Terahertz frequency-wavelet domain deconvolution for stratigraphic and subsurface investigation of art painting

Junliang Dong ; J. Bianca Jackson ; Marcello Melis ; David Giovanacci ; Gillian C. Walker ; Alexandre Locquet ; John W. Bowen, and D. S. Citrin

Abstract:

Terahertz frequency-wavelet deconvolution is utilized specifically for the stratigraphic and subsurface investigation of art paintings with terahertz reflective imaging. In order to resolve the optically thin paint layers, a deconvolution technique is enhanced by the combination of frequency-domain filtering and stationary wavelet shrinkage, and applied to investigate a mid-20th century Italian oil painting on paperboard, After Fishing, by Ausonio Tanda. Based on the deconvolved terahertz data, the stratigraphy of the painting including the paint layers is reconstructed and subsurface features are clearly revealed, demonstrating that terahertz frequency-wavelet deconvolution can be an effective tool to characterize stratified systems with optically thin layers.

Full article here.

Double Fano resonance with externally driven subradiant mode

Y.U. Lee ; J.W. Wu

Abstract:

In this study, we observe that a dark mode is not necessarily prerequisite for an asymmetric Fano resonance to take place in plasmonic structures. The characteristic asymmetry feature of Fano resonance is retained in a plasmonic structure when both superradiant and subradiant oscillators are externally driven. Double Fano resonances are experimentally and theoretically observed where a common subradiant driven oscillator is coupled with two superradiant oscillators. As a classical analogue of a four-level tripod atomic system, the extinction spectrum of the composite metamaterial exhibits a coherent effect based on double Fano resonances. Transfer of the absorbed power between two orthogonal superradiant oscillators is shown to be mediated by the common subradiant oscillator.

Full article available here.

Identification of traditional Chinese medicines by using terahertz time-domain spectroscopy

Jun Zhou

Abstract:

Terahertz time-domain spectroscopy (THz-TDS) has been applied to the identification of traditional Chinese medicines. It was found that THz-TDS combined with chemometrics can be used to identify traditional Chinese medicines very well.

Full article available here.

THz spatial filter integrating bimaterial switching for sensors

Varittha Sanphuang ;  Niru K. Nahar ;  John L. Volakis

Abstract:

We propose a THz spatial filter using frequency selective surfaces (FSS) integrated with bimaterial actuator for switching. The actuator consists of two materials that have different thermal expansion rates and can be designed based on temperature tuning. The goal for this design is to develop high performance reconfigurable filters operating in the THz band. The filter was fabricated using gold as filter pattern on silicon substrate. SiO2 and Al were used as bimaterial actuators. Simulations show excellent transmittance (>80%). Allowing different gap of the actuator (up and down), the peak frequency can vary from 0.35 to 0.37 THz.

Full article available here.

Pharmaceutical applications of terahertz spectroscopy and imaging

Daniel Markl ; Michael T. Ruggiero and J. Axel Zeitler

Terahertz spectroscopy and imaging techniques have advanced the chemical and physical characterisation of active pharmaceutical ingredients (APIs), excipients and final solid dosage forms. Terahertz radiation can be used to investigate both chemical and solid structures, as well as provide information on the bulk morphology of pharmaceutical materials. The penetrating and non-destructive properties of terahertz light, coupled with its high acquisition rate, makes this technology a promising candidate for process analytical technology (PAT) applications.

Terahertz radiation corresponds to frequencies between the microwave and infrared regions of the electromagnetic spectrum (300 GHz to 10 THz, or wavelengths of 1mm to 1μm). For many years the terahertz region had been referred to as the ‘terahertz gap’ because of the difficulties in generating and detecting terahertz light. This has changed over the past few decades due to major advances that have brought down costs and instrument size, from $500,000+ laser systems that can take up an entire laboratory space to sub-$100,000 benchtop – and even hand-held – devices. Such breakthroughs have brought terahertz techniques into the mainstream and have enabled terahertz technologies to be implemented in industrial settings.

The full article can be accessed here (subscription required): link
 

New Imaging Spectroscopy Facility at UWA

Professor Vincent Wallace

The University of Western Australia’s Physics Department boasts a new imaging and spectroscopy facility that has the potential to transform crude oil production and refinery processes.

Cutting edge technology is a priority for oil and gas companies who face an increasingly competitive market and are looking for an edge that makes them stand out against the rest.

At UWA our scientists are working with new technologies that will revolutionise the industry and add value to a company’s bottom line through improved productivity.

One such technology is a state-of-the-art terahertz (THz) imaging and spectroscopy system, the TeraPulse 4000, that has just been installed in the School of Physics and is the first of its kind in WA.

UWA’s Associate Professor Vincent Wallace is the co-inventor on several patents relating to THz technologies and he expands on why this technology is a novel tool for industry:

“For the oil and gas, and resources industry, THz spectroscopy provides the capability to understand numerous problems like water content and crude oil viscosity.”

