Performance Evaluation of a THz Pulsed Imaging System: Point Spread Function, Broadband THz Beam Visualization and Image Reconstruction

Abstract

Terahertz (THz) technology is a promising research field for various applications in basic science and technology. In particular, THz imaging is a new field in imaging science, where theories, mathematical models and techniques for describing and assessing THz images have not completely matured yet. In this work, we investigate the performances of a broadband pulsed THz imaging system (0.2–2.5 THz). We characterize our broadband THz beam, emitted from a photoconductive antenna (PCA), and estimate its point spread function (PSF) and the corresponding spatial resolution. We provide the first, to our knowledge, 3D beam profile of THz radiation emitted from a PCA, along its propagation axis, without the using of THz cameras or profilers, showing the beam spatial intensity distribution. Finally, we evaluate the THz image formation on a test-sample composed by a regular linen natural pattern.

Strontium Substituted Tricalcium Phosphate Bone Cement: Short and Long‐Term Time‐Resolved Studies and In Vitro Properties

“…These properties of media can be successfully monitored through THz-TDS, with the evaluation of dielectric parameters and/or the time-dependent changes in the maximal THz electric field amplitude and its position during the experiment time. A THz time-domain spectroscopy system [74,75] was used to the kinetics of the cement transformation upon its setting and hardening process, by analyzing the THz electric waveforms and their temporal evolution. The THz-TDS system works in the transmission mode and its operation is based on photoconductive switches, which generate a broadband THz radiation ranging between 0.2 and 2.5 THz.…”

Terahertz Spectroscopic Analysis in Protein Dynamics: Current Status

“…These systems have promoted the diffusion of THz radiation for spectroscopy applications. Thus, it was applied with success in various scientific fields e.g., gas sensing [75][76][77][78][79][80], chemical and pharmaceutical analysis [81,82], condensed matter [83][84][85], identification of crystalline polymorphs, microelectronics and security [86][87][88][89], agri-food industry [90] and cultural heritage [91], including the emerging support in the field of biomedicine and bio-imaging [92][93][94][95][96][97][98][99], etc. Thus, THz spectroscopy has become a valuable tool for rapid and non-invasive detection thanks to many advantages that make it particularly appealing for probing the intermolecular structure and dynamics of biomolecules [95,100,101].…”

“…The system, reported in Figure 5a,b, allows to obtain a polarization sensing, measuring the reflective polarization spectra for a liquidphase sample. To this aim, a traditional transmission THz-TDS [97,98] was modified, adding a reflection module (Figure 5b) to the bottom of the 3D printing sample cell and two rotatable THz polarizers at the emitting end and detection ports of the spectroscopic system (Figure 5a). The advantage is to measure the states of signals without the strong THz water absorption in reflection mode.…”

2021 IEEE 2nd International Conference on Big Data, Artificial Intelligence and Internet of Things Engineering (ICBAIE 2021)

“…In the early 2021, M. D. Fabrizio et al [25] thought Terahertz spectroscopy technology is a new field of imaging science, which still has a few short-comings, Associate Professor Sun Xu-dong thought so, and he proposed if this technology can be developed rapidly in recent years, it can be applied well not only in the field of food detection, but also in many other fields.…”