Jul 23 2009
With the "Reinhard Koselleck-Program" the Deutsche Forschungsgesellschaft (DFG) has an independent funding scheme for especially innovative and risky research since 2008. Now the experimental physicist Prof. Manfred Bayer from TU Dortmund is one of the supported scientists. With 1.5 million Euros, DFG enables his research in the field of ultrafast acoustics.
With the method of ultrafast acoustics a thin metal film is bombarded with a highly intensive laser pulse. The film reacts with a "breathing movement": it expands and then it contracts. What sounds banal at first gets interesting due to the fact that this movement takes place within a few tens picosecond. When this metal is in contact with another substance, the "breathing movement" is conveyed as a distortion wave with an extension of several nanometers. Form and intensity can relative precisely be adjusted by varying the strength of the laser bombardment.
When the wave rolls over an atom, the atom is immediately moved by some pecometers, representing an extreme severe deflection. Therefore the distortion wave can be regarded as a mighty nano-earthquake. Aim of the application is to physically understand the effects triggered by such an "earthquake" and to look for potential applications. The distortion causes the energy of electrons to change very fast: increased when the material is compressed, decreased when the material is expanded. That means that the emission of light from light-emitting-diodes and lasers can be modulated as fast as never before. Something that is highly interesting for optic telecommunications, for example. It could also open up new fields of quantum physics. With the distortion moving quantum structures could continuously be created or the interaction of light and matter could venture new frontiers. In systems consisting of many interacting particles, phase transitions can be forced which cause the collective behavior of the particles change due to the distortion wave. But these are only some of the examples the Dortmund scientist think about.