Dutch Terahertz Symposium 2015

Centre for Wireless Technology Eindhoven (CWTe)
Dutch Terahertz Symposium 2015
June 29, 2015

Opening and introduction

Dr. Marion Matters

TU/e - CWTe

The route to the large volume industrial THz application

Dr. Mook van Mechelen

ABB

Advanced Antenna Architectures for THz Sensing Instruments

Prof. Andrea Neto

TU Delft

On-wafer calibration and device characterization at sub-mm waves

Dr. Marco Spirito

TU Delft

THz plasmonics with metals and semiconductors

Prof. Jaime Gomez-Rivas

AMOLF, TU/e

Photoconductive microprobe enabled on-chip and wafer-scale Terahertz sensing applications

Dr. Michael Nagel

Protemics

Applications of THz time-domain spectroscopy in science and technology

Prof. Paul Planken

ArcNL

Application of an IR/THz free electron laser in molecular spectroscopy

Prof. Jos Oomens

RU Nijmegen

 

Large Terahertz Focal Plane Arrays for Astrophysics

Prof. Andrey Baryshev

SRON

 

Open discussion on Terahertz roadmap in NL

STW

 

For the detailed agenda pdf

For the abstracts and speaker bio's pdf

 

 

Opening and introduction

Speaker’s bio:
Marion K. Matters-Kammerer received the Bachelor (1997) and Master (1998) of physics and the Physikdiplom (1999) from Ecole Normale Superieure (Paris, France) and from TU Berlin (Germany). In 2006 she obtained the PhD degree in Physics from RWTH Aachen (Germany). In 1999 she joined Philips Research Aachen (Germany) and in 2004 Philips Research Eindhoven.

In 2012 she started as a associate professor at the faculty of Electrical Engineering at the TU Eindhoven.

Her research interests include System in Package and System on Chip integration of RF and microwave and ultrafast circuits for THz electronics. She has worked on RF design and technology development in LTCC, RF-laminate technologies, planar and 3D-micromachined integration in silicon as well as integration in CMOS technology in the RF and mm-wave and THz frequency range. At TU Eindhoven she is now leading the Short range terahertz observation program within the Center of Wireless Technology Eindhoven.

The route to the large volume industrial THz application

Abstract:
The growing maturity of THz technology is paving the road towards industrial applications. One field where the technology could be a real differentiator is quality control of automatized processes.  Recently, THz spectroscopy has been used to explore this topic on e.g. paper sheets, paint layers, pharmaceutical tablets, etc. Although the potential is widely recognized, a fundamental obstacle for the implementation is the often oversimplified data analysis. In this talk I first present a novel THz material analysis approach based on (i) a stratified dispersive model, (ii) an appropriate measurement configuration and (iii) a time-domain fitting procedure, which together allow for high precision material parameter determination. In the second part, this analysis approach is applied onto solventborne and waterborne paint layers studied in situ as a function of drying. I will show that the fundamental material knowledge obtained in this way is crucial to determine quality parameters that satisfy the industrial requirements.

Speaker’s bio:
Dook van Mechelen received his M.Sc. degree in the field of optical hydrogen sensing (Physics) in 2005 from the Vrije Universiteit Amsterdam and Ph.D. degree in solid state physics probed with broad band optical spectroscopy in 2010 from the University of Geneva, Switzerland. From 2010 to 2011 he was a post-doc at the University of Geneva, studying rare-earth materials with THz time-domain ellipsometry. Since 2011, as a research scientist at ABB Corporate Research (Switzerland), he leads the research in the areas of THz technology and optical hydrogen sensing. In the area of THz spectroscopy, his research interests are in fundamental and applied studies of materials and methods with the goal of large volume applications.

Advanced Antenna Architectures for THz Sensing Instruments

Abstract:
The talk will address the research performed in the THz Sensing Group of TU Delft. This is mostly oriented at introducing breakthrough antenna technology that will revolutionize THz Imaging, Time Domain sensing and Spectroscopic Space Science. In the long term the research will enable multi Tera-bit wireless communications.

