An undulator is the heart of a free-electron laser, because it transforms the energy of fast electrons into intense laser light through a special arrangement of magnets.
The FEL in Germany now covers the wavelength range, invisible to humans, from 3 to 150 micrometers. The asset of every free-electron laser is its tunability, which means the wavelength or the "colour" of the light can be adjusted at will over a large range.
Scientists at FZR have a particular interest in this far-infrared light, which is located between the ranges of microwaves and the infrared and is often called Terahertz (THz) radiation. The generation and application of this radiation has become a very hot topic recently, with many researchers worldwide active in this field. While many practical applications will eventually require compact and cheap sources, basic research needs also intense sources - and to date there are virtually no other intense THz sources available apart from free-electron lasers.
At FZR, THz radiation is used in particular to study the dynamical behavior of electrons in semiconductor nanostructures. Such knowledge is important for the development of ever faster electronic devices, and thus, computers.
COMPAMED.de; Source: Forschungszentrum Rossendorf