Terahertz detection and carbon nanotubes

Sunday, September 14, 2014

Lake Shore to Discuss THz Characterization and High-Frequency Probing at IRMMW-THz


Lake Shore Cryotronics, a leading innovator in solutions for measurement over a wide range of temperature and magnetic field conditions, announced that it will be exhibiting solutions for high-frequency material characterization at the 39th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz), Sept. 14–19, in Tucson, Ariz. Lake Shore specifically will discuss its fully integrated Model 8501 THz system for material characterization and its work toward developing THz-frequency solutions for cryogenic probe station-based measurement.

A non-contact spectroscopic platform, the Model 8501 enables researchers to more easily study research-scale electronic and magnetic materials with resonances in the THz regime. It uses uniquely designed continuous wave THz (CW-THz) emitter and detector components, supporting the ability to measure at 200 GHz to 1.5 THz frequencies and spectral resolution of better than 500 MHz.
Because the system includes a high-field cryostat and superconducting magnet, material responses can be measured across a range of temperatures and field strengths. These capabilities benefit research of materials at low temperatures at an early stage, when high magnetic fields (up to 9 T) may be required.
The Model 8501 system also includes intuitive management and analysis software, enabling quick setup of measurement profiles, automated measurement runs and real-time visualization of collected data. To see a demo of the software, IRMMW-THz attendees can stop by Lake Shore’s booth (#14). Also during the conference, Lake Shore will be conducting a poster session relating to field- and temperature-dependent thin film CW-THz characterization. This session will occur Thursday, Sept. 18, from 5:30 to 7 p.m. in the South Ballroom.
Separate from its THz material characterization solution, Lake Shore will also be discussing its most recent efforts toward developing a THz-frequency, on-wafer contact probing solution for cryogenic probe stations. This initiative is a collaboration of Lake Shore with several companies and university researchers. The goal is to enable high-speed device probing and performance measurements at variable temperatures and magnetic fields for next-generation electronics R&D. Conference attendees can learn more about this industry/university collaboration and see a prototype of Lake Shore’s cryogenic THz probe arm assembly by visiting the Lake Shore booth.
The company will also answer questions about its complete line of industry-leading cryogenic probe stations during the conference. These platforms enable non-destructive probing of materials and test devices as a function of temperature and field, whether for the study of electrical, magneto-transport, DC, RF or microwave properties. They are particularly useful for carbon-based nanotube (CNT), graphene, MEMS, gallium-nitride (GaN), silicon-germanium (SiGe), superconducting device and organic semiconductor research.

Saturday, September 13, 2014

Virginia Diodes is Exhibiting and Presenting at IRMMW- THz 2014

The 39th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) starts on Monday and runs to Friday. VDI is exhibiting and will be presenting 3 papers.

See you in Tucson.



Teraview to Attend and Present at IRMMW-THz 2014

TeraView invites you to visit us at IRMMW-THz 2014!

Dr. Philip Taday and Rob May will both be attending the event, with Rob May giving a keynote talk on Monday the 15th of September - 11:30 in the Tuscon Room:

Terahertz Car Paint Thickness Sensor: Out of The Lab and Into the Factory

Don't miss out on this opportunity to learn more about TeraView's recent development and applications!

TeraView will be at Booth #21

If you would like to pre-arrange a meeting, please e-mail Dr. Phil Taday.

Advantest to Exhibit and Present at IRMMW-THz Conference, Tucson, Arizona, September 14-19, 2014

PRINCETON, N.J., Sep 12, 2014 (BUSINESS WIRE) -- Leading semiconductor test equipment supplier Advantest Corporation ATE, -1.02% will promote its new TAS7500TS THZ wave spectroscopy and analysis platform at the International Conference on Infrared, Millimeter, and Terahertz Waves in Tucson, AZ. The TAS7500TS is an optical sampling system that enables full coverage of applications from R&D to industrial testing, and is part of the company’s TAS7500 family of compact and multipurpose terahertz spectroscopic / imaging systems.
The flexible design of the new system allows the user to freely configure the terahertz source and detector modules, creating unparalleled versatility. This system can be paired with a variety of terahertz source modules covering three different spectral ranges within the terahertz frequency band. With in-line, at-line, on-line, and off-line capabilities, Advantest’s terahertz systems are suitable for R&D, Quality, Manufacturing, and Process Analytical Technology (PAT).
Additionally, Advantest’s David Heaps will present a paper titled, An Investigation of Petrochemical Geological Samples by Terahertz Pulse Spectroscopy, which demonstrates that the THz spectra can be used to get different chemical and structural information from a potential hydrocarbon source.
The International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz), is the oldest and largest continuous forum devoted to the science and technology of long-wavelength radiation. The conference will be held at the University of Arizona in Tucson from September 14-19, 2014. More information on IRMMW can be found at: http://www.irmmw-thz2014.org/content/welcome-39th-international-conference-infrared-millimeter-and-terahertz-waves
About Advantest Corporation
A world-class technology company, Advantest is a leading producer of automatic test equipment (ATE) for the semiconductor industry and a premier manufacturer of measuring instruments used in the design and production of electronic instruments and systems. Its leading-edge systems and products are integrated into the most advanced semiconductor production lines in the world. The company also focuses on R&D for emerging markets that benefit from advancements in nanotech and terahertz technologies, and has introduced multi-vision metrology scanning electron microscopes essential to photomask manufacturing, as well as a groundbreaking 3D imaging and analysis tools. Founded in Tokyo in 1954, Advantest established its first subsidiary in 1982, in the USA, and now has subsidiaries worldwide. More information is available at www.advantest.com.
SOURCE: Advantest Corporation
Advantest Corporation 
Amy Gold, +1 212-710-0515 

