resonant laser heating of
non-aqueous components (proteins). The penetration depth at this
wavelength is on the order of several microns, which is comparable
to the cell size, and is therefore close to the optimum value, not
achievable by any other state-of-the-art lasers.
"There were so far no compact and reliable solid-state lasers
emitting at the desired mid-infrared wavelength," said Dr Valentin
Petrov from Max Born Institute for Nonlinear Optics and Short Pulse
Spectroscopy (MBI), coordinator of the consortium.
The project was launched in 2008 with the objective to close up
the gap for diode-pumped solid-state lasers in the mid-infrared
spectral range around 6.45 microns. At the MIRSURG final meeting in
spring 2012 in Saint-Louis, France, the project team presented a
rather compact all-solid-state prototype that fits on a table-top.
The desired optical wavelength of 6.45 microns is generated by
frequency conversion. A laser beam with a wavelength near 2 microns
is converted to the mid-infrared by the use of nonlinear optical
The challenge for the researchers was to achieve simultaneously
all the most appropriate but still technically feasible parameters
for soft tissue ablation. They managed to combine the desired
wavelength with high single pulse energy of more than 5 millijoules,
short pulse duration of about 30 nanoseconds and good focusing
capability. The repetition rate, long term stability and reliability
of the entire laser system seem ideally suited for practical
The project partners of MIRSURG intend to further optimize the
new table-top laser, assess its tissue ablation capabilities and,
possibly within a follow-up project, demonstrate real solid-state
laser surgery at 6.45 microns. "I hope that in the near future such
a laser could become a practical surgical tool in every specialized
operating room," said Petrov.
The MIRSURG website: