Bayesian Coupled-Pixel Terahertz-TDS Imaging /Author=Wang, Pu; Orlik, Philip V.; Wang, Bingnan; Ma, Rui; Teo, Koon Hoo; Tsujita, Wataru; Sadamoto, Kota; Sawa, Yoshitsugu /CreationDate=August 27, 2017 /Subject=Signal Processing

This paper considers Terahertz (THz) sensing of contents on a single-layer object with timedomain spectroscopy (TDS) in a reflection mode. With an extremely small pulse width, the THz-TDS sensing is highly sensitive to non-ideal configurations such as a tilted or uneven sample, depth variation due to mechanical scanning operations, and intra-layer reflections. One consequence is sweep distortion resulting from slightly different time delay from different scanning points. In this paper, we follow an existing alternative minimization scheme and propose a simple modification to take into account, in addition to the binary nature of reflection coefficients, the two-dimensional block feature of the content (i.e., letters and shapes) in the sample. Preliminary results with synthetic datasets show the effectiveness of the proposed method. International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THz) 2017 This work may not be copied or reproduced in whole or in part for any commercial purpose. Permission to copy in whole or in part without payment of fee is granted for nonprofit educational and research purposes provided that all such whole or partial copies include the following: a notice that such copying is by permission of Mitsubishi Electric Research Laboratories, Inc.; an acknowledgment of the authors and individual contributions to the work; and all applicable portions of the copyright notice. Copying, reproduction, or republishing for any other purpose shall require a license with payment of fee to Mitsubishi Electric Research Laboratories, Inc. All rights reserved. Copyright c © Mitsubishi Electric Research Laboratories, Inc., 2017 201 Broadway, Cambridge, Massachusetts 02139 Bayesian Coupled-Pixel Terahertz-TDS Imaging P. Wang∗, P. V. Orlik∗, B. Wang∗, R. Ma∗, K. H. Teo∗, W. Tsujita†, K. Sadamoto†, and Y. Sawa† ∗Mitsubishi Electric Research Laboratories, Cambridge, MA 02139, USA (Email: pwang@merl.com). †Mitsubishi Electric Corporation Advanced Technology R&D center, Amagasaki City, 661-8661, Japan. Abstract—This paper considers Terahertz (THz) sensing of contents on a single-layer object with time-domain spectroscopy (TDS) in a reflection mode. With an extremely small pulse width, the THz-TDS sensing is highly sensitive to non-ideal configurations such as a tilted or uneven sample, depth variation due to mechanical scanning operations, and intra-layer reflections. One consequence is sweep distortion resulting from slightly different time delay from different scanning points. In this paper, we follow an existing alternative minimization scheme and propose a simple modification to take into account, in addition to the binary nature of reflection coefficients, the two-dimensional block feature of the content (i.e., letters and shapes) in the sample. Preliminary results with synthetic datasets show the effectiveness of the proposed method.This paper considers Terahertz (THz) sensing of contents on a single-layer object with time-domain spectroscopy (TDS) in a reflection mode. With an extremely small pulse width, the THz-TDS sensing is highly sensitive to non-ideal configurations such as a tilted or uneven sample, depth variation due to mechanical scanning operations, and intra-layer reflections. One consequence is sweep distortion resulting from slightly different time delay from different scanning points. In this paper, we follow an existing alternative minimization scheme and propose a simple modification to take into account, in addition to the binary nature of reflection coefficients, the two-dimensional block feature of the content (i.e., letters and shapes) in the sample. Preliminary results with synthetic datasets show the effectiveness of the proposed method.