Automation and Control Technology, Inc. to partner with Advanced Photonix on the T-Gauge terahertz platform

My Note: Thanks to bucktailjig on the IV Board for alerting me to this PDF file.

http://www.autocontroltech.com/DS6012A.pdf

 T-Gauge® Terahertz Coating & Converting Solutions

Advanced Photonix T-Gauge® Picometrix sensor is the first web scanning Time Domain Terahertz solution for plant floor deployment to measure basis weight, caliper, density, moisture on laminated and multi-layer composites. Terahertz technology previously limited to research facilities, military, aerospace and homeland security is now available to the industrial web processing market.

Since the 1950’s on-line web measurement has been dependent upon nuclear isotope, ionizing x-ray, eddy-current, laser and infrared technologies for basis weight, caliper thickness, coating and moisture measurements. While accepted standards these technologies have often been costly , technically challenging to sustain and face increased regulatory control.
The T-Gauge® terahertz solution offers a unique non-nucleonic, non-ionizing, non-contacting multi-function sensor that measures basis weight, caliper thickness and percent moisture in one small ultra-fast reflection sensor.
T-Gauge® uniquely performs multiple layer thickness measurements, detecting delamination and missing components with speed of light precision. A single T-Gauge can be deployed to replace multiple scanners & βeta sensors where differential configurations where once needed for coating, lamination and composite webs. T-Gauge measurement is inherently same-spot and real-time “all-the-time” validation is assured with a patented techniques.
T-Gauge® can improve your process reducing control lag on startup and grade changes while documenting product quality. Caliper thickness is measured directly in a non-contact configuration without requiring a mass composition dependent conversion. T-Gauge enables feedback control for an automatic die using true caliper thickness precise to less than one femtosecond at the speed of light.
T-Gauge® sensors are compact, lightweight and safe, and includes a C1/D1 design for hazardous solvent environments.

Technical Data
Type of Measurement: Time Domain Terahertz
Range tolerance: 5 cm
Measurement rate: 100 or 1000 per second
Basis Weight Range: 10 to 10000+ gsm (2.5 to 2500+ #/ream)
BW Precision: ± 1 gsm (2σ)
Caliper Range 25 to 15000+ μm (1 to 600+ mils)
Caliper Precision: ± 2 μm (2σ)
% Moisture Range 2.5% to >>50%
% Moisture Precision: > ± 0.1% (2σ)
Measurement Footprint: 3 mm2
CD Streak Resolution: 2mm @ 200 mm/sec
Z-axis Tolerance: none
Operating Temperature: 0-50°C/ 32-122°F

Authorized Partner
Certified Integrator for T-Gauge®
Automation and Control Technology, Inc.
6141 Avery Road, Dublin, Ohio 43016
Telephone 614-495-1120
www.autocontroltech.com

Virginia Diodes Dr. Jeffry Hesler presents webinar

http://www.eetimes.com/electrical-engineers/education-training/webinars/4391404/Taking-the-mystery-out-of-mmwave-and-Terahertz-frequency-measurements

Taking the mystery out of mmwave and Terahertz frequency measurements

Date / Time

GMT Standard Time
Thu, Aug 23, 2012 06:00 PM

Eastern Daylight Time
Thu, Aug 23, 2012 02:00 PM

Pacific Daylight Time
Thu, Aug 23, 2012 11:00 AM

Time Zone Converter

System Requirements

Agilent Technologies, Electro Rent

Duration:60 minutes

Overview:
Development work on very high frequency devices and metamaterials has been limited by the difficulty in making good tests. Developers and users of amplifiers, mixers, filters, detectors, receivers, radios and metamaterials at these frequencies need tools for making critical measurements at mmwave and higher frequencies. This webinar show how instruments you are familiar with including Vector Network Analyzers, Signal Analyzers and Sources can be extended in frequency to make a variety of precision measurements at Gigahertz to Terahertz frequencies.

What attendees will learn:

• Key applications using mmwave to Terahertz frequencies
• Challenges in making measurements at very high frequencies
• Measurement capabilities available
• Test setups for component and metamaterial measurements

Presenter:
Dr. Jeffrey L. Hesler, Chief Technology Officer, Virginia Diodes, Inc.
Dr. Jeffrey L. Hesler received the B.S.E.E. in 1989 from Virginia Tech and the Ph.D. in 1996 from the University of Virginia. He is member of the Board of Directors and shareholder of Virginia Diodes, Inc. and serves as Chief Technology Officer of the corporation. In addition, he is affiliated with the University of Virginia as a Visiting Research Assistant Professor in the Department of Electrical and Computer Engineering. 

Northrop Grumman Demonstrates Integrated Receiver Circuit Operating at 850 GHz Under DARPA Terahertz Electronics Program

http://www.marketwatch.com/story/northrop-grumman-demonstrates-integrated-receiver-circuit-operating-at-850-ghz-under-darpa-terahertz-electronics-program-2012-07-31

Unprecedented Increase in Integrated Circuit Operating Speed is Important for Emerging Applications in Military Communications and Radar

REDONDO BEACH, Calif., Jul 31, 2012 (GlobeNewswire via COMTEX) -- Northrop Grumman Corporation has demonstrated an 850 gigahertz (GHz) integrated receiver that brings the company much closer to being the first to reach a Department of Defense goal for developing transistor-based electronics that can operate at center frequencies past 1 terahertz (THz).

