adding team

files/Publications.md

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+# Publications
+
+
+## Journal papers
+
+
+## Conferences
+
+
+## PhD thesis
+

files/Team.md

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+# Team
+
+
+## Core Team
+
+### Principal Investigator: Jan Genoe
+
+### Senior Staff
+
+### PhD students
+
+
+## Other contributors
+

files/VideoHolography.bib

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+@inproceedings{arturhermansGrowthThinFilm2018,
+  title = {Growth of Thin Film Organic Crystals with Strong Nonlinearity for On-Chip Second-Order Nonlinear Optics},
+  booktitle = {Proc. {{IEEE Photonics Benelux Symposium}}},
+  author = {{Artur Hermans} and {Robby Janneck} and {Cedric Rolin} and {S. Clemmen} and {Paul Heremans} and {Jan Genoe} and {Roel Baets}},
+  year = {November 15 - 16, 2018},
+  address = {{Brussels, Belgium}},
+  abstract = {We have measured strong second-harmonic generation in N-benzyl-2-methyl-4-nitroaniline (BNA) thin films at a fundamental wavelength of 1550 nm. The second-order nonlinearity was determined to be (61 {$\pm$} 10) pm/V, comparable to the benchmark nonlinear crystal LiNbO3. The crystals are grown by cooling BNA from its melting point to room temperature in the presence of a temperature gradient. This gives rise to millimeter-sized crystals with thicknesses of several 100 nanometers. Our results are a first step towards the implementation of second-order nonlinear functionalities in silicon nitride photonic integrated circuits, where monolithically integrated strongly nonlinear crystals are lacking}
+}
+
+@inproceedings{clementmercklingIntegratedPerovskitesOxides29,
+  title = {Integrated {{Perovskites Oxides}} on {{Silicon}}: {{From Optical}} to {{Quantum Applications}}},
+  booktitle = {241st {{ECS Meeting}}},
+  author = {{Clement Merckling} and {I. Ahmed} and {T. H. Wang} and {M. Kaviani} and {Jan Genoe} and {Stefan De Gendt}},
+  year = {29},
+  month = may,
+  publisher = {{ECS}},
+  address = {{Vancovouver}}
+}
+
+@inproceedings{croesSubwavelengthCustomReprogrammable2022,
+  title = {Sub-Wavelength Custom Reprogrammable Active Photonic Platform for High-Resolution Beam Shaping and Holography},
+  booktitle = {Active {{Photonic Platforms}} 2022},
+  author = {Croes, Guillaume and Gehlhaar, Robert and Genoe, Jan},
+  year = {2022},
+  month = oct,
+  volume = {PC12196},
+  pages = {PC1219619},
+  publisher = {{SPIE}},
+  address = {{San Diego, California, United States}},
+  doi = {10.1117/12.2632022},
+  urldate = {2022-12-12},
+  abstract = {We provide insight into the operation and driving mechanism of an electro-optic spatial light modulator based on a Barium Titanate waveguide and an optically transparent electrode cladding layer. We employ electric field simulations, non-linear optics and techniques found in signal analysis to achieve sub-wavelength refractive index modulation of the waveguide. Our generic approach is applicable to Pockels and Kerr cells as well as liquid crystals and is capable of high-quality beam shaping and sensing. In this presentation, we focus on the operation of a reprogrammable Active Photonic Platform in the context of high-quality video holography.}
+}
+
+@inproceedings{guillaumecroesHologramWavefrontShaping2023,
+  title = {Hologram Wavefront Shaping by a Non-Linear Electro-Optic Spatial Light Modulator},
+  booktitle = {Holography: {{Advances}} and {{Modern Trends VIII}}},
+  author = {{Guillaume Croes} and {Robert Gehlhaar} and {Jan Genoe}},
+  year = {2023},
+  month = apr,
+  address = {{Prague, Czech Republic}},
+  abstract = {We present a novel waveguide-based approach that enables custom wavefront shaping and holography by employing a non-linear electro-optic spatial light modulator. The device consists of a metamaterial electrode cladding that modulates the Barium Titanate waveguide on a sub-wavelength scale. Our generic modulation principle employs electric fields and non-linear optics to create any desired wavefront and is applicable to Pockels and Kerr cells as well as liquid crystals. Here, we present the operation of our tunable waveguide based SLM, specifically for its use as high-quality holographic display}
+}
+
+@inproceedings{guillaumecroesNonlinearElectroopticModelling2020,
+  ids = {croesNonlinearElectroopticModelling2020},
+  title = {Non-Linear Electro-Optic Modelling of a {{Barium Titanate}} Grating Coupler},
+  booktitle = {Proc {{SPIE}} :{{Optical Modeling}} and {{Performance Predictions XI}}},
+  author = {{Guillaume Croes} and {Nicolae Smolentsev} and {Tsang Hsuan Wang} and {Robert Gehlhaar} and {Jan Genoe}},
+  year = {2020},
+  month = aug,
+  volume = {11484},
+  pages = {114840D},
+  publisher = {{SPIE}},
