DaISy : diffuser-aided sub-THz imaging system

Wu, Shao-Hsuan and Zhang, Yiyao and Chen, Ke and Yang, Shang-Hua (2024) DaISy : diffuser-aided sub-THz imaging system. Optics Express, 32 (7). pp. 11092-11106. ISSN 1094-4087 (https://doi.org/10.1364/OE.516198)

[thumbnail of Wu-etal-OE-2024-DaISy-diffuser-aided-sub-THz-imaging-system]
Preview
Text. Filename: Wu-etal-OE-2024-DaISy-diffuser-aided-sub-THz-imaging-system.pdf
Final Published Version
License: Other

Download (16MB)| Preview

Abstract

Sub-terahertz (Sub-THz) waves possess exceptional attributes, capable of penetrating non-metallic and non-polarized materials while ensuring bio-safety. However, their practicality in imaging is marred by the emergence of troublesome speckle artifacts, primarily due to diffraction effects caused by wavelengths comparable to object dimensions. In addressing this limitation, we present the Diffuser-aided sub-THz Imaging System (DaISy), which utilizes a diffuser and a focusing lens to convert coherent waves into incoherent counterparts. The cornerstone of our progress lies in a coherence theory-based theoretical framework, pivotal for designing and validating the THz diffuser, and systematically evaluating speckle phenomena. Our experimental results utilizing DaISy reveal substantial improvements in imaging quality and nearly diffraction-limited spatial resolution. Moreover, we demonstrate a tangible application of DaISy in the scenario of security scanning, highlighting the versatile potential of sub-THz waves in miscellaneous fields.