Conference Agenda

POSTER SESSION and Exhibition
Wednesday, 14/Sept/2022:
12:00pm - 1:00pm

Location: Hallway

Main hallway of the building

The same posters will be presented on Wednesday's and Thursday's sessions.

ID: 327
TOM 1 Silicon Photonics and Guided-Wave Optics

DC Kerr effect in silicon waveguide

Jonathan Peltier1,2, Léopold Virot2, Christian Lafforgue1, Lucas Deniel1, Delphine Marris-Morini1, Guy Aubin1, Farah Amar1, Denh Tran3, Callum G. Littlejohns3, David J. Thomson3, Weiwei Zhang3, Laurent Vivien1

1University Paris Saclay, CNRS, Centre for Nanoscience and Nanotechnology (C2N), Palaiseau, 91120, France; 2University Grenoble Alpes, CEA, LETI, Grenoble, 38000, France; 3Optoelectronics Research Centre, Zepler Institute for Photonics and Nanoelectronics, Faculty of Engineering and Physical Sciences, University of Southampton, Southampton SO17 1BJ, UK

Integrated modulators are key components for communications, quantum, spectroscopy or LIDAR. These components require high-speed modulation and low power consumption. Silicon modulators, which are mainly based on the plasma dispersion effect, consume a lot of power and are limited in bandwidth. To overcome these limitations, such modulators can also rely on Pockels effect, an inherently fast and pure phase modulation effect. Since silicon does not have a natural chi2 due to its centrosymmetric structure, pure phase modulators cannot be achieved directly with silicon waveguides. Nevertheless, pure phase modulation in silicon can be realized either by associating materials with high chi2 such as polymer, BTO, PZT, lithium niobate, by straining silicon, or by using DC Kerr effect to electrically induce an effective chi2. The latter is studied in this paper for light modulation in a silicon Mach-Zehnder modulator based on PIN junctions. A clear linear behavior of the dynamic electro-optic response has been demonstrated under a reverse bias applied across a PIN junction. A modulation at twice the RF frequency applied is also shown and assigned to Kerr effect.

ID: 165
TOM 1 Silicon Photonics and Guided-Wave Optics

Hybrid polymer-titania waveguides for highly integrated circuits

Isaac Doughan, Kehinde Oyemakinwa, Olli Ovaskainen, Matthieu Roussey

University of Eastern Finland, Finland

We present an innovative waveguide based on the hybridization of a titanium dioxide nano-waveguide within a polymer strip. Through simulations and design, we demonstrate that the waveguide sustains principally the quasi-TM fundamental mode and that even in tight bends (radius smaller than 2 µm) light remains confined in the titania layer. Such a waveguide, in addition to enabling low loss propagation is a way towards efficient evanescent sensing in highly integrated scheme, i.e., small footprint. We also show that the fabrication, here based on electron beam lithography and atomic layer deposition, can be extended easily to large scale manufacturing using nanoimprinting technology.

ID: 179
TOM 7 Thermal radiation and energy management

Polycrystalline MoO3 films fabricated by pulsed laser deposition for infrared polarization manipulation.

Daniele Ceneda1, Federico Vittorio Lupo2, Maria Pia Casaletto3, Roberto Macaluso2, Marco Centini1, Sina Abedini Dereshgi4, Koray Aydin4, Maria Cristina Larciprete1

1Department of Basic and Applied Sciences for Engineering, SAPIENZA, University of Rome, Via A. Scarpa 16, 00161, Roma, Italy; 2Department of Engineering, University of Palermo, Viale delle Scienze, Ed. 9, Palermo, 90128, Italy; 3National Research Council (CNR), Institute of Nanostructured Materials (ISMN), Via Ugo La Malfa 153, Palermo, 90146, Italy; 4Department of Electrical and Computer Engineering, Northwestern University, Evanston, Illinois 60208, United States

We performed infrared optical characterization of polycrystalline MoO3 films deposited by pulsed laser deposition on fused silica substrates. Several samples have been fabricated using different parameters such as temperature and oxygen pressure. Our analysis shows that under appropriate fabrication conditions it is possible to obtain a dominant alpha-phase film, with a well-defined, normal to surface (z-axis) orientation. These results are confirmed by reflection spectra performed at 45° incidence angle revealing a strong modulation of the sharp z-phonon Reststrahlen band as a function of the incident field linear polarization.

