New type of 5-22 THz radiation sources based on semiconductor resonant reflectors

Abstract The growing requirements for mobile communication networks (data transfer rates over 100 Gbps) makes it necessary to use carrier signal with a frequency of at least 100 GHz. This requires the development of cheap and broadband sub-terahertz (sub-THz) detectors. Here we report on our recent efforts toward the development of a heterodyne sub-THz detector based on a single layer graphene two-terminal device integrated with a bowtie antenna on a sapphire substrate. Our detector operates at frequency of 140 GHz, which corresponds to the maximum transmission of THz radiation in the Earth’s atmosphere. The heterodyne detection is achieved by quasi-optical coupling of signals from two sub-THz radiation sources to the same detector. The measured frequency bandwidth is 5.8 GHz.

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A Compact Accelerator-Based Light Source for High-Power, Full-Bandwidth Tunable Coherent THz Generation

Applied Sciences ◽

10.3390/app112411850 ◽

2021 ◽

Vol 11 (24) ◽

pp. 11850

Author(s):

Kaiqing Zhang ◽

Yin Kang ◽

Tao Liu ◽

Zhen Wang ◽

Chao Feng ◽

...

Keyword(s):

Light Source ◽

High Power ◽

Pulse Energy ◽

Three Dimensional ◽

Thz Radiation ◽

Time Resolved ◽

Narrow Bandwidth ◽

Radiation Sources ◽

High Pulse ◽

Tunable Frequency

Terahertz (THz) radiation sources are increasingly significant for many scientific frontiers, while the generation of THz radiation with high-power at wide-tunable frequencies is still a limitation for most existing methods. In this paper, a compact accelerator-based light source is proposed to produce coherent THz radiation with high pulse energy and tunable frequency from 0.1 THz to 60 THz. By using a frequency beating laser-modulated electron beam and undulator taper, intense coherent THz radiation can be generated through undulators. Theoretical analysis and numerical simulations demonstrate that the proposed technique can generate narrow-bandwidth THz radiation with a pulse energy up to 6.3 millijoule (mJ) and the three-dimensional effects of beam has limited influence on its performance. The proposed technique will open up new opportunities for THz spectroscopic and time-resolved experiments.

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Two layer graphene heterostructures for waves slowing down: operator approach to waveguide problem

Journal of the Belarusian State University. Physics ◽

10.33581/2520-2243-2020-1-73-82 ◽

2020 ◽

pp. 73-82

Author(s):

Marina A. Yakovleva ◽

Konstantin G. Batrakov

Keyword(s):

Terahertz Radiation ◽

Chemical Potential ◽

Operator Approach ◽

Slowing Down ◽

Layer Graphene ◽

Dielectric Layers ◽

Radiation Sources ◽

New Type ◽

Anisotropic Layers ◽

Waveguide Problem

Slowing down the phase velocity of light in media has various applications. The generation of electromagnetic radiation using coherent Cherenkov mechanism is among them. Meanwhile, there is a need for compact terahertz radiation sources. Due to outstanding graphene properties, heterostructures consisting of alternating graphene/dielectric layers can operate as a medium for the generation of terahertz radiation. In the present paper, the slowing down and propagation coefficients for the modes supported in a two-layer graphene structure are studied. The study is conducted by means of the operator approach to wave propagation in stratified structures. The operator approach allows one to use coordinates-free notations and to consider consequently arbitrarily complex heterostructures (including anisotropic layers, for instance). The influence of interlayer distance and the value of graphene chemical potential on waves slowdown is determined. The obtained results open up prospects for creating a new type of terahertz radiation sources.

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