Company engineers reported they scaled the frequency rate to 850 GHz, or 0.85 trillion cycles per second under Phase 2 of the Defense Advanced Research Project Agency's (DARPA's) Terahertz Electronics program, setting a new performance record. Under Phase 1, they developed a Terahertz Monolithic Integrated Circuit that operated at 670 GHz, or 0.67 trillion cycles per second, in 2010.

"Integrated circuits operating at frequencies past 1 THz will enable submillimeter wave technology for covert, small aperture communications, high-resolution imaging and leap-ahead advancements in explosive detection spectroscopy," said Dr. William Deal, Terahertz Electronics program manager for Northrop Grumman's Aerospace Systems sector. "This unprecedented increase in integrated circuit operating speed is especially important for emerging applications in military communications and radar. The amplifiers and receivers we're demonstrating will enable more sensitive radar and produce sensors with highly improved resolution."

In addition to demonstrating low-noise integrated receivers under the DARPA program, the company developed and tested low-noise amplifiers and power amplifiers. "Success in the initial phase led to a $12.5 million contract, bringing the total value of the program to $28 million," Deal said.

The goal of DARPA's Terahertz Electronics program is to develop the critical device and integration technologies necessary to realize compact, high-performance electronic circuits that operate at center frequencies exceeding 1.0 THz. The program focuses on two areas: THz high-power amplifier modules and THz transistor electronics.

Northrop Grumman is a leading global security company providing innovative systems, products and solutions in aerospace, electronics, information systems, and technical services to government and commercial customers worldwide. Please visit www.northropgrumman.com for more information.

This news release was distributed by GlobeNewswire, www.globenewswire.com

SOURCE: Northrop Grumman Corp.

Abstract-Terahertz quantum cascade lasers and video-rate THz imaging

Title: Terahertz quantum cascade lasers and video-rate THz imaging
Author: Hu, Qing
Department: Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Issue Date: 2009-12
Abstract: Transitions between subbands in semiconductor quantum wells were suggested as a method to generate long wavelength radiation at customizable frequencies. The recently developed THz quantum-cascade lasers (QCL) hold great promise to bridge the so-called "THz gap" between conventional electronic and photonic devices.Using the high-power THz QCL and a 240x320 focal-plane array camera, we are now able to perform real-time THz imaging at video rate, that is, taking movies in "T-rays".
URI: http://hdl.handle.net/1721.1/71880
ISBN: 978-1-4244-3527-2
978-1-4244-3528-9
Citation: Hu, Qing. “Terahertz Quantum Cascade Lasers and Video-rate THz Imaging.” IEEE, 2009. 211–211. © Copyright 2009 IEEE
Version: Final published version
Terms of Use: Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Published as: http://dx.doi.org/10.1109/DRC.2009.5354977
Journal: Device Research Conference, 2009

Abstract-Exciton Mott Transition in Si Revealed by Terahertz Spectroscopy

http://prl.aps.org/abstract/PRL/v109/i4/e046402


Takeshi Suzuki and Ryo Shimano
Department of Physics, The University of Tokyo, Tokyo 113-0033, Japan
Received 15 March 2012; revised 8 June 2012; published 26 July 2012
We investigate the exciton Mott transition in Si by using optical pump and terahertz probe spectroscopy. The density-dependent exciton ionization ratio α is quantitatively evaluated from the analysis of dielectric function and conductivity spectra. The Mott density is clearly determined by the rapid increase in α as a function of electron-hole (e-h) pair density, which agrees well with the value expected from the random phase approximation theory. However, exciton is sustained in the high-density metallic region above the Mott density as manifested by the 1s-2p excitonic resonance that remains intact across the Mott density. Moreover, the charge carrier scattering rate is strongly enhanced slightly above the Mott density due to nonvanishing excitons, indicating the emergence of highly correlated metallic phase in the photoexcited e-h system. Concomitantly, the loss function spectra exhibit the signature of plasmon-exciton coupling, i.e., the existence of a new collective mode of charge density excitation combined with the excitonic polarization at the proximity of Mott density.

© 2012 American Physical Society


URL:


http://link.aps.org/doi/10.1103/PhysRevLett.109.046402


DOI:


10.1103/PhysRevLett.109.046402


PACS:


71.30.+h, 71.35.Cc, 71.35.Lk

Organic crystals put laser focus on magnetism

This thin green crystal, developed by a company in Switzerland, is used to convert near-infrared laser light into terahertz frequencies, which are useful for a range of experiments. (Photo by Glenn Roberts Jr.)
 http://phys.org/news/2012-07-crystals-laser-focus-magnetism.html#jCp






