39th Int. Conf. on Infrared, Millimeter, and THz Waves
September 14-19, 2014
The University of Arizona, Tucson, AZ
M2/C - 6. Industrial Applications and Instruments
Monday, September 15, 2014 11:00 am to 12:30 pm
Room: Tucson Room
Chairperson: Kiyomi Sakai
11:00 am 11:00 am : Terahertz Car Paint Thickness Sensor: Out Of The Lab And Into The Factory
Presenter: Robert May

A terahertz sensor to determine the individual thicknesses of car paint layers is deployed onto the factory floor of an automotive manufacturer. When illuminated with an incident terahertz pulse, reflections from the interfaces between layers are combined and detected. To precisely measure real paint formulations of representative thickness in situ on large curved panels, detailed calibrations of the refractive indices are required. We describe innovation to ensure that the instrument remains viable in the hostile environment of an industrial production line.

Author(s):
Ian Gregory - TeraView Limited
Axel Zeitler - Department of Chemical Engineering and Biotechnology, University of Cambridge
Robert May - TeraView Limited
Ke Su - Department of Chemical Engineering and Biotechnology, University of Cambridge
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11:30 am 11:30 am : Portable Solid State CW THz Radar System For Industrial Applications
Presenter: Andrej Svigelj

In the paper a FM solid state continues wave (CW) THz radar system is described. The requirements for the source are analyzed and the solutions are discussed. The system employs heterodyne mixing of the THz illumination signal and the reflected THz wave from the target. The two signals are generated by the use of THz beam splitter. The core of the system is a antenna-coupled titanium-based microbolometer THz sensor array capable of detection extremely low power reflected signal in the range of few pico-Watts. The sensor itself operates at room temperature and also performs the necessary mixing of the source THz wave with reflected THz wave. This technique is well known in FM radars. Industrial applications require portable THz radar at reasonable cost and robust operation giving reliable and accurate measured data. A concept of a versatile CW THz system has been realized and confirmed with measurement and characterization. The results show high reliability of the system and high measurement repetition accuracy. The results demonstrate capability of the system indicating various type of possible applications.

Author(s):
Andrej Svigelj - UL, Faculty of Electrical Engineering
Aleksander Sesek - UL, Faculty of Electrical Engineering
Irmantas Kasalynas - Center for Physical Sciences and Technology
Gintaras Valusis - Center for Physical Sciences and Technology
Janez Trontelj - UL, Faculty of Electrical Engineering
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11:45 am 11:45 am : Improved Image Quality Of Terahertz Transmission Microscope: Example Of Graphene Film Observation
Presenter: Tsutomu Ishi

This paper describes non-uniformity reduction in terahertz (THz) imaging system, using a coherent THz source and a THz camera. The beam wobbling technique reduces the interference pattern, but illumination distribution often remains. In order to reduce the illumination distribution, post-image process is applied. In this method, the raw image is divided by the reference image without the sample, which is found effective for improving image quality. The graphene sample is used for validation of this method. The phase shifter is also developed to obtain a high signal-to-noise ratio (SNR) and short image acquisition time in the lock-in imaging.

Author(s):
Tsutomu Ishi - NEC Corporation
Takayuki Sudou - NEC Corporation
Naoki Oda - NEC Corporation
Takao Morimoto - NEC Corporation
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12:00 pm 12:00 pm : Compact Quasi-Optical Schottky Detector With Fast Voltage Response
Presenter: Andreas Penirschke

Zero-bias Schottky diode detectors operated at room-temperature are the choice for applications, where the ultimate sensitivity of a cryogenic detectors is not needed. Furthermore Schottky detectors are intrinsically much faster than the latter ones. This paper describes a compact quasi-optically coupled zero-bias planar Schottky-diode detector with monolithically integrated log-spiral antenna for monitoring picosecond pulses of intense, coherent far-infrared radiation from the free-electron laser (FEL) FELBE at HZDR, Germany. The detector offers an intrinsic response time of less than 16.8 ps for short collimated THz pulses at 1.315 THz.

Author(s):
Andreas Penirschke - Technische Universit‰t Darmstadt
Mykola Sobornytskyy - ACST GmbH
Sascha Preu - Technische Universit‰t Darmstadt
Martin Mittendorff - Technische Universit‰t Dresden / Helmholtz-Zentrum Dresden Rossendorf
Stephan Winnerl - Helmholtz-Zentrum Dresden Rossendorf
Matthias Hoefle - ACST GmbH / Technische Universit‰t Darmstadt
Oleg Cojocari - ACST GmbH
Rolf Jakoby - Technische Universit‰t Darmstadt
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12:15 pm 12:15 pm : Non-metallic Foreign Objects Detection System For Industrial Inspection using Pulsed Terahertz System
Presenter: Tomofumi Ikari

We have demonstrated the detection of non-metallic foreign matter in packets of powder. These particles are typically not dense enough for X-ray detection. The system consists of a fiber coupled pulsed THz system, a high-speed THz beam scanner and an automatic anomaly detection algorithm. The detection capability of the THz system has been compared with that of an X-ray imaging system.

Author(s):
Tomofumi Ikari - Spectra Design
Norimasa Takahashi - Spectra Design
Ryoichi Fukasawa - Spectra Design
Irl Duling - Advanced Photonics Inc.
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