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Terahertz (THz) imaging and tomography are modern imaging techniques allowing 2D and 3D inspection of objects over a broadband frequency range. However, the transfer of this technique to medical applications is limited to surface or subsurface inspection due to the large concentration of water molecules which are an intrinsic characteristic of biological tissues. Then, we report the results of investigations...
Guided terahertz pulse reflectometry is a failure analysis method applied to detect and locate open circuits or impedance fluctuations in the advanced 3D packages. In this article. We propose use near field microprobe to test some transmission lines and defective circuits in the different level of the packaging. We do some finite element simulations of various types of terahertz waveguides by combining...
We present a novel approach for measuring aqueous solutions of biologically relevant components using a fully-integrated 0.53 THz near-field sensor implemented in 0.13 μm SiGe HBT technology. A successfully applied on-chip chopping technique resulting in a highly-improved signal-to-noise-ratio of up to 115 dB makes it possible to characterize the concentration level of lactose solved in de-ionized...
Terahertz waves can provide in-depth information on defects for structural health monitoring of composite materials. This paper describes the technology of a continuous-wave and a time-domain terahertz system operating on a 2-D and 3-D motion platform to provide 3-D high spatial resolution. The system as well as the overall detection performance will be described.
This study focuses on the seals, especially European wax seals. We use THz spectroscopy imaging for non-destructive evaluation of natural materials. Using a time domain THz spectroscopy and imaging system, THz reflection images are generated in the 0.1–3 THz range and demonstrate that we can inspect the internal structure under a thick layer of old wax. X-Ray images will be used as a reference and...
In this paper, a Lüneburg lens is characterized with millimeter waves. This gradient index lens is used in both transmission and reflection configurations.
This study focuses on the seals of validation, sealing written documents, used in the Western Middle Ages, especially wax seals. We use THz spectroscopy and imaging for non-destructive evaluation of natural materials within those seals. Using a time domain THz spectroscopy and imaging system, THz transmission images are generated in the 0.1–3 THz range and demonstrate that the spectral properties...
In this paper, a model of the beam propagation is developed according to the physical properties of THz waves used in THz computed tomography (CT) scan imaging. This model is first included in an acquisition simulator to observe and estimate the impact of the Gaussian beam intensity profile on the projection sets. Second, the model is introduced in several inversion methods as a convolution filter...
We present a theoretical model of metallic absorbers for electromagnetic waves. This model allows the design of any kind of structured absorber metallic films and dielectrics. The absorption theory of metallic structures was studied with aim of a room temperature bolometer design. To validate the theoretical concept, grids of size much larger than the wavelength were built and measured. Transmission,...
Abstract. The fragmentation functions of quarks and gluons into photons are studied beyond the Leading Logarithm approximation. We address the nature of the initial conditions of the evolution equation solutions and study problems related to factorization scheme invariance. The possibility of measuring these distributions in LEP experiments is discussed, and a comparison with existing data is made.
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