Speaker’s bio:
Andrea Neto received the Laurea degree (summa cum laude) in electronic engineering from the University of Florence, Italy, in 1994 and the Ph.D. degree in electromagnetics from the University of Siena, Italy, in 2000. Part of his Ph.D. was developed at the European Space Agency Research and Technology Center, Noordwijk, The Netherlands, where he worked for the antenna section for over two years.
 
In 2000-2001, he was a Postdoctoral Researcher at California Institute of Technology, Pasadena, working for the Sub-mm wave Advanced Technology Group. From 2002 to January 2010, he was Senior Antenna Scientist at TNO Defence, Security and Safety, The Hague, The Netherlands. In February 2010 he has been appointed Full Professor of Applied Electromagnetism at the EEMCS Department, of the Technical University of Delft, the Netherlands. His research interests are in the analysis and design of antennas, with emphasis on arrays, dielectric lens antennas, wideband antennas, EBG structures and THz antennas.

Prof. Neto was co-recipient of the H.A. Wheeler award for the best applications paper of the year 2008 in the IEEE Transactions on Antennas and Propagation. He was twice co-recipient of best paper awards at the ESA Antenna Workshops and he was co-recipient of the best paper award prizes at the European Conference on Antennas and Propagation (EuCAP) in 2010, 2013 and 2015.  In August 2011 he was awarded a 5 years starting grant from the European Research Council for Advanced THz antennas. He presently serves as associate editor for the IEEE Transactions on Antennas and propagation and for IEEE Antennas and Wireless Propagation Letters (AWPL).

On-wafer calibration and device characterization at sub-mm waves

Abstract:
With the reduction of the guided wavelength arising from the increased frequency at sub-mm-wave characterization, several of the practical mechanical constraints of a measurement setup begin to play crucial roles in the selection of probe-level calibration substrates.
The talk will review the impact of multi-mode propagation in electrically thick substrates used for mm-wave and sub-mm-wave calibration and present the result for fused-silica as a probe-level calibration substrate for mm-wave and sub-mm-wave frequencies.


Speaker’s bio:
Marco Spirito received the M.Sc. degree (cum laude) in electrical engineering from the University of Naples “Federico II,” Naples, Italy, in 2000, and the Ph.D. degree from the Delft University of Technology, Delft, The Netherlands, in 2006. From 2000 to 2001, he was a guest at Infineon Technologies, Munich, Germany. In 2006, he joined the department of Electronics and Telecommunications Engineering, University of Naples “Federico II.” In April 2008 he joined the Electronics Research Laboratory at the Delft University of Technology as an Assistant Professor, where he is an Associate Professor since April 2013. His research interests include the characterization of highly efficient and linear power amplifiers, the development of advanced characterization setups for millimeter and sub-millimeter waves, and the integration of mm-wave sensing systems. Dr. Spirito was the recipient of the Best Student Paper Award for his contribution to the 2002 IEEE Bipolar/BiCMOS Circuits and Technology Meeting (BCTM) he received the IEEE MTT Society Microwave Prize in 2008, was a co-recipient of the best student paper award at IEEE RFIC 2011, and the GAAS Association Student Fellowship in 2012.

THz plasmonics with metals and semiconductors

Abstract:
The versatile nature of semiconductors with a permittivity that can be controlled by the amount of free carriers, makes them excellent candidates for active THz plasmonics and metamaterials. Structures made out of semiconductors can give rise to the localized surface plasmon resonances arising from the coherent oscillation of free charges, which define the behavior of the metamaterial. The precise behavior of these structures depends on their geometry and permittivity; parameters that can be actively tuned. Subwavelength local field enhancements are the most relevant characteristic of localized resonances. These enhancements have triggered the interest for resonant metallic structures in sensing and spectroscopic applications.

