Share Email Print
cover

Proceedings Paper

Towards an active real-time THz camera: first realization of a hybrid system
Author(s): T. May; C. am Weg; A. Alcin; B. Hils; T. Löffler; H. G. Roskos
Format Member Price Non-Member Price
PDF $14.40 $18.00

Paper Abstract

We report the realization of a hybrid system for stand-off THz reflectrometry measurements. The design combines the best of two worlds: the high radiation power of sub-THz micro-electronic emitters and the high sensitivity of coherent opto-electronic detection. Our system is based on a commercially available multiplied Gunn source with a cw output power of 0.6 mW at 0.65 THz. We combine it with electro-optic mixing with femtosecond light pulses in a ZnTe crystal. This scheme can be described as heterodyne detection with a Ti:sapphire fs-laser acting as local oscillator and therefore allows for phase-sensitive measurements. Example images of test objects are obtained with mechanical scanning optics and with measurement times per pixel as short as 10 ms. The test objects are placed at a distance of 1 m from the detector and also from the source. The results indicate diffraction-limited resolution. Different contrast mechanisms, based on absorption, scattering, and difference in optical thickness are employed. Our evaluation shows that it should be possible to realize a real-time multi-pixel detector with several hundreds of pixels and a dynamic range of at least two orders of magnitude in power.

Paper Details

Date Published: 4 May 2007
PDF: 7 pages
Proc. SPIE 6549, Terahertz for Military and Security Applications V, 654907 (4 May 2007); doi: 10.1117/12.719197
Show Author Affiliations
T. May, Johann Wolfgang Goethe-Univ. Frankfurt am Main (Germany)
C. am Weg, Johann Wolfgang Goethe-Univ. Frankfurt am Main (Germany)
A. Alcin, Johann Wolfgang Goethe-Univ. Frankfurt am Main (Germany)
B. Hils, Johann Wolfgang Goethe-Univ. Frankfurt am Main (Germany)
T. Löffler, Johann Wolfgang Goethe-Univ. Frankfurt am Main (Germany)
H. G. Roskos, Johann Wolfgang Goethe-Univ. Frankfurt am Main (Germany)


Published in SPIE Proceedings Vol. 6549:
Terahertz for Military and Security Applications V
James O. Jensen; Hong-Liang Cui, Editor(s)

© SPIE. Terms of Use
Back to Top