+  address = {{Online Only, United States}},
+  doi = {10.1117/12.2568032},
+  abstract = {We provide insight into the driving mechanisms and requirements to create an electro-optic spatial light modulator based on a Barium Titanate waveguide and an optically transparent electrode cladding layer. This cladding is made from alternating pillars of transparent conductive oxides and index matched dielectrics. We have developed a generic framework of electric field simulations and non-linear optics to create any desired modulation in an area of interest, applicable for liquid crystals, Pockels and Kerr cells. Targeting our device structure, we have evaluated several design parameters of the arbitrarily reprogrammable SLM, capable of optical beamforming and high-quality holograms.},
+  isbn = {978-1-5106-3774-0 978-1-5106-3775-7},
+  langid = {english}}
+}
+
+@article{guillaumecroesPhotonicMetamaterialSubwavelength2023,
+  title = {Photonic Metamaterial with a Subwavelength Electrode Pattern},
+  author = {{Guillaume Croes} and {Renaud Puybaret} and {Janusz Bogdanowicz} and {Umberto Celano} and {Robert Gehlhaar} and {Jan Genoe}},
+  year = {2023},
+  month = jun,
+  journal = {Applied Optics},
+  volume = {62},
+  number = {17},
+  pages = {F14-F20},
+  publisher = {{Optica Publishing Group}},
+  issn = {2155-3165},
+  doi = {10.1364/AO.481396},
+  urldate = {2023-04-13},
+  abstract = {The next generation of tunable photonics requires highly conductive and light inert interconnects that enable fast switching of phase, amplitude, and polarization modulators without reducing their efficiency. As such, metallic electrodes should be avoided, as they introduce significant parasitic losses. Transparent conductive oxides, on the other hand, offer reduced absorption due to their high bandgap and good conductivity due to their relatively high carrier concentration. Here, we present a metamaterial that enables electrodes to be in contact with the light active part of optoelectronic devices without the accompanying metallic losses and scattering. To this end, we use transparent conductive oxides and refractive index matched dielectrics as the metamaterial constituents. We present the metamaterial construction together with various characterization techniques that confirm the desired optical and electrical properties.},
+  copyright = {\textcopyright{} 2023 Optica Publishing Group},
+  langid = {english},
+  keywords = {Aluminum doped zinc oxide,Effective refractive index,Electrooptical modulators,Holographic displays,Refractive index,Spatial light modulators}
+}
+
+@article{mercklingInvitedIntegratedPerovskites2022,
+  title = {({{Invited}}) {{Integrated Perovskites Oxides}} on {{Silicon}}: {{From Optical}} to {{Quantum Applications}}},
+  shorttitle = {({{Invited}}) {{Integrated Perovskites Oxides}} on {{Silicon}}},
+  author = {Merckling, Clement and Ahmed, Islam and Tsang, Tsang Hsuan and Kaviani, Moloud and Genoe, Jan and Gendt, Stefan De},
+  year = {2022},
+  month = jul,
+  journal = {ECS Meeting Abstracts},
+  volume = {MA2022-01},
+  number = {19},
+  pages = {1060},
+  publisher = {{IOP Publishing}},
+  issn = {2151-2043},
+  doi = {10.1149/MA2022-01191060mtgabs},
+  urldate = {2022-09-30},
+  abstract = {With the slowing down of Moore's law, related to conventional scaling of integrated circuits, alternative technologies will require research effort for pushing the limits of new generations of electronic or photonic devices. Perovskite oxides with the ABO3 chemical formula have a very wide range of interesting intrinsic properties such as metal-insulator transition, ferroelectricity, pyroelectricity, piezoelectricity, ferromagnetic and superconductivity. For the integration of such oxides, it is of great interest to combine their properties with traditional electronic, memory and optical devices on the same silicon-based platform. In the context of high-speed chip-to-chip optical interconnects, compact high-resolution beam steering and video-rate RGB hologram generation require the integration of fast and efficient optical modulators on top of silicon CMOS devices. For these applications the integration of high quality electro-optical materials A defect-free material-stack deposition on silicon wafers is hence required. Among the possible materials options, barium titanate (BaTiO3) is one promising candidate due to its large intrinsic Pockels coefficients that can be obtained. In a first part of the talk, we will review the different options to integrate BaTiO3 on Silicon substrate though different templates to control the polarization direction and discuss the influence on the physical, electrical and optical properties. Then in the second section we will discuss the use of perovskites