In this contribution, we demonstrate the THz near-field enhancement in the proximity of silicon and gold resonant structures. These near fields are measured in a broadband THz time-domain near-field microscope with micro-structured photo-conductive antennas that enable the independent measurement of the two in-plane field components. The measurements clearly show the resonant response of the structures and the concomitant subwavelength field enhancement. In order to achieve a full optical control of local THz resonances, we demonstrate the feasibility of the photo-generation of resonant structures on semiconductors by shaping an optical pump beam incident on a flat GaAs layer. This beam shaping has been realized with a spatial light modulator that structures the optical beam with the form of the structures. The incidence of the shaped beam on the semiconductor locally induces a metallic behaviour on the illuminated areas, with photo-excited free charges that are resonantly driven by the THz electric field. This approach provides an unprecedented flexibility in designing the far-field properties of the THz field, such as extinction and beaming, as well as the near field at the surface of the semiconductor. The photo-generation of metallic structures in semiconductors can be also extended to create THz waveguides.


Speaker’s bio:
Jaime Gómez Rivas is an experienced researcher in nanophotonics, plasmonics and THz spectroscopy. Gómez Rivas holds his PhD since 2002 from the University of Amsterdam (The Netherlands). From 2002 till 2005 he worked as postdoctoral researcher at the RWTH in Aachen (Germany), where he pioneered the field of THz plasmonics in semiconductors. Gómez Rivas is since 2005 group leader at AMOLF and since 2010 part-time professor at the Eindhoven University of Technology, where his research has focused on semiconductor nanowires and plasmonics at optical and THz frequencies. In 2010 he was awarded with an ERC Starting/Consolidator Grant to investigate plasmonic microstructures at THz frequencies. More recently, he has been awarded with an ERC Proof of Concept Grant to develop and commercialize a time-resolved THz near-field microscope. Gómez Rivas has co-authored more than 100 peer-reviewed manuscripts, has been invited speaker in more than 40 international conferences, workshop and symposia. Since 2015 Gómez Rivas is also employed by the American Institute of Physics where he works as Associate Editor for the Journal of Applied Physics.

Photoconductive microprobe enabled on-chip and wafer-scale Terahertz sensing applications

Abstract:
In this talk a range of scientifically and industrially relevant THz sensing applications enabled by photoconductive microprobe emitter and detector components will be presented. The microprobe devices are offering highly efficient THz signal transfer to micro- and nano-scale structures which is a key advantage over diffraction limited approaches.

Speaker’s bio:
Dr. Michael Nagel received his PhD from the RWTH Aachen University in 2003. From 2004 on he worked in chief engineer position at the Institute of Semiconductor Electronics, RWTH Aachen. In 2011 he changed to AMO GmbH, where he initiated and led several Terahertz technology transfer projects. Nagel is Co-founder and since 2014 managing director of Protemics GmbH – a company developing Terahertz technology-based measurement solutions. He has authored or co-authored over 160 publications and international conference presentations with more than 2000 citations and filed ten patents.

Applications of THz time-domain spectroscopy in science and technology

Abstract:
Terahertz (THz) time-domain spectroscopy, the ability to measure the time-dependent electric field of a broadband pulse of THz light, has become a useful tool in science and technology. Many materials emit short bursts of THz light when illuminated with femtosecond laser pulses. The emitted light provides information on carrier dynamics in semiconductors, metals and other materials. In turn, the absorption of THz light, as measured in THz-TDS, can be used to identify organic and inorganic materials in crystalline form. In some cases this can be done on a very small length scale by using clever tricks that circumvent the diffraction limit. In this presentation, after a short introduction to THz-TDS, some recent work will be presented on the laser-pulse induced emission of THz light by single layer graphene (collaboration with the group of Prof. DaiSik Kim, Seoul National University, Korea) and by nanostructured metal surfaces (work done mostly by Gopika Ramanandan). The first result is suprising because graphene is only one atom thick, the second is surprising because metals are usually near perfect reflectors of THz light. The advantages/disadvantages of THz-TDS from an applications perspective will be discussed briefly and some examples will be shown.