ID: 314
TOM 6 Optical Materials: crystals, thin films, organic molecules & polymers, syntheses, characterization and devices

Laser-printed emissive metasurface implemented with a planar thin-film resonator

Myeongkyu Lee, Yeongseon Kim, Dongkyun Kang, Jaeyong Kim

Yonsei University, Korea, Republic of (South Korea)

Optical security is a promising application of metasurfaces because light has large degrees of freedom in metasurfaces. Although many different structures/materials have been proposed for this purpose, the fabrication of dynamic metasurfaces in a straightforward and scalable manner while maintaining a high security level remains a significant challenge. Herein, a metasurface consisting of a phase-changing GeSbTe layer and a thin metal back reflector is presented to space-selectively and dynamically control the infrared emission of the surface by a spatially modulated pulsed laser beam. Unlike conventional laser processes using a focused beam, the employed laser printing is an expanded beam-based parallel process that enables the fabrication of wafer-sized emission patterns. Owing to the multispectral responses of GeSbTe, mutually independent visible and infrared images can be printed in one region. Grayscale emission patterns can also be obtained by gradually modulating the spatial profile of the laser beam, which makes the replication of laser-printed emission patterns extremely difficult. These encouraging features are experimentally verified using banknote and ordinary paper substrates, indicating that the presented emissive metasurface has the potential for use as an effective platform for anti-counterfeiting

ID: 171
TOM 11 Tapered optical fibers, from fundamental to applications

Operating range of efficient Raman converters based on nanofibers immersed in different liquids

Maha Bouhadida, Pierre-Enguerrand Verdier, Philippe Delaye, Sylvie Lebrun

Laboratoire Charles Fabry, France

We present the operating range of Raman wavelength converters based on silica nanofibers immersed in liquids for the design of all fibered wavelength converters. This range is bounded on the lower limit by the pump energy necessary to reach the Raman threshold and on the upper limit by the laser induced breakdown of the nanofiber. These breakdown energies are measured in the ns regime for different liquids (water, ethanol, isopropanol) and for air. We finally define guidelines that open the way to a new family of low-cost compact and efficient all-fibered Raman converters that can be directly inserted in optical fibered networks with very low losses.

ID: 258
TOM 13 Advances and Applications of Optics and Photonics

Characterization of a lobster-eye type X-ray telescope

Thorsten Döhring1, Veronika Stieglitz2,3, Rene Hudec3,4, Iryna Sapsai5, Peter Friedrich2, Vadim Burwitz2

1TH Aschaffenburg, Germany; 2Max-Planck-Institute for Extraterrestrial Physics, Germany; 3Czech Technical University in Prague, Czech Republic; 4Astronomical Institute, Czech Academie of Science, Czech Republic; 5Borys Grinchenko Kyiv University, Ukraine

Lobster-eye type X-ray telescopes use reflecting plano mirrors under grazing incidence and can observe a large field of view. As part of a Bavarian-Czech cooperation, two telescopes were build, equipped with mirrors coated with gold and iridium. Their X-ray characterization was carried out at the PANTER test facility, which simulates parallel starlight incident on the telescopes. The telescopes have an angular resolution of about 4 arc minutes in X-rays and a focal length of about 2 meters. The used X-ray mirrors reflect and focus visible light as well; their functionality in the optical regime was checked in laboratory tests. Now another test campaign will be carried out to examine the telescope resolution for real objects of the visible night sky and the imaging properties for star constellations.

ID: 223
TOM 11 Tapered optical fibers, from fundamental to applications

Single-mode ZBLAN fiber couplers

Mohsen Rezaei, Gebrehiwot Tesfay Zeweldi, Md Hosne Mobarak Shamim, Martin Rochette

McGill University, Canada

We demonstrate single-mode ZBLAN optical fiber couplers. A controlled tapering procedure leads to coupling ratios of 5%/95% and 14%/86% at a wavelength of 2200 nm, with insertion losses of 1.6 dB and 1.8 dB, respectively.

ID: 241
TOM 10 Frontiers in Optical Metrology

Retardance measurement by spatially probing the sample with optical vortices

Tomas Fordey, Petr Schovanek

Palacky University Olomouc, Czech Republic

Modern optical systems utilize various degrees of freedom, such as polarization, for shaping and controlling the light. Common representative of such a component is spatial light modulator (SLM), consisting of liquid crystal display, allowing for imposing predetermined retardation with given orientation of optical axis of anisotropy. Therefore, it is widely used for polarization coded phase shifting, polarization splitting of wavefront in digital holography etc. Narrowing tolerance in optical experiments puts higher demands on precise setting of the modulator and the parameters set. Consequently, measuring such devices and their parameters is essential for proper functionality. We present a single shot, common path method for measuring retardance map of the modulator, based on spatial probing the modulator with point images of spatially coherent light source and transforming them to optical vortices.

ID: 238
TOM 13 Advances and Applications of Optics and Photonics

Intelligent Optical Tweezers with deep neural network classifiers

Vicente Vieira Rocha1,2, João M. F. Oliveira1,2, Ariel R. N. S. Guerreiro1,2, Pedro A. S. Jorge1,2, Nuno A. Silva1,2

1INESC TEC, Centre of Applied Photonics, Rua do Campo Alegre 687, 4169-007 Porto, Portugal; 2Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto, Portugal

Optical tweezers use light to trap and manipulate mesoscopic scaled particles with high precision making them a useful tool in a plethora of natural sciences, with emphasis on biological applications. In principle, the Brownian-like dynamics reflect trapped particle properties making it a robust source of information. In this work, we exploit this information by plotting histogram based images of 250ms of position or displacement used as input to a Convolution Neural Network. Results of 2-fold stratified cross-validation show satisfying classifications between sizes or types of particles: Polystyrene and Polymethilmethacrylate thus highlighting the potential of CNN approaches in faster and non-invasive applications in intelligent opto and microfluidic devices using optical trapping tools.