"THz spectroscopy is ideally suited for probing intermolecular interactions and low-energy vibrational, rotational and librational modes of various components of crude oil and the aggregation of certain compounds like asphaltenes."

“Asphaltenes are heavy, polar aromatic molecules found in crude oils that due to aggregation increases its viscosity and thus make it more difficult to extract. Typically, solvents like toluene or benzene are used to dissolve these compounds but there is a lack of understanding as to why they form in the first place.”

 “It is this type of problem that I am looking to engage with industry and solve, using this cutting edge technology. By understanding why asphatelenes form, it will provide us the key to removing them prior to or during extraction and potentially transforming production quality.”

Full article here.

TeraView at SEMICON Taiwan

TeraView will be exhibiting at this year's SEMICON Taiwan. The event will take place between September 7-9 in Taipei, Taiwan.

We will be showcasing our latest product, the EOTPR 5000.

"TeraView’s proprietary Electro Optical Terahertz Pulse Reflectometry (EOTPR) technology provides a 5 micron resolution capability in isolating faults within advanced integrated circuits for mobile phones and computing, including complex packages such as Package on Package (PoP), flip chip, and 3D package with Through Silicon Vias (TSVs). EOTPR has been widely accepted by advanced IC package failure analysis community, and this technology is ready to be deployed in the high volume manufacturing environment for quality assurance inspection."

For further information on the event, please visit the webpage here.

 

TeraView is recruiting

FIELD SERVICE ENGINEER

TeraView Ltd is the world’s first and leading provider of terahertz solutions to Fortune 500 companies, in a variety of industries. TeraView was created in 2001 from a relationship between the Toshiba Corporation and the Cavendish Laboratory at the University of Cambridge. TeraView’s vision is to establish terahertz as the premier imaging and inspection tool for the 21st century.

An opportunity has arisen for a Field Service Engineer to join TeraView’s Service Team to service and support TeraView’s systems, both in the field and in house. You will have a minimum of 3 years experience of working in a field service role, gained within a scientific instrumentation/equipment environment, and be familiar with the set up and alignment of optical instrumentation. Qualified to a minimum of HNC level or above in electronics or other relevant technical discipline, you will be a self- starter with a positive attitude and a proven ability to work in small multi-disciplinary teams. The role entails a significant level of overseas travel, sometimes with little notice. Experience of working within a formal quality system, such as ISO9001 is important.

Key Tasks And Responsibilities Profile, Skills, Experience & Characteristics Required

•     Servicing and maintaining instruments both in the field and in-house.
•     Alignment of newly built instruments.
•     Factory Acceptance testing.
•     Assisting in the build of instruments.
•     Installation and Site acceptance testing. 

Profile, Skills, Experience & Characteristics Required

The ideal candidate will possess:

• HNC or above in electronics or similar technical discipline.
• Previous experience of working in service/support of scientific instrumentation.
• Knowledge of lasers and alignment.
• Knowledge of electronics.
• Excellent customer facing skills.
• Excellent technical communication skills both written and oral.
• The ability to work alone and on own initiative.
• Ability to travel abroad and at short notice.
• Own transport and a clean driving licence.
• Experience in the any of the following areas is desirable but is not required: spectroscopy, semiconductor or semiconductor equipment industry, semiconductor failure analysis, GHz TDR, and terahertz systems.

Further Information
The job location is Cambridge, UK but the successful candidate will be expected to spend up to 50% of their time at customer locations around the world. To apply for this vacancy, please send your CV together with a covering letter which should give details of your current remuneration and examples of where and how you have applied your skills in previous working environments. The letter should also highlight how your skills could be used within TeraView. These should be sent to: support@teraview.com

TeraView offers an excellent salary and benefits package, along with the opportunity for highly- motivated staff to work together in a friendly, intellectually stimulating and challenging environment where there is plenty of scope to influence and shape the development of products in one of the newest, and most exciting, areas of technology.

We are an equal opportunities employer and pride ourselves on our diverse workforce. For further information and background on the company, please visit our website on: www.teraview.com

EOTPR 5000 launches at SEMICON West, USA.

This year's SEMICON West event in San Francisco saw the launch of our fully automated integrated circuit (IC) package inspection system, the EOTPR 5000.

Building on the success of the EOTPR 2000 which has an established track record in the industry for rapid fault isolation and manual inspection, the EOTPR 5000 is a fully automated advanced IC package inspection system that utilizes TeraView’s proprietary EOTPR terahertz technology to detect weak or marginal interconnect quality in high volume manufacturing environments, which no other technology can detect today.

Don Arnone, TeraView CEO, spoke to Philip Stoten of EMSNowTV (above) to discuss what drove the technology and how it is currently being deployed.