by Glenn Roberts Jr.
(Phys.org) -- In the first successful experiment of its type at SLAC's Linac Coherent Light Source, scientists used terahertz frequencies of light to change the magnetic state of a sample and then measured those changes with ultrafast pulses from a powerful X-ray laser.
Invisible to human eyes, terahertz describes a band of frequencies between microwave and infrared light. These frequencies are alluring to scientists because they can be used to control and study magnetic and electric states in materials, and have been applied to fields ranging from data storage to biological imaging and explosives detection. They provide an atomic-scale window into fundamental processes such as magnetism, molecular motion and protein vibrations. But observations in the terahertz range were until recently largely out of reach for scientists, said Matthias Hoffman, a SLAC scientist specializing in terahertz laser research who worked on the latest experiments. "There were no real efficient sources and detectors. It was relatively difficult to do science" at terahertz frequencies, he said. The experiment in July involved a technique called pump-probe in which one laser, the "pump," is used to stimulate changes in the sample – in this case a material with exotic magnetic properties – while the X-ray laser probes these changes. A team led by Urs Staub of the Paul Scherrer Institute in Switzerland and Steven Johnson of the Institute for Quantum Electronics at ETH Zurich in Switzerland generated the terahertz laser pulses by aiming an infrared laser beam at a specialized crystal. The passage through the crystal changed the frequency of light from near-infrared to terahertz light. The terahertz pulses then hit a sample, and the researchers measured changes in the sample using closely synchronized pulses from the LCLS X-ray laser. The crystal they used was a special type of thin organic crystal known by the acronym DAST, grown by a private company in Switzerland. DAST crystals tend to be more fragile and susceptible to damage than some non-organic crystals designed for terahertz conversion, Hoffmann noted. He is working with the LCLS laser group to develop better sources of intense terahertz pulses as a regular option for LCLS users conducting pump-probe experiments. Hoffman said another possible way to generate terahertz frequencies is with the electron beams that power advanced synchrotrons and LCLS. "This can produce even higher pulse energies," he said, but has proven more challenging for use in experiments.

Terahertz radiation can induce insulator-to-metal change of state in some materials: study

Image showing a scanning electron microscope image of damaged vanadium dioxide in the gap of a terahertz metamaterial made of gold. The damage results when strong field enhancement of incident terahertz radiation in the gaps leads to a rapid increase in the energy density following the field-driven insulator-to-metal transition. (Credit: Image by Mengkun Liu and edited by Mario D'Amato.
http://phys.org/news/2012-07-terahertz-insulator-to-metal-state-materials.html
(Phys.org) -- A team of researchers at Boston University (BU), Massachusetts Institute of Technology (MIT) and a number of other institutions recently observed that certain materials undergo an insulator-to-metal transition under the influence of terahertz (THz) radiation. The study, under the direction of Richard Averitt, professor of physics at Boston University, and Keith Nelson, professor of chemistry at MIT, was published earlier this month in the journal Nature. The research team achieved a first by demonstrating the use of THz light pulses to control the phase (state of matter) of a material. In this case, the researchers were able to change vanadium dioxide (VO2), from an insulating electronic state to a conducting electronic state. Terahertz-frequency radiation lies between infrared radiation and microwave radiation in the electromagnetic spectrum and shares properties with each. Terahertz radiation can penetrate a wide variety of non-conducting materials, such as clothing, paper, cardboard, wood, masonry, plastic and ceramics, although the penetration depth is typically less than that of microwave radiation. According to Harold Hwang, a post-doctoral physical chemist at MIT, electrons moving in a THz electric field can gain considerable energy (charges accelerate in an electric field). Says Hwang, “Sub-picosecond THz pulses can allow us to initiate strong changes in a material. In the case of VO2, the THz pulse actually distorts the potential in which electrons lie, freeing them up to make the material a better conductor.” However, to do this requires very strong THz fields: In this case, the researchers used an antenna-like structure called a split ring resonator to concentrate the electric field of a THz pulse in a small area, increasing the electric field from hundreds of kilovolts per centimeter to about 4 megavolts per centimeter. “Electric fields of this magnitude can drive not only the phase transition in VO2, but also strong nonlinear responses in many different systems,” says Hwang. “This opens the door to , high-field THz control over electronic and magnetic responses in superconductors, magneto-resistive materials and other correlated electron systems, THz-induced ballistic electron transport in semiconductors, and THz-driven structural change in insulating crystals and glasses.
Hwang adds that, because THz frequencies match the resonant frequencies at which neighboring atoms and molecules in crystal lattices vibrate against each other, THz pulses can drive the lattice vibrations directly—possibly to large amplitudes. THz light can drive electrons and whole atoms and molecules far from their equilibrium locations in a crystal lattice, which can lead to phase transitions in electronic state and/or crystal structure. This can occur by literally moving the atoms into the positions they occupy in a new crystalline phase. Experimental attempts at THz-induced structural phase transitions are currently under way. Research interest in the THz region of the electromagnetic spectrum has increased significantly over the last decade, due to the promise THz light shows in applications ranging from security screening, to bio imaging, to electronics. The BU and MIT groups and their collaborators have demonstrated the ability to induce a phase transition that changes the conductivity of a VO2 film by two orders of magnitude. Further studies have shown conductivity changes of several orders of magnitude in semiconductors. “This shows a lot of promise in being able to detect THz radiation, since the change in conductivity can be read out with conventional electronics,” adds Hwang. “We are hopeful that this kind of technology will lead to more sensitive and cheaper THz detectors, possibly leading to practical THz imaging systems for use in several sectors in industry.” Another promising application of this research is for making Mott-based field-effect transistors (FET) that potentially might overcome intrinsic scaling limitations that currently are being encountered in Silicon (Si)-based transistors. “Electric field switching in the Mott transistors might be a potential substitute for the Si-based FET, in some applications,” says Mengkun Liu, a post-doctoral researcher at UCSD who was a graduate student in Boston University’s Physics Department for this study. “We showed that the THz electric field switching dynamics, investigated by our methods, could be on the order of a few picoseconds. This suggests that transition metal oxide transistors could be used for fast device switching in a wide frequency range (from DC all the way to optical frequency).”