ID: 163
TOM 13 Advances and Applications of Optics and Photonics

Secure key distribution using an ultra-long fiber laser with bi-directional EDFA

Beatriz Gomes Soares1, Ariel Ricardo Negrão da Silva Guerreiro1,2, Orlando José dos Reis Frazão1

1INESC TEC, Portugal; 2Faculdade de Ciências da Universidade do Porto, Portugal

In this paper we describe the implementation of a secure key distribution system based on an ultra-long fiber laser with a bi-directional erbium doped fiber amplifier. The resilience of the system was tested against passive attacks from an eavesdropper, having been observed a similarity in spectrum for both secure configurations of the system.

ID: 277
TOM 5 Resonant Nanophotonics

Optical characterization of DNA origami-shaped silver nanoparticles created through biotemplated lithography

Kabusure Mogasa Kabusure1, Petteri Piskunen2, Jiaqi Yang1, Mikko Kataja1, Mwita Chacha1, Sofia Ojasalo2, Boxuan Shen2,3, Tommi Hakala1, Veikko Linko2,4

1Department of Physics and Mathematics, University of Eastern Finland, Yliopistokatu 2, P.O Box 111, FI-80101, Joensuu, Finland.; 2Biohybrid Materials, Department of Bioproducts and Biosystems, Aalto University, P.O. Box 16100, FI-00076, Aalto, Finland.; 3Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 17165 Stockholm, Sweden.; 4LIBER Centre, Aalto University, P.O. Box 16100 FI-00076, Aalto, Finland.

Here, we study optically resonant substrates fabricated using the previously reported BLIN (biotemplated lithography of inorganic nanostructures) technique with single triangle and bowtie DNA origami as templates. We present the first optical characterization of BLIN-fabricated origami-shaped silver nanoparticle patterns on glass surfaces, comprising optical transmission measurements and surface-enhanced Raman spectroscopy. The formed nanoparticle patterns are examined by optical transmission measurements and used for surface-enhanced Raman spectroscopy (SERS) of Rhodamine 6G (R6G) dye molecules.

ID: 226
TOM 11 Tapered optical fibers, from fundamental to applications

Trapping a single atom in the evanescent field of a WGM-resonator

Gabriele Maron1, Xinxin Hu1, Luke Masters1, Lucas Pache1, Michael Scheucher2, Elisa Will2, Jürgen Volz1, Arno Rauschenbeutel1

1Humboldt Universität zu Berlin, Germany; 2Vienna Center for Quantum Science and Technology, TU Wien – Atominstitut, Austria

Whispering-gallery-mode (WGM) resonators are monolithic structures that guide light by total internal reflection.They exhibit ultra-high Q-factors and provide lossless in- and out-coupling of light in tapered optical fibres. Thus, WGM resonators can be realized in a fully integrated way and can be implemented as optical circuits on photonic chips. Furthermore, these resonators provide a chiral (i.e. direction dependent) light-matter interaction, which opens up new routes for photonic quantum information and communication applications.

We demonstrate, for the first time, trapping of single 85Rb atoms in the evanescent field of a WGM resonator by means of a tightly focused dipole trap retroreflected on the resonator surface. In order to compensate the trap-induced light shift of the atomic transition frequency, an additional light beam is employed to realize a dual-colour magic-wavelength trapping scheme. Using this method, we observe a vacuum Rabi splitting in the transmission spectrum of the coupled atom-resonator system, which indicates its operation in the strong coupling regime.

We are currently implementing a second generation trapping scheme, which will enable deterministic trap loading with improved trap lifetimes and a well-defined coupling strength.

ID: 129
TOM 7 Thermal radiation and energy management

Infrared emittance and polaron conductivity in rutile

Iñigo González de Arrieta1,2, Luis González-Fernández3, Telmo Echániz4, Leire del Campo1, Domingos De Sousa Meneses1, Gabriel A. López2

1CNRS, CEMHTI UPR3079, Univ. Orléans, F-45071 Orléans, France; 2Physics Department, University of the Basque Country UPV/EHU, E-48940 Leioa, Spain; 3Centre for Cooperative Research on Alternative Energies (CIC energiGUNE), Basque Research and Technology Alliance (BRTA), Alava Technology Park, Albert Einstein 48, 01510 Vitoria-Gasteiz, Spain; 4Applied Mathematics, University of the Basque Country UPV/EHU, E-48013 Bilbao, Spain

Polarised emittance measurements are reported for a rutile-phase TiO2 single crystal up to 2000 K in a broad spectral range. Above 1000 K, strong opacification was observed for most of the investigated spectral range. This phenomenon was thermally activated, with a 1.25 eV activation energy close to that of DC conductivity. The sample became opaque at temperatures significantly below the melting point. This anomalous optical phenomenon can be explained by small-polaron conduction, which is particularly strong for this material. The transition from transparency to high and flat emissivities in a broad near- and mid-infrared region has important implications for the use of TiO2 materials at high temperatures.

