Vincent Ginis

Job opening: Teaching Assistant – PhD student in Data Analytics, Artificial Intelligence, and Complexity Science

Position

Teaching:

In this position, you will function as one of the teaching assistants for various Mathematics courses (Calculus, Linear Algebra, Advanced Mathematics). You will be teaching exercises, supervising students, and supervising master and bachelor theses.

Research:

The Data Lab is a multidisciplinary group of enthusiastic researchers at the Vrije Universiteit Brussel. We exploit the link between data analysis and the properties of complex systems in analyzing interdisciplinary issues. In doing so, we develop data analysis tools based on information theory, nonlinear dynamics, and statistical physics. This combination enables an imaginative, cross-disciplinary, and insightful approach to complex problems. The research's primary focus is on gaining insight into the operation and application of artificial neural networks.

Your Profile

- You are curious, eager to learn, and creative.
- You have obtained a Master's degree in a relevant field: Mathematics, Physics, Engineering, Computer Science, Commercial Engineering, or (Applied) Economics.
- A teacher's degree or teaching experience is a definite plus.
- A sound basis of symbolic and numeric programming languages (e.g., Mathematica, Matlab, Python, C++) is a definite plus.

Female candidates and candidates from groups that are currently underrepresented are particularly encouraged to apply.

Offer

As an employee of the Vrije Universiteit Brussel, you work in a dynamic, diverse, and multilingual environment. Our campuses are both located in the middle of a green oasis on the edge of the center of the capital of Flanders, Belgium, and Europe. This center, with all its possibilities, can be reached by public transport in less than half an hour.

Depending on your experience and your academic merits, you will receive a salary in one of the scales established by the government. Hospitalization insurance and free use of public transport for commuting are standard conditions of employment. If you prefer to cycle to work, you will also be compensated for this. Both campuses have extensive sports facilities at your disposal, and a nursery is within walking distance.

Apply

For more information, please contact Prof. dr. Vincent Ginis, mail: vincent.ginis@vub.be, +32-2-6148339.

To apply, please submit your motivation letter, CV, copies of transcripts/M.Sc. Degree. You can apply for this job no later than February 28, 2021, by sending all the requested documents to vincent.ginis@vub.be. Applicants will be considered on a rolling basis.

Harnessing near-field light

Research paves the way for high resolution microscopy, more efficient optical communication and more
By Leah Burrows

There are many types of light — some visible and some invisible to the human eye.
For example, polarized light is invisible because even though it hits our eyes, our brain doesn’t have the tools to process it. But there is another type of light that is invisible because it never reaches our eyes. When light bounces off a surface, a small part of it sticks and remains behind. This type of light is called near-field light.

If harnessed, near-field light would have enormous potential for ultra-high-resolution microscopy, particle manipulation and optical communications. But unlike far-field light — the light that does reach our eyes — researchers haven’t developed a comprehensive toolkit to harness and manipulate it. At least, not yet.

“Today, we have a lot of tools and techniques to design what far-field light looks like,” said Vincent Ginis, a visiting scholar at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS). “We have lenses, telescopes, prisms and holograms. All these things enable us to sculpt freely propagating light in three-dimensional space. We hardly have any tools to do the same thing with near-field light.”

Until now. SEAS researchers have developed a system to mold near-field light at a distance, opening the door to unprecedented control over this powerful, unexplored type of light. The research is published in Science.

In order to manipulate near-field light, the researchers developed a device in which confined light bounces back and forth between two converters. When the light hits the converter, it changes mode and bounces back. As the light modes interact with each other, the near-field component of the light, which is sticks to the surface of the device, also changes. When all the different configurations of the near-field light are superimposed on each other, it creates a specific shape. The researchers can pre-program that shape by tuning the mode and amplitude of the bouncing light.

“When all these modes exist together, they add up to create a near-field landscape on the surface of the device,” said Marco Piccardo, a research associate at SEAS and co-author of the paper. “The shape of the landscape is determined by the combined properties of the cascading light.”

It’s a bit like music, said Ginis.

“The music that you are hearing is the superposition of many notes or modes. One note alone isn’t much but taken together you can generate any type of music,” said Ginis.

Over course, music operates in time while this near-field generator operates in three-dimensional shape.

