Multicolor Terahertz Frequency Mixer Using Multibunching of Free-Electron Beams

Liu, Weihao; Liang, Linbo; Jia, Qika; Wang, Lin; Lu, Yalin

doi:10.1103/physrevapplied.10.034031

Cited by 19 publications

(7 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Similarly, the vortex beam of TC = −2 will be generated at fS3 = 0.487 THz. However, since the intensity of the second wave harmonic S2 is much stronger than that of the third wave harmonic S3 [43], the second harmonic vortex radiation at fS2 is dominant, which agrees well with the frequency spectrum of Ez shown in the right inset of Fig. 3(b).…”

Section: Vortex Beam Emitter Based On Ssprsupporting

confidence: 84%

A Terahertz Vortex Beam Emitter With Tunable Topological Charge and Harmonic Excitation

Zhang

Zhu

et al. 2021

J. Lightwave Technol.

View full text Add to dashboard Cite

Terahertz (THz) vortex beams carrying orbital angular momentum (OAM) with high purity and tunable topological charge (TC) will undoubtedly bring extraordinary capacities for advanced imaging or communication systems. We propose a convenient and efficient method to generate a tunable and broadband vortex beam that is excited by superradiant Smith-Purcell radiation (SSPR) on a helical grating. This scheme fully explores the advantages of natural broadband evanescent wave carried by the electron beam and the Bloch's theorem regulated helical periodic systems. An explicit relation is established between the index of the spatial harmonic wave on the grating and the topological charge of the vortex beam. The electron energy in the SSPR can be customized to ignite the specific spatial harmonics and manipulate the OAM beam, accordingly. The separated radiation region also promises the high purity of the OAM spectrum. The harmonic excitation reduces the communality between the wavelength and the device size and alleviates the difficulty of device fabrication in the THz band. The proposed vortex scheme can not only be handily scaled to microwave and mid-infrared regions, but also bring possibilities to applications based on compact tunable vortex beam sources.

show abstract

Section: Vortex Beam Emitter Based On Ssprsupporting

confidence: 84%

A Terahertz Vortex Beam Emitter With Tunable Topological Charge and Harmonic Excitation

Zhang

Zhu

et al. 2021

J. Lightwave Technol.

View full text Add to dashboard Cite

show abstract

“…Since the intensity of the fundamental space harmonics is the highest, only the modes

{\mathop{\rm M}\nolimits} _{| m |}^ \pm

within

0 &lt; ( {L/2\pi } ) \cdot k_z^0 &lt; 2

will be discussed. [ 41,42 ]…”

Section: Resultsmentioning

confidence: 99%

“…Since the intensity of the fundamental space harmonics is the highest, only the modes M ± |m| within 0 < (L∕2𝜋) ⋅ k 0 z < 2 will be discussed. [41,42] Before verifying the above discussion, there is one more thing that affects the operating properties, namely the rotational symmetry. In the study of conventional slow-wave devices, the spatial distribution of the e-beam in the propagation direction has received more attention, while its lateral effects on the interacting system have been rarely explored, especially the lateral rotational symmetry.…”

Section: Concept Of Chiral Spoof Surface Plasmonmentioning

confidence: 97%

Chiral Plasmons Enable Coherent Vortex Smith–Purcell Radiation

Zhang

Zhu

et al. 2022

Laser & Photonics Reviews

View full text Add to dashboard Cite

Recent advances in vortex Smith–Purcell radiation (V‐SPR) have spurred many breakthroughs in the generation of vortex beams for their potential applications in chiral detection, particle acceleration, communication, and imaging. However, advanced multi‐mode applications of the V‐SPR suffer from the incoherent spectrum and poor purity in producing high‐order topological charges. Here, by exploiting the rotational symmetry and Brillouin‐folding phenomenon, it is proved that the coherent V‐SPR with independently steerable high‐order topological charge is directly emitted from chiral spoof surface plasmons. Moreover, both topological charges and operation frequencies can be readily tuned, thus enabling flexible adaptability over a broad bandwidth. A proof‐of‐concept prototype is designed and fabricated in the microwave regime, in which the method is demonstrated from the perspective of symmetry and tunability. The proposed methodology can be exploited as a platform to investigate the interaction between chiral plasmons and swift electrons, promising a feasible scheme for generating coherent and tunable vortex beams from the microwave to the terahertz band.

show abstract

“…According to previous analysis of the paper, we have achieved two degrees of radiation coherence: the first is obtained by letting the phase difference within the DNRG-cluster to be much less than unit (∆ ≪ 1); the other is by letting ∆ = 2pπ. In practice, we can use a train of well micro-bunched electron beam, which can be achieved by self-bunching of an dc beam [26,27] or prebunched beam from the photocathode [28,29], to interact with the proposed grating model. By letting the prebunching frequency to be close to one of the resonant frequency, the enhanced coherent radiation will be achieved as that in [29].…”

Section: Discussionmentioning

confidence: 99%

Spectrum discretization of Smith–Purcell radiation for efficient multicolor terahertz emission

Li¹,

Liu²,

Liu³

2020

J. Phys. D: Appl. Phys.

Self Cite

View full text Add to dashboard Cite

The Smith-Purcell radiation (SPR) is a promising way for developing compact and high power terahertz sources with broad application prospects. Yet, the conventional SPR is largely restricted by its low efficiency and incoherency. Here we illustrate an enhanced coherent SPR from a compound array of deep-narrow-rectangular-grooves (DNRGs). We show, by detailed theoretical analysis and simulations, that each DNRG is an effective resonant cavity with low radiating Q-factor and a cluster of closely adjacent DNRGs can get enhanced coherent emission. More notably, by setting clusters of DNRGs with gradient shapes to be periodically arranged in an array, we can change the conventional incoherent SPR to be a coherent emission with a series of specified frequencies at specified directions, namely, the radiation is discretized. The total radiation efficiency can be increased by more than an order of magnitude. Thus, it affords an efficient way for high power multicolor terahertz generations.

show abstract

Multicolor Terahertz Frequency Mixer Using Multibunching of Free-Electron Beams

Cited by 19 publications

References 37 publications

A Terahertz Vortex Beam Emitter With Tunable Topological Charge and Harmonic Excitation

A Terahertz Vortex Beam Emitter With Tunable Topological Charge and Harmonic Excitation

Chiral Plasmons Enable Coherent Vortex Smith–Purcell Radiation

Spectrum discretization of Smith–Purcell radiation for efficient multicolor terahertz emission

Contact Info

Product

Resources

About