1:30pm - 2:00pmInvitedID: 226
/ TOM5 S02: 1
TOM 5 Optical Materials
Exploiting the natural instability in thin and flexible dielectric solid films for sensing and photonic applications
Nicoletta Granchi1, Luca Fagiani2, Chiara Barri2, Mehrnaz Modaresialam3, Michele Gherardi2, Angelo gatta Zini2, Benedetta Maria Squeo4, Mariacecilia Pasini4, Andrea Chiappini5, Laura Pasquardini6, Alexey Fedorov7, Marco Abbarchi8, Maria Antonietta Vincenti9, Francesca Intonti1, Monica Bollani7
1LENS and Department of Physics and Astronomy, University of Florence, Italy; 2Department of Physics, Politecnico di Milano, Milano, Italy; 3Aix Marseille Univ, Université de Toulon, CNRS, IM2NP Marseille, France; 4Institute of Chemical Sciences and Technologies (SCITEC) – CNR, Milano, Italy; 5Institute of Photonics and Nanotechnology (IFN) – CNR, Trento, Italy; 6Indivenire srl, Trento, Italy; 7Institute of Photonic and Nanotechnology (IFN)- CNR, LNESS laboratory, Como, Italy; 8Solnil, 95 Rue de la République, Marseille, 13002, France; 9Department of Information Engineering, University of Brescia, Brescia, Italy
Flexible and stretchable photonics are emerging fields aiming to develop novel applications where the devices need to conform to uneven surfaces or whenever lightness and reduced thickness are major requirements. However, owing to the relatively small refractive index of transparent soft matter, these materials are not well adapted for light management at visible and near-infrared frequencies. Here we demonstrate simple, low cost and efficient protocols for fabricating Si1−xGex-based, sub-micrometric dielectric antennas with ensuing hybrid integration into different plastic supports. The dielectric antennas are realized exploiting the natural instability of thin solid films to form regular patterns of monocrystalline atomically smooth silicon and germanium nanostructures. Efficient protocols for encapsulating them into flexible and transparent, organic supports are investigated and validated. We benchmark the optical quality of the antennas with light scattering measurements, demonstrating the control of the islands structural colour and the onset of sharp Mie modes after encapsulation.
2:00pm - 2:15pmID: 315
/ TOM5 S02: 2
TOM 5 Optical Materials
Fabrication and assessment of mechanically flexible 1D photonic crystals
Giacomo Zanetti1,4, Alice Carlotto1, Thi Ngoc Lam Tran1,2,3, Anna Szczurek5, Bartosz Babiarczuk5, Osman Sayginer6, Stefano Varas1, Justyna Krzak5, Oreste Bursi7,1, Daniele Zonta7,1, Anna Lukowiak8, Giancarlo Righini9, Maurizio Ferrari1, Giacomo Baldi4, Matteo Bonomo10, Simone Galliano10, Claudia Barolo10, Nicola Bazzanella11, Silvia Maria Pietralunga12, Alessandro Chiasera1
1IFN-CNR, CSMFO Lab. and FBK Photonics Unit, Via alla Cascata 56/C, 38123 Povo (TN), Italy; 2Dept. of Physics, Politecnico di Milano, P.zza L. da Vinci 32, 20133 Milan, Italy; 3Dept. of Materials Technology, Faculty of Applied Sciences, Ho Chi Minh City University of Technology and Education, Vo Van Ngan Str. 1, Thu Duc District, 720214 Ho Chi Minh City, Vietnam; 4Department of Physics, University of Trento, Via Sommarive 14, 38123 Povo (TN), Italy; 5Dept. of Mechanics, Materials and Biomedical Engineering, Wroclaw University of Science and Technology, Smoluchowskiego 25, Wroclaw, 50-370, Poland; 6Biological Imaging and TranslaTUM, Technische Universität München, Ismaninger Str. 22, Munich, D-81675, Germany; 7Dept. of Civil, Environmental and Mechanical Engineering, University of Trento, via Mesiano 77, Trento, 38123, Italy; 8Institute of Low Temperature and Structure Research, PAS, ul. Okólna 2, Wroclaw, 50422, Poland; 9National Research Council (CNR), Institute of Applied Physics (IFAC) “Nello Carrara”, Via Madonna del Piano 10, Florence, Sesto Fiorentino, 50019, Italy; 10Department of Chemistry, NIS Interdepartmental Centre and INSTM Reference Centre, University of Turin, Via Pietro Giuria 7, Turin, 10125, Italy; 11Laboratorio Idrogeno Energia Ambiente (IdEA), Department of Physics, University of Trento, Via Sommarive 14, 38123 Povo (TN), Italy; 12IFN-CNR, P.zza Leonardo da Vinci 32, Milan, 20133, Italy
Flexible glass photonics is a cutting-edge technological and scientific research field that, thanks to a very broad spectrum of applications, has tremendously grown during the last decade and is now a strategic topic. Here, we present the results of the spectral transmittance and reflectance of a 10-layer SiO2/TiO2 1D photonic crystal deposited on a flexible polymeric substrate under different bending conditions, obtained with a home-made adjustable sample holder.
