Friday, 23 December 2011

Multiferroic transition-metal oxides: Analysis of the polar groundstates by dielectric spectroscopy

Source:(2011) Auch gedruckt erschienen: ISBN 978-3-86664-977-4
Dokument 1.pdf (5.469 KB)
PhD Thesis, work carried out using TeraView's Spectra 3000

Transition-metal oxides show a broad spectrum of fascinating physical effects. Among these, materials with multiferroic properties play a prominent role in basic research and technical application.

The present work deals with several multiferroic compounds and the origins of their polar orders. LiCuVO4 and the rare-earth manganites RMnO3 show a polar order due to a complex magnetic structure. By measurements of polarisation in external magnetic fields, the relation between magnetic and polar order in LiCuVO4 is analysed. Dielectric spectroscopy reveals a relaxation process as key to the magnetocapacitive effects in the rare-earth manganites. Magnetite, which shows relaxorferroelectricity, is a system where the polar order is connected to the charge order of the system.

in German

Institute:Physics/ Materials Science
Faculty:Faculty of Mathematics and Natural Sciences
Dewey Decimal Classification:Physics
Document type:Dissertation
Advisor:Loidl, Alois (Prof. Dr.)
Date of examination:17.05.2011
Year of creation:2011
Date of publication:22.07.2011

Wednesday, 21 December 2011

Maskless multiple-beam laser lithography for large-area nanostructure/microstructure fabrication

Applied Optics, Vol. 50, Issue 35, pp. 6536-6542 (2011)


This paper reports a maskless multiple-beam laser lithography technique for large-area nanostructure/microstructure fabrication. This lithography technique can flexibly generate arbitrary nanostructures/microstructures over a large area at a high speed. The feature size of the nanostructures/microstructures can be controlled by exposure time and moving speed of the nanostage. Functional predesigned patterns, including split-ring resonator metamaterials for terahertz waves, can be obtained. More complicated structures can be made by single- and double-exposure schemes to make hybrid nanostructures/microstructures and tune surface plasmonic resonance properties. Meanwhile, microstructures with large height to lateral dimension ratios (2.5D microstructures) fabricated on silicon substrates can be used as mold tools for soft lithography. This technology shows its unique capacity to create various nanostructures/microstructures for extensive applications.

Measurements were performed using TeraView's TPS Spectra 3000 
... The line width of the SRR structure is 6μm, and the SRR dimension is 40μm. The trans-
mission spectra of the terahertz metamaterials are characterized by a terahertz time-domain
spectro- scope (TeraView, TPS3000) with a normal incident ...

Min Tang, Zai Chun Chen, Zhi Qiang Huang, Yoo Sang Choo, and Ming Hui Hong, "Maskless multiple-beam laser lithography for large-area nanostructure/microstructure fabrication," Appl. Opt. 50, 6536-6542 (2011)

Tuesday, 13 December 2011


Journal of Molecular Structure
Volume 1006, Issues 1-3, 14 December 2011, Pages 66-76 STRUCTURAL APPLICATIONS OF TERAHERTZ SPECTROSCOPY

doi:10.1016/j.molstruc.2011.05.048 | How to Cite or Link Using DOI
  Permissions & Reprints

Terahertz spectroscopy: Its future role in medical diagnoses Edward Philip John Parrott a, Yiwen Sun a, 1, Emma Pickwell-MacPherson b, ,

a     Electronic Engineering Department, The Chinese University of Hong Kong, New Territories, Hong Kong
b     Electronic & Computer Engineering, The Hong Kong University of Science & Technology, Clear Water Bay, Hong Kong
Available online 13 June 2011.

Over the past two decades, terahertz radiation has received a lot of interest due to advances in emission and detection technologies in the late 1980s and early 1990s which allowed the construction of coherent source/detection regimes. This paper focuses on reviewing the use of terahertz radiation in the investigation and understanding of biological systems and medical diagnosis. In particular, research on terahertz spectroscopy of biomolecules, from amino acids to proteins is presented, and examples of potential medical applications are discussed.

