Dresden 2011 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
TT: Fachverband Tiefe Temperaturen
TT 60: SC \& MLT: Cryodetectors
TT 60.8: Vortrag
Freitag, 18. März 2011, 12:45–13:00, HSZ 301
Coherent broadband THz spectrometer using photomixers in combination with magneto-cryostats: A compact solution for spectroscopy at low temperature and high magnetic field — •Komalavalli Thirunavukkuarasu1, Andreas Janssen1, Malte Langenbach1, Holger Schmitz1, Iván Cámara Mayorga2, Rolf Güsten2, Axel Roggenbuck3, Anselm Deninger3, Markus Grüninger1, and Joachim Hemberger1 — 1II. Physikalisches Institut, Universität zu Köln, D-50937 Köln, Germany — 2Max-Planck Institute for Radio Astronomy, Auf dem Hügel 69, D-53121 Bonn, Germany — 3TOPTICA Photonics AG, Lochhamer Schlag 19, D-82166 Gräfelfing, Germany
We present the first results of the integration of a cw THz spectrometer together with magneto-cryostats for use at low temperatures and high magnetic fields. The high-resolution spectrometer employs photomixing of two NIR-DFB lasers for generation and phase sensitive detection of THz radiation in the frequency range from 60 GHz to 1.5 THz. A fiber-based phase modulation technique is used to accurately determine the amplitude and the phase at a given frequency. The complex optical functions can be evaluated from the full phase information of the THz beam. Recently, this compact spectrometer was successfully integrated within a magneto-cryostat. This system is one of the very few experimental realizations that allow for investigations at magnetic fields up to 16 T and temperatures down to 3 K with excellent reliability. The response of photomixers and the general operation of the spectrometer in these experimental conditions will be outlined.