Accelerator-Based THz Radiation Sources

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.

Download Full-text

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.

Download Full-text

A Survey of Recent Patents on THz Radiation Sources

Recent Patents on Electrical Engineering ◽

10.2174/1874476111003030193 ◽

2010 ◽

Vol 3 (3) ◽

pp. 193-199

Author(s):

Weidong Zhang ◽

Dwight L. Woolard

Keyword(s):

Thz Radiation ◽

Radiation Sources

Download Full-text

Negative conductivity of graphene with direct electric current

Nonlinear World ◽

10.18127/j20700970-202102-06 ◽

2021 ◽

Author(s):

I.M. Moiseenko ◽

V.V. Popov ◽

D.V. Fateev

Keyword(s):

Reflection Coefficient ◽

Electric Current ◽

Terahertz Radiation ◽

Room Temperature ◽

Negative Real Part ◽

Wave Incident ◽

Thz Radiation ◽

Direct Electric Current ◽

Radiation Sources ◽

Dc Current

Problem formulating. Currently, there are no compact, efficient terahertz radiation sources operating at room temperature. To create such sources and amplifiers, structures based on graphene with DC-current can be used. Goal. Finding conditions for achieving the negative real part of graphene conductivity and amplification of THz radiation in graphene with a direct electric current. Result. It is shown that for a certain value of direct electric current in graphene, the reflection coefficient of the THz wave incident on the structure based on graphene with DC-current exceeds unity, which indicates the amplification of THz radiation in the structure. The amplification of the THz radiation in graphene is achieved due to negative values of the real part of the graphene conductivity. Practical meaning. Results can be used to create sources and amplifiers of terahertz radiation.

Download Full-text