Berlin 2018 – scientific programme

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KFM: Fachverband Kristalline Festkörper und deren Mikrostruktur

KFM 27: Postersession KFM

KFM 27.14: Poster

Thursday, March 15, 2018, 15:00–17:00, Poster E

Construction of a broadband Sub-THz-Spectrometer — •Max Pargmann, Christoph Grams, and Joachim Hemberger — Universität zu Köln

Between the highest frequencies that are accessible with conventional dielectric spectroscopy (≈2E10 Hz) and the lowest in optical free-beam spectroscopy (≈2E11 Hz), measurements are difficult due to technical limitations [1]. We try to close this frequency gap by building a new time-domain spectrometer enabling us to measure a wide frequency range starting from 5 GHz up to 500 GHz. We use a pulsed laser setup with a variable delay up to 500 ps combined with a pulse picker to customize the average optical power. For measurement, we use an on-chip emitter detector design in microstrip geometry, with embedded GaAs photoconductive switches, which allows for generation and detection of pulses ≈ 300 fs [2]. The spectrometer is compact and complete fiber based therfore it can be easily implimentated in commerical magneto cryostats without the need of free beam.

This work is supported by the Deutsche Forschungsgemeinschaft via SFB1238 (Cologne).

[1] C. Matheisen et al, IEEE Xplore 15598877(2015)

[2] M.B. Byrne et al, Appl. Phys. L93, 182904 (2008)