ID: 278
TOM 13 Advances and Applications of Optics and Photonics

Micro-reactors fabricated by Subaquatic indirect Laser-Induced Plasma-Assisted Ablation on soda-lime glass substrates.

M.Teresa Flores-Arias1, Ana I. Gomez-Varela1, Alberto P Munuzuri2, Alejandro Carballosa2, Carmen Bao-Varela1

1Photonics4Life research group, Department of Applied Physics, Facultade de Física and Institute of Materials (iMATUS), Universidade de Santiago de Compostela, Campus Vida, E-15782 Santiago de Compostela, Spain; 2Group of Nonlinear Physics, Department of Physics and Galician Center for Mathematical Research and Technology (CITMAga),, University of Santiago de Compostela, E-15782 Santiago de Compostela, Spain

Synchronization control of complex systems is a field that emerged with huge interest and aims to study new possible routes to synchronization in networks of non-locally coupled chemical oscillators. Light can be used to stimulate these systems and to be able to synchronize the different micro-reactors involved in the complex system. To this end, transparent reactors with good optical qualities are needed. Glass is the most appropriated material to be used for fabricating the micro-reactors. Subaquatic indirect Laser-Induced Plasma-Assisted Ablation is presented as a laser technique that combines underwater ablation with shock waves as a potential technique for fabricating these micro-reactors by using a Nd:YVO4 laser.

ID: 281
TOM 13 Advances and Applications of Optics and Photonics

The effect of frequency modulation on the FSR of a Fabry-Perot cavity using an Optical Spectrum Analyser

João Manuel Reis1,3, António V. Rodrigues1,2, Paulo Robalinho1,2, Susana Novais1, João Maia1, Paulo Marques1,3, D Roma4,5, J Salvans4,5, M Canal4,5, J Ramos4,5, V Gualani4,5, S Sisteré4,5, V Martin4,5, M Nofrarias4,5, Susana Silva1, Orlando Frazão1

1INESC TEC, Portugal; 2Faculdade de Engenharia da Universidade do Porto,; 3Faculdade de Ciências da Universidade do Porto,; 4Institut de Ciències de l’Espai (ICE, CSIC), Campus UAB; 5Institut d'Estudis Espacials de Catalunya (IEEC)

It is presented a study of the dependence between the free spectral range (FSR) and the cavity length in Fabry-Perot interferometers. Furthermore, the effect of frequency modulation on the FSR is studied when an optical spectrum analyser (OSA) is used as an interrogator. For low frequency range it is possible to observe this behaviour in the OSA and using an appropriate processing signal it is possible to use the white light interferometry technique.

ID: 237
TOM 13 Advances and Applications of Optics and Photonics

Convolutional neural network optimisation to enhance ESPI fringe visibility

Jose Crespo, Vicente Moreno

Universidade de Santiago de Compostela, Spain

The use of convolutional neuronal networks (CNN) for the treatment of interferometric fringes has been introduced in recent years. In this paper, we optimize and build a CNN model, based U-NET architecture, to maximize its performance processing electronic speckle interferometry fringes (ESPI)

ID: 190
TOM 11 Tapered optical fibers, from fundamental to applications

Large evanescently-induced Brillouin scattering at the surrounding of a nanofibre

Jean-Charles Beugnot


Brillouin scattering has been widely exploited for advanced photonics functionalities such as microwave photonics, signal processing, sensing, lasing, and more recently in micro- and nano-photonic waveguides. Due to the small transverse dimension, the tapered optical fiber have a number of optical and mechanical properties that make them very attractive for both fundamental physics and technological applications. Contrary to standard telecom fiber where the Brillouin scattering effect is characterized by a single Lorentzian resonance centred at 10.86 GHz (@ 1550nm), in tapered silica fiber, we identified several Brillouin resonances at different frequencies from 5 GHz to 10 GHz coming from surface, shear and compression elastic waves. And for a large evanescent optical field surrounding the nanofiber, we observe an efficient Brillouin scattering in gas. We show drastic Brillouin scattering enhancement by increasing the gas pressure with a maximum Brillouin which is 79 times larger than in a standard single-mode fibre.

ID: 214
TOM 10 Frontiers in Optical Metrology

Particle detection enhancement by combining coherent Fourier scatterometry with synthetic optical holography

Haoyang Yin, Dmytro Kolenov, S.F. Pereira

TU Delft, Netherlands, The

We demonstrated that the sensitivity of nanoparticle detection on surfaces can be substantially improved by implementing synthetic optical holography (SOH) in coherent Fourier scatterometry (CFS), resulting in a phase-sensitive confocal differential detection technique that operates at a very low power level (P = 0.016 mW). The improvement in sensitivity is due to two reasons: firstly, the boost in the signal at the detector due to the added reference beam, and secondly, the reduction of background noise caused by the electronics.

