High-Intensity THz Radiation From a Large Interdigitated Array Photoconductive Emitter

Abstract Diffraction is the ultimate limit at which details of objects can be resolved in conventional optical spectroscopy and imaging systems. In the THz spectral range, spectroscopy systems increasingly rely on ultra-broadband radiation (extending over more 5 octaves) making a great challenge to reach resolution limited by diffraction. Here, we propose an original easy-to-implement wavefront manipulation concept to achieve ultrabroadband THz spectroscopy system with diffraction-limited resolution. Applying this concept to a large-area photoconductive emitter, we demonstrate diffraction-limited ultra-broadband spectroscopy system up to 14.5 THz with a dynamic range of 103. The strong focusing of ultrabroadband THz radiation provided by our approach is essential for investigating single micrometer-scale objects such as graphene flakes or living cells and besides for achieving intense ultra-broadband THz electric fields.

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Detection of high intensity thz radiation by field effect transistors

26th International Conference on Indium Phosphide and Related Materials (IPRM) ◽

10.1109/iciprm.2014.6880540 ◽

2014 ◽

Author(s):

Dmytro B. But ◽

Mikola V. Sakhno ◽

Jonathan Oden ◽

T. Notake ◽

Nina V. Dyakonova ◽

...

Keyword(s):

High Intensity ◽

Field Effect ◽

Field Effect Transistors ◽

Thz Radiation

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High-intensity terahertz generation by nonlinear frequency-mixing of lasers in plasma with DC magnetic field

Laser and Particle Beams ◽

10.1017/s0263034615000609 ◽

2015 ◽

Vol 33 (3) ◽

pp. 519-524 ◽

Cited By ~ 16

Author(s):

Anil K. Malik ◽

Kunwar Pal Singh

Keyword(s):

Magnetic Field ◽

High Intensity ◽

Ponderomotive Force ◽

Wave Number ◽

Thz Radiation ◽

Nonlinear Frequency ◽

External Static Magnetic Field ◽

Radiation Generation ◽

Tunable Frequency ◽

Frequency Mixing

AbstractWe propose a mechanism of highly focused, tunable and high-intensity terahertz (THz) radiation generation by frequency-mixing of two super-Gaussian lasers with frequencies ω1, ω2 and wave numbers k1, k2 (laser profile index p > 2) in a corrugated plasma in the presence of external static magnetic field ${B_0}\hat z$. In this process, a strong nonlinear ponderomotive force is offered to the plasma electrons at frequency ω′ = ω1 − ω2 and wave number k′ = k1 − k2 by laser beams. The ponderomotive force results in a strong, controllable nonlinear transverse oscillatory current, which can be optimized by optimizing the external magnetic field, ripple parameters, and laser indexes. This controllable current produces focused and intense THz radiation of tunable frequency and power along with a remarkable efficiency ~25%.

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AlGaN/GaN HEMT’s photoresponse to high intensity THz radiation

Opto-Electronics Review ◽

10.1515/oere-2015-0026 ◽

2015 ◽

Vol 23 (3) ◽

Cited By ~ 7

Author(s):

N. Dyakonova ◽

D.B. But ◽

D. Coquillat ◽

W. Knap ◽

C. Drexler ◽

...

Keyword(s):

Terahertz Radiation ◽

Radiation Intensity ◽

High Intensity ◽

Thz Radiation ◽

Gan Hemt ◽

Gan Hemts ◽

Thz Detector ◽

Pulsed Regime

AbstractWe report on the photoresponse dependence on the terahertz radiation intensity in ALGaN/GaN HEMTs. We show that the ALGaN/GaN HEMT can be used as a THz detector in CW and in pulsed regime up to radiation intensity of several kW/cm

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Detection of high intensity THz radiation by InP double heterojunction bipolar transistors

2017 42nd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) ◽

10.1109/irmmw-thz.2017.8067039 ◽

2017 ◽

Author(s):

Nina Dyakonova ◽

Dominique Coquillat ◽

Dmytro B. But ◽

Frederic Teppe ◽

Wojciech Knap ◽

...

Keyword(s):

Heterojunction Bipolar Transistors ◽

High Intensity ◽

Bipolar Transistors ◽

Thz Radiation ◽

Double Heterojunction

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A New High Intensity Grid Cap for RCA-EMU-3 Electron Microscopes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100101323 ◽

1968 ◽

Vol 26 ◽

pp. 316-317

Author(s):

George Christov ◽

Bolivar J. Lloyd

Keyword(s):

Electron Beam ◽

Electron Microscope ◽

High Voltage ◽

High Intensity ◽

Electron Gun ◽

Tungsten Filament ◽

Fluorescent Screen ◽

Electron Microscopes ◽

Pass Through ◽

Ground Potential

A new high intensity grid cap has been designed for the RCA-EMU-3 electron microscope. Various parameters of the new grid cap were investigated to determine its characteristics. The increase in illumination produced provides ease of focusing on the fluorescent screen at magnifications from 1500 to 50,000 times using an accelerating voltage of 50 KV.The EMU-3 type electron gun assembly consists of a V-shaped tungsten filament for a cathode with a thin metal threaded cathode shield and an anode with a central aperture to permit the beam to course the length of the column. The cathode shield is negatively biased at a potential of several hundred volts with respect to the filament. The electron beam is formed by electrons emitted from the tip of the filament which pass through an aperture of 0.1 inch diameter in the cap and then it is accelerated by the negative high voltage through a 0.625 inch diameter aperture in the anode which is at ground potential.

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