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This Week’s Events

The poor man’s LIGO

Group: Electronics and Nanoscale Engineering
Speaker: Jean-Claude Diels, University of New Mexico
Date: 25 April, 2018
Time: 14:00 - 15:30
Location: Rankine Building, Room 514

*** The poor man’s LIGO ***

Jean-Claude Diels

Department of Physics & Astronomy

Department of Electrical & Computer Engineering

Center for High Technology Materials

The University of New Mexico

When & where: Wednesday 25th April 2018, 14:00-15:00, room 514, Rankine Building

Host: Matteo Clerici, contact: matteo.clerici@gasgow.ac.uk

Abstract: It seems absurd to associate the words “poor” with the multimillion euro LIGO project. However, one may dream... or not?

Frequency combs are revolutionising metrology, providing absolute frequency calibration over the optical spectrum, as well as a link between optical and RF frequencies. Sophisticated schemes of electronic stabilisation have been elaborated to control the wavelength of a particular tooth of the comb, and the teeth spacing.

This researcher, however, does not even have enough funding to buy an electronic stabilisation system! I will show instead that all parameters of a frequency comb can be controlled by a purely optical method, inserting an optical element inside the laser cavity. No other electronics than the power supply of the laser is involved (which, unfortunately, is not that cheap).

Metrology with lasers is generally performed by interfering two laser beams. Performing that operation inside a laser can lead to a considerable increase in sensitivity. This should not come as a surprise since a laser oscillator can be considered as a Fabry-Perot of infinite finesse. It is sometimes taken for granted that spatial resolution with light is limited to the wavelength. Through intracavity phase interferometry, we have demonstrated a phase sensitivity of 1 part in 100,000,000, which corresponds to resolving optically periodic changes in the optical path of femtometres. Two ultrashort pulses are circulating in the laser cavity, producing two interfering frequency combs. The noise in the two output combs is correlated, resulting in a sub-Hertz beat note bandwidth, even when the individual tooth of each frequency comb is several MHz wide (typical of an unstabilised laser).

We are thriving to bring this resolution down to the attometre, through a new method of phase response amplification. In this analogue of “electronic amplifier with feedback”, each tooth of the frequency combs is locked to a giant dispersion. 

Bio: Jean-Claude Diels started his career in Research constructing a CO2 laser as part of his one-year military service (too long) in Belgium.  He went then for 5 years (much too long) as a Research Scientist in the fundamental Research laboratories of “Philips Gloelampenfabrik" in Eindhoven, with the assignment to "do modern research" with "unlimited budget” (which was soon exceeded).  He spent the next 3 years (way too short) to do PhD thesis research on coherent pulse propagation in two-level systems with Professor Erwin L. Hahn at UC Berkeley.  The next two years (too long) were spent at the Max Plank Institute with Professor Fritz Schaefer, the colourful (usually covered with red) father of dye lasers.  He got an appointment as Associate Research Professor at the University of Southern California ("What??? I have to raise my own salary?").  After experiencing the "Centre d’Energie Atomique” of Saclay near Paris (not the Texan Paris), and before the collapse of the Center for Laser Studies at USC, he moved to the CAQE (Center for Applied Quantum Electronics) of the University of North Texas in Denton, where he stayed for 5 years (too long), interrupted by a sabbatical at the University of Bordeaux, France.  He has been since (much too long) at the University of New Mexico, where he graduated more than 50 PhD students.  He co-authored with Wolfgang Rudolph the graduate textbook Ultrashort Laser Pulse Phenomena: Fundamentals, Techniques and Applications on a Femtosecond Time Scale and with Ladan Arissian the book, Lasers:  The Power and Precision of Light, celebrating the 50th anniversary of the laser, and published 5 book chapters.    He is the recipient of the 51st Annual Research Lecturer Award (April 2006), and of the 2006 Engineering Excellence Award of the Optical Society of America. 

Tea/coffee will be served. All welcome!

Upcoming Events

The poor man’s LIGO

Group: Electronics and Nanoscale Engineering
Speaker: Jean-Claude Diels, University of New Mexico
Date: 25 April, 2018
Time: 14:00 - 15:30
Location: Rankine Building, Room 514

*** The poor man’s LIGO ***

Jean-Claude Diels

Department of Physics & Astronomy

Department of Electrical & Computer Engineering

Center for High Technology Materials

The University of New Mexico

When & where: Wednesday 25th April 2018, 14:00-15:00, room 514, Rankine Building

Host: Matteo Clerici, contact: matteo.clerici@gasgow.ac.uk

Abstract: It seems absurd to associate the words “poor” with the multimillion euro LIGO project. However, one may dream... or not?

Frequency combs are revolutionising metrology, providing absolute frequency calibration over the optical spectrum, as well as a link between optical and RF frequencies. Sophisticated schemes of electronic stabilisation have been elaborated to control the wavelength of a particular tooth of the comb, and the teeth spacing.

This researcher, however, does not even have enough funding to buy an electronic stabilisation system! I will show instead that all parameters of a frequency comb can be controlled by a purely optical method, inserting an optical element inside the laser cavity. No other electronics than the power supply of the laser is involved (which, unfortunately, is not that cheap).

Metrology with lasers is generally performed by interfering two laser beams. Performing that operation inside a laser can lead to a considerable increase in sensitivity. This should not come as a surprise since a laser oscillator can be considered as a Fabry-Perot of infinite finesse. It is sometimes taken for granted that spatial resolution with light is limited to the wavelength. Through intracavity phase interferometry, we have demonstrated a phase sensitivity of 1 part in 100,000,000, which corresponds to resolving optically periodic changes in the optical path of femtometres. Two ultrashort pulses are circulating in the laser cavity, producing two interfering frequency combs. The noise in the two output combs is correlated, resulting in a sub-Hertz beat note bandwidth, even when the individual tooth of each frequency comb is several MHz wide (typical of an unstabilised laser).

We are thriving to bring this resolution down to the attometre, through a new method of phase response amplification. In this analogue of “electronic amplifier with feedback”, each tooth of the frequency combs is locked to a giant dispersion. 

Bio: Jean-Claude Diels started his career in Research constructing a CO2 laser as part of his one-year military service (too long) in Belgium.  He went then for 5 years (much too long) as a Research Scientist in the fundamental Research laboratories of “Philips Gloelampenfabrik" in Eindhoven, with the assignment to "do modern research" with "unlimited budget” (which was soon exceeded).  He spent the next 3 years (way too short) to do PhD thesis research on coherent pulse propagation in two-level systems with Professor Erwin L. Hahn at UC Berkeley.  The next two years (too long) were spent at the Max Plank Institute with Professor Fritz Schaefer, the colourful (usually covered with red) father of dye lasers.  He got an appointment as Associate Research Professor at the University of Southern California ("What??? I have to raise my own salary?").  After experiencing the "Centre d’Energie Atomique” of Saclay near Paris (not the Texan Paris), and before the collapse of the Center for Laser Studies at USC, he moved to the CAQE (Center for Applied Quantum Electronics) of the University of North Texas in Denton, where he stayed for 5 years (too long), interrupted by a sabbatical at the University of Bordeaux, France.  He has been since (much too long) at the University of New Mexico, where he graduated more than 50 PhD students.  He co-authored with Wolfgang Rudolph the graduate textbook Ultrashort Laser Pulse Phenomena: Fundamentals, Techniques and Applications on a Femtosecond Time Scale and with Ladan Arissian the book, Lasers:  The Power and Precision of Light, celebrating the 50th anniversary of the laser, and published 5 book chapters.    He is the recipient of the 51st Annual Research Lecturer Award (April 2006), and of the 2006 Engineering Excellence Award of the Optical Society of America. 

Tea/coffee will be served. All welcome!

