O4.1 - First results in the IR and THz spectral range at the Metrology Light Source

SENSOR+TEST Conferences 2009
2009-05-26 - 2009-05-28
Congress Center Nürnberg
Proceedings OPTO 2009 & IRS² 2009
OPTO 4 - Optical Inspection and Quality Assurance
R. Mueller, A. Bawagan, A. Hoehl, R. Klein, G. Ulm - Physikalisch-Technische Bundesanstalt, Berlin, Germany, J. Feikes, M. v. Hartrott, U. Schade, G. Wuestefeld - BESSY GmbH, Berlin, Germany
93 - 97


Electron storage rings are nearly ideal radiation sources for metrology over a broad spectral range from the IR/THz to the X-ray region. Over the past two decades, the use of synchrotron radiation (SR) in the fields of physics, chemistry, biology, medicine and elsewhere has expanded rapidly. The number of synchrotron radiation sources currently worldwide in operation is about 60, and about 10 new facilities are under constnuction or being planned. Some national metrology institutes make extensive use of synchrotron radiation for metrology, especially radiometry. The PTB, the German national metrology institute, has been using synchrotron radiation for photon metrology at the electron storage rings BESSYI and BESSYII for about 25 years. At present PTB operates a laboratory at BESSYII with main emphasis on the EUV and X-ray region. in April 2008, the PTB's new electron storage ring, the Metrology Light Source (MLS), went into user operation.
In recent years, the strength of electron storage rings as unique sources of IR radiation has also become apparent and is increasingly being exploited around the world. In particular, IR radiation in the mid infrared wavelength region is used in research by means of Fourier transform spectroscopy on biological tissues down to single cells, high-pressure and micro-sample measurements and in investigations or surfaces and thin films applying IR ellipsometry with a high lateral resolution. A rapidly growing number of IR beamlines at several storage rings has been realized or is planned taking advantage of this unique IR light sources. Synchrotron radiation sources have major advantages in the IR range compared to conventional thermal sources: a broader spectral range (continuous from the far-lR to the visible), higher photon flux in the far-lR, higher brilliance (as it is almost a point source the light can be focused down to the diffraction limited size), pulsed radration in the ps range (the light is emitted from electron bunches which allows fast time-resolved measurements), polarized radiation, and at a few storage rings intense coherent synchrotron radiation (CSR) in the lower energy part of the far iR (sub-THz to THz) with gain up to 6 to 9 orders of magnitude compared to conventional synchrotron radiation emission.