To demonstrate their design, the researchers molded near-field light into the shape of an elephant. Or, more specifically, an elephant inside a boa constructor, an homage to the play on dimensions in Antoine de Saint-Exupéry’s classic The Little Prince.

The researchers also shaped the light into a curve, a plateau and a straight line.

“This research provides a new path towards unprecedented three-dimensional control of near-field light,” said Capasso. “We show that we could eventually have the same degree of control in the near-field as we have in far-field light.”

The paper was co-authored by Michele Tamagnone, Jinsheng Lu, Min Qiu, and Simon Kheifets. It was supported in part by the Air Force Office of Scientific Research under grant no AFOSR FA9550-14-1-0389.

To what extent can we shift the frequency of signals using time-dependent surfaces?

Time-dependent metasurfaces are playing an increasingly important role as a platform to change the frequency of optical signals. This is a result of the fact that the interaction length through a single surface is so small that it is nearly impossible to generate new spectral components using nonlinear effects. However, although the idea to generate new spectral components using time-dependent metasurfaces has been around for quite some time, this emerging research field is still lacking a coherent, self-consistent framework that explains how frequencies of optical pulses can be manipulated.

In this manuscript, we introduce such a general framework that allows for the understanding and designing of time-dependent metasurfaces that shift the frequencies of electromagnetic pulses. Based on an analytical model and FDTD numerical simulations, we obtain physical insight into the complex process that occurs when broadband electromagnetic pulses interact with time-varying metasurfaces. In particular, we find that there is an intriguing relation between the bandwidth of the incident pulse, the targeted frequency shift, and the number of Lorentzian resonators that need to be implemented. We also demonstrate that in certain parameter regimes, pulse distortion and deviating pulse amplitudes cannot be avoided.

We thus expose a fundamental limitation of time-dependent metasurfaces. These results are independent of the mechanism that generates the time-dependence and they do not dependent on the operating frequencies, nor the geometry, size or material of the unit cell. They are a direct result of the subtle interplay of Lorentzian resonances. In addition, we provide a widely usable design method for anyone who wants to use time-dependent metasurfaces to shift frequencies of electromagnetic pulses.

The manuscript was published in Physical Review B as a Rapid Communication and can be found here. Full Pdf.

Open Science Conference 2018 – Back-to-Back Belgium-European Commission

Open Science goes beyond open access to publication, encompassing the sharing of open research data and citizen science. It also paves the way for the development of appropriate metrics, incentives and rewards. Since Open Science solutions have to be developed in a coherent way both at national and European level, this conference combines a discussion of the Belgian Open Science policies with debates relating to a H2020 Policy Support Facility Mutual Learning Exercise on Open Science with a prominent European outlook. Special emphasis is put on researchers working in an Open Science environment, skilling, incentivising and rewarding them.

I am honored to be one of the Belgian researchers in the panel debating open science and open access (Plan S).

Opportunities and challenges for implementing Plan S

Publicly funded research should not be hidden behind payment walls, but it should also not become a pay-to-publish game.

In a joint statement by several Young Academies, including the Belgian, a convinced “yes” to Open Access sounds. At the same time, the young scientists call for reflection on the best possible implementation of Plan S: stakeholder consultation with, among others, Young Academies is necessary.

The statement was authored by Koen Vermeir, Moritz Riede and Sabina Leonelli on behalf of the Global Young Academy (GYA), based on input from and discussion with the members of the respective Young Academies provided by Ericka Johnson and Jens Hjerling-Leffler (Young Academy of Sweden), Gergely Toldi (on behalf of the Hungarian National Young Academy Initiative), Ian Overton (Young Academy of Scotland), Olli Peltola (Young Academy Finland), Rens van de Schoot (Dutch Young Academy), Udi Sommer (Israel Young Acad- emy) and Vincent Ginis (Belgian Young Academy).

Mindblowers 2018

For the second year in a row, KVS and VUB unite forces to kick off the academic and cultural year. At MINDBLOWERS, don’t expect any puffed-up speeches or highfalutin lectures. No: short, powerful interventions at the crossroads of arts, culture, research and reflection. At the intersection of activism, ‘artivism’ and academia.

This second edition of MINDBLOWERS will be an ode to the imagination. Academics and artists both work from a place of curiosity, wonder, freedom, creativity and critical thinking. Only by imagining and envisioning the impossible can arts and science create new horizons.