Past Events

Towards fully atomistic simulations of nano-devices (17 April, 2018)

Speaker: Mathieu Luisier

Abstract: With the rapid decrease of the semiconductor device dimensions, technology computer aided design (TCAD) has entered a new era where one- dimensional models and (semi-)classical approximations such as the drift-diffusion, energy-balance, or Boltzmann Transport equations are no more valid to simulate the properties of nanoscale components. These approaches must be replaced by more advanced, but computationally more intensive ones based on discrete quantum mechanics, including energy quantization, geometrical confinement, and tunneling currents, capable of going beyond the ballistic limit of transport, and operating at the ab-initio level (from first-principles). In this talk, two applications of a simulator fulfilling these requirements will be presented: the investigation of devices based on 2-D materials and the study of atomic-scale conductive bridging random access memory (CBRAM) cells. It will be shown how an accurate modeling tool can reveal the physics of these systems and provide design guidelines to experimentalists.
 
Bio: Since 2016 Mathieu Luisier is Associate Professor of Computational Nanoelectronics at ETH Zurich, Switzerland. He graduated in electrical engineering in 2003 and received his Ph.D. in 2007, both from ETH Zurich. After a one-year post- doc at the same institution, he joined in 2008 the Network for Computational Nanotechnology at Purdue University, USA, as a research assistant professor. In 2011 he returned to ETH Zurich to become Assistant Professor. His current research interests focus on the modeling of nanoscale devices, such as multi-gate nanowires, III-V MOSFETs, band-to-band tunneling transistors, 2-D semiconductors, memristors, or lithium ion batteries. He won an honorable mention at the ACM Gordon Bell Prize for high performance computing in 2011 and was finalist in 2015. In 2013, he received a Starting Grant from the European Research Council (ERC).

Towards fully atomistic simulations of nano-devices (17 April, 2018)

Speaker: Mathieu Luisier

Abstract: With the rapid decrease of the semiconductor device dimensions, technology computer aided design (TCAD) has entered a new era where one- dimensional models and (semi-)classical approximations such as the drift-diffusion, energy-balance, or Boltzmann Transport equations are no more valid to simulate the properties of nanoscale components. These approaches must be replaced by more advanced, but computationally more intensive ones based on discrete quantum mechanics, including energy quantization, geometrical confinement, and tunneling currents, capable of going beyond the ballistic limit of transport, and operating at the ab-initio level (from first-principles). In this talk, two applications of a simulator fulfilling these requirements will be presented: the investigation of devices based on 2-D materials and the study of atomic-scale conductive bridging random access memory (CBRAM) cells. It will be shown how an accurate modeling tool can reveal the physics of these systems and provide design guidelines to experimentalists.

 

Bio: Since 2016 Mathieu Luisier is Associate Professor of Computational Nanoelectronics at ETH Zurich, Switzerland. He graduated in electrical engineering in 2003 and received his Ph.D. in 2007, both from ETH Zurich. After a one-year post- doc at the same institution, he joined in 2008 the Network for Computational Nanotechnology at Purdue University, USA, as a research assistant professor. In 2011 he returned to ETH Zurich to become Assistant Professor. His current research interests focus on the modeling of nanoscale devices, such as multi-gate nanowires, III-V MOSFETs, band-to-band tunneling transistors, 2-D semiconductors, memristors, or lithium ion batteries. He won an honorable mention at the ACM Gordon Bell Prize for high performance computing in 2011 and was finalist in 2015. In 2013, he received a Starting Grant from the European Research Council (ERC).

Processing Data with Nanoscale Memristors (07 February, 2018)

Speaker: Prof Themis Prodromakis

Abstract: Large attention has been recently given to a novel technology named memristor, for having the potential of becoming the new electronic device standard. Memristors are dynamic nanoscale electron devices that are nowadays regarded as a promising solution for establishing next-generation memory and computation, owing to their potential of achieving “more” (functionality/information storage) for “less” (power and physical dimensions). Most interestingly, it has been envisioned that mimicking the functionality of biological brain systems could fulfil its potential. During this talk, I will present how memristors can be exploited in practical applications, with particular emphasis in the areas of memory and computation. I shall highlight the opportunities that this emerging technology brings for addressing the needs of modern massively parallel computing and identify the current challenges hindering their full potential.

Surface Enhanced Raman Scattering (SERS) sensors for the detection of pollutant in water (28 November, 2017)

Speaker: Dr Nathalie Lidgi-Guigui

Abstract: The Raman scattering is a well known analytical chemistry technique where the light is scattered by the vibrating bounds of a molecule. As so it gives a molecular fingerprint of a specific compound. However, Raman scattering is not a very sensitive technique. To circumvent this drawback, it is possible to take advantage of the optical properties of metallic nanoparticles (NP). When exposed to light, coherent oscillations of the free electron gas are taking place on the NP. These so called Localized Surface Plasmon (LSP) create an electromagnetic field which is the basis of the near field enhancement of Raman scattering. This electromagnetic effect is responsible for an enhancement factor that can be as high as 10^8. Another effect, the chemical effect, has a weaker contribution to the Raman scattering enhancement. Its origin is discussed among the community but is probably based on the shifting of the molecules energy levels when it is bound to the NP surface.

In this talk we will focus on the use of SERS substrate for the detection of pollutant in water. We will present results concerning hydrophobic and hydrophilic compounds. The first are organic molecules, consisting of two or more fused aromatic rings known as polycyclic aromatic hydrocarbons (PAHs). This group of compounds have received considerable attention due their toxicity and carcinogenicity. The hydrophilic compound that we have worked on is paracetamol. This is the most used drug around the world and as so it is highly found in waste water. However, in order to study its impact on the marine environment it is first needed to be able to quantify its presence.

Obviously, these two class of pollutants do not present the same issues in terms of sensing. In the first case it is important to reach a very low limit of detection when the quantification and the specificity are the key for the hydrophilic pollutants. We will present the strategy of surface functionalization we have adopted in both case that include the use of Molecular Imprinted Polymers (MIP) for the detection of paracetamol and the exploitation of pi-pi stacking for the detection of naphthalene, fluoranthene and benzo[A]pyrene.

In the last part of the talk, I will show how the nanostructured surface can play an active role in the functionalization. We have recently demonstrated that the LSP can support chemical reactions such as the well known click chemistry thiol-ene reaction. It is even possible to go further and to performed a different functionalization on different direction of a nanostructure by taking advantage of the light polarization.

Biography: After completing my undergraduate studies in material sciences at the University Pierre and Marie Curie in Paris, I followed my interest in nanotechnologies by enrolling in a doctoral program at the Unité Mixte de Physique CNRS Thales where I developed my field of expertise the nanoparticles growth and their electronic properties. After obtaining my Ph.D. in 2005, I joined the team of Prof. R. E. Palmer at the University of Birmingham where I studied the growth and deposition of size selected clusters and their interactions with proteins. The skills I developed in liquid phase AFM were valued through my second post-doc at the University of Evry. Since 2010 I am a reader at the University Paris 13. My main research interests focus on the development of highly sensitive sensors for biomolecules and pollutants. In my group, we use and develop original lithography techniques to fabricate large assembly of organized nanostructures for SERS (Surface Enhanced Raman Spectroscopy). Through the years we have developed several functionalization paths that have enable us to pre-concentrate analytes, to detect their presence in low concentration and to follow their structural evolution. Recent results are focusing on the possibility of making these sensors active by exploiting the tremendous ideas of plasmon based chemistry.

From iCub to R1 - Building your personal humanoid (13 November, 2017)

Speaker: Prof Giorgio Metta

Abstract: The iCub is a humanoid robot designed to support research in embodied AI. At 104 cm tall, the iCub has the size of a five-year-old child. It can crawl on all fours, walk and sit up to manipulate objects. Its hands have been designed to support sophisticate manipulation skills. The iCub is distributed as Open Source following the GPL licenses and can now count on a worldwide community of enthusiastic developers. The entire design is available for download from the project’s repositories (http://www.iCub.org). More than 30 robots have been built so far which are available in laboratories across Europe, US, Korea, Singapore, and Japan. It is one of the few platforms in the world with a sensitive full-body skin to deal with the physical interaction with the environment including possibly people. I will present the iCub project in its entirety showing how it is evolving towards fulfilling the dream of a personal humanoid in every home.

