DPG Phi
Verhandlungen
Verhandlungen
DPG

Berlin 2012 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

TT: Fachverband Tiefe Temperaturen

TT 33: Superconductivity, Measuring Devices, Matter at Low Temperature: Poster Session

TT 33.72: Poster

Wednesday, March 28, 2012, 15:00–19:00, Poster B

Coherent broadband THz spectrometer using photomixers for accurate determination of complex dielectric function — •Malte Langenbach1, Komalavalli Thirunavukkuarasu1, Holger Schmitz1, Ernesto Vidal1, Jennifer Marx1, Iván Cámara Mayorga2, Rolf Güsten2, Axel Roggenbuck3, Anselm Deninger3, Joachim Hemberger1, and Markus Grüninger11II. Physikalisches Institut, Universität zu Köln, Köln, Germany; — 2Max-Planck-Institut für Radioastronomie, Bonn, Germany; — 3Toptica Photonics AG, Gräfelfing, Germany

We report on a novel cw THz spectrometer for measurements in high magnetic fields and at low temperatures. The spectrometer employs photomixing of two NIR lasers for generation and phase-sensitive detection of THz radiation from 60 GHz to 1.8 THz. A fast phase-modulation technique using two fiber stretchers is used to determine the amplitude and the phase at a given frequency with excellent reliability. The phase accuracy is increased with further implementation of a third laser which enables correction of phase drifts mainly caused by thermal drifts. Thus, the complex dielectric function can be determined very accurately with a very high resolution in the MHz range. This compact spectrometer in combination with the magneto-cryostat allows for investigations in magnetic fields up to 8 T and temperatures down to 3 K with excellent reliability. Various aspects of the above-mentioned developments will be outlined.

100% | Mobile Layout | Deutsche Version | Contact/Imprint/Privacy
DPG-Physik > DPG-Verhandlungen > 2012 > Berlin