With this new system, we were able to detect a 60 nm polystyrene latex (PSL) particle at wavelength of 633 nm (\lambda/10) on a silicon wafer with an improvement in the signal-to-noise ratio (SNR) of about 4 dB.

ID: 308
TOM 4 Bio-Medical Optics

3D printed FBG based sensor for vital signal monitoring – Influence of the infill printing parameters

Alexandra Ferreira1, Cátia Tavares1,2, Cátia Leitão1,2, Daniela Lo Presti3, M. Fatima Domingues2, Nélia Alberto2, Hugo Silva4,5, Paulo Antunes1,2

1Department of Physics & I3N, Portugal; 2Instituto de Telecomunicações and University of Aveiro, Aveiro, Portugal; 3Unit of Measurements and Biomedical Instrumentation, Departmental Faculty of Engineering, Università Campus Bio-Medico di Roma, Rome, Italy.; 4Instituto de Telecomunicações, Instituto Superior Técnico, University of Lisbon, Lisbon, Portugal; 5PLUX - Wireless Biosignals, S.A, Lisboa, Portugal

The fused deposition modelling technique has been used in the production of strain sensors in which fibre Bragg gratings (FBGs) are encapsulated during the 3D printing process. This paper reports the study of the influence of the FBG position and the material filling, in this case a flexible polymer material, on the sensors’ sensitivity and overall performance. In addition, this study preliminarily evaluated the ability of the strain sensor to monitor (heart rate) HR and (respiratory rate) RR as a wearable on the wrist and as a non-intrusive solution on the back of an office chair

ID: 184
TOM 4 Bio-Medical Optics

Polarization sensitive digital holographic imaging in biology

Giuseppe Coppola1, Maria Mangini2, Gianluigi Zito1, Edoardo De Tommasi1, Anna Chiara De Luca2, Maria Antonietta Ferrara1

1National Research Council, Institute of Applied Sciences and Intelligent Systems ‘E. Caianiello’; 2National Research Council, Institute of Experimental Endocrinology and Oncology ‘G. Salvatore’

A new, simple digital holography-based polarization microscope for quantitative birefringence imaging of biological cells is presented. As a proof of concept, two different class of cells have been characterized by polarization sensitive digital holographic imaging (PSDHI). These two cases study reported are: differentiation of leukaemia cells and identification of reacted sperm cells. Although further experimentation is necessary, the suggested approach could represent a prospective label-free diagnostic tool for use in biological and medical research and diagnosis.

ID: 195
TOM 8 Non-linear and Quantum Optics

Static multi-vortex structures in nonlinear optical media

Angel Paredes, Jose Ramón Salgueiro, Humberto Michinel

Universidade de Vigo, Spain

We demonstrate through numerical simulations the existence of a new type of nonlinear waves in optical media: structures of vortex solitons that remain static in certain configurations, which depend on their relative positions and topological charges. Several examples are presented to illustrate this surprising behavior.

ID: 152
TOM 13 Advances and Applications of Optics and Photonics

Determination of a source's temporal coherence function via depolarization in liquid crystal

Cristian Eduardo Hernández Cely, Rafael Angel Torres Amaris

Universidad Industrial de Santander, Colombia

Based on the fact that the degree of polarization of a light source is given in terms of the absolute value of its complex degree of coherence, we design a depolarization experiment using a variable retarder in which we measured the degree of polarization as a function of the retarder's birefringence. We show that if the incident light is previously linearly polarized we can perform a direct measurement of the light source's coherence using a Stokes meter.

ID: 144
TOM 8 Non-linear and Quantum Optics

Multi-beam vortex generation induced by the non-linear optical anisotropy of graphene.

Luis Plaja, Ana García-Cabrera, Roberto Boyero-García, Óscar Zurrón, Julio San Román, Carlos Hernández-García

Universidad de Salamanca, Spain

We analyse the high harmonic emission from single-layer graphene driven by infrared vector beams. We demonstrate that graphene’s anisotropy offers a privileged scenario to explore non-trivial light spin-orbit couplings, which substantially extends the possibilities for the generation of high-harmonic structured beams currently studied in atomic and molecular targets. In our case, graphene’s crystal symmetry introduces a spin-dependent diffraction pattern that, coupled with the fundamental conservation of the driver’s topological phase, leads to the splitting of the harmonic field in a multi-beam structure, composed of spatially diverging vortices. Our work demonstrates that anisotropic targets are extraordinary tools to sculpt complex structured short-wavelength beams.

ID: 191
TOM 4 Bio-Medical Optics

Open-view binocular double-pass system for the study of dynamic accommodation

Fracisco Ávila1, Rafael Navarro2, Ebrahim Safarian Baloujeh2, Ana Sánchez-Cano1

1Departamento de Física Aplicada, Universidad de Zaragoza, Zaragoza, 50009, Spain; 2INMA, Consejo Superior de Investigaciones Científicas & Universidad de Zaragoza, Zaragoza, 50009, Spain

We present a new open-view dynamic double-pass (DP) system for the study of accommodative response in binocular natural viewing conditions. The DP point spread function (PSF) of the eye is analyzed to compute the Visual Strehl Ratio (VSR) fluctuation as a function of time at 50 Hz frame rate. Preliminary results showed that the proposed method can quantify the temporal dynamic of the optical and visual quality of both eyes simultaneously.