THz Beam Shaping Based on Paper Diffractive Optics

Agnieszka Siemion ; Andrzej Siemion ; Jaroslaw Suszek ; Adam Kowalczyk ; Jaroslaw Bomba ; Artur Sobczyk ; Norbert Palka ; Przemysław Zagrajek ; Andrzej Kolodziejczyk ; Maciej Sypek

Abstract:

Fast and intensive development of terahertz (THz) technology requires designing dedicated optical elements. Here, we generated complicated THz field distribution thanks to simple binary diffractive optical elements (DOEs) made from paper. The paper fabricated structures are lightweight, inexpensive, feasible for fast-prototyping purposes and they have high transparency in the THz range. Structures were designed and simulated in nonparaxial approach which suppresses the influence of geometrical aberrations and enables large apertures in comparison with their focal lengths. Such DOEs can be used in THz tomography, scanners, radiation sources collimation, focusing and gathering the radiation on the detector.

Full article available here.

Analysis of Wire-Grid Polarisers in Terahertz Spectral Range

Mičica ; Martin ; Bucko ; Václav ; Postava ; Kamil ; Vanwolleghem ; Mathias ; Lampin ; Jean-François ; Pištora ; Jaromír

Abstract:

Polarisers are important components in many optical applications working with polarised radiation, therefore it is need to know their behaviour at specified spectral range. Interest in terahertz (THz) radiation and its application in science, where we need polarisers was our motivation for study of commonly used polarisers this spectral range. In our paper we present THz measurement of free standing wire-grid (5 μm tungsten wire, 12.5 μm period) and polyethylene foil wire-grid (0.5 μm metallic stripes, 1.2 μm period) polariser.

Measurements were performed by terahertz time domain spectroscopy in the range from 60 GHz to 3 THz (2–100 cm−1) at different rotation of azimuth angle. For quality evaluation was from measured data calculated extinction ratio and phase shift. Both polarisers were compared and their suitability for THz application is discussed. Results show better properties of free standing wire-grid polariser in the range up to 60 cm−1 while properties of polyethylene polariser are better at higher wavenumbers. Polarisers are described in the frame of Jones matrix calculus.

Full article available here.

Moisture contamination detection in adhesive bond using embedded FBG sensors

Magdalena Mieloszyka ; Wiesław Ostachowicza

Abstract:

The paper presents an application of embedded fibre Bragg grating (FBG) sensors for moisture contamination detection in an adhesive bond between two composite elements. FBG sensors are a great tool to Structural Health Monitoring of composite structures due to their high corrosion resistance as well as their small size and weight. Adhesive bonds are very popular in many industrial branches. One of the major problem limits the use of an adhesive joints is they sensitivity on water form ambient. Even the 1% of moisture affects an adhesive bond layer strength. FBG sensors can be use for detection of even a small amount of moisture concentration (1–3% of sample weight). It can be also used for determination of moisture concentration changes during both soaking and drying processes.

Full article available here.

Effect of swelling of a photoresist on electromagnetic resonance of terahertz metamaterials

Wei-Fan Chiang ; Yu-Ting Hsieh ; Song-Hang Wang ; Hsin-Yuan Miao ; Jih-Hsin Liu ; and Chia-Yi Huang

Abstract:

This work uses isopropyl alcohol (IPA) to develop a photoresist. IPA dissolves the photoresist that is not exposed to UV light, and swells the photoresist that is exposed to UV light. The swelling of the photoresist distorts the split-ring resonators (SRRs). The distorted SRRs have a larger loop length, smaller line width, and smaller split gap than undistorted SRRs. The change in the dimensions of the SRRs is caused by the extension of the SRR arms in their longitudinal directions. The resonance frequency of the distorted SRRs is smaller than that of the undistorted SRRs, and the resonance frequency decreases with the development time.

The resonance frequency of the distorted SRRs depends on not only their dimensions, but also the bending of their arms. The distorted SRRs in this work have a frequency tuning range with a maximum width of 0.13 THz. The method that is proposed herein uses IPA to fabricate passively tunable terahertz metamaterials, which exhibit the advantages of high reliability, low cost, and ease of fabrication.

Full article available here.

Bow-Tie Plasmonic Arrays Loaded with Graphene for the Fast Room Temperature Detection of Terahertz Quantum Cascade Lasers

Riccardo Degl'Innocenti ; Long Xiao ; David Jessop ; Stephen Kindness ; Christian W. Sol ; Yuan Ren ; Hungyen Lin ; Axel J. Zeitler ; Philipp Braeuninger-Weimer ; Stephan Hofmann ; Harvey Beere ; David Ritchie

Abstract:

We present a fast room temperature terahertz detector based on interdigitated bow-tie antennas asymmetrically doping and contacting graphene. The device was tested with a 2 THz quantum cascade laser yielding a responsivity of 0.5 μAW^-1.

Full article available here.