oxide in the field of topological based qubits which is one of the promising methods for realizing fault-tolerant computations. It is recognized that superconductor/topological insulator heterostructure interfaces may be a perfect host for the exotic "Majorana" particles. These have relevant topological protection nature as required for processing information. Therefore, the physics at the superconductor/topological insulator heterostructure interface need to be studied further, starting at the material level. In this work, a candidate material Barium Bismuthate (BBO) is studied utilizing the Oxide Molecular Beam Epitaxy (MBE) process. The perovskite structure provides opportunity for easily tailored functionality through substitutional doping. Incorporation of potassium into the lattice of BBO results in a superconducting phase with Curie temperature as high as \textasciitilde{} 30K. In addition, BBO is according to DFT based studies, predicted to form topological surface states when doped with Fluorine. In our work, we integrate BBO perovskite on Si(001) substrate, using an epitaxially grown strontium titanate (STO) single-crystalline buffer layer and discuss the structural and chemical properties of the heterostructure will be established by utilizing physical characterization techniques such as AFM, and TEM in later stages. This will go hand in hand with the understanding of the ARPES studies and related surface reconstruction of BBO observed by RHEED as a criterion for the high-quality films. This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreements No 864483 and 742299)},
+  langid = {english}
+}
+
+@inproceedings{t-hwangInterfaceControlCharacterization20,
+  title = {Interface {{Control}} and {{Characterization}} of {{SrTiO3}}/{{Si}}(001)},
+  booktitle = {Proc. {{E-MRS-fall}}},
+  author = {{T-H Wang} and {Robert Gehlhaar} and {T. Conard} and {Jan Genoe} and {Clement Merckling}},
+  year = {20},
+  publisher = {{MRS}},
+  address = {{online Only}},
+  abstract = {Epitaxially grown strontium titanate (SrTiO3, STO) is an essential interlayer that enables the integration of functional perovskite oxides on large scale substrates of Si(001) thus enabling a wide range of applications in electronics and photonics. As a buffer layer, the crystallinity of STO directly impacts the properties of the oxides on top. In this study, we varied the molecular oxygen exposure amount prior to the STO growth to control the SrO/Si interface conditions. We show how the oxygen not only impacts the interface but also the crystallinity and more interestingly the stoichiometry in the STO films. With overexposure of molecular oxygen, the chemical binding states show the formation of SiOx, resulting in amorphous growth of the STO. In addition, the stoichiometry of Sr/(Sr+Ti) ratio changed dramatically as the exposure amount increased. The change of crystal quality and stoichiometry is also reflected in the optical constants, with a reduction n k observed. The change of stoichiometry is linked to the formation energy of different oxides, confirming the importance of controlling the oxygen amount in direct STO epitaxy on Si substrates. Finally, additional annealing shows an improvement by reducing the absorption of the STO films, which is crucial for photonic applications.}
+}
+
+@article{tsang-hsuanwangInterfacialControlSrTiO32022,
+  ids = {wangInterfacialControlSrTiO32022b},
+  title = {Interfacial Control of {{SrTiO3}}/{{Si}}(001) Epitaxy and Its Effect on Physical and Optical Properties},
+  author = {{Tsang-Hsuan Wang} and {Robert Gehlhaar} and {Thierry Conard} and {Paola Favia} and {Jan Genoe} and {Clement Merckling}},
+  year = {2022},
+  month = mar,
+  journal = {Journal of Crystal Growth},
+  volume = {582},
+  pages = {126524},
+  issn = {0022-0248},
+  doi = {10.1016/j.jcrysgro.2022.126524},
+  urldate = {2022-01-17},
+  abstract = {The direct heteroepitaxy of strontium titanate (SrTiO3, STO) oxide on Si(001) substrate is an important step to integrate other functional perovskite oxides onto large scale wafers. In this study, we focused on the SrO interfacial layer in function of molecular oxygen gas exposure amount prior to the STO growth. The various formed interfaces showed large impact on the subsequent STO growth, including crystal quality and stoichiometry. The chemical binding states showed that the formation of thick SiOx interfacial layer was strongly correlated with the molecular oxygen exposure amount. More interestingly, the film stoichiometry is also strongly affected with overexposure, which resulted in optical properties degradation of the STO films. The STO optical constants, extracted from the spectroscopic ellipsometry (SE), exhibit obvious differences between crystalline and amorphous samples. Finally, post-deposition annealing was used to reduce the optical extinction, which is of primary importance for photonic applications.},
