Author Archives: Lode

New jobs for real-time holography applications

We are currently looking for 2 new colleagues at imecc to strengthen our team for real-time holography applications. We are currently looking for a Senior mixed signal circuit design engineer and a System architect. Are you looking for a new and exciting, multidisciplinary challenge?

Melting gold at room temperature – See how in our new paper in Physical Review Materials

Our latest paper, entitled “Electric-field-controlled reversible order-disorder switching of a metal tip surface” has been published in Physical Review Materials.

In this work led by Ludvig de Knoop and Mikael Juhani Kuisma, the deformation at the very tip of a gold nanocone was studied on the atomic level using TEM (transmission electron microscopy). When a large electric field is applied, the topmost atomic layers of the cone make a reversible switch from a crystalline to a disordered state. When the electric field exceed a threshold of about 25V/nm, gold atoms can be evaporated from the tip at room temperature. These observations were also studied using ab initio molecular dynamics (AIMD) simulations, which were in excellent agreement with the measured data.

The samples for these experiments were fabricated during one of my last work days at Chalmers, using our transfer protocol to decorate a gold wire with a pattern of nanocones for use in the TEM experiments.

Presentation at Advanced Photonics Congress in Zurich

On July 5th, I will be presenting some recent results at the Advanced Photonics Congress in Zurich about our Niobium Oxide based waveguide platform for visible light applications. This platform we are developing at imec has the advantage that the refractive index of Niobium Oxide is significantly larger than that one of Silicon Nitride, the most common waveguide platform in this wavelength range. Increasing the refractive index of a waveguide allows to scale down the component sizes significantly, allowing to increase the density of photonic integrated circuits.

More details can be found in our abstract or at the conference.

New paper published in IEEE Photonics Technology Letters

Our latest paper entitled Grating Coupler Design for Reduced Back-Reflections just got published in IEEE Photonics Technology Letters.

This work was led by my colleague Jeong Hwan Song and it illustrates how efficient grating couplers with low back reflections can be made in our silicon nitride waveguide platform. In many photonic applications, back-reflections from the grating couplers can result in undesired interferences in the components that are being tested. By designing asymmetric grating couplers, these back reflections can be suppressed by over 5 dB with almost no impact on the coupling efficiency.

New paper published in Scientific Reports

Our latest paper entitled Multiscale Conformal Pattern Transfer just got published in Scientific Reports.

In this work we show a very versatile platform for decorating 3D objects with nano- or microscale-structures, by means of a transfer lithography protocol. The structures to be transferred are first defined by means of a conventional lithography method of choice on top of 10 nm thick amorphous carbon film on top of a sacrificial layer. After submerging the parent substrate in a selective etch solution in order to dissolve the sacrificial layer, the pattern is transferred to the air/water-interface by means of the parent substrate. Subsequently the 3D host substrate is used to pick up the structures to be transferred, and if required the carbon film is etched to finalise the transfer. We illustrate this technique for a variety of nano- and micro-structures that can be applied in many different fields of research.

This work was conducted during my Post-doctoral studies at Chalmers University and was the result of a close collaboration between different research groups there.

pattern_transfer
The Chalmers University logo with a scale of 100 micrometer is transferred onto a commercial LED and projected it with 500 times magnification onto a wall using a microscope objective. The roughness of the LED surface is clearly visible in the microscope pictures and the projection.

New paper from the PNV project published in Nanoscale

Our latest paper entitled Highly conformal fabrication of nanopatterns on non-planar surfaces was published recently in Nanoscale. In this work lead by my former colleague Inès Massiot and in close collaboration with my current employer imec, we show the potential for applying colloidal lithography on highly non-planar substrates. We show how nanopatterning silicon substrates with micron-scale roughness results in an increase of the efficiency for photovoltaic cells with as much as 50%.

PhotoNVoltaics project featured in imec magazine

The PhotoNVoltaics project, part of the EU FP7-framework has ended now. The highlights of the project are discussed in the latest version of the IMEC magazine.

On a personal note, this was a very interesting project for me, as it allowed me to stay in touch with my former colleagues at imec during my 3 year stay at Chalmers University of Technology in Sweden. Thanks to everyone that made this such an enjoyable experience!

New paper published in Nanoscale

Our latest paper entitled Dimer-on-mirror SERS substrates with attogram sensitivity fabricated by colloidal lithography was published today in Nanoscale. In this work lead by Aron Hakonen we studied the performance of colloidal lithography based substrates for ultra sensitive SERS spectroscopy, reaching attogram concentrations. Next to conventional measurements in the lab, the substrates also proved to perform superb for in-field experiments using a handheld device.