Studying the Kinetics of n-Butyl-Cyanoacrylate Tissue Adhesive and Its Oily Mixtures

Marie Nedvedova ; Vojtech Kresalek, ; Hana Vaskova ; Ivo Provaznik

Abstract:

This study deals with the measurement of the kinetics of tissue adhesives used for supporting the hemostasis and wound closure during surgical intervention. There are available several types of adhesives of different composition which is closely related with their application. When selecting an appropriate adhesive, the time of curing could play an important role because some applications may require very fast polymerization for prompt vessel or wound closure; conversely, some situations need slower solidification because of longer manipulation with the glue during surgery.

The terahertz time-domain spectroscopy is used for studying the kinetics of the n-butyl-cyanoacrylate glue in this study. An oily substance is added to the glue samples to slow the reaction rate. The technique of attenuated total reflection is used in this application; the defined amount of glue sample or its mixture is applied on the silicon crystal and the terahertz response is measured in time. This time dependences are analyzed to find time constants for mathematical description of the glue kinetics. Further, the investigated samples were analyzed using light microscopy and Raman spectroscopy for description of the structures and compositions.

Full article here.

Transmission and Reflection Terahertz Spectroscopy of Insensitive Melt-Cast High-Explosive Materials

Norbert Palka, Mateusz Szala

Abstract:

Currently, artillery shells and grenades that are introduced into the market are based on melt-castable insensitive high explosives (IHEs), which do not explode while they run a risk of impact, heat or shrapnel. Particles of explosives (such as hexogen, nitroguanidine and nitrotriazolone) are suspended in different proportions in a matrix of 2.4-dinitroanisole.

In this paper, we investigated samples of commonly used IHEs: PAX-41, IMX-104 and IMX-101, whose internal structures were determined by a scanning electron microscope. Terahertz time domain spectroscopy was applied in both transmission and reflection configurations. At first, the complex refraction indices of four pure constituents creating IHEs were determined and became the basis of further calculations.

Next, the experimentally determined transmission and reflection spectra of IHEs and pure constituents were compared with theoretical considerations. The influence of the grain size of constituent material and scattering on the reflection spectra was analysed, and good agreement between the experimental and theoretical data was achieved.

Full article available here.

CLEO 2016: Terahertz Science and Technologies

TeraView's Dr Philip Taday will preside over the Terahertz Measurement Systems and Applications session at this years CLEO 2016.

The session will take place on Monday June 6th, between 8am - 10am (Meeting Room 212 B, Convention Center)

CLEO 2016 runs from the 5th to the 10th of June.

Full details of the event can be found here.

TeraView present poster at this years ETCC conference

TeraView's Dr Robert May gave a successful presentation at this years ETCC congress on our new Non-Contact, Multi-Layer Coating Thickness Sensor.

The sensor can determine the individual thickness of multiple paint layers on both metallic and non-metallic substrates and offers significant benefits over existing techniques, representing a significant leap beyond the current method of measurement for quality and process control in automotive paint application. See our product page for more information.

Thanks to all involved for putting on a great event!

Electric Properties of Graphene-Based Conductive Layers from DC Up To Terahertz Range

Pawel Kopyt ; Bartlomiej Salski ; Przemyslaw Zagrajek ; Daniel Janczak 

Abstract:

This paper describes results obtained using a hybrid measurement methodology employed to investigate electric properties of thin conductive layers based on graphene nanoplatelets in the frequency band spanning from dc up to terahertz range. As many as four different measurement methods were employed to cover the band of interest, including the terahertz time-domain spectroscopy and the Fourier-transform infrared spectroscopy besides resonator techniques applicable in the microwave band and the four-point dc technique. Raw measurement data obtained using these approaches were processed and based on the results a relationship between frequency and sheet resistance for various types of new graphene-based conductive layers was extracted. Eventually, several models that help to explain the observed behavior of each of the analyzed conductive inks were proposed.

Full article here

Electron beam irradiation of materials and components to be used in mid-IR spectroscopy

Dan Sporea ; Laura Mihai ; Adelina Sporea ; Gabriela Crăciun ; Elena Mănăilă

Abstract:

In this paper, we report the results concerning electron beam irradiation of mid-IR windows and mid-IR detectors for possible use in trace gas detection systems, in the 1 μm to 5 μm spectral range under ionizing radiation conditions. Four windows materials (CaF2, BaF2, ZnSe, and sapphire) for the mid-IR were tested as they were exposed to electron beam irradiation at a dose rate of 4 kGy/min, for doses from 0.5 kGy to 2.2 kGy.

Two IR detectors (photoconductive – PbSe, photovoltaic – InAs) were subjected to the same type of irradiation at dose rate of 4 kGy/min, in three subsequent exposures, for a total dose up to 6.8 kGy. Before the irradiation and after each irradiation step the windows were measured as it concerns the spectral optical transmittance, spectral optical diffuse reflectance, and, in the THz range (0.06 THz – 3 THz), the dielectric constant and the refractive index were evaluated. THz imaging analysis of the irradiated samples was done. For the IR detectors we measured at different irradiation stages the spectral responsivity and the dark current. The most affected by electron beam irradiation was the CaF2 window, in the spectral interval 250 nm – 800 nm.