ID: 193
TOM 10 Frontiers in Optical Metrology

Hybrid optical measurement technique for detection of defects in epitaxially grown 4H-SiC layers

Elena Ermilova, Matthias Weise, Andreas Hertwig

Bundesanstalt für Materialforschung und –prüfung (BAM), Germany

Recent developments in power electronics require the use of new wide bandgap compound semiconductor. We demonstrate the use of the ellipsometry and white light interference microscopy to detect defects in epitaxially grown SiC layers on SiC substrates. Such hybrid optical metrology methods can be used to better understand the mechanism of the development of the defects as well as their effects on the material´s optoelectronic properties.

ID: 215
TOM 10 Frontiers in Optical Metrology

Multi-beam coherent Fourier scatterometry

Sarika Soman, Silvania F. Pereira

Delft University of Technology, Netherlands, The

Recent technological advancements in the past decades have been driven by the miniaturisation of devices using surfaces with nano-scale features. These advancements require fast, large area measurement techniques that can be used in process control to detect surface contaminations or to monitor fabrication quality. Here we present a modified version of the scanning coherent Fourier scatterometer with multiple beams that can be used to scan larger areas without increasing the scan time or decreasing the spatial resolution.

ID: 273
TOM 8 Non-linear and Quantum Optics

Nonlinear pulse routing in plasmonic couplers

José Ramón Salgueiro1, Albert Ferrando2

1Universidade de Vigo, Spain; 2Universitat de València, Spain

We present a system able to discriminate pulses according to their duration with potential applications in all-optical signal multiplexing. The device is based on a directional coupler with nonlinear cores and metallic claddings with dimensions in a nanometric scale. Simulations are carried out using the FDTD technique for ultrashort pulses of femtosecond order. It is shown that the device is able to separate such pulses respect to a time-width threshold which depends on the total energy of the pulse.

ID: 123
TOM 5 Resonant Nanophotonics

A rigorous computational framework employing coupled-mode theory for assessing lasing with transition metal dichalcogenide bilayers in the nanoscale

Georgios Nousios1, Thomas Christopoulos1, Dimitrios C. Zografopoulos2, Emmanouil E. Kriezis1

1School of Electrical and Computer Engineering, Aristotle University of Thessaloniki (AUTH), Thessaloniki GR-54124, Greece; 2Consiglio Nazionale delle Ricerche, Instituto per la Microelettronica e Microsistemi (CNR-IMM), Roma 00133, Italy

A whispering-gallery mode nanophotonic laser cavity having as active medium a transition-metal-dichalcogenide (TMD) bilayer is examined. The proposed system is analysed and designed utilizing a strict and rigorous computational framework based on the coupled-mode theory. Our framework is capable of accurately and efficiently handling the gain properties of two-dimensional materials, such as contemporary TMD monolayers, multilayers, and heterostructures. The presented lasing cavity exhibits an adequately low pump threshold and light emission in the order of milliwatts is predicted. Exploiting the capabilities of the developed framework, we were in position to efficiently design the cavity as well as to estimate quantitative lasing parameters such as the pumping threshold and the lasing frequency.

ID: 120
TOM 5 Resonant Nanophotonics

Controlling chromaticity by lamellar gratings

Hiroyuki Ichikawa, Naoki Arita, Keigo Shikimi, Ryunosuke Tani

Ehime University, Japan

Fundamental numerical study on controlling chromaticity with the simplest diffractive structure is carried out. Observed various characteristics on transmission/reflection and dielectric/metal will be useful guidelines for practical optimisation of device structures.

ID: 150
TOM 8 Non-linear and Quantum Optics

Light propagation in disordered aperiodic Mathieu photonic lattices

Jadranka M Vasiljević1, Dejan V Timotijević2, Dragana M Jović Savić1

1Institute of Physics, University of Belgrade, Belgrade, Serbia; 2Institute for Multidisciplinary Research, University of Belgrade, Belgrade, Serbia

We present the numerical modeling of two different randomization methods of photonic lattices. We compare the results of light propagation in disordered aperiodic and disordered periodic lattices. In disordered aperiodic lattice disorder always enhances light transport for both methods, contrary to the disordered periodic lattice. For the highest disorder levels, we detect Anderson localization for both methods and both disordered lattices. More pronounced localization is observed for disordered aperiodic lattice.