Short bio: Giorgio Metta is Vice Scientific Director at the Istituto Italiano di Tecnologia (IIT) and Director of the iCub Project at the same institute where he coordinates the development of the iCub robotic platform. He holds a MSc cum laude (1994) and PhD (2000) in electronic engineering both from the University of Genoa. From 2001 to 2002 he was postdoctoral associate at the MIT AI-Lab. He was previously with the University of Genoa and since 2012 Professor of Cognitive Robotics at the University of Plymouth (UK). He is member of the board of directors of euRobotics aisbl, the European reference organization for robotics research. Giorgio Metta research activities are in the fields of biologically motivated and humanoid robotics and, in particular, in developing humanoid robots that can adapt and learn from experience. Giorgio Metta is author of more than 250 scientific publications. He has been working as principal investigator and research scientist in about a dozen international as well as national funded projects.

Integrated circuit and system design for next-generation multi-metabolite sensing devices (02 November, 2017)

Speaker: Dr Sara Ghoreishi-zadeh

Abstract: Next-generation implantable and wearable medical devices are emerging to address specific unmet healthcare needs, particularly those in medical monitoring and diagnostics. Monitoring of metabolites (e.g., glucose, lactate) in human body is of significant importance in health-care and personalised therapy. In this talk, I will present our sub-mW CMOS IC that enables the fabrication of miniaturised, inductively powered, and implantable devices for multi-metabolite detection. Next, I will illustrate a novel differential sensing technique to enhance the electrochemical sensing performance. I will also present promising results from our sensors that are developed, for the first time, by growing Pt nano-structures on CMOS IC. 

Despite remarkable advances in electrochemical sensor design, the constant need of the sensors for calibration remains a barrier to their diagnostic potential. I will briefly discuss our latest results showing how electrochemical impedance spectroscopy (EIS) may be used to auto-calibrate the sensors. In the second part of the talk, I will present our on-chip interface for recovering power and providing full-duplex communication over an AC-coupled 4-wire lead between active implantable devices. 

Biography: Dr. Sara Ghoreishi-zadeh received the B.Sc. and M.Sc. degrees (both with distinction) in Electrical engineering from Sharif University of Technology, Iran, and the PhD degree from Ecole Polytechnique Federale de Lausanne (EPFL), Switzerland, in 2015. She then joined the Centre for Bio-inspired Technology, Department of Electrical and Electronic Engineering, Imperial College London, UK.  where she is currently a Junior Research Fellow. Her current research focus is integrated circuit and system design for implantable and wearable medical devices. She has been a Review Committee Member and track chair for IEEE conferences including ICECS 2016 and BioCAS 2017. She is an editor of the Journal of Microelectronics and a member of IET and the IEEE CAS, EMB and SSC societies.

Implantable and Wearable Wireless Medical Sensors (02 November, 2017)

Speaker: Prof JC Chiao

Abstract: Recent advances in micro- and nano-technologies provide unique interfacing functionalities to human tissues, with features of miniaturization and low power consumption. Interfaces between biological objects and electronics allow quantitative measurement and documentation of physiological and biochemical parameters, and even behaviors. The interfaces also provide direct modification of cells, tissues, or organs by electrical stimulation making it possible to manage chronic diseases with a closed loop between body and portable computer. Wireless communication and power transfer in the implantable systems enable in-situ sensing for freely-behaving animals or patients without constrains. Wireless networking also allows ubiquitous access to physiological information for treating complex problems in body. 

This lecture focuses on our research progress in wireless micro sensors for clinical and neurobiological applications. The systems are based on integrated platforms such as wireless energy transfer for batteryless implants, miniature and flexible electrochemical sensors, nanoparticle modified surfaces, MEMS devices, and wireless communication. Several implantable, wireless diagnosis and therapeutic systems targeting management of pain and gastric disorders will be discussed with emphases on the sensor technologies. These technologies empower new personalized medicines to improve human welfare and assist better living. Sensor device designs, fabrication, characterization, system integration and clinical experiments will be presented.

Biography: J.-C. Chiao is Greene professor and Garrett professor of Electrical Engineering at University of Texas - Arlington. He received his PhD at Caltech and was with Bellcore, University of Hawaii-Manoa and Chorum Technologies before he joined UT-Arlington in 2002.  

Dr. Chiao has published more than 260 peer-reviewed papers and received 12 patents. He received the 2011 O'Donnell Award in Engineering presented by The Academy of Medicine, Engineering and Science of Texas. He received the Tech Titan Technology Innovator Award; Lockheed Martin Aeronautics Excellence in Engineering Teaching Award; Research in Medicine milestone award by Heroes of Healthcare; IEEE MTT Distinguished Microwave Lecturer; IEEE Region 5 Outstanding Engineering Educator; and IEEE Region 5 Individual Achievement awards. His works have been covered by National Geographic magazine, Henry Ford Innovation Nation, National Public Radio and many media.  

Currently, he is an IEEE Sensors Council Distinguished Lecturer and serving as the Editor-in-Chief for Journal of Electromagnetics, RF and Microwaves in Medicine and Biology.

Dielectrics in soft devices (27 October, 2017)

Speaker: Siegfried Bauer

Abstract: In the talk, I will briefly discuss the use of dielectrics in soft devices, together with future applications in electronic skin, soft forms of robots and energy harvesters. Dielectrics employed include hard metal oxides, ferroelectrets, ferroelectric polymers, polymers and elastomers. Valve metal oxides are critically important in capacitors and as gate and floating gate dielectric in ultraflexible, imperceptible electronic skin. Here, ultrathin polymer films employed for foil capacitors form the substrate for electronic circuits enabling crumpling like a piece of paper without affecting performance. We demonstrated filters and coupling capacitors for integrated ultraflexible circuits and amplifiers. Ferroelectrets and ferroelectric polymers transform electronic skin into pressure and touch sensitive devices. Soft elastomers with high dielectric breakdown strength are widely considered for the advancement of dielectric energy harvesting devices. Recent work indicates natural rubber to be versatile for the sustainable conversion of mechanical into electrical energy. Developing stable soft elastomer electrets may lead to novel concepts for bias voltage free energy harvesting and stretchable piezoelectric materials. Soft elastomers are also ideally suited as a substrate for mechanically deformable electronic skin. In the talk, I will give a tour d’horizon on our recent research on dielectrics in soft devices. Future applications may arise in wid ranging fields, from consumer and mobile appliances to biomedical systems, sports and healthcare.


Biography: Siegfried Bauer studied physics at the University of Karlsruhe, where he graduated with the Diplom in 1986. In 1990 he received a PhD in physics from the same university. In 1992 he joined the Heinrich Hertz Institute for Telecommunication Engineering in Berlin. In 1996 he received the Habilitation degree from the University of Potsdam. In 1997 he joined the Johannes Kepler University in Linz, Austria, where he became a full professor and head of the Soft Matter Physics Department in 2002. Siegfried Bauer is a member of the editorial board of Advanced Science, Advanced Materials Technologies, Applied Physics Reviews, Applied Physics A and the IEEE Transactions on Dielectrics and Electrical Engineering. He received several awards for his work, including the Karl Scheel award of the Physical Society of Berlin in 1997, a pioneer of smart production award from the Austrian Society for Environment and Technology in 2010, and an ERC Advanced Investigators Grant in 2011. In 2016, he has been elevated to IEEE Fellow, in 2017 he was distinguished speaker of the Southwest Mechanics Lecture Series in the US. His research centers on soft materials for sensors, transducers, flexible and stretchable electronics. He has coauthored more than 180 refereed scientific publications, including contributions to Science and journals of the Nature family. His work has received more than 13.000 citations with an h-index of 62 on Google Scholar.

