May 31, 2012 Laser frequency combs can be used for the
calibration of astronomical spectrographs. This will help to
find extra-solar planets, i.e. planets that are orbiting a star
outside our solar-system. By refining this technology it might
become possible to directly measure even very small changes in
the expansion velocity of the universe. Since their invention
some ten years ago, laser frequency combs have proven to be a
vital tool in many laser laboratories around the world.
Originally developed for the investigation of the quantum world,
they are now making their way into astronomy and astrophysics. A
team of scientists from the Laser Spectroscopy Division of
Professor Theodor W. Hänsch at the Max Planck Institute of
Quantum Optics (Garching), in collaboration with the European
Southern Observatory (ESO), the Instituto de Astrofísica de
Canarias, and the Menlo Systems GmbH (Martinsried), has now
modified the frequency comb technique in a way that it can be
applied for the calibration of astronomical sp