ID: 251
TOM 13 Advances and Applications of Optics and Photonics

Chip integrated photonics for ion based quantum computing

Steffen Sauer1,2, Anastasiia Sorokina1,2, Carl-Frederik Grimpe3, Guochun Du3, Pascal Gehrmann1,2, Elena Jordan3,5, Tanja Mehlstäubler3,4, Stefanie Kroker1,2,3

1Institut für Halbleitertechnik, Technische Universität Braunschweig, Hans-Sommer-Str. 66, 38106 Braunschweig, Germany; 2Laboratory for Emerging Nanometrology, Langer Kamp 6a/b, 38106 Braunschweig, Germany; 3Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany; 4Institut für Quantenoptik, Leibniz Universität Hannover, Welfengarten 1, 30167 Hannover, Germany; 5DLR-Institut für Satellitengeodäsie und Inertialsensorik, Leibniz Universität Hannover, Welfengarten 1, 30167 Hannover, Germany

Ion traps are a promising platform for the realisation of high-performance quantum computers. To enable the future scalability of these systems, integrated photonic solutions for guiding and manipulating the laser light at chip level are a major step. Such passive optical components offer the great advantage of providing beam radii in the µm range at the location of the ions without increasing the number of bulk optics. Different wavelengths, from UV to NIR, as well as laser beam properties, such as angle or polarisation, are required for different cooling and readout processes of ions. We present simulation results for different optical photonic components, such as grating outcouplers or waveguide splitters and their applications on ion trap chips. Furthermore, we will introduce the experimental setup for the optical characterisation of the fabricated structures.

ID: 287
TOM 3 Optical System Design, Tolerancing and Manufacturing

Design and testing of a Kirkpatrick-Baez optics variation

Veronika Stieglitz1,2, Vadim Burwitz1, Thorsten Döhring3, René Hudec2, Stanislav Vitek2

1Max Planck Institute for Extraterrestrial Physics, Germany; 2Czech Technical University in Prague, Czech Republic; 3TH Aschaffenburg – University of Applied Science, Germany

Beside Wolter I X-ray optics, which are used at most in currently operating X-ray space telescopes, there exist also other optical designs and their usability for space observations is still the matter of studies. This article covers preliminary testing results of an optical module which is based on a modified Kirkpatrick-Baez optics. This X-ray optics, consisting of four sub-modules, was assembled in Prague and tested at the PANTER test facility of MPE afterward. The sub-modules use different reflective coatings, in part developed by our research group, on complementary flat mirrors, which approximate the shape of a Kirkpatrick-Baez optical design. In this contribution we summarise the design of the optical modules, the details of applied coating layers, and the X-ray characterisation results at the PANTER test facility.

ID: 261
TOM 8 Non-linear and Quantum Optics

Dynamics of passive modelocking in class-B lasers with saurable absorber

Franco Prati1, Auro Perego2, German de Valcarcel3

1Unversità dell'Insubria, Italy; 2Aston University, UK; 3Universitat de Valencia, Spain

We address the problem of passive modelocking in class-B lasers with saturable abosrber taking into account the fast dynamics of both gain and absorption. Our model, which is derived from a delay differential equation model, treats in a rigorous way the definition of the fast and slow times which are typically used in the master equation approach. In that way all the dynamical variables obey exact periodic boundary conditions and this makes the model suitable for analytic and numerical treatment. The model accounts for behaviours different from fundamental modelocking, such as Q-switching modelocking and harmonic modelocking.

ID: 234
TOM 9 Opto-electronic Nanotechnologies and Complex Systems

Experiments and simulations of chiro-optical response in low-cost nanohole arrays in silver

Emilija Petronijevic1, Zakaria El-ansary2, Bilal Brioual3, Alessandro Belardini1, Hari Prasath Ram Kumar1, Tiziana Cesca4, Carlo Scian4, Giovanni Mattei4, Concita Sibilia1

1Sapienza University of Rome, Italy; 2Ibn Tofail University Kénitra, Morocco; 3Abdelmalek Essaâdi University Tanger, Morocco; 4University of Padova, Physics and Astronomy Department, Padova, Italy

2D metasurfaces based on periodic nanoholes in metal have been proposed in various plasmonic platforms. Specifically, their resonant features have led to applications spanning in biosensing. Here we investigate additional degree of freedom in elliptical nanohole arrays with hexagonal geometry: chiro-optical effects. Namely, the in-plane asymmetry and a slightly elliptical shape of nanoholes were previously shown to differently extinct light of opposite handedness, even at normal incidence. We now fully characterize nanoholes in Ag, fabricated by low-cost nanosphere lithography. We first measure the dependence of the transmitted intensity for opposite handedness, in a broad spectral and angle of incidence range. We then resolve the circular polarization degree of the transmitted light when the nanohole array is excited with linear polarization. Finally, we numerically investigate the origin of the chiro-optical effect at the nanoscale. We believe that circular polarization resolving of the transmitted degree could be further adapted as a highly sensitive tool in chiral sensing.

ID: 154
TOM 1 Silicon Photonics and Guided-Wave Optics

Scattering parameters of a non-reciprocal magneto-optical integrated coupler used as an isolator

Yann G. Boucher1,2,4, Yuliya S. Dadoenkova1,2,3, Florian F.L. Bentivegna1,2,3

1CNRS, France; 2Institut FOTON (UMR CNRS 6082); 3Lab-STICC (UMR CNRS 6285); 4École Nationale d’Ingénieurs de Brest

We theoretically investigate a non-reciprocal magneto-optical integrated slab directional coupler.