Quantum transport in graphene-based single-molecule devices (25 October, 2017)

Speaker: Jan Mol

Abstract: Graphene nanoelectrodes [1] provide a versatile platform for contacting individual molecules. Unlike metal electrodes, graphene is atomically stable at room temperature and screening of the gate electric field is strongly reduced by the two-dimensional nature of the electrodes [2]. Molecules can be anchored to the graphene via π-π stacking bonds. I will present single electron transport measurements of single pyrene-functionalised C60 molecules [3]. Strong electron-phonon coupling in these molecules leads to the observation of Franck-Condon blockade (see Figure 1). In addition to spectroscopic transport features arising from the electronic and mechanical degrees of freedom of the fullerene molecule, we observe the effect of quantum interference in the graphene leads [4]. Density-of-states fluctuations due to multi-mode Fabry-Perot interference in graphene result in energy dependent coupling between the graphene leads and the molecule [5]. Finally, I will present thermoelectric measurements of our graphene-based nanostructures, and show the energy dependent Seebeck coefficient both in the sequential electron tunnelling and quantum interference regime. Our experiments demonstrate the capability of graphene-based molecular junctions for studying transport in single molecules, and highlight spectroscopic features that cannot readily be observed in metal-molecule junctions.

Space-Division Multiplexed Optical Communications Over Multi-mode Fiber (25 September, 2017)

Speaker: Nicolas Fontaine

Abstract: Space-division multiplexed (SDM) systems use the multiple spatial modes in either multi-core fiber (separated modes), or the spatially overlapping but orthogonal modes in multi-mode fibers to either increase the capacity or photon-efficiency of optical fiber links. The new challenges in SDM are how to couple into and out of the various SDM fibers without insertion loss (IL) or mode-dependent loss (MDL), and building components that have comparable performance to, and that offer a cost advantage over systems using multiple single-mode fibers.  We will show several components for space-division multiplexing in multi-mode fibers including "photonic lantern" spatial multiplexers which are lossless adiabatic single-mode to multi-mode converters, multimode amplifiers, and wavelength selective switches for routing signals in few-mode fiber. These components enable transmission of signals across multi-mode fiber using up to 30 spatial and polarization modes.


Biography: Nicolas Fontaine obtained his Ph. D. in 2010 at the University of California, Davis in the Next Generation Network Systems Laboratory [http://sierra.ece.ucdavis.edu] in Electrical Engineering. In his dissertation he studied how to generate and measure the amplitude and phase of broadband optical waveforms in many narrowband spectral slices. Since June 2011, he has been a member of the technical staff at Bell Laboratories at Crawford Hill, NJ in the advanced photonics division.  At Bell Labs, he develops devices for space-division multiplexing in multi-core and few mode fibers, builds wavelength crossconnects and filtering devices, and investigates spectral slice coherent receivers for THz bandwidth waveform measurement.

Resonant Tunnelling Diode based Optoelectronic Integrated Circuits (29 August, 2017)

Speaker: Dr José Figueiredo

Abstract: Microwave photonics brings together a variety of techniques used in microwave and in photonics engineering to provide new functionalities at radio frequencies very difficult or virtual impossible to achieve using only microwave or photonic techniques. New approaches to light modulation, light detection and light and RF generation at microwave and millimetre-wave frequencies have been investigated by combining double barrier quantum well (DBQW) resonant tunnelling diodes (RTDs) with optical components such as optical waveguides, photodetectors and semiconductor lasers. The seminar reviews the collaborative work between the Universities of Algarve and Glasgow aiming the development of novel electronic and optoelectronic integrated devices and circuits that take advantage of the high-speed and highly non-linear properties of RTDs to achieve high frequency optical modulation, photo-detection and to operate as optical and voltage controlled microwave photonic oscillators with significantly lower power consumption and operating voltage, with a small footprint compared with current devices and circuits.

Biography: José Figueiredo received the degree in Physics (Optics and Electronics) and the Master of Optoelectronics and Lasers, both from the University of Porto, Portugal, in 1991 and 1995, and the PhD in Physics (Microelectronics and Optoelectronics) also from the University of Porto in co-supervision (Professor Charles Ironside) with the University of Glasgow (2000). He is currently an Assistant Professor with the Department of Physics, Faculty of Science and Technology, University of Algarve. His research interests include electronic and optoelectronic circuits employing negative differential resistance devices for high frequency applications spanning from radio-over-fibre and related wireless-photonics links, to wireless sensors and neuromorphic information processing circuits.

Abstract: Microwave photonics brings together a variety of techniques used in microwave and in photonics engineering to provide new functionalities at radio frequencies very difficult or virtual impossible to achieve using only microwave or photonic techniques. New approaches to light modulation, light detection and light and RF generation at microwave and millimetre-wave frequencies have been investigated by combining double barrier quantum well (DBQW) resonant tunnelling diodes (RTDs) with optical components such as optical waveguides, photodetectors and semiconductor lasers. The seminar reviews the collaborative work between the Universities of Algarve and Glasgow aiming the development of novel electronic and optoelectronic integrated devices and circuits that take advantage of the high-speed and highly non-linear properties of RTDs to achieve high frequency optical modulation, photo-detection and to operate as optical and voltage controlled microwave photonic oscillators with significantly lower power consumption and operating voltage, with a small footprint compared with current devices and circuits. 

 

Abstract: José Figueiredo received the degree in Physics (Optics and Electronics) and the Master of Optoelectronics and Lasers, both from the University of Porto, Portugal, in 1991 and 1995, and the PhD in Physics (Microelectronics and Optoelectronics) also from the University of Porto in co-supervision (Professor Charles Ironside) with the University of Glasgow (2000). He is currently an Assistant Professor with the Department of Physics, Faculty of Science and Technology, University of Algarve. His research interests include electronic and optoelectronic circuits employing negative differential resistance devices for high frequency applications spanning from radio-over-fibre and related wireless-photonics links, to wireless sensors and neuromorphic information processing circuits.

Sub-optical-cycle interaction of light and matter (16 August, 2017)

Speaker: Dr Daniele Brida

Abstract: Many fundamental and ubiquitous physical phenomena have origin at the ultrafast timescale. The possibility to investigate various primary processes on their intrinsic timescales relies on the generation of ultrashort pulses with widely tunable carrier frequency, from ultraviolet to mid- and far-infrared. These optical waveforms allow the investigation of microscopic light-matter interactions in a wide variety of condensed material systems to unveil the deep origin of their optoelectronic properties. 

A novel idea consist in exploiting the optical field itself to control the properties of crystals and nanostructures. With this approach, it becomes possible to access phenomena occurring within a oscillation of light as benchmarked by three experiments: i) optical switching of plasmonic resonances in semiconducting nanostructures; ii) quasi-instantaneous localization of electronic wavefunctions in GaAs by non-resonant bias with intense THz radiation; ii) ultrafast electron transport driven by the peak electric field of a single-cycle optical pulses focused on nanostructured gold circuits.

Biography: I am group leader at the Physics Department of University of Konstanz (Germany) with a position funded by Zukunftskolleg, an interdisciplinary center promoting independence for young academics, and by the Excellence Initiative of the German Federal Government and States. Previously I was employed as Assistant Professor in the Physics Department of Politecnico di Milano (Italy) where I worked in the group of Prof. Giulio Cerullo. My main scientific interests are generation of broadband optical pulses ranging from UV to mid-IR, their temporal compression down to few optical cycles with adaptive techniques and the passive stabilization of the carrier-envelope phase. I also use ultrashort pulses for condensed-matter spectroscopy with extreme temporal resolution: I have studied coherent phonons in nanotubes and carotenoids, charge transfer in polymers and electronic dynamics in metals and superconductors. I am also interested in ultrafast phenomena occurring in nanostructures.

I have published more than 50 scientific papers in renowned international journals of high impact factor (including Nature, Nature Materials, Nature Physics, Nature Communications, PNAS, Laser & Photonics Review and Physical Review Letters) and I am author and coauthor of more than 100 proceedings presented at international conferences. Several of these contributions were invited. I co-authored a book chapter about ultrafast optical parametric amplifiers and I am also an inventor with two pending patent applications. I participated in several symoposia and colloquia as invited speaker.

