A novel detection scheme for THz waves based on upconversion at room temperature

2005 ◽  
Author(s):  
W. Shi ◽  
Y.J. Ding ◽  
N. Fernelius ◽  
F.K. Hopkins
Keyword(s):  
Room Temperature ◽  
Detection Scheme ◽  
Thz Waves

scholarly journals Room Temperature Direct and Heterodyne Detection of 0.28–0.69-THz Waves Based on GaN 2-DEG Unipolar Nanochannels

2016 ◽  
Vol 63 (1) ◽  
pp. 353-359 ◽  
Author(s):  
Carlos Daher ◽  
Jeremie Torres ◽  
Ignacio Iniguez-de-la-Torre ◽  
Philippe Nouvel ◽  
Luca Varani ◽  
...  
Keyword(s):  
Room Temperature ◽  
Heterodyne Detection ◽  
Thz Waves

PROGRESS ON WIDELY-TUNABLE MONOCHROMATIC THz SOURCES AND ROOM-TEMPERATURE DETECTIONS OF THz WAVES

2006 ◽  
Vol 15 (01) ◽  
pp. 89-111 ◽  
Author(s):  
YUJIE J. DING ◽  
WEI SHI
Keyword(s):  
Peak Power ◽  
Room Temperature ◽  
Difference Frequency Generation ◽  
Infrared Laser ◽  
Output Wavelength ◽  
Infrared Laser Beam ◽  
Order Of Magnitude ◽  
Thz Sources ◽  
Thz Waves ◽  
Thz Power

We have further developed widely-tunable monochromatic THz sources. These sources are based on difference-frequency generation (DFG) in GaSe and GaP crystals. Using a 47 mm long GaSe crystal the output wavelength was tuned in the range from 66.5 to 5664 μm (from 150 to 1.77 cm-1) with the peak powers reaching 389 W. This record-high power corresponds to a conversion efficiency of ~0.1%. On the other hand, using a 20 mm long GaP crystal the output wavelength was tuned in the range 71.1–2830 μm whereas the highest peak power was 15.6 W. The advantage of using GaP over GaSe is obvious: crystal rotation is no longer required for wavelength tuning. Instead, one just needs to tune the wavelength of one mixing beam within the bandwidth of as narrow as 15.3 nm. Most recently, we implemented a new scheme for detecting THz waves based on upconversion at room temperature, i.e. by mixing the THz wave with an infrared laser beam, we observed the upconverted signal at a wavelength just slightly longer than that of the infrared laser. To date the detectable THz power is just an order of magnitude higher than that for a bolometer. This scheme allows us to measure the pulse energy density, wavelength, linewidth, and pulse width of a THz beam at room temperature. Using our widely-tunable monochromatic THz beam, we directly measured the absorption spectra of three different families of the homologues of the chemical vapors.

scholarly journals Room temperature excitation spectroscopy of single quantum dots

2011 ◽  
Vol 2 ◽  
pp. 516-524 ◽  
Author(s):  
Christian Blum ◽  
Frank Schleifenbaum ◽  
Martijn Stopel ◽  
Sébastien Peter ◽  
Marcus Sackrow ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Single Molecule ◽  
Room Temperature ◽  
Cdse Nanocrystals ◽  
Photoluminescence Excitation ◽  
Single Quantum ◽  
Excitation Spectra ◽  
Detection Scheme ◽  
Single Quantum Dots ◽  
The Individual

We report a single molecule detection scheme to investigate excitation spectra of single emitters at room temperature. We demonstrate the potential of single emitter photoluminescence excitation spectroscopy by recording excitation spectra of single CdSe nanocrystals over a wide spectral range of 100 nm. The spectra exhibit emission intermittency, characteristic of single emitters. We observe large variations in the spectra close to the band edge, which represent the individual heterogeneity of the observed quantum dots. We also find specific excitation wavelengths for which the single quantum dots analyzed show an increased propensity for a transition to a long-lived dark state. We expect that the additional capability of recording excitation spectra at room temperature from single emitters will enable insights into the photophysics of emitters that so far have remained inaccessible.