The scattering parameters of the structure are derived in the frame of the Coupled-Mode Theory (CMT). By properly designing the coupler, it is possible to achieve a perfect non-reciprocity (with 100% contrast) between the two directions of propagation. Other operating points can also be defined, especially since modal dispersion in the spectral domain is naturally taken into consideration.

ID: 199
TOM 1 Silicon Photonics and Guided-Wave Optics

Tantalum pentoxide micro-resonators for frequency comb generation

Jake Daykin1, Jonathan R C Woods2, Stephen C Richardson1, Oliver J Trojak1, Folly Eli Ayi-Yovo3, Jonathan M Silver3, Nicholas T Klokkou1, Amy S K Tong4, Patrick Gill3, Alberto Politi1, Peter Horak4, James S Wilkinson4, Vasilis Apostolopoulos1

1School of Physics and Astronomy, University of Southampton, Southampton, SO17 1BJ; 2Aquark Technologies, Unit 2, Abbey Enterprise Centre, Premier Way, Abbey Park Industrial Estate, Romsey, Hampshire, SO51 9AQ; 3National Physical Laboratory, Hampton Rd, Teddington, TW11 0LW; 4Optoelectronics Research Centre, University of Southampton, Southampton, SO17 1BJ

We present the design, fabrication, simulation and initial characterisation of tantalum pentoxide (Ta2O5) optical waveguides and micro-ring resonators for the purpose of supercontinuum and frequency comb generation. Spectral broadening results are presented for linear Ta2O5 waveguides for a range of central pump wavelengths between 900 nm and 1500 nm. These results are used as the basis for the dispersion engineering and development of Ta2O5 micro-ring resonators. The losses for sputtered and TEOS PECVD deposited SiO2 top cladded waveguides are characterised using a Fabry-Pérot loss measurement set-up. A solver based on the Lugiato-Lefever equation is presented and used to simulate the expected emission from the Ta2O5 micro-ring resonators. Promising initial experimental results show critical coupling and a Q-factor of 3.7×10^4.

ID: 367
TOM 3 Optical System Design, Tolerancing and Manufacturing

Design of an optical parametric oscillator using a BBO partial cylinder for a continuous tunability between 0.4 µm and 0.9 µm

Baptiste Bruneteau1,2, Basile Faure1, Jérôme Debray2, Dazhi Lu3, Grégoire Souhaité1, Jiyang Wang4, Patricia Segonds2, Benoît Boulanger2

1Teem Photonics, France; 2Univ. Grenoble Alpes, CNRS, Institut Néel, France; 3Shandong University, State Key Lab of Crystal Materials, China; 4Tianjin University of Technology, Institute of Functional Crystals, China

This work describes the different steps of the design of a cylindric Optical Parametric Oscillator. It is based on a BBO nonlinear crystal shaped as a partial cylinder to be pumped by a commercial micro-laser at 0.355 µm for an energetic and sub-nanosecond emission continuously tunable between 0.4 µm and 0.9 µm.

ID: 395
Post Deadline submission

Selective femtosecond and picosecond infrared laser crystallization of an amorphous Ge/Si multilayer stack

Nadezhda M. Bulgakova1, Vladimir A. Volodin2,3, Yuzhu Cheng3, Yoann Levy1, Jiri Beranek1,4, Siva Sankar Nagisetty1,5, Martin Zukerstein1, Alexander A. Popov6, Alexander V. Bulgakov1

1HiLASE Centre, Institute of Physics of the Czech Academy of Sciences, Dolni Brezany, Czech Republic; 2Rzhanov Institute of Semiconductor Physics SB RAS, Novosibirsk, Russia; 3Novosibirsk State University, Novosibirsk, Russia; 4Czech Technical University, Faculty of Nuclear Sciences and Physical Engineering, Prague, Czech Republic; 5Coherent LaserSystems GmbH & Co. KG, Goettingen, Germany; 6Valiev Institute of Physics and Technology, Yaroslavl Branch, Russian Academy of Sciences, Yaroslavl, Russia

We report on single-short laser crystallization of Ge/Si multilayer stacks consisting of alternating amorphous nanosized films of silicon and germanium using near- and mid-infrared femtosecond and picosecond laser pulses. The phase composition of the irradiated stacks was investigated by the Raman scattering technique. Several non-ablative regimes of crystallization were found, from partial crystallization of germanium without intermixing the Ge/Si layers to complete intermixing of the layers with formation of GexSi1-x solid alloys. The roles of one- and two-photon absorption, thermal and non-thermal (ultrafast) melting processes, and laser-induced stresses in selective pico- and femtosecond laser annealing are analysed based on theoretical estimations and comparison with experimental data. It is concluded that, due to a mismatch of the thermal expansion coefficients between the adjacent stack layers, efficient explosive solid-phase crystallization of the Ge layers is possible at relatively low temperatures, well below the melting point. The possibility of ultrafast non-thermal phase transition in germanium in the studied regimes is also discussed.