Towards sensing outside the lab: Biomagnetic-field sensing and multiplexed protein sensing (10 August, 2017)

Speaker: Prof Martina Gerken

Abstract: Point-of-care and wearable biomedical sensors require a compact, portable setup as well as room-temperature operation. Results of our research on two types of biomedical sensors are presented: Magnetic-field sensors and protein sensors. We investigate magnetic-field sensors based on resonant magnetoelectric cantilevers of strain-coupled magnetostrictive, piezoelectric, and substrate layers. Also, surface-acoustic-wave (SAW) based sensors with a magnetostrictive layer at the surface are discussed. Both sensor types have the potential to measure biological signals in an unshielded environment at room temperature. For sensing protein concentrations in fluids, we employ specifically-functionalized, nanostructured, optical slab waveguides as transducers and an intensity-based optical readout scheme. A handheld measurement setup is demonstrated that allows for imaging detection of binding events at the surface. The performance of LED-based and laser-based readout of refractive index changes is compared.

Biography: Martina Gerken received the Dipl.-Ing. degree in Electrical Engineering from the University of Karlsruhe, Germany, in 1998, and the Ph.D. degree in Electrical Engineering from Stanford University, Stanford, CA, USA in 2003. From 2003 to 2008 she was assistant professor at the University of Karlsruhe, Germany. In 2008 she was appointed as a full professor of Electrical Engineering and Head of the Chair for Integrated Systems and Photonics at Kiel University, Germany. In 2016 she was on a 6-months sabbatical at the University of Glasgow.

Connectivity in Electromagnetic Nanonetworks: Requirements, and Challenges (02 August, 2017)

Speaker: Dr Najah Abu Ali

Abstract: Nanonetworks is a promising revolutionary advancement in several fields such as health, industry, agriculture, environment, sport, etc. The latest achievements in realizing nanoscale sensors provide an unprecedent opportunity to augment almost every sector in our lives with a myriad of nanoscale sensors which can reach previously inaccessible locations in objects or living things. Recent progress and active research in nanosensing technology have led to increasing interest in the interconnection of nanosensing devices with traditional networks to form the Internet of nanothings (IoNT). In this talk, we investigate the requirements and challenges of the connectivity of nanonetworks with traditional BAN, WiFi, and cellular networks to realize the application of IoNT on one level. We also examine the seamless connectivity and data dissemination in electromagnetic nanonetworks on another level.  We evaluate current applications and case studies regarding the practical deployment of nanosensor networks and expand on them to comprise the implementation of IoNT.

Biography: Dr Najah Abu Ali is currently an Associate Professor at the Faculty of Information Technology in the United Arab Emirates University (UAEU). She earned her Ph.D. from the Department of Electrical and Computer Engineering at Queen's University in Kingston, Canada, specializing in resource management in computer networks. Her MSc and BSc were both attained in Electrical Engineering at the University of Jordan. Her general research interests include modelling wireless communications, resource management in wired and wireless networks, and reducing the energy requirements in wireless sensor networks. More recently, she has strengthened her focus on the Internet of Things, particularly at the nano-scale communications level, in addition to vehicle-to-vehicle networking. Her work has been consistently published in key publication venues for journals and conference. She has further co-authored a Wiley book on 4G and beyond cellular communication networks. She has also delivered various seminar and tutorials at both esteemed institutions and flagship gatherings. Dr Abu Ali has also been awarded several research fund grants, particularly from the Emirati NRF/UAEU funds and the Qatar National Research Foundation.

Diamond electronic devices for power electronics (22 June, 2017)

Speaker: Etienne Gheeraert

The key to the efficient transmission and conversion of low-carbon electrical energy is the improvement of power electronic devices. Diamond is considered to be the ultimate wide bandgap semiconductor material for applications in high power electronics due to its exceptional thermal and electronic properties. Two recent developments - the emergence of commercially available electronic grade single crystals and a scientific breakthrough in creating a MOS channel in diamond technology, have now opened new opportunities for the fabrication and commercialisation of diamond power transistors.
These will result in substantial improvements in the performance of power electronic systems by offering higher blocking voltages, improved efficiency and reliability, as well as reduced thermal requirements thus opening the door to more efficient green electronic systems.
The current research carried out mainly in Japan and Europe will be presented, with the various device architectures explored, including MOSFET, MESFET, JFET and rectifiers. Results obtained in the framework of the first European research collaboration on diamond devices, aiming at fabricating the first HVDC diamond based converter will also be presented.

Latest achievements of single crystal diamond growth: breakthroughs and remaining challenges (22 June, 2017)

Speaker: Jocelyn Achard

For the past 10 years, diamond, and more particularly single crystal diamond, has attracted a strong interest from the scientific community, mostly fueled by the significant progresses achieved in the synthesis of high purity and crystalline quality material and the reduction of its production cost. Thus new devices and new areas of application are emerging, especially in the field of electronics device and quantum sensing that are currently booming. This presentation will outline the steps that enabled spectacular progresses in diamond growth, in particular in obtaining thicker and larger single diamond crystals. We will then address the developments that have been made to try to reduce the production costs of the material which remain a major impediment to its development. Finally, even if significant growth rates have been achieved, it is also essential to control the crystal quality and more particularly dislocations. The latest development done in this area will be presented.

Terahertz Sensing (20 April, 2017)

Speaker: Professor Michael S. Shur

Professor Michael S. Shur, Patricia W. and C. Sheldon Roberts Professor, Rensselaer Polytechnic Institute, will be visiting the School of Engineering. As part of his visit he will deliver the Electronic Systems Design Centre Spring Lecture entitled, "Terahertz Sensing"

Abstract

Terahertz sensing is enabling technology for detection of biological and chemical hazardous agents, cancer detection, detection of mines and explosives, providing security in buildings, airports, and other public space, short-range covert communications (in THz and sub-THz windows), and applications in radioastronomy and space research. This lecture will review the-state-of-the-art of existing THz sources, detectors, and sensing systems. As application examples, I will discuss THz space exploration, sensing of biological materials, broadband THz reflection and transmission detection of concealed objects, THz explosive identification, THz nanocomposite spectroscopy, and THz remote sensing.

Most existing terahertz sources have low power and rely on optical means of the terahertz radiation. THz quantum cascade lasers using over thousand alternating layers of gallium arsenide and aluminum gallium arsenide have achieved high THz powers generated by optical means. Improved designs and using quantum dot medium for THz laser cavities are expected to result in improved THz laser performance. Large THz powers are generated using free electron lasers or THz vacuum tubes.

Two-terminal semiconductor devices are capable of operating at the low bound of the THz range, with the highest frequency achieved using Schottky diode frequency multipliers (reaching a few THz). High speed three terminal electronic devices (FETs and HBTs) are approaching the THz range (with cutoff frequencies and maximum frequencies of operation above 1 THz and close to 0.5 GHz for InGaAs and Si technologies, respectively. A new approach called plasma wave electronics recently demonstrated terahertz emission and detection in GaAs-based and GaN-based HEMTs and in Si MOS, SOI, and FINFETs and in FET arrays, including the resonant THz detection. It has potential to become a dominant THz electronics technology.

IET Colloquium - Millimetre-wave and Terahertz Engineering & Technology 2017 (30 March, 2017)

Speaker: Various

This joint colloquium with the IET RF & Microwave, IET Antennas and Propagation and IET Electromagnetics Networks provides researchers the opportunity to present their latest research activities in the areas of millimetre-wave and terahertz engineering and technology. 

This event would be of interest to people who may have an interest or are working within the following areas: applications in science, engineering and technology that exploit the microwave, millimetre-wave, terahertz and optical regions of the electromagnetic spectrum. Key technologies are electronics and photonics.