Terahertz Plasmonics and Nano-Carbon Electronics for Nano-Micro Sensing and Imaging

2018 ◽  
Vol 12 (1) ◽  
pp. 87-96 ◽  
Author(s):  
Xiangying Deng ◽  
Yukio Kawano ◽  
◽  
Keyword(s):  
Room Temperature ◽  
Three Dimensional ◽  
Plasmonic Structures ◽  
Nano Carbon ◽  
Thz Sensing ◽  
Thz Detector ◽  
Flexible Imaging ◽  
Bull's Eye ◽  
Thz Waves ◽  
Carbon Based

Sensing and imaging with THz waves is an active area of modern research in optical science and technology. There have been a number of studies for enhancing THz sensing technologies. In this paper, we review our recent development of THz plasmonic structures and carbon-based THz imagers. The plasmonic structures have strong possibilities of largely increasing detector sensitivity because of their outstanding properties of high transmission enhancement at a subwavelength aperture and local field concentration. We introduce novel plasmonic structures and their performance, including a Si-immersed bull’s-eye antenna and multi-frequency bull’s-eye antennas. The latter part of this paper explains carbon-based THz detectors and their applications in omni-directional flexible imaging. The use of carbon nanotube films has led to a room-temperature, flexible THz detector and has facilitated the visualization of samples with three-dimensional curvatures. The techniques described in this paper can be used effectively for THz sensing and imaging on a micro- and nano-scale.

Room-temperature semiconductor modulators for free-space signal transmission with THz waves

2004 ◽  
Author(s):  
Thomas Kleine-Ostmann ◽  
Klaus Pierz ◽  
G’nter Hein ◽  
Philip Dawson ◽  
Martin Koch
Keyword(s):  
Free Space ◽  
Room Temperature ◽  
Signal Transmission ◽  
Thz Waves

Status and progress of ion-implanted βNMR at TRIUMF

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
W. Andrew MacFarlane
Keyword(s):  
Thin Films ◽  
Nuclear Magnetic Resonance ◽  
Ionic Liquids ◽  
Soft Matter ◽  
Room Temperature ◽  
Room Temperature Ionic Liquids ◽  
Detection Scheme ◽  
Nuclear Detection ◽  
General Aspects ◽  
Spin Basis

Abstract Beta-detected NMR is a type of nuclear magnetic resonance that uses the asymmetric property of radioactive beta decay to provide a “nuclear” detection scheme. It is vastly more sensitive than conventional NMR on a per nuclear spin basis but requires a suitable radioisotope. I briefly present the general aspects of the method and its implementation at TRIUMF, where ion implantation of the NMR radioisotope is used to study a variety of samples including crystalline solids and thin films, and more recently, soft matter and even room temperature ionic liquids. Finally, I review the progress of the TRIUMF βNMR program in the period 2015–2021.

scholarly journals Theoretical Study on Characteristics of Glow Discharged Neon Gas and Its Interaction With Terahertz Waves

2021 ◽  
Vol 9 ◽  
Author(s):  
Lei Hou ◽  
Yaodong Wang ◽  
Junnan Wang ◽  
Lei Yang ◽  
Wei Shi
Keyword(s):  
Room Temperature ◽  
High Sensitivity ◽  
Response Speed ◽  
Fast Response ◽  
Terahertz Waves ◽  
Thz Wave ◽  
Wave Detector ◽  
Discharge Model ◽  
Neon Glow Discharge ◽  
Thz Waves

Discharge gases have been used to detect terahertz (THz) waves, however, there are few relevant theoretical studies. The neon glow discharge model is established by COMSOL Multiphysics software, the characteristics of glow discharged neon and the interaction of the discharged gas with THz waves were investigated. The results show that with the increase of THz wave’s frequency, the transmittance increases, the change of plasma discharge characteristics caused by THz wave can be used for THz wave detection. The results provide a theoretical basis for the development of cheap, room temperature THz wave detector with fast response speed, and high sensitivity.

scholarly journals Nondestructive Internal Defect Detection Using a CW–THz Imaging System in XLPE for Power Cable Insulation