The spectral transmittance of the four windows remained unchanged after their exposure to ionizing radiation in the near-IR and mid-IR. Noticeable variations of the spectral responsivity appeared upon electron beam irradiation in the case of the InAs detector. © (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

Link

Graphene based plasmonic terahertz amplitude modulator operating above 100 MHz

D. S. Jessop, S. J. Kindness, L. Xiao, P. Braeuninger-Weimer, H. Lin, Y. Ren, C. X. Ren, S. Hofmann, J. A. Zeitler, H. E. Beere, D. A. Ritchie and R. Degl'Innocenti

Abstract:

The terahertz (THz) region of the electromagnetic spectrum holds great potential in many fields of study, from spectroscopy to biomedical imaging, remote gas sensing, and high speed communication. To fully exploit this potential, fast optoelectronic devices such as amplitude and phase modulators must be developed. In this work, we present a room temperature external THz amplitude modulator based on plasmonic bow-tie antenna arrays with graphene. By applying a modulating bias to a back gate electrode, the conductivity of graphene is changed, which modifies the reflection characteristics of the incoming THz radiation. The broadband response of the device was characterized by using THz time-domain spectroscopy, and the modulation characteristics such as the modulation depth and cut-off frequency were investigated with a 2.0 THz single frequency emission quantum cascade laser. An optical modulation cut-off frequency of 105 ± 15 MHz is reported. The results agree well with a lumped element circuit model developed to describe the device.

Link

False detection of dangerous and neutral substances in commonly used materials by means of the standard THz time domain spectroscopy

V. A. Trofimov, S. A. Varentsova

Abstract:

Essential limitations of the standard THz Time Domain Spectroscopy (TDS), which lead to false detection of dangerous and neutral substances in commonly used materials, are demonstrated using the physical experiment with chocolate under real conditions as well as with semiconductors under laboratory conditions. To overcome this disadvantage, we propose using the time-dependent spectrum of the THz pulse, transmitted through or reflected from a substance. For quality assessment of the standard substance absorption frequency presence in the signal under analysis, we use time-dependent integral correlation criteria. The influence of aperture placed in front of the sample on spectral properties of silicon wafers with different resistivity is demonstrated as well.

Link

Terahertz solutions for industry workshop is a great success

TeraView wishes to thank everyone who took part in the Terahertz solutions for industry workshop held in Bordeaux this week. With over 60 attendees from across Europe the event was highly successful and proved to be a great interface between science and industry.

The event also marked the beginning of an ongoing working relationship between TeraView and the University of Bordeaux with the signing of a collaborative agreement.

TeraView would especially like to thank Patrick Mounaix and the University of Bordeaux for hosting this years event and very much look forward to the next one.

TeraView's CEO Don Arnone signing the collaborative agreement.

SPIE Defense + Commercial Sensing 2016

SPIE Defense + Commercial Sensing (formerly SPIE DSS), the leading global technical conferences, courses, and exhibition on sensing, imaging, and photonics technologies for defense, security, industry, and the environment.

TeraView's Dr Philip Taday will be giving a talk at this years event covering recent progress of terahertz usage in several key technology areas, such as the automotive and semiconductor industries. The talk is part of the Novel THz Image Sensing Technologies and Applications II Session, and will be held on Thursday 21 April.

April 17th - 21st 2016; Baltimore Convention Center, Baltimore, MD, USA

Click here for more details.

 

7th International THz-Bio Workshop 2016

TeraView's Dr Philip Taday will be speaking at this years International THz-Bio Workshop with a talk entitled Terahertz, where next?. The event will take place between the 6th - 8th April in Seoul, South Korea.

This years theme is THz-Bio: Challenges and Opportunities for Industrialization, and will feature guest speakers from industries and universities from around the world.

Full details of the event, including program, can be found here.

TeraView at the 'Advances in Terahertz Spectroscopy' meeting held in Cambridge, UK

Last week the 'Advances in Terahertz Spectroscopy' meeting was held at the Gonville and Caius College in Cambridge UK, with the event being jointly hosted by Teranet (an EPSRC-funded network of UK Universities and companies active in terahertz science and technology) and the the Royal Society of Chemistry.  

TeraView brought along its latest product, the TeraPulse 4000.  TeraView is grateful for all of the feedback received, especially the positive comments and suggestions from the hands-on session.

Below are some pictures from the workshop.

If you would like to participate in a hands-on workshop and learn more about terahertz applications and technology please do not hesitate to contact us or sign up for our next workshop in Bordeaux, France. More information on the Bordeaux event can be found here.