THz Diffractive Optics for Practical Applications (28 March, 2017)

Speaker: Dr Maciej Sypek

Abstract

The performance of modern THz systems can be improved by the use of sophisticated optics. Such optical elements can be used for better coupling of the THz radiation into detectors as well as for controlling beam profiles from THz emitters. Many THz sources can emit narrowband, spatially coherent radiation. In such cases the use of diffractive optics is feasible. Additionally, such optics can be utilized together with matrices of detectors. Different topologies of matrices with detectors can work as focal plane arrays (FPA), standard linear sensors, enhanced spatial resolution sensors or moth-eye like elements. The Orteh Company designs and manufactures standard matrices of detectors based on field-effect transistors (FETs) with signal processing done by fast FPGA circuits. The typical multiplexing technique is replaced by parallel pixel processing. This innovative solution enables utilization of the separate lock-in for each pixel to enlarge the dynamics and sensitivity for the registered signal. The static mode solution provides extremely fast image acquisition. Different modules are scalable and flexible and can be used in many applications for medicine, defense, security, avionics, nondestructive inspection etc. Several THz optical setups composed of diffractive elements and detector modules will be described, including specific designs and applications. Theoretical background, numerical simulations and practical applications will also be presented.

Biography

Maciej Sypek received his M.Sc., Ph.D. and habilitation degrees from the Warsaw University of Technology in 1987, 1992 and 2009, respectively. He is now the CEO of the Polish innovative company Orteh active in the areas of information technologies and optics. He deals with optical design and numerical simulations of propagation electromagnetic radiation in demanding configurations from the extreme ultra-violet to the terahertz range. He is an expert in the design and characterization of subwavelength elements. He is an author or co-author of more than 50 articles published in peer-reviewed scientific journals.

Adaptive Quantum Sensing with Single Spins (27 March, 2017)

Speaker: Dr Cristian Bonato

Abstract

A sensor based on a single spin can be used to map magnetic fields at the ultimate limit in spatial resolution, down to the limit of few nanometers. In the past decade, ground-breaking experiments have demonstrated this concept using individual electronic spins associated to the nitrogen-vacancy (NV) centre in diamond. The NV centre effectively behaves as a single atom trapped in the diamond lattice and its electronic spin can be controlled and measured, up to room temperature, by a combination of optical and radio-frequency pulses.
In this talk, I will provide a general introduction to spin-based quantum technology with nitrogen-vacancy centres in diamond and will address the question of how the sensitivity of a quantum sensor can be enhanced by adaptive techniques. Given a quantum system, what is the best measurement protocol to extract the most information about unknown parameters? Given a sequence of measurements on a single spin, outcomes obtained by earlier measurements within the sequence could be used to optimize the settings for later measurements (adaptive estimation). What kind of advantage can this provide? Is adaptive estimation advantageous also in the presence of noise, decoherence and imperfect measurements? I will present an optimized adaptive protocol for quantum sensing that performs better than the best known non-adaptive protocol, leading to a record sensitivity (Nature Nano 11, 247 - 2016)

Biography

Cristian is Assistant Professor at Heriot Watt University. He studied physics at the University of Padova ("Laurea" degree, 2004 - PhD, 2008). In Padova, he worked with Prof. Paolo Villoresi on experiments leading to the first demonstration of single photon exchange between an orbiting satellite and a ground-based optical station. During his PhD, he spent two years at Boston University, in the lab of Prof. Alexander Sergienko, studying the spatial properties of photonic entangled states. After his PhD, his research interests shifted towards quantum optics in solid-state systems, in particular on the interaction between single spins and photons. He moved to the Netherlands for two post-doctoral positions, one in Leiden with Prof. Dirk Boumeester on cavity quantum electrodynamics with self-assembled quantum dots and one in Delft with Prof. Ronald Hanson on single spins associated with defects in diamond.

Designs of Advanced Quantum Information Systems with Si:P alloy (27 March, 2017)

Speaker: Dr. Hoon Ryu

Abstract

Silicon(Si)-based quantum computing has attracted attention since Si is known to have the extremely log decoherence time that is suitable to conserve quantum information (Qubits). Rapid progress in the scanning tunneling microscope (STM) lithography opened the possibility for designs of the core cell of Si-based quantum computer as well as other novel devices such as ultra-thin interconnectors and extremely shallow junctions etc., by integrating Phosphorus (P) atoms in bulk Si with a 0.5 nm precision. Needs for the corresponding modeling researches, therefore, have been also increased to predesign such systems&devices with consideration of diverse atomistic effects. In this seminar, (1) we brief the core logistics of charge-based quantum computing using single P atoms in Si layers, (2) introduce the recent modeling works for physically realized P quantum dots in bulk Si and (3) highly doped P nanowires in Si that can be used as ultrathin interconnects in read-out circuits. (4) Finally, we introduce our in-house code and address the particular need for simulations coupled to the high performance computing, to guide designs of scalable Si-based qubit systems that integrate many P donors.

Biography

Hoon Ryu received BSEE in Seoul National University (Republic of Korea), MSEE and PhD in Stanford and Purdue University (USA), respectively. He was with System LSI division, Samsung Electronics Corp., and is now with National Institute of Supercomputing and Networking, Korea Institute of Science and Technology information (KISTI), where he works as a principal researcher. He was one of the core developers of 3D NanoElectronics MOdeling tool (NEMO-3D) in Purdue University, and now leads the Intel Parallel Computing Center (IPCC) in KISTI. His research interest covers modelling researches of advanced nanoscale devices, and high performance computing with a focus on parallelization and performance optimization of large-scale PDE (partial differential equation) problems.

Studying Nanoscale Interfaces in 2D-3D Heterojunctions (23 March, 2017)

Speaker: Prof. B. R. Mehta

Abstract

Studying the nature of interface between two dissimilar semiconductors has ever been a complex experimental and theoretical issue. Due to the extremely small thickness of 2D materials, studying the junction involving a 2D layered materials is even more challenging.  In this presentation, our recent CAFM and KPFM based experiments on understanding the nature of nanoscale interface formed between Graphene-Si, MoS2-ZnS and CdS-CZTS junctions will be presented. Surface potential changes at the graphene-Si junctions under light conditions have been examined using Kelvin probe force microscopy investigations in surface and junctions configurations. Voc nanoscale maps derived from these measurements show that topographical impurities and wrinkled boundaries on the graphene surface affect junction performance. In a separate study, patterned MoS2 2D layers having feature size varying from 10 um to 1 um have been grown by a combination of stencil lithography and magnetron sputtering technique. Structural, optical and junction properties of composite layers having wide band gap ZnS films and 2D MoS2 layers have been investigated. 2D heterojunction having mono and few layers MoS2 thickness result in high interface photovoltage in comparison to bulk MoS2 layer. KPFM based difference method has been used to observe the nanoscale changes in the junction behaviour at the grain boundaries with respect to crystalline grain in ZnO/CdS/CZTS/Mo device. A direct measurement and nanoscale mapping of an atomically thin junction in the final finished device without any adverse influence of contact layers, adsorbates and surface impurities are some of the important highlights of the present methodology.

Biography

Prof. B. R. Mehta is currently Schlumberger Chair Professor of Semiconductor Physics at Indian Institute of Technology Delhi, New Delhi, India. He is also Institute level Dean of Research and Development. He did his M.Sc. in Physics from Punjabi University Patiala, M. Tech in Solid State Materials and Ph. D in Physics from IIT Delhi. He has worked as post-doctoral fellow at University of British Columbia, Canada; guest scientist at University of Saarbrucken, Germany; and guest professor at University of Duisburg, Germany. His major research interests are; Science and Technology of Thin Films and Nanostructured Materials for Solar Cell, Resistive Memory, Thermoelectric and Gas Sensor Devices. He is the recipient of MRSI Medal (Material Research Society of India, 2002), DAAD Fellowship (Deutscher Akademischer Austausch Dienst, 2000) and Marie Curie International Fellowship (European Commission, 2006) and Material Science Prize of MRS India 2017. He is on the Editorial Board of Journal of Nanoscience and Nanotechnology and has about 200 journal publications. One of his projects-NanoSwitch- has been selected by European Commission as a Success Story project.