2020 ◽  
Vol 10 (6) ◽  
pp. 2055 ◽  
Author(s):  
In-Sung Lee ◽  
Joong Wook Lee
Keyword(s):  
Nondestructive Testing ◽  
Continuous Wave ◽  
Imaging System ◽  
Electrical Power ◽  
Coherent Detection ◽  
Power Cable ◽  
Thz Imaging ◽  
Cable Insulation ◽  
Detection Scheme ◽  
Thz Waves

The demand for internal nondestructive testing and inspection techniques is rapidly increasing. Using a continuous wave (CW) terahertz (THz) imaging system, we demonstrate that the internal defects in cross-linked polyethylene (XLPE) plates for power cable insulation can be detected. In a coherent detection scheme based on photomixers, which serve as the THz emitters and receivers, the change of phase occurring with the defects inside the XLPE plates is distinctly measured by the change in the amplitude of the transmitted THz waves. According to the two-dimensional images of THz waves transmitted through the XLPE plates, defects of up to 0.5 mm size located inside the XLPE plates can be detected by the internal nondestructive examination method based on CW–THz waves. This technique will be useful for internal nondestructive testing and inspection of insulation materials that require high resolution in various industries, including the automobiles, electronics, and electrical power industries.

Dependence of Intergranular Fracture on Boundary Topography and Cohesion

1973 ◽  
Vol 31 ◽  
pp. 150-151
Author(s):  
J. E. Doherty ◽  
A. F. Giamei ◽  
B. H. Kear ◽  
C. W. Steinke
Keyword(s):  
Grain Boundary ◽  
Room Temperature ◽  
Nickel Base Superalloy ◽  
Boundary Shear ◽  
Room Temperature Ductility ◽  
Solid Solution Matrix ◽  
Nickel Base ◽  
Solution Matrix ◽  
Different Levels ◽  
Base Superalloy

Recently we have been investigating a class of nickel-base superalloys which possess substantial room temperature ductility. This improvement in ductility is directly related to improvements in grain boundary strength due to increased boundary cohesion through control of detrimental impurities and improved boundary shear strength by controlled grain boundary micros true tures.For these investigations an experimental nickel-base superalloy was doped with different levels of sulphur impurity. The micros tructure after a heat treatment of 1360°C for 2 hr, 1200°C for 16 hr consists of coherent precipitates of γ’ Ni3(Al,X) in a nickel solid solution matrix.

Hepatocyte Alterations in Guinea Pigs FED Polychlorinated Biphenyls (PCBs), Dibenzodioxins (PCDD), AND DIBENZOFURANS (PCDF)

1982 ◽  
Vol 40 ◽  
pp. 56-57
Author(s):  
J. N. Turner ◽  
D. N. Collins
Keyword(s):  
Guinea Pigs ◽  
Room Temperature ◽  
Dose Group ◽  
Methyl Cellulose ◽  
Uranyl Acetate ◽  
Target Organ ◽  
Office Building ◽  
Lead Citrate ◽  
Control Groups ◽  
Cooling Fluid

A fire involving an electric service transformer and its cooling fluid, a mixture of PCBs and chlorinated benzenes, contaminated an office building with a fine soot. Chemical analysis showed PCDDs and PCDFs including the highly toxic tetra isomers. Guinea pigs were chosen as an experimental animal to test the soot's toxicity because of their sensitivity to these compounds, and the liver was examined because it is a target organ. The soot was suspended in 0.75% methyl cellulose and administered in a single dose by gavage at levels of 1,10,100, and 500mgm soot/kgm body weight. Each dose group was composed of 6 males and 6 females. Control groups included 12 (6 male, 6 female) animals fed activated carbon in methyl cellulose, 6 males fed methyl cellulose, and 16 males and 10 females untreated. The guinea pigs were sacrificed at 42 days by suffocation in CO2. Liver samples were immediately immersed and minced in 2% gluteraldehyde in cacadylate buffer at pH 7.4 and 4°C. After overnight fixation, samples were postfixed in 1% OsO4 in cacodylate for 1 hr at room temperature, embedded in epon, sectioned and stained with uranyl acetate and lead citrate.

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