Read more at: http://phys.org/news/2012-07-terahertz-insulator-to-metal-state-materials.html#jCp

My Note: I am on vacation and will be posting from my Ipad this week. Just FYI. this story is not new news but has some interesting discussion.

Researchers at Cornell University (Ithaca, NY) have developed tunable solid-state terahertz sources that employ inexpensive CMOS technology. This chip-based approach, according to the scientists, could enhance medical imaging applications and may even allow for the development of scanners capable of identifying skin cancer indicators that are invisible to the naked eye.

The Cornell researchers have strayed from the path typically taken by current methods of generating terahertz radiation, which often entail the use of large or costly lasers, vacuum tubes, or special circuits that must be cooled near absolute zero, for example. Instead, the team, led by Ehsan Afshari, assistant professor of electrical and computer engineering at Cornell, explored the possibility of generating terahertz signals on an inexpensive silicon chip.

"We present a solid-state tunable terahertz source that exploits the theory of coupled oscillators to simultaneously achieve high output power and frequency tuning," the researchers explain in an abstract for the American Physical Society. "Our proposed structure effectively generates and combines high-power harmonics from multiple synchronized solid-state oscillators in a loop configuration. We study the dynamics of the system, find the stable modes, and show how the structure can dynamically select a desired coupling mode. Using this method, we fabricated 0.29- and 0.32-THz tunable sources with peak output powers of 0.76 and 0.5 mW both in a standard 65-nm bulk complementary metal-oxide semiconductor technology."

Using this novel method yielded a power level approximately 10,000 times larger than that previously achieved at terahertz frequencies on a silicon chip, according to the researchers. These promising early results demonstrate promise for the use of such a technology for a variety of future medical applications.

Investing in chips and in the TSA-Commentary: Complex semiconductors could change industry

BERKELEY, Calif. (MarketWatch) — Over the past week or two, a number of articles appeared about a so-called laser device that could scan a whole airport for explosive devices, lessening the need for invasive body checks at airports. It would all be done by some sort of modern terahertz scanner.

John Dvorak's Second Opinion

http://www.marketwatch.com/story/investing-in-chips-and-in-the-tsa-2012-07-20?link=MW_latest_news

Curiously, this is kind of possible. Terahertz technology is considered by many to be the holy grail of scanning.

The problem is being able to build anything that can generate and detect a terahertz wave. This is a frequency similar to that used by the millimeter-wave machines found at some airports.

Click to Play

Generally speaking, the spectrum for these waves goes from 300 GHz to 3,000 GHz. It is nonionizing, meaning it does not irradiate you but can pass through clothes, wood, bricks, plastic. It cannot penetrate water or metal.

If you could see this spectrum, everyone would be naked — a dream come true for the Transportation Security Administration.

Such technology is extremely complex and normal semiconductor technology cannot easily make any circuits for it. You need all the rare-earth, wild semiconductors that are hard to build, and consequently are very expensive. The materials required include indium phosphide, indium gallium arsenide and even zirconium dioxide, among other odd blends.

You can be sure companies like Intel Corp. INTC -1.84%  are always playing with these designs, and if any of the specialty semiconductor companies finds a breakthrough circuit or process, they will be gobbled up overnight at a healthy premium.

There are a couple of these companies worth tracking. All work with various rare semiconductor structures to develop the kind of high-speed chip needed for terahertz technologies.

Reuters

A security official demonstrates a full-body scanner in Hamburg, Germany.

The first and one of the most famous is Vitesse Semiconductor VTSS -3.41% . Once upon a time, the stock was well more than $1,500 a share. It’s still in the game, although it actually makes networking gear for a living.

Broadcom Corp. BRCM -2.39%  also plays in this game and always has to be considered. It’s probably less of a buyout candidate if the company ever hit the home run with a high-speed breakthrough. It’s a more conservative bet and a perpetually overlooked winner.

Now if you want to look at a rank OTC speculation, then check out SMG Indium Resources Ltd. SMGI -7.27% , a mineral company involved in stockpiling indium, which has many uses other than exotic semiconductors.

Most semiconductor firms keep their eye on the possibilities for a superfast breakthrough, but the industry as a whole stays within the confines of the CMOS process, which is the manufacturing technology that dominates the sector. This process limits chip makers on what designs can be made.

Everyone does know that someday this has to change. It may be because of the great desire to develop the fascinating terahertz technologies.

Here’s looking at you. 

