Active THz imaging system with improved frame rate

W. von Spiegel; C. am Weg; R. Henneberger; R. Zimmermann; T. Loeffler; H. G. Roskos

doi:10.1117/12.817925

30 April 2009 Active THz imaging system with improved frame rate

W. von Spiegel; C. am Weg; R. Henneberger; R. Zimmermann; T. Loeffler; H. G. Roskos

Author Affiliations +

Proceedings Volume 7311, Terahertz Physics, Devices, and Systems III: Advanced Applications in Industry and Defense; 73110O (2009) https://doi.org/10.1117/12.817925
Event: SPIE Defense, Security, and Sensing, 2009, Orlando, Florida, United States

Abstract

We present a scanning THz-camera with active illumination. Three different fully electronic transceiving techniques are evaluated: The first employs a commercial 230-320GHz frequency-modulated continuous-wave system with a harmonic mixing detector. Its bandwidth allows a ranging resolution in the mm-range. The second one is based on heterodyne detection operating at 645GHz with sub-harmonic mixer and provides a dynamic range beyond 100 dB. Like in the first system, we employ local illumination (THz beam focused on observed pixel). The third one equals the second one, but utilizes global illumination of the scene. In all cases, the scanning optics consists of a Cassegrainian telescope with a primary mirror diameter of 23 cm and a scanning mirror, which is spinning about a slightly tilted axis which itself is slowly rotated in a perpendicular direction to provide the second scan-dimension. With a typical distance of 0.5m between the scanning mirror and the object plane, the field of view covers several 100cm². While the fast mirror axis spins with about 660RPM, the slow axis turns with at least 1 deg. per second and the data acquisition samples about 40000 points for each THz-image. Single-pixel detectors are used; the frame acquisition time is below 10 s. The development of a video-rate multi-pixel imager with up to 32 sub-harmonic mixers as detectors is in progress.

Citation Download Citation

W. von Spiegel, W. von Spiegel, C. am Weg, C. am Weg, R. Henneberger, R. Henneberger, R. Zimmermann, R. Zimmermann, T. Loeffler, T. Loeffler, H. G. Roskos, H. G. Roskos, } "Active THz imaging system with improved frame rate", Proc. SPIE 7311, Terahertz Physics, Devices, and Systems III: Advanced Applications in Industry and Defense, 73110O (30 April 2009); doi: 10.1117/12.817925; https://doi.org/10.1117/12.817925

ACCESS THE FULL ARTICLE

PERSONAL SIGN IN
Full access may be available with your subscription

Email or Username Forgot your username?

Password Forgot your password?

Show

Remember Email/Username on this computer

Remember Password

No SPIE account? Create an account
or Institutional Sign In via Shibboleth

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members: $14.40

Non-members: $18.00 ADD TO CART

Show All Keywords

Keywords/Phrases

Search In:

Publication Years