Friday, September 12, 2014

Room-temperature bow-tie terahertz detectors integrated with focusing optics

Linas Minkevičius (R) and Karolis Madeikis (L) investigating the THz detector with compact diffractive optics

Read more at: http://phys.org/news/2014-09-room-temperature-bow-tie-terahertz-detectors-focusing.html#jCp
Room-temperature bow-tie terahertz detectors have been successfully integrated with focusing optics for the first time. This achievement, from researchers at the Center for Physical Sciences and Technology in Lithuania, not only makes the detector much more compact and reliable, but the use of zone plates also enables an order of magnitude increase in the detection capability, making this system very attractive for use in terahertz imaging applications.

Smaller solutions
Terahertz (THz) imaging is a powerful tool in many applications such as security systems, materials testing and their identification and medical diagnostics. One of the limitations of these imaging systems at the moment is their physical size. Reducing the size is not only key to integrating the focusing optics and active components on to one chip, but also to making the system cheaper, more reliable and comfortable to use.
There are two 'elements' to the system that are being actively studied worldwide in order to reduce the size: more compact THz emission sources are being developed using quantum cascade lasers; and broadband and sensitive THz sensors are being developed using compact technology such as nanometric field effect transistors, Schottky diodes, microbolometers and bow-tie diodes. Less commonly studied are solutions to replace the bulky passive optical components such as parabolic or spherical mirrors from conventional imaging systems.
All in one
The team from Lithuania is focused on finding solutions to the challenges of THz imaging and spectroscopy, and one of their topics is the development of compact room-temperature operating sensors for real-time THz imaging cameras and sensor arrays for spectroscopic THz imaging.
Room-temperature bow-tie terahertz detectors integrated with focusing optics
The focusing features of the compact optics placed on the same chip with the THz sensor. 
In their earlier research, they concentrated on the development of compact diffractive optics components for THz imaging systems.
"The first in this direction was the fabrication of free-standing zone plates and cross shape filter arrays, made from thin metal film used for focusing and frequency selection purposes," said Linas Minkevičius, lead author in this work. "The second step – filter array integration into the free standing zone plate – aimed to reduce the number of components and make the system more compact."
In the latest step, presented in this issue of Electronics Letters, the team show how they have further advanced the miniaturisation of THz imaging systems by integrating a room temperature InGaAs-based bow-tie THz diode, that has broadband operation up to 2.5 THz, with the secondary diffractive optics in a single chip.
"We have managed to attach the detector and the  on separate sides of the semi-insulating semiconductor substrate," said Minkevičius. "This allowed us to simultaneously make the system more reliable and more compact while improving the sensing properties of InGaAs THz detector."
The measurements made with the detector at different angles of incidence showed an enhancement in the detected signal of an order of magnitude, which agreed with the team's numerical simulations, proving the effectiveness of the focusing performance of the zone plates.
Combined experience
Minkevičius believes that the key factors leading to the success of this work were collaboration, experience and technology.
"There are three important matters: first, the zone plate and detector design were selected by simulating the properties of the electric field distribution via the zone plate and substrate to the detector's apex using the 3D finite difference time domain method; secondly, fruitful collaboration with Prof. H. G. Roskos' group from Goethe University, Germany, and their experience in processing technology, let us overcome difficulties in the detector's manufacturing process; and finally, the most challenging issue was to arrange the zone plate focal spot and the detector active part at one geometrical point from both sides of substrate – this was achieved by employing advantages from our laser direct writing technique."
This solution is not only more compact, but also removes the problems arising from the need for precise optical alignment, as this strongly affects image quality and resolution. Another advantage is that this solution is not restricted to THz sensors of this type; it can be extended to other types of planar technology-based detectors as well.
More information: "On-chip integration of laser-ablated zone plates for detection enhancement of InGaAs bow-tie terahertz detectors" L. Minkevičius, et al. Electronics Letters, Volume 50, Issue 19, 11 September 2014, p. 1367 – 1369 DOI:  10.1049/el.2014.1893