The missing switch: High-performance monolithic graphene transistors created

http://www.extremetech.com/computing/132988-the-missing-switch-high-performance-monolithic-graphene-transistors-created

• By Sebastian Anthony

Hardly a day goes by without a top-level research group announcing some kind of graphene-related breakthrough, but this one’s a biggy: Researchers at the University of Erlangen-Nuremberg, Germany have created high-performance monolithic graphene transistors using a simple lithographic etching process. This could be the missing step that finally paves the way to post-silicon electronics.
As you probably know by now, graphene has a long and wonderful list of desirable properties, including being the most conductive material yet discovered. In theory, according to early demos from the likes of IBM and UCLA, graphene transistors should be capable of switching at speeds between 100GHz and a few terahertz. The problem is, graphene doesn’t have a bandgap — an innate ability to switch on and off, depending on the voltage; it isn’t a natural semiconductor, like silicon — and so it is proving very hard to build transistors out of the stuff. Until now!

The process employed by the researchers is quite simple. Basically, by baking silicon carbide — a simple crystal of silicon and carbon, which also happens to be a well-understood semiconductor — the silicon atoms can be driven off from the layer of the crystal, leaving a single layer of graphene. A layer of graphene on its own is useless, though; you need sources, drains, and gates to produce an actual transistor. To do this, a lithographic mask is laid down, and reactive ion etching is used to define each of the transistors. Another key point was the introduction of hydrogen gas during the growth of the middle graphene channel, turning it from contact (source/drain) graphene into gate graphene. Voila: graphene transistors, with the silicon carbide and its delicious bandgap acting as the conducting layer.
Now, unfortunately, because the researchers did their work on a very large scale — each transistor is around 100 micrometers across, or 100,000nm — we don’t really have an accurate measure of just how fast this graphene transistor is. The researchers say that current performance “corresponds well with textbook predictions for the cutoff frequency of a metal-semiconductor field-effect transistor,” but they also point out that very simple changes could increase performance “by a factor of ~30.”
The main thing is that the University of Erlangen-Nuremberg has now provided “the missing switch” that graphene transistors so desperately needed. It will now be up to actual semiconductor manufacturers, such as IBM or Intel, to shrink the process down to a size that can compete — or beat — conventional silicon electronics.
Read more at Nature Communications: doi:10.1038/ncomms1955, or read more about post-silicon electronics

TeraView Brings New Techniques to the Study of Industrial Coatings

Submitted by William Gunnar  07/14/2012 

http://industrialcoatingsworld.com/newsstory/teraview-brings-new-techniques-study-industrial-coatings
TeraView,which is commercialising active terahertz technology, now brings techniques developed for medicine and pharmaceutical products to non-destructive testing for coatings, studies of adhesion.
"First, we have to distinguish between active and passive terahertz, " explains Professor Sir Michael Pepper, Scientific Director for TeraView. "In the passive case the terahertz emitted by objects measured has no industrial relevance, unlike the active case, which measures the response to illumination by terahertz generated in our equipment."
Terahertz radiation is situated between the microwave and infra-red and until recently was not utilised in any significant way. However the situation changed when TeraView (founded 2001 in Cambridge UK), showed that it was possible to image a human tooth with more detail than X-Rays. Using a successive sequence of pulses, the non-ionising technology, with its 3-dimensional reconstructions and depth resolution better than 10-3 cms, could also differentiate cancer from healthy tissue now in clinical trials.
"The basis for the action of terahertz is that it acts rather like high frequency radar," Pepper adds. "The radiation is reflected each time there is a change in material. The time of arrival is measured and then various algorithms complete the picture by developing 3D fine feature images and precise material identifications."
How does this pertain to industrial coatings?
Terahertz can measure thickness across a substrate precisely and it can also obtain the density of the coating. Unlike ultrasonics, the probe is not in contact with the sample and no preparation of the sample is required. It is totally non-invasive.
Delamination of coatings are also detectable using terahertz. If two surfaces have bonded effectively, there is a graded region where one passes into the other, either utilising adhesives or else by chemical bonding. The amplitude of the terahertz reflection and the line shape can be used to obtain the strength of the bond and assess whether delamination has occurred locally or whether it is likely to occur.
The technology has considerable relevance to composite coating materials, where layers are deposited sequentially. Terahertz can detect if a defect is present, including foreign inclusions, impurities, stresses on film formation.
Because the measurements of coating films are real time (a single pixel, taking about 20 milliseconds), measurements can be taken during the coating process to give an accurate picture of what is taking place in a deposition chamber or similar equipment.
These are just a few examples of the remarkable scope and power of terahertz imaging.
For more information, contact Michael Pepper at: michael.pepper@teraview.com.
www.teraview.com

New Amplifier created at JPL for use from distant galaxies to the quantum level

The new amplifier consists of a superconducting material (niobium titanium nitride) coiled into a double spiral 16 millimeters in diameter.[Credit: Peter Day]