Principles of terahertz spectroscopy. Properties of terahertz light. Time and frequency domain analysis of terahertz data. Molecular and medical terahertz spectroscopy.

Keywords: Terahertz imaging; Terahertz spectroscopy; Protein spectroscopy; Biomedical; Intermolecular interactions; Cancer

Article Outline
1. Introduction to terahertz radiation
1.1. Generation and detection of broadband pulses of terahertz radiation 1.2. Time-domain analysis 1.3. Frequency-domain analysis 1.4. Introduction to intermolecular interactions 2. Molecular spectroscopy 2.1. Introduction 2.2. Amino acids and peptides 2.3. Deoxyribonucleic acid (DNA) 2.4. Proteins 3. Medical spectroscopy 3.1. Understanding contrast 3.2. Enhancing contrast 3.3. Other medical applications 4. Summary Acknowledgments References

Corresponding author. Tel.: +852 2358 5034.

1Present address: Medical School, Shenzhen University, Guangdong, 518060, People’s Republic of China.

Friday, 9 December 2011

First Sale in Russia for TeraView

TeraView (, the pioneer and leader in Terahertz technology, along with its distributor in the region, Bruker Optics (,  has just delivered and installed its first instrument in the Russian Federation at the Russian Academy of Sciences,  Institute of Cell biology (ICB RAS).
ICB was formed in 1990 under the prestigious umbrella of the Russian Academy of Sciences and performs studies in to the biophysics of cell function. The terahertz instrument will perform research intermolecular interactions and hydrogen bonding in cells structures in vitro.
The sale adds to TeraView’s growing installed base worldwide, and helps strengthen its position into an expanding research market in Russia.
Dr Don Arnone, TeraView’s CEO stated ‘Yet another sale of the TPS spectra 3000 adds to the growing list of prestigious academic institutes choosing our equipment and is an important first sale into the Russian academic market. We are hopeful it will lead to more users in the region”.

About Terahertz

Terahertz waves sit in the spectrum between Infrared and Microwave and as such have unique properties which enables them to pass through/into objects, and whilst so doing to transmit images and spectra which provide unique information in a safe, fast and non destructive manner.

Thursday, 1 December 2011

Collective Mode Frequency Shifts in L-Serine and a Series of Isotopologues in the Terahertz Regime

by: David C. Hufnagle, Anita R. Taulbee-Combs, Wolfgang U. Spendel, Gilbert E. Pacey


Terahertz (THz) time-domain spectroscopy was used to monitor collective mode shifts in L-serine, L-serine-2,3,3-d3, L-serine-d4, and L-serine-d7 at both room and liquid nitrogen (LN2) temperatures. Increasing the molecular mass by deuteration caused an expected absorbance red-shift; however, the magnitude of the displacement could not be predicted using normal mode analysis. Both modes at 67.8 cm−1 and 91.4 cm−1 demonstrated a greater peak shift upon deuterium substitution at non-hydrogen bonding sites than at sites that participated in hydrogen bonding. This is evident in the larger peak shifts observed in L-serine-d3 than in L-serine-d4, despite a smaller increase in mass. This leads to the conclusion that both peaks present in the room temperature spectra of L-serine likely arise primarily from other intermolecular interactions with <50% contribution from hydrogen bonding. This goes against the prediction that peaks in the THz spectra of amino acids are predominantly due to the hydrogen bonding network that makes up the crystal lattice.

View Abstract

Wednesday, 23 November 2011



AIP Conf. Proc. -- June 23, 2011 -- Volume 1335, pp. 533-540

Issue Date: 23 June 2011

David K. HsuKwang-Hee ImChien-Ping Chiou, and Daniel J. Barnard
Center for Nondestructive Evaluation, Iowa State University, Ames, Iowa 50011