Wide angle terahertz sensing with a cross-dipole frequency selective surface

P. Rodríguez-Ulibarri | S. A. Kuznetsov | M. Beruete

Abstract:

In this work, a terahertz sensor based on a cross dipole frequency selective surface is analyzed and experimentally tested. The sensing structure is optimized for operation at the fundamental band-stop resonance near 0.7 THz and characterized under normal and oblique incidence. The sensing performance as a function of the incidence angle and the wave polarization is evaluated with good agreement between simulations and measurements. It is shown that a figure of merit for the proposed sensor can be enhanced from 0.2 up to 0.6 due to switching from normal to oblique excitation, which yields the maximum performance for TM polarization at the incidence angle of 70°. The presented results demonstrate a wide angle operation regime in THz sensing that opens up an alternative approach in improving capabilities of sensing devices.

Full article available here.

Advances in Terahertz Spectroscopy Meeting, Cambridge UK

 

 TeraView's Dr Philip Taday will give a talk at this years event in Cambridge, UK, with the title:

 

'Industrial Applications of THz spectroscopy'

 

The Event will take place on 17–18 March 2016, Gonville and Caius College, Cambridge  

 

This two day meeting will cover many aspects of Terahertz spectroscopy and includes research presentations from both International and UK research groups. The meeting is being sponsored by the EPSRC Teranet fund and is free to attend for all RSC members. To register for this event please contact Professor Cunningham [j.e.cunningham@leeds.ac.uk].

Further information can be found on the event webpage here.

How TeraHertz could revolutionize your business - Terahertz solutions for industry workshop

TeraView with the support of cluster Laphia and the “pôle de compétitivité route des lasers” invite you to the Terahertz solutions for industry workshop, which will take place on April 12th 2016 at the University of Bordeaux, France (Building A31).

The key points of the day include:

• Seminars discussing the technology
• Networking Sessions
• Demonstrations of the technology

Objectives are:

• To demonstrate technical expertise of the University and companies
• To bring together leading experts to explore the solutions that terahertz offers
• To deliver state-of-the-art presentations on the technology
• To give participants a thorough understanding of the technology
• Create an information exchange of ideas

For more information please feel free to contact: patrick.mounaix@u-bordeaux.fr or on 05 240002602.
UMR 5218 - IMS - Laboratoire de l’Intégration du Matériau au Système Adresse:
351 Cours de la libération, 33405 Talence cedex, France.

Compulsory registration (no registration fees)

Full programme details and registration form (editable PDF) can be found here.

Terahertz Imaging Platform to Characterize the Growth of In-Vitro Breast Tumors

Abstract:

This study aimed at evaluating the ideal plating method and density for imaging with the terahertz (THz) spectrometer. In this study, different methods were used to grow in-vitro tumors using the 4T1 cell line. Here, attempts to grow breast tumors in-vitro were conducted. Results were produced in two environments, flat-bottomed plates and round-bottomed multiwell plates. The second method allowed for faster clumping and increased cell aggregation, producing tumors up to 7mm. Terahertz spectroscopy produced images that correlated well to photomicrographs taken of the in-vitro tumors. This methodology shows great promise for providing a reliable, parameter-controlled source of in-vitro breast tumors for research needs on breast tumor margins. 

Link to PDF

Non-destructive evaluation of puncture region in polyethylene composite by terahertz and X-ray radiation

Norbert Palkaa ;  Robert Panowiczb ; Marek Chalimoniukc ; Rene Beigang 

Abstract:

An ultra-high molecular weight polyethylene composite sample has been non-destructively imaged via X-ray and Terahertz waves. The sample stopped a projectile, which resulted in delaminations, a bulge, and a chamber. Although the X-ray computed tomography reliably showed all interesting internal features of the sample, the axial resolution was moderate and artefacts and deformations limited its performance. A terahertz time domain spectroscopy system was used both for transmission and reflection raster scanning of the sample. The propagation of the THz pulse through the sample was compared with a theoretical model. Transmission investigations roughly determined the distribution of delaminations and size of the chamber. The reflection scanning through the time-of-flight analysis and signal processing enabled a detailed 3D imaging of the sample. A very good agreement of X-ray and THz images was achieved. Both measurement methods were compared and discussed.

Full article here

First Call for Papers – 41st International Conference on Infrared, Millimeter and Terahertz Waves

The 41st International Conference on Infrared, Millimeter and Terahertz Waves (IRMMW-THz 2016) is now accepting submissions of one-page abstracts for the technical program of the conference. Abstract submission deadline is April 15th, 2016.

This year’s edition of IRMMW-THz will take place in wonderful Copenhagen, Denmark, in the period 25-30th September, 2016. The conference venue is the top-modern Bella Center, the largest conference center in Scandinavia, conveniently located with easy transportation between Copenhagen International Airport and central Copenhagen.