+  langid = {english},
+  keywords = {Interfaces,Reflection high energy electron diffraction, Molecular beam epitaxy, Perovskites,Titanium compounds},
+}
+
+@article{tsang-hsuanwangPolarizationControlEpitaxial2020,
+  ids = {wang2020polarizationpseudosubstrate},
+  title = {{Polarization control of epitaxial barium titanate (BaTiO3) grown by pulsed-laser deposition on a MBE-SrTiO3/Si(001) pseudo-substrate}},
+  author = {{Tsang-Hsuan Wang} and {Po-Chun (Brent) Hsu} and {Maxim Korytov} and {Jan Genoe} and {Clement Merckling}},
+  year = {2020},
+  month = sep,
+  journal = {Journal of Applied Physics},
+  volume = {128},
+  number = {10},
+  pages = {104104},
+  publisher = {{American Institute of Physics}},
+  issn = {0021-8979},
+  doi = {10.1063/5.0019980},
+  urldate = {2020-09-14},
+  abstract = {Barium titanate (BaTiO3 or BTO) is a perovskite structure material with interesting intrinsic properties, such as spontaneous ferroelectricity or electro-optical behavior, which strongly depend on thin film crystallinity. For such functional oxide systems, the pulsed-laser deposition (PLD) approach is one promising growth technique due to its precise stoichiometry control of the metals composing the perovskite crystal and higher oxygen environment compared to the classically used molecular beam epitaxy (MBE) approach. In this article, we demonstrate a BTO epitaxial layer by PLD onto an Si(001) substrate thanks to a thin pseudomorphic SrTiO3 buffer layer grown by MBE. In our study, the various investigated PLD parameters show strong impacts on the BTO polarization orientation. Hence, adjusting the growth conditions allows control of the polarization orientation, which is crucial for both electronic and optical applications. In addition, lattice parameter changes of BTO layers are investigated using x-ray diffraction and cross-sectional transmission electron microscopy, which evidenced a correlation between mismatch relaxation and oxygen growth pressure. Finally, with the analysis of BTO C\textendash V curves, the polarization direction transition is demonstrated electrically.},
+  langid = {English (EN)}
+}
+
+@phdthesis{tsang-hsuanwangStudyPerovskiteOxide2023,
+  title = {Study of {{Perovskite Oxide}} and Its {{Application}} on {{Video Holography}}},
+  author = {{Tsang-Hsuan Wang}},
+  year = {Monday, Feb 13, 2023 @17h00},
+  address = {{Leuven, Belgium}},
+  school = {KULeuven}}
+}
+
+@inproceedings{tsanghsuanwangSingleCrystallineBaTiO32020,
+  ids = {wang2020singlepseudosubstrate,zotero-15826},
+  title = {Single {{Crystalline BaTiO3 Grown}} by {{Pulsed-laser}} Deposition ({{PLD}}) on {{SrTiO3}} / {{Si Pseudo-substrate}}},
+  booktitle = {Proc. {{E-MRS}}  Spring},
+  author = {{Tsang Hsuan Wang} and {M. Korytov} and {P. C. Hsu} and {Jan Genoe} and {Clement Merckling}},
+  year = {2020},
+  month = may,
+  series = {Advanced Functional Films Grown by Pulsed Deposition Methods},
+  address = {{Strasbourg, France}},
+  abstract = {Future applications such as high-speed chip-to-chip optical interconnects, compact high-resolution beam steering and video-rate RGB hologram generation require the integration of fast and efficient optical modulators on top of silicon CMOS devices. For these applications the integration of high quality electro-optical materials on silicon wafers is hence required. Among the possible material options, barium titanate (BaTiO3) is one promising candidate due to its large intrinsic Pockels coefficients. However, the reported Pockels coefficients in literature strongly depend on the obtained crystal lattice stress and axis orientation. In this work, we demonstrate a single-crystalline PLD-grown BaTiO3 (BTO) on top of a MBE-SrTiO3 /Si(001) pseudo-substrate. We investigated the orientation of the polarization axis of single-crystalline BTO under different growth conditions by X-ray diffraction. Larger Pockels coefficients are obtained for a-oriented BTO with its elongated axis lying parallel to sample surface. The control of growth conditions enables us to change polarization by selecting between c- and a-growth axis orientation with tetragonality control of single crystalline BTO films ranging from 0.98 to 1.02. For the a-BTO, the out-of-plane {$\omega$}-scan shows good crystalline quality with FWHM of 0.37\r{}. Using STEM and NBD, we relate the crystalline orientation switch to strain relaxation inside BTO films.},
+  langid = {english}
+}
 

files/_toc.yml

@@ -2,4 +2,6 @@ format: jb-book
 root: intro
 chapters:
 - file: Overview
+- file: Team
+- file: Publications
 - file: bib