http://www.newkerala.com/news/newsplus/worldnews-52314.html
PASADENA, Calif.—Researchers at the California Institute of Technology (Caltech) and NASA's Jet Propulsion Laboratory (JPL) have developed a new type of amplifier for boosting electrical signals. The device can be used for everything from studying stars, galaxies, and black holes to exploring the quantum world and developing quantum computers.
"This amplifier will redefine what it is possible to measure," says Jonas Zmuidzinas, Caltech's Merle Kingsley Professor of Physics, the chief technologist at JPL, and a member of the research team.
An amplifier is a device that increases the strength of a weak signal. "Amplifiers play a basic role in a wide range of scientific measurements and in electronics in general," says Peter Day, a visiting associate in physics at Caltech and a principal scientist at JPL. "For many tasks, current amplifiers are good enough. But for the most demanding applications, the shortcomings of the available technologies limit us."
Conventional transistor amplifiers—like the ones that power your car speakers—work for a large span of frequencies. They can also boost signals ranging from the faint to the strong, and this so-called dynamic range enables your speakers to play both the quiet and loud parts of a song. But when an extremely sensitive amplifier is needed—for example, to boost the faint, high-frequency radio waves from distant galaxies—transistor amplifiers tend to introduce too much noise, resulting in a signal that is more powerful but less clear.
One type of highly sensitive amplifier is a parametric amplifier, which boosts a weak input signal by using a strong signal called the pump signal. As both signals travel through the instrument, the pump signal injects energy into the weak signal, therefore amplifying it.
About 50 years ago, Amnon Yariv, Caltech's Martin and Eileen Summerfield Professor of Applied Physics and Electrical Engineering, showed that this type of amplifier produces as little noise as possible: the only noise it must produce is the unavoidable noise caused by the jiggling of atoms and waves according to the laws of quantum mechanics. The problem with many parametric amplifiers and sensitive devices like it, however, is that they can only amplify a narrow frequency range and often have a poor dynamic range.
But the Caltech and JPL researchers say their new amplifier, which is a type of parametric amplifier, combines only the best features of other amplifiers. It operates over a frequency range more than ten times wider than other comparably sensitive amplifiers, can amplify strong signals without distortion, and introduces nearly the lowest amount of unavoidable noise. In principle, the researchers say, design improvements should be able to reduce that noise to the absolute minimum. Versions of the amplifier can be designed to work at frequencies ranging from a few gigahertz to a terahertz (1,000 GHz). For comparison, a gigahertz is about 10 times greater than commercial FM radio signals in the U.S., which range from about 88 to 108 megahertz (1 GHz is 1,000 MHz).
"Our new amplifier has it all," Zmuidzinas says. "You get to have your cake and eat it too."
The team recently described the new instrument in the journal Nature Physics.
One of the key features of the new parametric amplifier is that it incorporates superconductors—materials that allow an electric current to flow with zero resistance when lowered to certain temperatures. For their amplifier, the researchers are using titanium nitride (TiN) and niobium titanium nitride (NbTiN), which have just the right properties to allow the pump signal to amplify the weak signal.
Although the amplifier has a host of potential applications, the reason the researchers built the device was to help them study the universe. The team built the instrument to boost microwave signals, but the new design can be used to build amplifiers that help astronomers observe in a wide range of wavelengths, from radio waves to X rays.
For instance, the team says, the instrument can directly amplify radio signals from faint sources like distant galaxies, black holes, or other exotic cosmic objects. Boosting signals in millimeter to submillimeter wavelengths (between radio and infrared) will allow astronomers to study the cosmic microwave background—the afterglow of the big bang—and to peer behind the dusty clouds of galaxies to study the births of stars, or probe primeval galaxies. The team has already begun working to produce such devices for Caltech's Owens Valley Radio Observatory (OVRO) near Bishop, California, about 250 miles north of Los Angeles.
These amplifiers, Zmuidzinas says, could be incorporated into telescope arrays like the Combined Array for Research in Millimeter-wave Astronomy at OVRO, of which Caltech is a consortium member, and the Atacama Large Millimeter/submillimeter Array in Chile.
Instead of directly amplifying an astronomical signal, the instrument can be used to boost the electronic signal from a light detector in an optical, ultraviolet, or even X-ray telescope, making it easier for astronomers to tease out faint objects.
Because the instrument is so sensitive and introduces minimal noise, it can also be used to explore the quantum world. For example, Keith Schwab, a professor of applied physics at Caltech, is planning to use the amplifier to measure the behavior of tiny mechanical devices that operate at the boundary between classical physics and the strange world of quantum mechanics. The amplifier could also be used in the development quantum computers—which are still beyond our technological reach but should be able to solve some of science's hardest problems much more quickly than any regular computer.
"It's hard to predict what all of the applications are going to end up being, but a nearly perfect amplifier is a pretty handy thing to have in your bag of tricks," Zmuidzinas says. And by creating their new device, the researchers have shown that it is indeed possible to build an essentially perfect amplifier. "Our instrument still has a few rough edges that need polishing before we would call it perfect, but we think our results so far show that we can get there."
The title of the Nature Physics paper is "A wideband, low-noise superconducting amplifier with high dynamic range." In addition to Zmuidzinas and Day, the other authors of the paper are Byeong Ho Eom, an associate research engineer at Caltech, and Henry LeDuc, a senior research scientist at JPL. This research was supported by NASA, the Keck Institute for Space Studies, and the JPL Research and Technology Development program.
Written by Marcus Woo

Deborah Williams-Hedges

626-395-3227

debwms@caltech.edu

Abstract-Double graphene-layer plasma resonances terahertz detector

http://iopscience.iop.org/0022-3727/45/30/302001

We propose a detector of terahertz radiation based on a double graphene-layer heterostructure utilizing the tunnelling between graphene layers and the resonant excitation of plasma oscillations (standing plasma waves). Using the developed device model, we substantiate the detector operation and calculate the spectral characteristics. It is shown that the detector responsivity exhibits the resonant peaks when the frequency of incoming terahertz radiation approaches the resonant plasma frequencies. These frequencies are tuned by the bias voltage. The height of the responsivity resonant peaks in sufficiently perfect double graphene-layer heterostructures can markedly exceed those in the resonant plasma–wave detectors based on the standard heterostructures and utilizing the plasma hydrodynamic nonlinearity.