Topics at the conference include, but are not strictly limited to:

1. Astronomy and Environmental Science
2. Applications in Biology and Medicine
3. Applications in Security and Defense
4. Applications in Industry
5. Spectroscopy and Material Properties
6. Protein Dynamics and Molecular Spectroscopy
7. Spectroscopy of Gases, Liquids, and Solids
8. Sources, Detectors, and Receivers
9. Imaging and Remote Sensing
10. Modeling and Analysis Techniques
11. Metamaterial Structures and Applications
12. Devices, Components, and Systems
13. R&D, Future Applications, and Market Directions
14. High-Field THz Wave Generation and Nonlinear THz Physics
15. Frequency and Time Domain Instruments
16. MMW systems, Transmission Lines and Antennas
17. MMW and Sub-millimeter Wave Radar and Communications
18. Ultra High Speed MMW Digital Devices
19. Laser Driven THz Sources
20. Quantum Cascade Lasers
21. Gyro-Oscillators and Amplifiers
22. Free Electron Lasers and Synchrotron Radiation
23. Planetary and Earth Science Applications
24. Applications in Art Conservation studies
25. Ultrafast Measurements
26. Plasma Diagnostics
27. Metrology

We are looking very much forward to welcome you in Copenhagen for a week with 250+ exciting talks and plentiful poster sessions reporting on the latest advances in the field, as well as technical exhibits with the newest THz technology and networking with your old and new colleagues in the largest forum for IR, millimeter and terahertz wave science and technology!

At the web site of the conference (www.irmmw-thz2016.org) you will be able to find further information about the conference, including plenary speakers, registration details, and information about travel and accommodation. Information will be added in the coming weeks. Registration and full travel/accommodation information will be available shortly.

European Technical Coatings Congress 2016

TeraView’s Dr Robert May will be giving a poster presentation at this years European Technical Coatings Congress on the subject of TeraView’s new Non-Contact, Multi-Layer Coating & Thickness Sensor.

The sensor can determine the individual thickness of multiple paint layers on both metallic and non-metallic substrates and offers significant benefits over existing techniques, representing a significant leap beyond the current method of measurement for quality and process control in automotive paint application. See our product page for more information.

The poster presentations will be held on 26 May, 12.30-14.00, with the conference itself running from 25-26 May at the Birmingham National Exhibition Centre (NEC), UK.

More details on the conference can be found here.

Photon16 - Call for abstracts - THz Applications

This years Photon 16 Conference will be hosting a session on Terahertz Near-Field Interactions, with the aim of organising a focused, stimulating and productive discussion of recent advances in this area of research.
Whether you develop THz sensors that take advantage of near-field coupling, investigate interactions within THz metamaterials or enable sub-wavelength spatial resolution using THz near-field microscopy methods, this meeting will be a fantastic opportunity to present your recent achievements and share your ideas.

Photon 16 is the largest photonics conference in the UK, and will take place in Leeds on 5th-8th September, 2016.

Full details are available here

Active Control of Electromagnetically Induced Transparency Analog in Terahertz MEMS Metamaterial

Prakash Pitchappa ; Manukumara Manjappa ; Chong Pei Ho ; Ranjan Singh ; Navab Singh ; Chengkuo Lee

Abstract

Independent control of near-field-coupled bright and dark resonators for active modulation and frequency tuning of electromagnetically induced transparency analog in terahertz spectral region is experimentally demonstrated. Out-of-plane reconfigurable microcantilever is the active element for resonator control. The proposed metamaterial is miniaturized, electrically controlled, and can achieve up to an order of magnitude change in THz group-delay bandwidth product.

Full article here

Innovate UK 2016 - Emerging Imaging Showcase

TeraView's Mike Evans will be giving a talk at this years Innovate UK event discussing the recent project 'Sensor Array for Terahertz Imaging in Non-destructive test' (SATIN), a collaboration between TeraView and The Engineering & Computing Science Department at the University of Durham, which focused on non-destructive testing for industrial applications.

The event itself is hosted by Innovate UK and the Knowledge Transfer Network and will be held on Tuesday, 26 January 2016, in Birmingham, United Kingdom.

Event Details

To celebrate the successful conclusion of the projects funded by Innovate UK under the Emerging Imaging call, “Seeing more than before”, Innovate UK and the KTN are pleased to host a showcase event for each of the projects. 

The event will give you a chance to hear from each of the project teams on the work they have done and the benefit their technology can bring to your problems.

You will also hear from our access to finance team about the opportunities to appear on our new investor showcase platform – the growth showcase and there will also be an overview of the current and future european funding opportunities from the Enterprise Europe Network.

For those companies receiving Innovate UK grants, there will be a chance to speak to the access to finance team to discuss options for accessing the investor market.

https://www.eventbrite.co.uk/e/emerging-imaging-showcase-tickets-19706404386

OMICS International Best Poster Award

TeraView would like to congratulate Dan Sporea, Laura Mihai, Adelina Sporea and Ion Vata on being presented with the Best Poster Award at the Third International Conference and Exhibition on Lasers, Optics and Photonics, for their paper entitled:

‘Testing of ZnSe, CaF₂, BaF₂ and sapphire windows under alpha particles irradiation’

Our TPS Spectra 3000 was used by the team to investigate IR materials under ionizing radiation exposure, and is the first time that such materials have been studied under alpha particle irradiation and Terahertz.

