Laser Physics Advances Under Spotlight in Munich

Enhanced lasers are the focal point of this year's Laser World of Photonics trade show, being held from May 23 to 26 in Munich. With the help of these lasers, it is possible to show structures of complex biomolecules, arthritically modified cartilages at a very early stage and the tiniest of tumors. Besides tumor diagnosis, tumor therapy is an important long-term objective on which physicists and medical scientists jointly research.

The power enhancement of the lasers demands special amplifier techniques and mirrors that have not made it to the market yet. In the Munich-Centre of Advanced Photonics (MAP) Service Centre, scientists produce chirped mirrors: custom-made mirrors for every wavelength and every research problem. The production requires extensive experimental and computational efforts, which can take several days.

The aim of the Cluster of Excellence is to develop intense lasers and to control and steer the light waves. Therefore, the scientists need mirrors, which are suited for high laser capacities of 100 TW/cm² and high repetition rates of up to 1 kHz. (Images: Thorsten Naeser)

Modern research lasers are strong enough to generate and accelerate particles such as ions and electrons. This is the second main area of the MAP Service Centre, the only team in the world to produce razor-thin carbon foils of atoms in a diamondlike structure. If an intense laser pulse strikes such a foil, it separates the atoms in faster electrons and heavier and, thus slower, ions. These particles are driven by light pressure and automatically align in single pulses. For these two main areas, the MAP Service Centre received the Selected Landmark 2011 award.

Visitors can obtain more detailed information at two public talks by MAP scientists at the Application Panel, which will be held May 24 from 2 to 4:30 p.m. Panel organizer Dr. Ronald Sroka will give an overview of modern applications of lasers in medicine. Professor Jan Wilkens, a medical physicist at Klinikum rechts der Isar, will explain his vision of a combined and compact device for the diagnosis and therapy of tumors and how such a device will finally be within reach with the help of laser-plasma acceleration. Dr. Martin Bech, who works with the chairman of biomedical physics at Technical University of Munich (TUM), will show stunning images generated by Professor Franz Pfeiffer's group using the phase-contrast and dark-field techniques of the past few years.

These diamondlike carbon foils are only 3 nm thick and stable enough to stand alone. If a focused laser pulse hits them, they behave such as light sail, and the generated electrons are accelerated up to almost light velocity.

At this year’s World of Photonics Congress, laboratories of Ludwig Maximilian University of Munich (LMU) at the Research Campus in Garching will be open for the first time on May 27. Participants may gain insight into some research projects of the Cluster of Excellence and will not only be able to see the mirror production, but also two laser labs with ultrafast single-electron diffraction and photoemission spectroscopy.

As a common project of LMU Munich and TUM, the Center for Advanced Laser Applications (CALA) is being built at the research campus in Garching. CALA is based on the research results of the Cluster of Excellence MAP but will further develop the laser-driven brilliant sources for x-ray and particle beams and do research on their possible use in biomedical applications. The emphasis will be on biomedical imaging with x-ray beams for the early detection of cancer and local tumor therapy with laser-generated proton and carbon ion beams. A further research focus is the ultrafast radiation biology, with the goal to better understand and optimize the processes of the therapy with ion beams.

(Also see: Innovation on display at Laser Munich)

For more information, visit: www.munich-photonics.de