June 2012 IHS Jane's Airport Review features article on the Advanced Photonix Anomaly Detection System

The June 2012, Jane's Airport Security and Safety Review, http://jar.janes.com/public/jar/safety.shtml features an interesting article written by Barry Cross, and Ben Vogel, about both the Advanced Photonix (API), Anomaly Detection System, as well as a discussion of the work by the French Government through it's CEA-Leti, program to employ terahertz scanning systems to fill current security gaps in airport screening, to prevent terrorists efforts to bring weapons, bombs, or toxic chemical or biological devices onto airplanes or other public places or events. The present API system alerts or registers a "threat" or "no-threat", but in the future will most likely include a classification of the type of threat.
Irl Duling, director of terahertz business development for API, noted that the anomaly detection system will allow TSA security personnel to discontinue the practice of physically "patting-down" passengers after initial scanning by threshold airport security systems reveals an anomaly on the person's body, which might be a concealed object, (or simply a person wearing  religious headgear which can't be removed.)
The system's terahertz pulse which covers a wide bandwidth from 20 GHz, to almost 4 THz, and is capable of detecting a wide range of chemical or biological signatures, which it then compares against the library of spectroscopic signatures it has been programmed to detect.
Duling indicated that the accuracy of the detection program was very high, and that there is a low false alarm rate. The detection system is based upon proprietary algorithms written by Duling and API engineers for use in the system's internal semiconductors.
Jane's reports that at present, the system when purchased in bulk will retail at around $70,000 per unit.
Jane's article also reports that the device is relatively maintenance free, and because it uses automated software user training is very minimal, (5-10 minutes) to achieve operator proficiency.
The entire article is available at the present time only to subscribers, but is a very interesting read, and contains much more information about this exciting device, which is currently being vetted for use by the TSA, as a result of API's development partnership of the device,  with In-Q-Tel.
(The article also details the very interesting work of CEA-Leti, to develop and deploy their THz system for airport security uses, which I hope to blog about in the near future).

US Homeland Security reportedly set to deploy Genia Photonics, ultra-sensitive spectrometer

My Note: I almost hate to post this story, since, I have a hard time believing it's true, (based upon  the TSA's tortoise like, pace in adopting new technologies). The In-Q-Tel, agreement with Genia Photonics to develop this product was not even signed until last November, Advanced Photonix, anomaly detection device which is also under review by the TSA, was (and is) the subject of a similar In-Q-Tel development contract signed in November of 2010, and the prototypes (beta version) shipped to TSA in March of 2012. I'm posting the article below, because the story is  making such a huge buzz on the net.  You can make your own decisions. I'm trying to make contact with Genia to find out the real truth of this story.  Stay posted. 

http://phys.org/news/2012-07-homeland-reportedly-deploy-ultra-sensitive-spectrometer.html
by Bob Yirka
(Phys.org) -- Online tech magazine, Gizmodo has stirred up a hornet’s nest of paranoid editorials across the globe by printing an article written by an unknown PhD student who claims that the US Homeland Security department is planning to deploy a new kind of scanning device that is so sensitive it will make all other security measures at airports moot; and worse will be able to do so at a distance allowing the process to occur without the knowledge of the person being scanned.

In the piece, the author, designated simply as NAC, says that the device has been developed by a private company called Genia Photonics, which is apparently chock full of physicists and engineers. It’s described as being able to pick up on the presence of mere molecules of suspicious substances (using apparently harmless, terahertz radiation) such as chemical weapons, gunpowder residue or even heightened levels of adrenaline in the bloodstream, all from a distance of up to 50 meters. What’s more it’s really fast, doing its work in picoseconds, and portable, meaning that DHS could set up the scanner at airports, train stations, border crossings or wherever else they believe a possible threat exists. What appears to worry some though, is the possibility of being mistakenly labeled as a suspect, criminal, terrorist, etc. People encounter many innocuous substances every day that could be construed as dangerous or even illegal. Stepping on a leftover marijuana stub without knowing it, could for example cause such a scanner to go off, as could applying fertilizer to the home garden prior to heading for the airport. Something else that seems to cause alarm is the fact that the technology behind the device appears to be sound, and in fact has apparently been done before. The difference this time is the speed at which it works; because of that, a single device could conceivably be used to scan every single person passing through an airport’s terminals, which means, that if deployed the days of singling out individuals for extra security measures would be over. If a person goes to an airport, they will be scanned, and most won’t even know it’s happened. The author of the article says an undersecretary at DHS has stated that the scanner will be ready for deployment within one or two years. © 2012 Phys.org

Abstract-Conversion of Terahertz Wave Polarization at the Boundary of a Layered Superconductor due to the Resonance Excitation of Oblique Surface Waves

http://prl.aps.org/abstract/PRL/v109/i2/e027005
Yu. O. Averkov¹, V. M. Yakovenko¹, V. A. Yampol’skii^1,2, and Franco Nori^2,3
1A. Ya. Usikov Institute for Radiophysics and Electronics, Ukrainian Academy of Sciences, 61085 Kharkov, Ukraine
²Advanced Science Institute, RIKEN, Saitama, 351-0198, Japan
³Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA

Received 27 December 2011; published 10 July 2012

We predict a complete TM↔TE transformation of the polarization of terahertz electromagnetic waves reflected from a strongly anisotropic boundary of a layered superconductor. We consider the case when the wave is incident on the superconductor from a dielectric prism separated from the sample by a thin vacuum gap. The physical origin of the predicted phenomenon is similar to the Wood anomalies known in optics and is related to the resonance excitation of the oblique surface waves. We also discuss the dispersion relation for these waves, propagating along the boundary of the superconductor at some angle with respect to the anisotropy axis, as well as their excitation by the attenuated-total-reflection method.