Comparison of Data with Multiple Degrees of Freedom for EMC Applications (22 February, 2017)

Speaker: Professor Alistair Duffy

Abstract: EMC data is increasingly multi-dimensional with, for example, ready access to simulation technology producing surface or volumetric analysis on modest computing platforms.  This means that a method to compare results of model iterations is now essential in EMC analysis.  This paper looks at a technique that can objectively quantify differences in this multi-dimensional data based on the Feature Selective Validation (FSV) method.  The talk provides an overview of the FSV method and then demonstrates how this can be applied to multi-dimensional data, with verification of performance based on image quality assessment.

Biography

Alistair Duffy is Professor of Electromagnetics and Head of Research and Innovation in the Faculty of Technology at De Montfort University, Leicester, UK.  He received the Bachelor’s degree in electrical and electronic engineering and the M.Eng. degree from University College, Cardiff, UK, in 1988 and 1989, respectively.  After receiving the Master’s degree, he joined the research group of professors Christopoulos and Benson at Nottingham University. There he worked on experimental validation of numerical modeling and received his Ph.D. in 1993.  Dr. Duffy completed his professional education in 2004 with an MBA from Open University, UK.  He is widely published, with over 200 technical papers and articles, mostly on his research interests of validation of computational electromagnetics; physical layer components, particularly communications cabling, and electromagnetic compatibility testing.  

Dr. Duffy has contributed to many successful conferences through refereeing functions or organizing committee responsibilities.  He currently serves on the Board of Directors of the International Wire and Cable Symposium, which attracts approximately 1,000 delegates annually.  He also serves on the Board of Directors of the EMC Society, taking up the role of Vice President for Conferences for the 2017 and 2018 sessions. He is an Associate Editor for the IEEE Transactions on EMC and an Associate Editor of the ACES Journal.  Other professional activities include standards body work in the UK (British Standards Institute) and in the IEEE, where he is currently Chair of the EMC Society's Standards Development and Education Committee (SDECom).  He is also the Society’s Global EMC Symposium Coordinator.  From 2008 to 2009 he served the IEEE EMC Society as a Distinguished Lecturer.  In 2015, Dr. Duffy was elected to the grade of IEEE Fellow for the development of validation methods in computational electromagnetics.

Dr. Duffy was a Series Editor for undergraduate textbooks published by Butterworth-Heinemann (now part of Elsevier) and SciTech Publishing (now part of the IET) on EMC.    He has supervised 20 Ph.D. students during his career.

Characterisation of Filamentary and Non-filamentary Resistive Switching Memory (RRAM) (20 January, 2017)

Speaker: Prof Wei Zhang

Abstract: The latest development in Resistive Switching Memory (RRAM) device technology will be reviewed and its future development and application in neuromorphic computing for IoT and in programmable computing will be discussed. The latest results at LJMU will be presented, including the ones published at IEDM 2016 and VLSI Technology Symposium 2016. A novel Random-Telegraph-Noise based characterisation technique has been developed at LJMU, which, for the first time, provides non-destructive evidence to a range of switching and failure mechanisms in state-of-the-arts filamentary and non-filamentary RRAM devices.

 

Short Bio: Wei Zhang is a Professor of Nano-electronics at Liverpool John Moores University. He is the leader of the memory device research area at LJMU. He specialises in the quality and reliability assessment of novel dielectrics and structures in resistive-RAM memories, Flash memories, Si and Ge based MOSFETs, and GaN devices. Prof. Zhang has been the principal investigator and co-investigator of a number of research projects with a total value of over £2.5 million, supported by EPSRC and the world-leading IMEC Memory Device Consortium whose members include Intel, Micron, Samsung, SanDisk, SK Hynix and Toshiba. In 2007 he worked at IMEC for 6 months and has since led a successful collaboration with the consortium for 10 years on developing future generation memory devices.  His publications are predominantly in world-leading international journals with high ISI impact factors, including Applied Physics Letters, IEEE Electron Device Letters, IEEE Transactions on Electron Devices. He co-authored 9 papers in the flagship IEEE International Electron Device Meeting (IEDM) and 5 papers in IEEE Symposium on VLSI Technology (VLSI) since 2007. 

 

Tea/coffee + biscuits will be served. All welcome!

The non-equilibrium Green's function approach: modeling of electronic and opto-electronic nano-devices (30 November, 2016)

Speaker: Prof Marc Bescond

For almost two decades, the non-equilibrium Green's function (NEGF) approach has been intensively developed to perform realistic modeling of quantum transport phenomena in nano-structures and devices [1].  After a brief presentation of the NEGF method, the seminar will first address the impact of a single dopant impurity [2,3] and the access region geometry [4] in ultimate silicon nanowire transistors. In the second part, we will show that it is possible to treat electron-photon interactions and to apply this formalism to the modeling and optimization of III-V third generation solar cells [5]. We will discuss in the last section about an alternative treatment of inelastic interactions in NEGF [6] that significantly reduce the computational time.

[1] H. Haug and A.-P. Jauho, Quantum Kinetics in Transport and Optics of Semiconductors, Vol. 123 of Springer Series in Solid-State Sciences (Springer, Berlin, New York, 1996).

[2] H. Carrillo-Nuñez, M. Bescond, N. Cavassilas, E. Dib, M. Lannoo, J. Appl. Phys., 116, 164505 (2014).

[3] M. Bescond, H. H. Carrillo-Nuñez, S. Berrada, N. Cavassilas and M. Lannoo, Solid State Electron. 122, 1 (2016).

[4] S. Berrada, M. Bescond, N. Cavassilas, L. Raymond and M. Lannoo, Appl. Phys. Lett. 107, 153508 (2015).

[5] N. Cavassilas, C. Gelly, F. Michelini, M. Bescond, IEEE Journal of Photovoltaics, 5, 1621 (2015).

[6] Y. Lee, M. Lannoo, N. Cavassilas, M. Luisier, and M. Bescond, Phys. Rev. B 93, 205411 (2016).

Electronic Systems Design Centre Annual Lecture: From ultraslow plasmons to ultrafast drug discovery (07 October, 2016)

Speaker: Prof Donhee Ham

As part of Prof Donhee Ham's visit to the School of Engineering he will deliver the Electronic Systems Design Centre Annual Lecture.

Abstract
We develop solid-state devices and circuits for applications in EE, biology, and physics. I will highlight these efforts with selected recent works:

(1) Dimensionality profoundly influences condensed-matter electron behaviors, with 2D conductors enabling discoveries of intriguing fundamental phenomena. One great effect of this reduced dimensionality concerns ultraslow plasmons. We obtained 2D plasmons 700× slower than free-space light. These ultraslow plasmons open up new exciting vistas for light manipulation, light-matter interaction, and bandgap-less gain. I will present a host of 2D plasmonic circuits that manipulate light in a broad variety of ways, and discuss 2D plasmonics experiments to measure the mass of massless graphene electrons and to obtain bandgap-less plasmonic gain.

(2) NMR spectroscopy that can elucidate structure and function of biomolecules at atomic resolution is a paramount analytical tool in biology and medicine and has proven enormously fruitful in pharmaceutical screening, structural biology, and metabolomics. But it suffers critically from inherently low throughput. I will share our program to develop a massively parallel––thus ultrahigh throughput––biomolecular NMR paradigm by exploiting silicon chip technology, and its applications in structural biology, drug discovery, and metabolomics.

(3) Another biotech work is to create, in collaboration with Prof. Hongkun Park, CMOS-assisted vertical nanowire arrays as a new neurotechnology tool that parallelizes intracellular access into neurons. Experimentations with this nano-bio interface will be discussed together with its applications in neurobiology, implanted technology, and brain machine interface.