We report an investigation of terahertz waves for the nondestructive evaluation of composite materials and structures. The modalities of the terahertz radiation used were time domain spectroscopy (TDS) and continuous wave (CW). The composite materials and structures investigated include both non-conducting polymeric composites and carbon fiber composites. Terahertz signals in the TDS mode resembles that of ultrasound; however, unlike ultrasound, a terahertz pulse can detect a crack hidden behind a larger crack. This was demonstrated in thick GFRP laminates containing double saw slots. In carbon composites the penetration of terahertz waves is quite limited and the detection of flaws is strongly affected by the angle between the electric field vector of the terahertz waves and the intervening fiber directions. The structures tested in this study include both solid laminates and honeycomb sandwiches. The defects and anomalies investigated by terahertz waves were foreign material inclusions, simulated disbond and delamination, mechanical impact damage, heat damage, and water or hydraulic fluid ingression. The effectiveness and limitations of terahertz radiation for the NDE of composites are discussed. ©2011 American Institute of Physics

View abstract online

Friday, 18 November 2011

Explosives characterization in terahertz range (Proceedings Paper)

Author(s): I. Maestrojuán; I. Palacios; D. Etayo; J. C. Iriarte; J. Teniente; I. Ederra; R. Gonzalo
Date: 13 October 2011

Paper Abstract

A Thz spectral characterization of the behaviour of different explosives is presented in this paper. This characterization will be done in the frequency range from 20 GHz to 4 THz using a Teraview Spectra 3000. This system has a capacity of measuring from 20 GHz to 4 THz fed by a laser source. With the Teraview Spectra 3000 equipment will be possible to calculate the refractive index, the absorbance and other important parameters of the explosive samples. With this study it will be possible to characterize some of the most common used explosives, i.e., gun explosive, gunpowder mine, pent, TNT, RDX, etc, and it will allow to determine their electromagnetic peculiarities in order to design a future imaging system that allow detecting them in security and defense sectors.

Millimetre Wave and Terahertz Sensors and Technology IV, Keith A. Krapels;Neil A. SalmonEddie Jacobs, Editors, 81880N

DOI: 10.1117/12.898152

Thursday, 3 November 2011

Terahertz Time-Domain Spectroscopy of Solid Samples: Principles, Applications, and Challenges

... Different ranges are specified in both the peer-reviewed literature (2–4) and documentation from instrument vendors (55. TeraView. “Terahertz radiation”. Available at:

Ryan M. Smitha & Mark A. Arnolda
pages 636-679
Available online: 07 Oct 2011


Advances in ultrafast lasers and semiconductor technologies have facilitated access to the terahertz (THz) frequency range for spectroscopic and imaging purposes. THz time-domain spectroscopy (TDS) is commonly used to acquire spectral data having high signal-to-noise ratios (SNRs) over a broad range of THz frequencies. THz-TDS instrumentation is commercially available, thereby enabling novel applications of THz time-domain (TD) imaging and spectroscopy in a myriad of applications. This review gives a general description of the instrumentation available for collecting THz-TD data and focuses on measurements of solid samples. Measurement geometries useful for collecting THz-TD data from solid samples are reviewed and a summary is presented of the major applications to the analysis of solid samples related to security issues, as well as samples originating from the pharmaceutical industry, dental sciences, biological samples, and polymer materials. Emphasis is also given to analytical applications in a discussion of the analytical challenges met in quantification of solid analytes by THz-TDS methods.

To read more about this review:

for more information about  the Spectra 3000 spectrometer click here

Friday, 28 October 2011


Progress In Electromagnetics Research M, Vol. 21, 93-104, 2011

C. Morari*, I. Balan, J. Pintea, E. Chitanu, and I. Iordache

*National Institute for Research and Development in Electrical
Engineering ICPE-CA, Splaiul Unirii, No. 313, Bucharest 030138,

Abstract   There is increasing interest in electromagnetic interference
(EMI) shielding due to the serious electromagnetic environment
pollution caused by the continuously increased use of the electrical
products and electronic devices. Electrical conductivity and EMI
shielding effectiveness (SE) of composite materials made from silicone
rubber with carbon powder and ferrite powder have been studied
in microwaves and terahertz frequency ranges and the results are
presented in this paper. In microwaves range, samples with higher
electrical conductivity show a small variation of shielding performance
with frequency, whereas the performance of samples with lower
conductivity falls away with increasing frequency. It is shown that
the variation of attenuation with frequency relates to the conductivity
of the material

... The samples were then studied in the 0.06–3THz (2–100cm−1) frequency range using the TeraView TPS spectra 3000terahertz transmission spectrometer. First, a reference spectrum was acquired with no sample mounted on the sample holder. ...

