Terahertz market set to diversify and accelerate

16 Jan 2012 http://optics.org/news/3/1/16

The ALMA telescope project will soon be completed but new applications will more than compensate, says BCC Research

ALMA has been a significant driver of the total THz sector The total market for terahertz systems was worth $83.7 million at the end of 2011, according to a new report from Massachusetts-based BCC Research, of which the bulk was associated with ALMA, the Atacama Large Millimeter/submillimeter Array under construction in Chile. As that project winds down, more diverse applications will start to appear, and the total market for the THz technology is set to expand over the coming years. ALMA, an internationally funded observatory located 5000 meters above sea level, is said to be the largest and most complex astronomical project currently in progress. It will eventually feature an array of 66 radio antennae, scanning the sky at wavelengths between 0.3 to 9.6 mm. The telescope produced its first images in October 2011, even though only around one-third of the intended antennae are currently up and running. The scale of the ALMA installation has meant that much of last year's total market for THz systems was closely linked to the astronomical imaging work underway there, according to BCC's figures. The same was true in 2010, when the market was worth a similar $82.8 million. ALMA is due to be completed by the end of 2012, but new applications for THz systems will arise in the second half of the decade, taking up any slack and expanding the total market. BCC expects that applications in public safety and security will help to grow the overall THz market to $125.5 million in 2016, and accelerating diversification in the second half of the decade should push that figure to an impressive $565 million by 2021. Within those totals, BCC predicts that the THz imaging sector will grow slightly from $73 million in 2011 to $74.2 million in 2016, before expanding much more rapidly to $243.8 million by 2021. By then other sensors, such as THz biochips and moisture detectors, are likely to account for more than 30 percent of the total THz market, compared to their minimal presence today. Computer-related devices, primarily high-performance computer interconnects, should capture another 12 percent, and communications devices will account a further 10 percent. Consequently the overall THz sector is expected to show a compound annual growth rate of 8.4 percent over the first half of the decade, before accelerating to a CAGR of more than 35 percent between 2016 and 2021. Terahertz Radiation Systems: Technologies and Global Markets, report ref IAS029, will be published by BCC Research in February 2012. • An indication of where THz technology might be headed came with the announcement by Technische Universität Darmstadt of a transmitter generating what is claimed to be the highest frequency ever attained by a microelectronic device. A team at TU Darmstadt’s Institute for Microwave Technology and Photonics used a resonance tunnel diode, designed in such a way that electromagnetic waves generated within a terahertz oscillator were repeatedly amplified rather than attenuated, to achieve a frequency of 1.111 THz. The same design principle should be able to generate frequencies up to 3 THz, according to the team. • As evidence of the current market for THz imaging, Advanced Photonix has announced the sale of its T-Ray 4000 system to two companies in the Fortune 100 list. One customer is using the system to develop the quality control protocol for a packaged nutritional supplement product, while the other is using it to develop process and quality control protocols for inspection of its products. Both customers plan to deploy multiple systems on the manufacturing floor in the future, according to Advanced Photonix.

TU Darmstadt tiny microelectronic device paves way for new applications

http://www.nanowerk.com/news/newsid=23950.php (Nanowerk News) A terahertz transmitter developed at the TU Darmstadt has generated the highest frequency ever attained by a microelectronic device. The innovative device is also minuscule and operates at room temperature, which could lead to it paving the way for new applications in, e.g., nondestructive testing or medical diagnostics.

Although terahertz (THz) electromagnetic radiation, which has wavelengths ranging from 0.1 mm and 1 mm, penetrates common materials, such as plastics, paper, fabrics, or ceramics, allows, e.g., nondestructively testing workpieces, analyzing processes occurring in engine combustion chambers while engines are running, inspecting packages and letters for hazardous biological substances without need for opening them, it has yet to establish a reputation for itself in scientific and engineering fields. One of the hindrances involved was that, until now, transmitters and receivers operating at THz-frequencies were bulky and very expensive.

However, that situation might soon be reversed, since a team of physicists and engineers led by Dr. Michael Feiginov at the TU-Darmstadt's Institute for Microwave Technology and Photonics has developed a resonance tunnel diode (RTD) for generating terahertz electromagnetic radiation that takes up less than a square millimeter and may be produced using more or less conventional semiconductor-device fabrication technologies. Furthermore, their innovative transmitter has set a new frequency record, 1.111 THz, for microelectronic devices (see paper in Applied Physics Letters: "Resonant-tunnelling-diode oscillators operating at frequencies above 1.1 THz").

Terahertz-transmitter

The highest frequency ever generated by an active semiconductor device

Feiginov, a physicist, noted, that, "That is the highest frequency ever generated by an active semiconductor device." He was also able to theoretically prove that a minuscule transmitter, like that developed by his group, should be capable of generating much higher frequencies extending up to 3 THz. As Feiginov, who intends to continue pursuing development work on the transmitter over the coming years until generation of such higher frequencies has been achieved, went on to say, "That was formerly regarded as impossible by those involved in terahertz research." Achieving such higher frequencies would allow attaining better spatial resolutions, i.e., recognizing finer details, employing terahertz electromagnetic radiation in materials testing and analysis than would be possible at lower frequencies.

That the RTD his group has developed operates at room temperature makes it even more attractive for use in engineering applications. He further commented that, "It might, for example, be utilized in spectroscopic analyses of molecules that have transitions falling within the THz-range."

According to Feiginov, that would mean that substances that have thus far escaped spectroscopic analysis in the THz-range could be investigated employing that widely practiced, scientific method, which would be of great benefit in various fields, among them medicine, where it might, e.g., allow distinguishing diseased body tissues from healthy body tissues in vivo. Since active semiconductor devices, such as the THz-transmitter developed by the TU-Darmstadt group, represent the heart of modern informatics and telecommunications technologies, as well as all sorts of electronic equipment, Feiginov presumes that the device developed by his group will prove useful in many other application areas that cannot readily be foreseen at this stage.

As he put it, "Extracting higher frequencies from the device would lead to new applications, or application areas, in the fields of computers, mobile telephones, and other types of electronic equipment."

In the course of miniaturizing their new device, the group of TU-Darmstadt researchers spent the past few years taking microelectronics close to the limits of the technically feasible. The heart of their RTD is a dual-barrier structure, within which a quantum well (QW) is embedded. A QW is a very thin layer of indium-gallium arsenide semiconductor sandwiched between a pair of ultrathin barrier layers of aluminum-arsenide semiconductor. Every one of those layers is just one nanometer to a few nanometers thin. This dual-barrier structure, plus a quantum-mechanical effect, provides that electromagnetic waves generated within a terahertz oscillator will be repeatedly amplified, rather than attenuated, which means that the oscillator will emit continuous-wave electromagnetic radiation at terahertz frequencies. The group of TU-Darmstadt researchers collaborated with ACST GmbH, a local fabricator of microelectronic circuit components, in producing their diode.

Source: Technische Universität Darmstadt