New paper published in Nano Letters

Our latest paper just got accepted in Nano Letters and is entitled “Active magnetoplasmonic ruler“. This work was lead by Irina Zubritskaya and performed in collaboration with our partners in CIC NanoGUNE in Donostia-San Sebastian and the University of Gothenburg.

In this work, we show how magnetoplasmonic dimers can be exploited as very sensitive plasmonic rulers, which will self-align towards the most optimal configuration due to the application of an external magnetic field. This opens up opportunities for future applications in bio-sensing and localized drug delivery among many others.

Hejdå Sverige, vi ses igen!

For those of you that are not Swedish, the title says: Goodbye Sweden, we’ll see each other again. After nearly 3 years living in Gothenburg, the time has nearly come to move on. In a bit less than 1 month, I’ll exchange Gothenburg for Leuven (Belgium). I will start working at imec again, now as “Photonics design engineer”. In that sense, I’ll be coming home again, even though the project will be totally different from my Ph. D. work in imec, or my post-doc work in Sweden. I’ll start working in the team of Xavier Rottenberg, in close collaboration with my former supervisor Pol Van Dorpe. The project is part of imec’s life science program, which is briefly outlined in the movie below.

The main idea is to use nanotechnology in order to come to new miniaturised lab-on-chip devices, which in future will lead to a dramatic reduction in health care spendings, while at the same time obtaining test results much faster than with current technologies. Needless to say that I like this challenge a lot, and look forward to coming home again in Leuven.

In fact, I must admit that the last 3 years have really flown by, which means that I truly enjoyed the time in Gothenburg. Therefore, I want to take the time to say thank you to quite some people that have been an important part of my life in the last few years.

Let’s start from the start, the reason why I moved to Sweden, being my job at Chalmers. Thanks a lot to my boss Sascha Dmitriev for offering me the opportunity to be part of his research team within the division of BioNanoPhotonics of Mikael Käll. I want to thank everybody in the department for the fun times we’ve had, both on the job and at social side activities. Apart from that, I also want to take the time to say thank you to some of our collaborators within Chalmers, most importantly the work done together with Eva Olsson. At the same time, I want to thank our hardcore magnetism friends from the Åkerman lab, namely Johan Åkerman and Randy Dumas, who were always there to help us out when our magnetism knowledge was to limited.

I was also fortunate enough to be involved in quite a few international collaborations, and I would like to thanks everybody involved. First of all, I want to thank everybody in the PhotoNVoltaics project, you are with too many to address every one of you individually. Also, I want to thank our friends Paolo Vavassori and Nicolò Maccaferri from NanoGUNE in San Sebastian, for the very fruitful collaboration. The same goes for my predecessor at Chalmers, Valentina Bonnani and her colleague Francesco Pineider in the university of Firenze. Also, I would like to thank many more collaborators from all around the world: Ilya Razdolski (Radboud University Nijmegen), Maxim Shcherbakov (Moscow State University, Russia), Niels Verellen (Imec, Belgium), Tavakol Pakizeh (K. N. Toosi University, Tehran, Iran), Daniel Higley (Stanford University, USA), Anke Sanz-Valesco (Chalmers, Sweden), Casey Miller (University of South Florida), and probably a few more that I forget at this time…

Obviously, there was also plenty of time to relax, and that often involved a few pints in the two Dubliner pubs at Kungsportsplatsen and Järntorget, where I made many, many, many friends. I want to thank everybody at Dubs for always making me feel welcome, you were my second home during the last 3 years. Now that we’re on the subject of Dubs, this immediately brings me to my freelance stagehand job at The Gothenburg Crew, with whom I enjoyed a lot of nice working nights over the past few years. Thanks in particular to Kevin for getting me into the crew, and arranging me a spot on the shows that I really didn’t want to miss (Metallica, Roger Waters, Volbeat, In Flames to just name a few). Also born – or should I say reborn? – at Dubs is our dart team The Assassins, with whom I spent so many lovely evenings. So thanks to our “manager” Scouse Steve, Gary – Shrek – McKiernan, Gerry – Gandalf – Lions, Gerrard – Gerry Jr. – O Callaghan, Davey G (THE best barman in town), Aidan and Andy. Hope to see the lot of you in Lommel and Edinburgh for some more Euro-League games, and I’ll promise I’ll bring the Belgian team over to Gothenburg next summer 😉

Oh, and before I forget: I couldn’t leave Sweden without throwing a party, so mark your calendar for the 9th of May if you want to join for a few beers and some good craic. (Check Facebook or your mail for more details ;-))