If you would like to read more about this article please click here

Monday, 17 October 2011

Our second International Terahertz Hands-on Workshop has been a great success!

Last week we held the second International Terahertz Hands-on workshop. Everybody enjoyed the workshop, while learning about terahertz applications and technology. 

Thank you for all your positive feedback!

After great demand, we have decided to hold a third International Terahertz Workshop in Spring 2012, if you would like to express your interest in participating to it please contact us through our website at or writing an email to

Below are some pictures from last week's workshop.

Thank you all for reading our news on this blog!

Thursday, 13 October 2011

Terahertz pulsed imaging in vivo: measurements and processing methods

J. Biomed. Opt. 16, 106010 (Oct 03, 2011); doi:10.1117/1.3642002

Edward P. J. ParrottStanley M. Y. Sy, and Thierry Blu
Chinese University of Hong Kong, Department of Electronic Engineering, Shatin, Hong Kong
Vincent P. Wallace
University of Western Australia, School of Physics, Perth, WA 6009, Australia
Emma Pickwell-MacPherson
The Hong Kong University of Science & Technology, Electronic and Computer Engineering, Clearwater Bay, Hong Kong

This paper presents a number of data processing algorithms developed to improve the accuracy of results derived from datasets acquired by a recently designed terahertz handheld probe. These techniques include a baseline subtraction algorithm and a number of algorithms to extract the sample impulse response: double Gaussian inverse filtering, frequency-wavelet domain deconvolution, and sparse deconvolution. In vivo measurements of human skin are used as examples, and a comparison is made of the terahertz impulse response from a number of different skin positions. The algorithms presented enables both the spectroscopic and time domain properties of samples measured in reflection geometry to be better determined compared to previous calculation methods.

Note from the editor:
The hand-held probe that was used in the Hong Kong University of Science and Technology is designed by TeraView Ltd, just another demonstration of TeraView's worldwide install base!

....As a result, in vivo imaging is performed in reflection geometry. Since skin is the most easily
accessible organ of the body, we have been using it to conduct in vivo experiments with
a handheld probe designed by Teraview Ltd (Cambridge, UK). ...

View more on this article

Thursday, 6 October 2011

2nd International Workshop - spaces now full

Our 2nd International Workshop will be taking place next week!
This particular one is fully booked, but given the interest, we are planning a third one in Europe!
This will take place most likely in Cambridge - UK in Spring 2012.

If you are interested in possibly taking part in the workshop, drop us an email at

We look forward to hearing from you.

For more infromation on the workshop follow the link on our website.

Tuesday, 4 October 2011

THz Reflection Spectroscopy of Explosives Measured by Time Domain Spectroscopy


N. Palka

Institute of Optoelectronics, Military University of Technology
S. Kaliskiego 2, 00-908 Warsaw, Poland


Reflection spectra of pure explosive materials and their simulants were measured in transmission and reflection by means of time domain spectroscopy in the range 0.1–3 THz. Spectra measured in two reflection configurations:
specular with incident angle equal to 45 degrees and stand-off with close to normal incidence and distance 30 and 40 cm. to a sample.

Spectra were acquired using commercial time domain spectroscopy (TDS) setup from TeraView (TPS Spectra 3000) with appropriate accessories in atmosphere with humidity less than 1%.

To read more about this article follow this link:

Friday, 30 September 2011

International THz Conference - November 24-25, 2011 – Villach, Austria

In recent years the technology enabling terahertz imaging and spectroscopy has progressed remarkably. Techniques that were previously confined to the laboratory are now finding applications in industry.
The International Terahertz Conference will bring together experts in the development of Terahertz techniques, as well as those applying the technology to industrial applications.

The conference will focus on recent advances in the generation and detection of Terahertz radiation as well as its use for imaging, spectroscopy and industrial applications. At the International Terahertz Conferenceyou will have the opportunity to meet and talk with leading experts in the field. If you have already a particular application in mind we could discuss this prior the conference.