Speaker’s bio:
Prof. dr. Paul C. M. Planken, obtained his PhD in 1991 from the UVA for research performed at the FOM-Institute for Atomic and Molecular Physics in Amsterdam on the generation and application of ultrashort infrared laser pulses . After a two year postdoctoral stay at AT&T Bell Laboratories (“generation of THz pulses from quantum wells”) he returned to Netherlands where, for five years, he worked at the Free-elctron laser facility FELIX in Nieuwegein. In 1998 he went the University of Technology Delft where he became Antoni van Leeuwenhoek Professor in 2007, working on generation, detection and applications of THz pulses. In September 2014, he moved to the newly established Advanced Research Center for Nanolithography (ARCNL) where he is now a leader of the group “Extreme UV targets” and has a simultaneous appointment as professor of Nanophotonics at the UVA. Prof. Planken received a VICI grant in 2007 on the topic of THz microscopy. He is the founder of the first focusgroup on THz science and technology of the European Optical Society and co-organizer of the first THz focusgroup meeting on this topic (now a biennial event). He has 25 years experience of working in the field of THz science and technology. His scientific interests include, but are not limited to plasmonics, nanophotonics and THz science and technology.

Application of an IR/THz free electron laser in molecular spectroscopy

Abstract:
IR spectroscopy is one of the primary analytical tools in molecular structure determination. In its standard form, the attenuation of transmission through a sample is recorded as a function of IR wavelength. According to Lambert-Beer’s law, some minimum sample density is required to induce an observable attenuation of the incident light beam. At the FELIX free electron laser facility, we have developed methods to obtain vibrational spectra of extremely low-density (gaseous) samples. An important application is the IR spectroscopy of molecular ions in a tandem mass spectrometer, which have typical densities of 105 cm-3 or lower. These IR spectra provide a wealth of information on the structure of the gaseous ionic species that is not obtainable from mass spectrometric information alone.

Speaker’s bio:
Jos Oomens (1968), Professor at Radboud University, obtained his PhD degree in molecular spectroscopy in 1996. He developed methods for infrared ion spectroscopy using the FELIX free electron laser, then at the FOM Institute Rijnhuizen. A substantial fraction of the FELIX beamtime allocated to external researchers of the facility is now devoted to ion spectroscopy. Oomens’ research interests include the IR spectra of large ionized carbonaceous molecules of astrochemical interest and molecular structures of products in ion chemistry, in particular in dissociation reactions of (de)protonated peptides. In2012, he was awarded an NWO VICI grant.

Large Terahertz Focal Plane Arrays for Astrophysics

Abstract:
The need of astronomical observations has always been a technology push for detectors in THz range. Both Herschel space mission and ALMA observatory played an important role in development of CW Terahertz sources. In this presentation we will discuss development of highly sensitive large format cryogenic arrays for another astrophysical instrument AMKID. The 25 kilo pixel class instrument is largest of its kind and is based on kinetic inductance detector (KID) array technology. KID allow the most efficient read out multiplexing method to date with up to several thousands pixels per one line. We will present focal plane arrays design based on planar antenna - lens coupled system. We also present and discuss lab measurements and performance of final arrays.

Speaker’s bio:
Andrey Baryshev is a senior instrument scientist and works since 1998 within SRON Low Energy Astrophysics Division and Kapteyn Astronomical Institute, University of Groningen, The Netherlands. He has received his master’s degree (summa cum laude) in physical quantum electronics in 1993 in Moscow Physical Technical institute. Since 1993, he was working as instrument scientist in Institute of Radio Engineering and Electronics in Moscow in the field of sensitive superconducting heterodyne detectors. Since 2000 he has joined an effort to develop an SIS receiver (600-720 GHz) for Atacama Large Millimiter Array, where he designed SIS mixer, quasi-optical system and contributed to a system design. Dr. A. Baryshev received his Ph.D. degree from Technical University of Delft in 2005 on the subject of “Superconducting Integrated Receiver combining SIS mixer and Flux Flow oscillator on one chip”. In 2008 Dr. Baryshev has received NWO-VENI grant for the research on heterodyne focal plane arrays technology and in 2009 he received EU commission Starting Researcher Grant for research on focal plane arrays of direct detectors. In 2013 Andrey Baryshev has become an associate professor for astronomical instrumentation in far infared at Kapteyn Astronomical Institute.  Currently his main research interests are in area of application heterodyne and direct detectors for large focal plane arrays in THz frequencies and quasi-optical systems design and experimental verification.