© 2012 American Physical Society

URL:

http://link.aps.org/doi/10.1103/PhysRevLett.109.027005

DOI:

10.1103/PhysRevLett.109.027005

PACS:

74.78.Fk, 42.25.Ja, 74.25.N-

Development of 'Slater Insulator' That Rapidly Changes from Conductor to Insulator at Room Temperature may lead to new Terahertz devices

(Left) Photograph of a crystal of Perovskite type osmium oxide and (right) schematic diagram of its crystal structure. White circles: sodium ions, red circles: oxygen ions. Osmium ions exist in the central part of the octahedron. (Credit: Copyright NIMS)

http://www.sciencedaily.com/releases/2012/07/120711134534.htm

ScienceDaily (July 11, 2012) — Dr. Kazunari Yamaura, a Principal Researcher of the  Strongly Correlated Materials Group, Superconducting Properties Unit, in joint work with a researchNIMS group at the Oak Ridge National Laboratory (United States), has succeeded in developing a Slater insulator which functions at room temperature.

Dr. Kazunari Yamaura, a Principal Researcher of the Strongly Correlated Materials Group, Superconducting Properties Unit, National Institute for Materials Science (NIMS; President: Sukekatsu Ushioda), in joint work with a research group at the Oak Ridge National Laboratory in the United States, succeeded in development of a Slater insulator which functions at room temperature.
Slater insulators have been studied for more than 50 years as insulators with special properties. Although Slater insulators display the properties of metals at a sufficiently high temperature, they become insulators when cooled to a certain temperature (transition temperature) peculiar to the substance concerned. Because this transition temperature was conventionally far lower than room temperature, study had been limited to scientific research, and virtually no research had been done aiming at development to applications.
This research clarified the fact that a new material (Perovskite type osmium oxide), which was synthesized for the first time by NIMS in 2009, is the Slater insulator with the highest transition temperature to date. This result was verified through joint experimental research with a research group at the Oak Ridge National Laboratory in the United States using the neutron diffraction method.
Because this new material displays the characteristics of a Slater insulator at room temperature without requiring cooling, it is not only scientifically interesting, but also has the potential for development to application as a new material. If further progress can be achieved in research with this new material as a starting point, there is a possibility that new materials and devices with unprecedented functions can be developed. Concretely, application to solid state devices for detecting signals in the terahertz region, new thermoelectric conversion materials, etc. is considered possible. In the future, research will be carried out aiming at development of new materials with possible practical applications.

Genia Photonics Enters into Strategic Partnership with IQT

My note: This is old news but I just heard about it today. I  hadn't heard of Genia Photonics either, until today, but they have some interesting terahertz applications.  (Thanks to poster hemecity on the IV board, for alerting me to this story.)
http://www.iqt.org/news-and-press/press-releases/2011/Genia-Photonics.html
November 1, 2011
Genia Photonics Inc., a high technology company specializing in fiber-laser-based systems, announced a strategic partnership and technology development agreement with In-Q-Tel (IQT), the non-profit, strategic investment firm that delivers innovative technology solutions to support the missions of the U.S. Intelligence Community.
"Our partnership with Genia Photonics will build on the company's success in the commercial market," says Simon Davidson, partner on IQT's Investments team. "Genia Photonics' fiber-based technology will lead to unique possibilities for our customers in the U.S. Intelligence Community." The technology is being developed for the Department of Homeland Security Science and Technology Directorate (DHS S&T), an IQT customer agency.
This strategic partnership between Genia Photonics and IQT will promote Genia's fiber-based laser technology development to a higher level and provide new opportunities for Genia's product applications. "Genia Photonics' mission is to provide solutions that benefit society and improve quality of life," says François Gonthier, CEO of Genia Photonics. "Our partnership with IQT will create new opportunities for leveraging Genia's versatile and multifunctional fiber-based technologies into related applications."
In addition to the value for the defense and security communities, Genia Photonics' Synchronized Programmable Laser platform has applications such as non-linear spectroscopy for the biomedical and industrial communities. An important benefit of Genia Photonics' implementation as compared to existing solutions is that the entire synchronized laser system is comprised in a single, robust, and alignment-free unit that may be easily transported for use in many environments.
About Genia Photonics
Genia Photonics Inc. is an innovative technology company specializing in multi-functional measurement systems based on its patented fiber-based lasers. Genia’s easy-to-use, portable and computer controlled systems will change the methodology of various applications in the medical, industrial and defense and security communities. For more information, visit www.geniaphotonics.com.