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相关论文: A mathematical approach towards THz tomography for…

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Terahertz (THz) wave manipulation based on laser filaments-plasma channels formed by femtosecond laser-induced air ionization-has emerged as a promising platform for free-space THz applications. However, in-situ characterization of the…

Terahertz (THz) waves are electromagnetic waves in the 0.1 to 10 THz frequency range, and THz imaging is utilized in a range of applications, including security inspections, biomedical fields, and the non-destructive examination of…

图像与视频处理 · 电气工程与系统科学 2023-12-05 Woon-Ha Yeo , Seung-Hwan Jung , Seung Jae Oh , Inhee Maeng , Eui Su Lee , Han-Cheol Ryu

This work presents a fast direct solver strategy allowing full-wave modeling and dosimetry at terahertz (THz) frequencies. The novel scheme leverages a preconditioned combined field integral equation together with a regularizer for its…

English: This paper concerns the image reconstruction from a few projections in Computed Tomography (CT). The main objective of this paper is to show that the problem is so ill posed that no classical method, such as analytical methods…

数据分析、统计与概率 · 物理学 2007-05-23 Ali Mohammad-Djafari

An approach to diffraction tomography is investigated for two-dimensional image reconstruction of objects surrounded by an arbitrarily-shaped curve of sources and receivers. Based on the integral theorem of Helmholtz and Kirchhoff, the…

数学物理 · 物理学 2014-11-20 G. T. Clement

We propose an all-optical Knife Edge characterization technique and we demonstrate its working principle by characterizing the sub-{\lambda} features of a spatially modulated Terahertz source directly on the nonlinear crystal employed for…

In this work, we present a novel approach to photothermal super resolution based thermographic resolution of internal defects using two-dimensional pixel pattern-based active photothermal laser heating in conjunction with subsequent…

图像与视频处理 · 电气工程与系统科学 2023-03-01 Julien Lecompagnon , Philipp Daniel Hirsch , Christian Rupprecht , Mathias Ziegler

Terahertz (THz) generation by optical rectification in LiNbO$_3$ (LN) is a widely used technique for generating intense THz radiation. The spatiotemporal characterization of THz pulses from these sources is currently limited to far-field…

The nonlinear optical response of materials under high-intensity electromagnetic fields is key to advancing THz optical technologies. This study introduces a theoretical approach to estimate the nonlinear refractive index coefficient n2 of…

Providing continuous bandwidth over several tens of GHz, the Terahertz (THz) band (0.1-10 THz) supports space-air-ground integrated network (SAGIN) in 6G and beyond wireless networks. However, it is still mystery how THz waves interact with…

系统与控制 · 电气工程与系统科学 2023-08-03 Zhirong Yang , Weijun Gao , Chong Han

A non-iterative method of reconstruction is proposed from data of MRI system and of a harmonic electro-magnetic field at Larmor frequency. The method is based on the exact analytic formula for the contrast source function. A geometric…

数值分析 · 数学 2019-05-13 Victor Palamodov

Following recent advances in terahertz (THz) technology, there is a consensus on the crucial role of THz communications in the next generation of wireless systems. Aiming at catalyzing THz communications research, we propose TeraMIMO, an…

Thermoelectric measurement of the dimensionless zT parameter requires multiple physical quantities to be measured, therefore there is great interest to find an experimental setup capable of measuring all these properties at once. Previous…

We propose a stable and fast reconstruction technique for parallel-beam (PB) tomographic X-ray imaging, relying on the discrete pseudo-polar (PP) Radon transform. Our main contribution is a resampling method, based on modern sampling…

数值分析 · 计算机科学 2018-03-29 Shahar Tsiper , Yonina C. Eldar

We report on terahertz (THz) radiation under electrical pumping from a degenerate semiconductor possessing an electron accumulation layer. In InN, the random grating formed by topographical defects provides high-efficiency coupling of…

材料科学 · 物理学 2015-05-19 T. V. Shubina , N. A. Gippius , V. A. Shalygin , A. V. Andrianov , S. V. Ivanov

The Diffuse Optical Tomography (DOT) has received considerable attention in the recent years in the field of biomedical imaging and disease detection. However, imaging through highly diffusive medium is a challenge and stability is always…

图像与视频处理 · 电气工程与系统科学 2020-03-31 Tapan Das , P. K. Dutta

We present a temporally-multiplexed dual-colour terahertz (THz) imaging technique using THz-to-optical conversion in atomic vapour. By rapidly alternating the pump laser frequency, we sequentially excite two atomic states, each absorbing a…

原子物理 · 物理学 2025-07-16 Lucy A. Downes , C. Stuart Adams , Kevin J. Weatherill

The emission properties of terahertz(THz) photoconductive antenna (PCA) have been numerically studied by three-dimensional finite-difference-time-domain method based on the full-wave model. The dependence of the THz radiation on various…

光学 · 物理学 2014-07-11 Jitao Zhang

We study iterative signal reconstruction in computed tomography (CT), wherein measurements are produced by a linear transformation of the unknown signal followed by an exponential nonlinear map. Approaches based on pre-processing the data…

最优化与控制 · 数学 2024-07-19 Vasileios Charisopoulos , Rebecca Willett

Topo-Tomography (TT) is a synchrotron-based X-ray diffraction imaging technique used to characterize grain shape and crystal orientation in polycrystalline samples. This work aims to provide a decisive and fundamental understanding of 3D…

计算物理 · 物理学 2025-10-13 Zheheng Liu , Nicola Vigano , Henry Proudhon , Wolfgang Ludwig