Terahertz filter integrated with a subwavelength structured antireflection coating

Abstract

Micro-pyramid shaped subwavelength structures (SWSs) were integrated on both sides of a terahertz (THz) filter by means of stamping methods. Two silicon-based stamping molds fabricated via crystallographic wet etching were utilized to replicate SWSs onto cyclo-olefin copolymer (COC) films coated onto both sides of a THz filter at the same time. The SWSs act as an broadband antireflection coating to reduce the surfacereflection loss in a frequency range of 0.2 THz to 1.4 THz. Compared to a THz filter without SWSs, the filter integrated with double-sided SWSs exhibits a low standing wave ratio inside the substrate and THz signal transmission enhancement of up to 10.8%.

Full article available here

High-Temperature H2O Vapor Measurement Using Terahertz Spectroscopy for Industrial Furnace Applications

Abstract

We verified that high-temperature (773 K) H₂O vapor can be measured quantitatively with terahertz (THz) spectroscopy in the frequency range of 0.5–0.8 THz. The linear relationships between the absorbance peak area and the H₂O vapor volume mixing ratio (VMR) at three absorption peaks (0.557 THz, 0.658 THz, and 0.752 THz) match HITRAN-based simulations closely, which indicates that the HITRAN database can be used for practical applications. Particularly, since the peak at 0.658 THz only appears at high temperatures, it can be used to measure high-temperature H₂O vapor directly in the presence of room-temperature ambient H₂O vapor.

Full article here

Terahertz Detection of Wavelength-Size Metal Particles in Pressboard Samples

Abstract

Results of a theoretical and experimental investigation of THz detection of randomly-oriented metal particles smaller than 1 mm embedded in pressboard are reported and critically compared with X-ray scanner results. A theoretical description based on Gaussian beam theory and a transfer function approach enabled simulation of signals transmitted around and reflected from real particles and was able to predict signal detectability. Simulated signals and detection limits were compared with experimental transmission and reflection time domain spectroscopy (TDS) raster scanning data. Simulated and measured pulse amplitude and shape were in agreement. Reflection mode was superior to transmission mode in terms of both particle visibility and hit ratio. Imaging of particles was also possible in “reflection in transmission” mode, which can be used to complement classical transmission mode. X-ray images did not detect the smallest particles sufficiently and, therefore, could not be used as reference data for comparison with THz data. The results demonstrate that TDS reflection scanning is able to determine the position of small metal particles and the technique could be possibly used for quality control of pressboard insulation.

Read full article here 

Norfloxacin-loaded collagen/chitosan scaffold for skin reconstruction: Preparation, evaluation and in-vivo wound healing assessment

Abstract

Biomaterial scaffolds are versatile tools as drug carrier for treatment of wounds. A series of norfloxacin-loaded scaffolds were synthesized for treatment of wounds by combining collagen with two different types of chitosan using freeze-drying technique. Subsequently, scaffolds were screened in terms of morphology, water absorption and retention capacity, biodegradation, ex-vivo bioadhesive strength, in-vitro drug release biological compatibility, x-ray diffractometry, differential scanning calorimetry as well as in-vivo evaluation. The results indicate that the scaffold mechanical strength is dependent on the type of used chitosan. The prepared scaffolds contained interconnected porous architecture. The scaffolds had high water uptake and retention capacity with extended biodegradation rate. Scaffolds prepared with chitosan HCl showed superior bioadhesive strength compared to those prepared with low molecular weight chitosan. All scaffolds showed almost 100% drug release within 24 hours. As identified by the terahertz pulsed imaging measurements, there is single scaffold area with the same concentration. After 28 days of wound dressing with selected norfoloxacin-loaded or unloaded collagen/chitosan scaffolds in Albino rats, it was found that the tissue regeneration time was fast compared to non-treated wounds. Furthermore, the drug-loaded scaffolds showed normal structure of an intact epidermal layer as well as the underlying dermis as revealed by histopathological studies. The obtained results suggest that the investigated norfloxacin-loaded collagen/chitosan scaffold is a potential candidate for skin regeneration application.



Full article available here

Equivalent circuit for VO2 phase change material film in reconfigurable frequency selective surfaces

Abstract

We developed equivalent circuits of phase change materials based on vanadium dioxide (VO2) thin films. These circuits are used to model VO2thin films for reconfigurable frequency selective surfaces (FSSs). This is important as it provides a way for designing complex structures. A reconfigurable FSS filter using VO2 ON/OFF switches is designed demonstrating −60 dB isolation between the states. This filter is used to provide the transmission and reflection responses of the FSS in the frequency range of 0.1–0.6 THz. The comparison between equivalent circuit and full-wave simulation shows excellent agreement.

Read full article here