Biography
Donhee Ham is Gordon McKay Professor of Applied Physics and EE at Harvard. He earned a B.S. in physics from Seoul National Univ., graduating atop the College of Natural Sciences with Presidential Prize and Physics Gold Medal. Following a military service in Korea, he went to Caltech for graduate training in physics; he worked on relativistic astrophysics while in physics, and later obtained a Ph.D. in EE winning the Charles Wilts best thesis award. His doctoral work examined the statistical physics of electrical circuits. He was the recipient of the IBM Doctoral Fellowship, Li Ming Scholarship, IBM Faculty Partnership Award, IBM Research Design Challenge Award, and Korea Foundation of Advanced Studies Fellowship. He was recognized by MIT Technology Review as among the top 35 young innovators in 2008 (TR35). He was a 4-time Harvard Yearbook Favorite Professor (2011-2014), and among 8 Harvard Thinks Big speakers in 2012 chosen by college-wide votes. Other experiences include LIGO, IBM Watson Research, consulting visiting professorship at POSTECH, distinguished visiting professorship at Seoul National Univ., TPCs in IEEE ISSCC and IEEE ASSCC, advisory board for IEEE ISCAS, guest editorship for IEEE JSSC, IEEE SSC Distinguished Lecturer, and associate editorship for IEEE Tbiocas.

Resonant-Tunnelling-Diode Terahertz Oscillators and its Applications (06 October, 2016)

Speaker: Prof Safumi Suzuki

Abstract
Compact and coherent source is a key component for various applications of the terahertz wave. We report on our recent results of terahertz oscillators using resonant tunnelling diodes (RTDs). The RTD is an InGaAs/AlAs double-barrier structure on InP substrate, and integrated with a planar slot antenna as a resonator and radiator. The output power is obtained from the substrate side through a Si lens. To achieve high-frequency oscillation, a narrow quantum well and an optimized collector spacer thickness were used. The former reduces the electron dwell time in the resonant tunneling region and the latter simultaneously reduces the electron transit time and the capacitance at the collector depletion region. The conduction loss of the slot antenna was also reduced with an optimized antenna length and an improved air bridge structure between the RTD and antenna. By these structures, fundamental oscillation up to 1.92 THz were obtained at room temperature. Oscillation above 2 THz is further expected in theoretical calculation. An oscillator with dipole antenna array, in which a Si lens is unnecessary, was fabricated. In a preliminary experiment, output power of 440 µW was obtained at 0.9 THz in a three-element array. Wireless data transmission using direct intensity modulation was demonstrated with the data rate of 34 Gbps and the bit error rate below the forward error correction limit. By integrating a varactor into the slot antenna, electrical frequency tuning was achieved with a tuning range of 580-900 GHz in an array device. Application of frequency-tunable RTD oscillators to measurements of absorption spectra was also demonstrated.

Biography
Safumi Suzuki received the B.E. degree in Electrical and Electronic Engineering and the M.E. and D.E. degrees in Electronics and Applied Physics from the Tokyo Institute of Technology, Japan, in 2005, 2007, and 2009, respectively. From 2009 to 2014, he was an Assistant Professor in the Department of Electronics and Applied Physics, Tokyo Institute of Technology, and was an Associate Professor in the Department of Physical Electronics from 2014 to 2016. He has been an Associate Professor in the Department of Electrical and Electronic Engineering since 2016. He is currently engaged in research on THz electron devices.

ICs Design Techniques for Space Applications: from Digital to Mixed-signal (05 October, 2016)

Speaker: Dr Umberto Gatti

Abstract
In some environments such as space and avionics altitudes, electronic components must have a certain level of radiation hardness in terms of Total Ionizing Dose and Single Event Effects (depending on the final application). Commercial integrated technologies do not have a sufficient radiation resiliency to guarantee a good reliability for all these environments, leading to the need to find new solutions. In this seminar the basic requirements, issues and solutions related to the design of custom digital ICs for these applications will be firstly discussed, with particular focus on the so-called Radiation-Hardened-By-Design (RHBD) techniques. The development of RHBD digital libraries using standard sub-micrometric CMOS processes (from 180nm down to 130nm) is briefly presented. The libraries include also rad-hard static memory cells which have been used to implement several SRAM memory devices, whose sizes range from 512kbit up to 4Mbit. Similar RHBD techniques have been propagated to mixed-signal ICs, since the main part of the available commercial analog components is made radiation resistant only by using dedicated packages or processes, with penalties on costs and area. A quick overview of issues related to the design and layout of data converters and auxiliary blocks are presented. A final section of the seminar is devoted to the description of the test techniques of the above circuits under radiations (namely Gamma ray and Heavy Ions) and related criticalities.

Biography
Dr. Umberto Gatti received the Laurea degree (summa cum laude) in Electronic Engineering and the Ph.D. in Electronics and Information Engineering from the University of Pavia, Italy, in 1987 and 1992, respectively. From 1993 to 1999, he worked in the Central R&D Lab of Italtel, Italy, and then in the R&D Lab of Siemens, Italy, as Sr. ASIC Engineer. Besides developing analog and mixed analog-digital CMOS/BiCMOS ICs for telecom (data converters, base-band wireless transceivers, burst mode PON interfaces), he was the coordinator of funded projects under the frameworks of FP and Eureka, focused on high-speed Nyquist rate and sigma-delta converters. In 2007 he joined Nokia Siemens Networks, Italy, where he was a Sr. Power Supply Architect for telecom equipment. Currently he is member of the Executive Staff of RedCat Devices, Italy, and also holds research cooperation with the University of Pavia. His present research interests are in the area of CMOS mixed-signal ICs, in particular in rad-hard digital libraries and static memories (SRAMs), data converters, power management and testing techniques under irradiations. He holds 2 international patents, is co-author of more than 60 papers and serves also as reviewer for IEEE magazines and conferences. He is also Member of the Information Technology Commission at Engineers Professional Association of Pavia, where he takes care of the organization of educational activities for Engineering Professionals.

Recent Progress and Status of Nitride and Photonic Device Research for Next Generation Energy Efficient Network in Korea (03 October, 2016)

Speaker: Dr Eun-Soo Nam

Abstract
Data center networks form the backbone infrastructure of many large-scale enterprise applications as well as emerging cloud-based services. This is in line with the rapid development in the field of Internet of Things (IoT). Core networks, including backbones and data centers, are expected to have the biggest increase in electricity consumption in the future, since their energy consumption is increasing almost proportionally to the traffic. Optical technologies are widely accepted as a future proof and cost-effective approach for supporting the future traffic demands and services at the lowest energy footprint possible. The future data center networks with optical interconnects are supported by several novel architectures, such as optical circuits, optical switching, optical OFDM, and others. In this talk, we extensively review recent research findings and emerging technologies, such as a Gallium-Nitride transistors (GaN), digital coherent detection and the flexible grid dense wavelength-division multiplexed channel technology for SDN.

Biography
Dr Eun-Soo Nam received a B.Sc. degree in Physics from Kyung-Pook National University, Daegu, Korea in 1983, and M.Sc. and Ph.D. degrees in Physics from the State University of New York, Buffalo, USA, in 1992 and 1994, respectively. In 1994, he joined the Electronics and Telecommunications Research Institute (ETRI), Daejeon, Korea, where his research involved compound semiconductor devices, including GaAs and GaN based high frequency power device platform, long wavelength InP semiconductor photonic devices, OEIC (Optoelectronic Integrated Circuit) for microwave circuits, and SDN network devices. In 2006, he was a Visiting Scholar at the Division of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA. He is now Vice President, managing the materials and devices R&D in ETRI, Korea. He is the recipient of many distinguished awards and honors, including the 2014 Korean Prime Minister's award for global leadership, 2010 ETRI Outstanding Electrical and Computer Engineer Award, and Best Paper Awards. He has published more than 100 reviewed papers, and presented many plenary talks in international meetings. He is also a co-inventor of 90 international patents in the fields of RF devices and photonics. He is currently serving as the Korean Optoelectronic Society Vice President for Technical Activities.

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