We look forward to your visit, because
„what is to change the world tomorrow, has to be developed today“

International THz Conference -November 24-25, 2011 – Villach, Austria

Friday, 23 September 2011


AIP Conf. Proc. -- June 23, 2011 -- Volume 1335, pp. 581-588

Issue Date: 23 June 2011
Chien-Ping Chiou, David K. Hsu, Dan Barnard, Kwang-Hee Im, and R. Bruce Thompson
Center for Nondestructive Evaluation, Iowa State University, Ames, Iowa 50011
Terahertz radiation (a.k.a. T-ray) has emerged as a powerful inspection technique in recent years. It extends into the lower region of far-infrared in the electromagnetic spectrum, and has been proven very effective in many NDE applications. T-ray is particularly useful insome areas where accessibility is difficult or even not possible for other conventional NDE methods. Here we report a modeling effort of T-ray signal in one such application: the detection of “hidden delamination”, a special situation that a delamination was shadowed by another. This special case was experimentally simulated by two parallel saw-cuts in glass composites. In this paper, we also explore the feasibility of combing T-ray and Fourier transform infrared spectroscopy using a unified least-squares scheme for material characterization. ©2011 American Institute of Physics

Monday, 12 September 2011

Understanding the terahertz spectra of crystalline pharmaceuticals: Terahertz spectroscopy and solid-state density functional theory study of (S)-(+)-ibuprofen and (RS)-ibuprofen

Journal of Pharmaceutical Sciences

Journal of Pharmaceutical Sciences

Matthew D. King,William D. Buchanan,Timothy M. Korter

Article first published online: 2 SEP 2010

Timothy M. Korter
Article first published online: 2 SEP 2010


The potential applications of terahertz (THz) spectroscopy in the analysis of pharmaceutical products in their crystalline state have prompted the need for a more thorough understanding of the fundamental vibrational motions contributing to the THz spectra. The detection of variations in crystal structure and the reliable assignment of observed THz absorption features can be aided by the use of solid-state density functional theory (DFT). In this study, solid-state DFT with periodic boundary conditions was used to simulate the crystalline structure and assign the experimental THz spectra (10–90 cm−1) of the enantiomerically pure and racemic forms of the common pharmaceutical compound ibuprofen. The results clearly demonstrate the capabilities of DFT methodologies to accurately reproduce the THz spectra of large complicated molecular systems and provide insight into the internal and external vibrational motions that form the basis of THz spectroscopy. © 2010 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 100:1116–1129, 2011

Wednesday, 7 September 2011

3D THz Imaging of Heritage Objects

Dr. Gianluca Pastorelli from University College London, in collaboration with TeraView Ltd., is giving a talk at Lacona IX concference on 3D THz imaging of Heritage Objects. The talk will be given at the British Museum, London, at 12.50 on Friday 9th of September.
All measurements on heritage objects analysed were done at TeraView Ltd. using a Spectra3000.
More information on the conference schedule can be found here.

Summary of paper  "3D THZ Imaging of Heritage Objects"
7th September 2011

In the past few years, the way for Terahertz (THZ) technology into heritage science and conservation has been paved slowly but securely [1]. THZ radiation occupies the band between far-IR and microwaves (100 µm – 1 mm ~ 0.3 – 3 THz) and its recent advance is related to development of the necessary radiation sources and detectors.