2:15pm - 2:30pmID: 367
/ TOM5 S02: 3
TOM 5 Optical Materials
Design and fabrication of a vanadium dioxide-based actively switchable wire grid polarizer for near-infrared applications
Markus Walther1, Thomas Siefke1,2, Kristin Gerold2, Uwe Detlef Zeitner2,3
1Friedrich Schiller University Jena, Germany; 2Fraunhofer Institute for Applied Optics and Precision Engineering IOF; 3Munich University of Applied Sciences
This study introduces an actively switchable wire grid polarizer exploiting the semiconductor-metal transition of vanadium dioxide. Operating at a near-infrared wavelength, the device features a SiO2 substrate with VO2 deposited by atomic layer deposition. We demonstrate the design using rigorous coupled wave analysis and show a viable fabrication route. Polarisation-resolved spectral transmission measurements show switching of the extinction ratio from 37.5 (on-state) to 1.6 (off-state). Despite observed deviations between measured and theoretical transmission values, the device shows potential in miniaturized imaging processes, polarization measurements, and ellipsometry.
2:30pm - 2:45pmID: 455
/ TOM5 S02: 4
TOM 5 Optical Materials
Micro-porous aluminum nitride wick for non-photo-thermal desalination
James Leung, Ji Feng, Luat Vuong
UCRIVERSIDE, United States of America
Aluminum nitride is a white, hydrophilic, high-band-gap ceramic. Here we report on the light-induced evaporation of saltwater through a capillary wick composed of drop-cast microparticles. Saltwater evaporation rates are significantly higher than expected. Our results point to significant potential for this interface-driven approach in solar non-thermal desalination and water separation technologies.
2:45pm - 3:00pmID: 446
/ TOM5 S02: 5
TOM 5 Optical Materials
Exciton fine structure of a single highly anisotropic CsPbBr3 nanocrystal
Victor Guilloux1, Amal Ghribi2, Kaïs Boujdaria2, Thierry Barisien1, Laurent Legrand1, Emmanuel Lhuillier1, Christophe Testelin1, Maria Chamarro1
1Institut des NanoSciences de Paris, CNRS UMR 7588, Sorbonne Université, F-75005 Paris, France; 22LR01ES15 Laboratoire de Physique des Matériaux: Structure et Propriétés, Faculté des Sciences de Bizerte, Université de Carthage, Bizerte 7021, Tunisia
We measured the photoluminescence (PL) of single CsPbBr3 nanocrystals (NCs) that have a highly anisotropic shape and orthorhombic crystal phase. As the thickness of these NCs is much more smaller than the other two dimensions, they are also called nanoplatelets (NPLs). We obtain PL spectra characterized by doublets separated in energy by about 2 meV in average and showing orthogonal and linearly polarized polar lines. We identified these doublets as the two bright-exciton states of the exciton fine structure contained in the plane of the NPLs. By a comparison between theory and experiments, we were able to obtain fundamental parameters as tetragonal and orthorhombic crystal field. We measured and analysed the time-resolved PL evolution as a function of temperature of small ensemble of NPLs. We thus succeed at framing the experimental value of the bright-dark exciton splitting (5-7meV) that is slightly smaller than the theoretical value.
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