A Practical and Portable Solids-State Electronic Terahertz Imaging System
<p>Examples of the system improvement steps with varied hardware and the beam guiding schemes.</p> "> Figure 2
<p>A view of the full system mounted on a portable optical plate (450 mm × 750 mm) showing a linearly aligned source-lenses-sample-detector scheme and a removable beam splitter (inset) for changing between transmission and reflection mode.</p> "> Figure 3
<p>Schematic of the quasi-optical THz transmission and reflection imaging system.</p> "> Figure 4
<p>(<b>a</b>) A transmission image of a computer floppy disk; a scanned area of 50 mm × 50 mm at a resolution of 0.5 mm. The black lines indicate the single line scans at vertical line 17 and horizontal line 23; (<b>b</b>) is the photograph of the floppy disk flipped to correspond to scanned image.</p> "> Figure 5
<p>Line scans of the image data: the detected signal level of the transmitted THz beam <span class="html-italic">versus</span> the pixel point (upper <span class="html-italic">x</span>-axis) and spatial position (lower <span class="html-italic">x</span>-axis). (<b>a</b>) corresponds to the single line scans at vertical line 17 in <a href="#sensors-16-00579-f004" class="html-fig">Figure 4</a>a and (<b>b</b>) corresponds to the horizontal line 23 shown in <a href="#sensors-16-00579-f004" class="html-fig">Figure 4</a>a. The upper <span class="html-italic">x</span> axis shows the image pixel points (0.5 mm each step) and lower axis is converted the position points in both figures.</p> "> Figure 6
<p>Imaging of a 50 cents coin and a Kangaroo key ring in a reflection mode (note that the experiment was carried out before the introduction of the cube mounted beam splitter shown in <a href="#sensors-16-00579-f002" class="html-fig">Figure 2</a>).</p> "> Figure 7
<p>Imaging in reflection mode, showing a hidden object in shoe lining.</p> "> Figure 8
<p>Photograph (<b>a</b>) and the transmission THz image (<b>b</b>) of a fresh leaf.</p> "> Figure 9
<p>Real-time detector voltage output V<sub>RF</sub> (t) traces of the modulated THz beam using a mechanical optical chopper (<b>a</b>) and an electronic signal via the TTL port on the AMC THz source (<b>b</b>).</p> "> Figure 10
<p>The THz transmission image of the computer disk acquired using the TTL electronic signal modulation at the same chopper speed of 1 kHz and scanning conditions as that used in <a href="#sensors-16-00579-f004" class="html-fig">Figure 4</a> image modulated with an optic chopper.</p> ">
Abstract
:1. Introduction
2. Experimental Setup—Hardware and System Configurations
3. Results and Discussion
3.1. Image Scanning and Resolution
3.2. Imaging Results in Reflection Mode
3.3. Imaging Results in Transmission Mode
3.4. TTL Electronic Modulation versus Optical Chopper
4. Conclusions
Acknowledgments
Author Contributions
Conflicts of Interest
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Smart, K.; Du, J.; Li, L.; Wang, D.; Leslie, K.; Ji, F.; Li, X.D.; Zeng, D.Z. A Practical and Portable Solids-State Electronic Terahertz Imaging System. Sensors 2016, 16, 579. https://doi.org/10.3390/s16040579
Smart K, Du J, Li L, Wang D, Leslie K, Ji F, Li XD, Zeng DZ. A Practical and Portable Solids-State Electronic Terahertz Imaging System. Sensors. 2016; 16(4):579. https://doi.org/10.3390/s16040579
Chicago/Turabian StyleSmart, Ken, Jia Du, Li Li, David Wang, Keith Leslie, Fan Ji, Xiang Dong Li, and Da Zhang Zeng. 2016. "A Practical and Portable Solids-State Electronic Terahertz Imaging System" Sensors 16, no. 4: 579. https://doi.org/10.3390/s16040579