The particular advantage of THZ radiation in comparison to other optical techniques is that it induces interactions between large molecules thus rendering itself particularly suitable for characterisation of macromolecular and supramolecular structures. THZ spectroscopy has been used for determination of glass transition temperature of polymers [2], has recently been shown to contain quantitative chemical information on polymeric materials [3] and spectral libraries have been built of a number of historically significant pigments [1].
In this work, we present a state-of-the-art THZ pulsed semiconductor-based imaging system developed specifically to monitor the thickness, uniformity and density of laminar and coated structures and to identify structural features such as cracks, dislocations and delaminations [4]. The emitter and receiver are based on a femtosecond pulsed laser system working in the range of 0.06 THz – 3 THz. The resolution of the system depends on the wavelength employed, and is typically in the range of several 10 µm.
The system operates on the principle of reflection of THZ pulses on (subsurface) phase boundaries, i.e. boundaries between materials with different refractive indices. Since both the emitter and the detector can be moved across a sample in the x-y direction, a 3D image of an object can be obtained.
Several case studies were selected to explore the capabilities of 3D THZ imaging, particularly plastic heritage objects. Using a degraded cellulose acetate (CA) negative, it was possible to image the typical delaminations observed as a consequence of advancing degradation. On other types of CA objects, depth distribution of cracks can be observed very effectively, while on polyurethane foam objects, the degradation process can be followed by imaging the cell shape and structure.
Due to its properties, combining a significant depth of penetration into opaque organic materials with a significant amount of chemical information, THZ imaging could significantly improve the present practice of structural and chemical monitoring of heritage objects of organic origin.

1. K. Fukunaga: Innovative Terahertz Spectroscopy and Imaging Technique for Art Conservation Science, e-Cons. Mag. no. 10, 2009, 30-42.
2. C. Jansen, S. Wietzke, O. Peters, M. Scheller, N. Vieweg, M. Salhi, N. Krumbholz, C. Jördens, T. Hochrein, M. Koch: Terahertz imaging: applications and perspectives, Appl. Opt. 49, 2010, E48-E57.
3. T. Trafela, M. Mizuno, K. Fukunaga, M. Strlič: THZ spectroscopy and chemometrics for quantitative characterisation of historic paper, LACONA IX, 2011.
4. L. Ho, R. Muller, K. C. Gordon, P. Kleinebudde, M. Pepper, T. Rades, Y. Shen, P. F. Taday, J. A. Zeitler: Monitoring the Film Coating Unit Operation and Predicting Drug Dissolution Using Terahertz Pulsed Imaging, J. Pharm. Sci. 98 (2009) 4866-4876.

Thursday, 1 September 2011

Fault isolation in semiconductor product, process, physical and package failure analysis: Importance and overview

citation from paper:
"... Recently TeraView together with an industry partner developed a Terahertz “TDR” called the Electro Optical Terahertz Pulsed Reflectometry (EOTPR) promising resolution of <10 μm....The EOTPR application on the real failure unit was presented at Electronic Components and Technology Conference (ECTC), 2010, and one of the case studies showed that the conventional TDR analysis was not able to isolate the defect, but with EOTPR, there was a difference between the waveform of the passing and failing unit..."

Fault isolation in semiconductor product, process, physical and package failure analysis: Importance and overview

JM Chin, V Narang, X Zhao, MY Tay, A Phoa… - Microelectronics Reliability, 2011

Jiann Min Chin, a, , Vinod Naranga, Xiaole Zhaoa, Meng Yeow Taya, Angeline Phoaa, Venkat Ravikumara, Lwin Hnin Eia, Soon Huat Lima, Chea Wei Teoa, Syahirah Zulkiflia, Mei Chyn Onga and Ming Chuan Tana
a Advanced Micro Devices Singapore, 508 Chai Chee Lane, Singapore 469032, Singapore
Received 29 June 2011;  
accepted 30 June 2011.  
Available online 9 August 2011. 

a Advanced Micro Devices Singapore, 508 Chai Chee Lane, Singapore 469032, Singapore
Received 29 June 2011;  
accepted 30 June 2011.  
Available online 9 August 2011.


Failure analysis plays a major role in all areas of the semiconductor company especially during product development cycle, 1st silicon stage, or in wafer processes and fabrication as well as assembly and package development. Different companies have different FA flows but all FA steps will need to start with fault isolation. Fault isolation is the step to narrow down the focus area of a failing component or product to a manageable area that will allow us to (a) improve success of finding the defect that is causing the failure and, (b) significant speed up turn-around time for analysis.

This paper provides an overview of all the available failure analysis on fault isolation methodologies and tools, for device/product level and expanding to package/assembly and PFA level isolation. The aim of the paper is to provide sufficient depth to each topic including some case studies to emphasize the key points related to each methodology. The tutorial will also cover some future directions/roadmaps.