T-Ray Sensing and Imaging

Mickan, Samuel P.; Zhang, Xicheng

doi:10.1142/s0129156403001843

Cited by 110 publications

(51 citation statements)

References 417 publications

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“…Compact narrow-band far-infrared, or terahertz (THz), sources have potential applications in a large number of fields including biology, chemistry, and materials science [1,2]. The current THz sources in existence either produce short-pulsed broadband radiation, or require very large facilities.…”

Section: Introductionmentioning

confidence: 99%

Three-dimensional theory of the Cerenkov free-electron laser

Andrews

Brau

2007

Journal of Applied Physics

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We present an analytical theory for the operation of a Cerenkov free-electron laser which includes diffraction of the optical mode in the direction transverse to the electron beam. Because the width of the optical mode depends on gain, the usual cubic dispersion relation is replaced by a 5/2-power dispersion relation, which allows two roots. These roots both have positive real parts, indicating that they are slow waves. For a narrow electron beam, the optical mode is much wider than the beam, thus reducing the gain by an order of magnitude from that predicted by the two-dimensional theory. In the limit of a wide electron beam, the two-dimensional theory is recovered.

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Section: Introductionmentioning

confidence: 99%

Three-dimensional theory of the Cerenkov free-electron laser

Andrews

Brau

2007

Journal of Applied Physics

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“…Terahertz radiation (THz), which is situated between infrared and microwave radiation on the electromagnetic spectrum, typically refers to frequencies from 100 GHz to 30 THz [3], [4], [11] [12]. During the past few decades, many researchers attempted to development the dual goal of low loss and smaller-sized THz waveguides.…”

Section: Introductionmentioning

confidence: 99%

Hybrid Plasmonics Slot THz Waveguide for Subwavelength Field Confinement and Crosstalk Between Two Waveguides

Xiao

Wei

Yang

et al. 2017

IEEE J. Select. Topics Quantum Electron.

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Abstract-The slot waveguide has attracted considerable attention because of its ability to confine and guide electromagnetic energy at the subwavelength scale beyond the diffraction limit. We propose a novel terahertz slot waveguide structure to achieve a better tradeoff between propagation length and field confinement capacity, the novel waveguide consisting of a two slot structure. The performances of terahertz waveguides were investigated using the finite-element method. The results demonstrated that the hybrid slot waveguide (HSW) provides significantly enhanced field confinement in low index slot regions: more than five times that of traditional low index slot waveguides (LISWs). An optimized HSW structure was achieved by tuning the tradeoff between mode confinement and propagation length. We also showed that its integration in conventional planar waveguide circuits was greatly improved compared with the LISWs, by comparing their crosstalk. The proposed new HSW structure has great potential to enable THz production of compact integration and could lead to true semiconductor-basedTHz applications with high performance.

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“…Smith-Purcell radiation (SPR) is one particularly promising choice for developing such THz sources, which have significant potential applications in many areas, such as high-resolution imaging, noninvasive sensing, high-data rate communications and material analysis [1,2,[4][5][6][7][8][9][10][11].…”

Section: Introductionmentioning

confidence: 99%

Enhancement of coherent Smith-Purcell radiation at terahertz frequency by optimized grating, prebunched beams, and open cavity

Zhang

Ang

Gover

2015

Phys. Rev. ST Accel. Beams

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This paper studies various mechanisms to enhance the coherent Smith-Purcell radiation (SPR) at terahertz frequencies using particle-in-cell (PIC) simulations. A simple analytical dispersion relation is derived to predict the frequency of the evanescent surface wave of the open grating, which is excited by a backward-wave oscillation mechanism and emits radiation at harmonics of this frequency, and the cavity mode frequencies of the Orotron-like device, all in excellent agreement with the simulation data. The grating parameters are optimized to minimize the starting current of a continuous electron beam for exciting coherent SPR. It is demonstrated that a prebunched beam can be used to selectively excite coherent SPR at desired SPR angle and frequencies that are higher harmonics of the beam bunching frequency, where the starting current requirement is eliminated. Our PIC simulations show the dynamics of modes development and competition for the Orotron-like open cavity structure, which owns a lower starting current than the surface mode process. This oscillation mode dominates at steady state and enhances the radiated power by more than 2 orders of magnitude.

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T-Ray Sensing and Imaging

Cited by 110 publications

References 417 publications

Three-dimensional theory of the Cerenkov free-electron laser

Three-dimensional theory of the Cerenkov free-electron laser

Hybrid Plasmonics Slot THz Waveguide for Subwavelength Field Confinement and Crosstalk Between Two Waveguides

Enhancement of coherent Smith-Purcell radiation at terahertz frequency by optimized grating, prebunched beams, and open cavity

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