Abstract
A real-time terahertz (THz) imaging system was demonstrated based on a 320 × 240 uncooled microbolometer detector combined with a 2.52 THz far-infrared CO2 laser. On the top of micro-bridge structure (35 × 35 μm2), a 10 nm nickel-chromium (NiCr) thin film was deposited to enhance THz absorption, which was fabricated by a combined process of magnetron sputtering and reactive ion etching (RIE). By mechanical simulation using design of experiment (DOE) method, the minimum deformation was optimized to 0.0385 μm, and a measured deformation of 0.097 μm was achieved in the fabrication. The fabricated micro-bridge pixel was used for THz detection, and a responsivity of 1235 V/W was achieved with a noise equivalent power (NEP) of 87.4 pW/Hz1/2. THz imaging of metal gasket covered by label paper, paper clip in an envelope, and watermark of a banknote was demonstrated by a combination of histogram equalization (HE) and linear enhancement algorithm.
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Acknowledgment
This work was partially supported by National Science Funds for Creative Research Groups of China (No. 61421002), the National Natural Science Foundation of China (No. 61235006, 61501092), the Fundamental Research Funds for the Central Universities (No. ZYGX2015KYQD016).
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Zheng, X., Wu, Z., Gou, J. et al. Enhancement of Real-Time THz Imaging System Based on 320 × 240 Uncooled Microbolometer Detector. J Infrared Milli Terahz Waves 37, 965–976 (2016). https://doi.org/10.1007/s10762-016-0287-4
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DOI: https://doi.org/10.1007/s10762-016-0287-4