TeraFoils: Design and Rapid Fabrication Techniques for Binary Holographic Structures in the Terahertz Region - SIGGRAPH 2021 Poster

This presentation was created for the poster session at the SIGGRAPH 2021.
https://s2021.siggraph.org/

【Publication】
Kenta Yamamoto, Kosaku Namikawa, and Yoichi Ochiai. 2021. TeraFoils: Design and Rapid Fabrication Techniques for Binary Holographic Structures in the Terahertz Region. In ACM SIGGRAPH 2021 Poster (SIGGRAPH ’21). ACM, New York, NY, USA, Article 3, 2 pages. DOI: https://doi.org/10.1145/3450618.3469157 (to appear)
https://digitalnature.slis.tsukuba.ac.jp/2021/07/terafoils-publication/

【Project page】
https://digitalnature.slis.tsukuba.ac.jp/2021/07/terafoils/

【Project movie】
(coming soon)

【Presenter】
Kenta Yamamoto (山本健太)
University of Tsukuba
Graduate School of Comprehensive Human Science
Digital Nature Group (Yoichi Ochiai)

【Abstract】
In this paper, we introduce TeraFoils, a method for designing and fabricating material-based structures using binary holograms in the terahertz region. We outline the design, fabrication, imaging, and data processing steps for embedding information inside physical objects and exploring a method to create holographic structures with silver-foiled paper. This paper is a sheet on which silver foil is pasted where the ink is printed, using a home-use laser printer and an electric iron. Wave propagation calculations were performed to design a binary-amplitude hologram. Along with the designed pattern, we fabricated silver-foiled binary holograms in the subterahertz range (0.1 THz) and confirmed their functions using a two-dimensional THz sensor.

Transcript

1. TeraFoils: Design and Rapid Fabrication Techniques for
   Binary Holographic Structures in the Terahertz Region
   Kenta Yamamoto1, Kosaku Namikawa1, Yoichi Ochiai1,2
   1University of Tsukuba, Digital Nature Group
   2Pixie Dust Technologies, Inc.
   

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2. 2
   Overview of TeraFoils
   Hologram Calculation
   After Aberration Correction
   Rapid Fabrication Imaging
   We introduce TeraFoils,
   a method for designing and fabricating material-based structures using binary holograms in the terahertz region.
   

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3. Background
   

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4. 4
   Background
   PoS System [Willis 2013]
   After Aberration Correction
   Communication [Federici 2010] Foreign Substance Inspection
   [Lee 2012]
   In the terahertz range, various applications have been proposed.
   Due to the property of transmitting various materials like radio waves and having coherence like light waves.
   

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5. 5
   Background
   3D Print [Furlan 2016]
   After Aberration Correction
   Paper [Siemion 2012] Natural Stone [Han 2013]
   Caramelized Sucrose [Sterczewski 2016] Liquid Crystal [Ji 2017]
   Holograms in the terahertz region made of various materials.
   

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6. 6
   Background
   Paper and Silver Foil
   After Aberration Correction
   A method for generating holograms in the terahertz region
   that can be rapid-fabricated using paper and silver foil.
   

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7. Method
   

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8. 8
   Step1: Hologram Computation
   1. Backward Propagation 

   (calculate amplitude hologram)
   2. Binarization 

   (determine hologram pattern)
   3. Forward Propagation 

   (simulate reconstructed image)
   Fresnel Diffraction Equation
   Binarization Equation
   

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9. 9
   Step2: Rapid Fabrication
   After Aberration Correction
   Thermocompression Method [Segawa 2019]
   A method of printing metal leaf on paper by thermocompression bonding.
   

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10. 10
    Step2: Rapid Fabrication
    After Aberration Correction
    Rapid Fabrication
    Silver foil is thermocompression-bonded to the paper.
    

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11. 11
    After Aberration Correction
    Optical Setup for Imaging
    Optical system.
    A 2D image sensor for terahertz waves was attached to the XZ stage.
    2D Sensor (32x32)
    XZ Stage Hologram Light Source
    Step3: Imaging
    

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12. 12
    Step3: Imaging
    After Aberration Correction
    Imaging Process
    Move the sensor to scan a large area.
    

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13. Simulation & Experiment Results
    

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14. 14
    Simulation & Experiment Results
    After Aberration Correction
    Input Image / Fabricated Hologram / Simulated Result / Captured Result
    Input
    Fabricated
    Simulated
    Captured
    

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15. Discussion
    

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16. 16
    Discussion
    After Aberration Correction
    Input
    Fabricated
    Simulated
    Captured
    Input
    Fabricated
    Simulated
    ed
    1. Low Quality Hologram
    Our bainarization process is too simple. A better algorithm should be adopted.
    Low Quality Hologram
    Binary Hologram Optimization
    [Yamamoto 2021]
    Yamamoto et al. "Gradient-based Optimization ofTime-Multiplexed Binary Computer-GeneratedHolograms by Digital Mirror Device." 2021.
    

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17. 17
    Discussion
    2. Noise in Imaging
    The result measured by used sensor was noisy. It is necessary to adjust a light source and a sensor.
    Our Imaging System
    Another System [Liao 2020]
    Noisy Imaging Result
    Liao et al. "All-optical diffractive neural networked terahertz hologram." 2020.
    

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18. TeraFoils: Design and Rapid Fabrication Techniques for
    Binary Holographic Structures in the Terahertz Region
    Kenta Yamamoto1, Kosaku Namikawa1, Yoichi Ochiai1,2
    1University of Tsukuba, Digital Nature Group
    2Pixie Dust Technologies, Inc.
    

    View Slide