2017 Poster Session WP1

Photonic Integrated Circuit Platform using III-V on SiC Wafer

Mitsuru TAKENAKA, Shinichi TAKAGI
Department of Electrical Engineering and Information Systems,
The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan

Photonic integrated circuits (PICs) based on a high-index-contrast waveguide have paved a pathway to large-scale integration for photonics in the past ten years. Similar to Si photonics, we have investigated III-V CMOS photonics platform based on III-V on insulator (III-V-OI) wafer as shown in Fig. 1(a). We are able to fabricate ultrasmall InP PICs owing to the high-index contrast between III-V layers and SiO2 buried oxide (BOX). Like Si-on-insulator (SOI) wafers, III-V-OI wafers can be fabricated by using direct wafer bonding. Thus, we have demonstrated various passive components based on InGaAsP strip/rib waveguides including micro bends, arrayed waveguide gratings, and grating couplers. Active components including modulators/switches, laser didoes (LDs), photodetectors, and variable optical attenuators have also been reported so far.


Buried Waveguides using a Quasi-Planar Process

Stéphane CALVEZ, Alexandre ARNOULT, Pierre-François CALMON, Aurélie LECESTRE, Chantal FONTAINE, Antoine MONMAYRANT, Olivier GAUTHIERLAFAYE, Guilhem ALMUNEAU
Laboratoire d’Analyse et d’Architecture des Systèmes, Université de Toulouse, CNRS, UPS, 7 avenue du colonel Roche,
F-31400 Toulouse, France

The oxidation of Al-containing III-V semiconductors is an established technology to selectively transform a high-index (2.9) semiconductor layer into an insulating lowindex (n~1.6) aluminium oxide (AlOx) and which, thereby, allows the fabrication of buried oxide apertures in either vertical-cavity surface-emitting lasers or waveguidebased devices [1-4]. Because of the chemical selectivity of the process, the oxidation is conventionally carried out as a lateral oxidation from the sides of etched mesas (see Fig. 1 left), resulting in a loss of wafer planarity which, in turns, renders the subsequent fabrication stages of waveguide devices more complex.


Inducing second-order susceptibility in amorphous silicon nitride waveguides

Marco A. G. PORCEL, Jörn P. EPPING, Marcel HOEKMAN, Arne LEINSE,
Laser Physics and Nonlinear Optics Group, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217,
Enschede 7500 AE, The Netherlands
LioniX International B.V., PO Box 456, Enschede 7500, The Netherlands

Optical waveguides based on stoichiometric silicon nitride (Si3N4) grown via lowpressure chemical vapor deposition (LPCVD) provide a reliable photonics platform characterized by low loss and a spectrally broad transparency ranging from the visible to the mid-infrared. Engineering the waveguide dispersion is of special interest since it allows phase-matching of third-order nonlinear optical processes such as four-wave mixing, supercontinuum and frequency comb generation.


Photo-Thermo-Refractive Glass Doped with Rare Earth Ions as a Substrate for Monolithic Integration of Optical Elements

Nikolay NIKONOROV, Sergey IVANOV, Yevgeniy SGIBNEV,
Alexander IGNATIEV
ITMO University, Birzhevaya line 4, St. Petersburg, 199034, Russia

Today with progress of miniaturization, optical microsystems integrate a large number of functionalities in a small volume. There are two approaches for developing integrated optical devices: hybrid and monolithic integration. The latter one suggest performing all components of a device on one substrate. Materials for monolithic integration should allow emission, propagation, amplifying, multiplexing/demultiplexing, and detection of light. In this work, we present new material for monolithic integration that can be used in integrated optics.


Design of Hybrid Integrated Graphene Optical Switch with an III-V-on-Si laser

Leili Abdollahi Shiramin, Dries Van Thourhout
Photonics Research Group, INTEC, Ghent University -IMEC, Ghent,
9052, Belgium
Center for Nano-and Biophotonics (NB-Photonics), Ghent University, Ghent B-9000, Belgium

Monolithic integration of photonic devices such as switches and modulators with lasers is a complex process. Often these devices require materials with different band-gaps, which makes their co-integration costly and complicated. As an alternative, materials exhibiting interesting optical and electronic functionality such as graphene and other 2D-materials can be hybridly combined with Si and III-V platforms, simplifying the fabrication process and providing complex integrated optical systems on a smaller footprint. A big advantage of graphene is its optically broadband operating window and the fact that its optoelectronic properties are tunable by electrical gating or chemical doping.


Ge-rich graded-index SiGe waveguides as enabling building blocks for broadband mid Infrared integrated photonics

Joan Manel RAMIREZ, Vladyslav VAKARIN, Jacopo FRIGERIO, Qiankun LIU, Andrea BALLABIO, Papichaya CHAISAKUL, Xavier LE ROUX, Laurent VIVIEN, Giovanni ISELLA, Delphine MARRIS-MORINI

The mid -Infrared (mid-IR) photonic integrated platform is recently drawing attention due to its foreseen potential as alternative compact solution to several challenges and limitations taking place in current mainstream technologies. Improved performance is expected in a wide palette of topics such as sensing, thermal imaging, nonlinear optical devices, astronomy or secure datacom, among others. Up to date, different material platforms have been considered to develop mid-IR devices with functionalities beyond the state of the art. In that framework, Si and Ge have risen as promising alternative raw materials to develop mid-IR photonic devices leveraging from the higher refractive index of Ge over Si and their compatibility with the standardized CMOS platform. Also, Si and Ge possess a wavelength transparency window up to λ = 8 µm and 14 µm respectively, in concordance with the spectral range where several substances display their main spectral absorption peaks, hence opening the route towards highly-sensitive and selective label-free chemical sensors. Additionally, none of these materials experience significant nonlinear losses at those wavelengths, as Two-Photon Absorption (TPA) and other related second-order effects are strongly reduced in the mid-IR. This last point in particular, makes SiGe approaches an interesting choice to explore novel nonlinear optical devices operating in the mid-IR range, taking advantage from the commercially available high-power and largely tunable mid-IR quantum cascade lasers.


Fabrication considerations for differential absorption based optofluidic sensors to measure ionic content in water

Gerrit W. STEEN, Adam D. WEXLER, Elmar C. FUCHS, Herman L. OFFERHAUS
Wetsus, European Centre of Excellence for sustainable water technology, P.O. Box 1113, Leeuwarden, 8900 CC, The Netherlands
University of Twente, P.O. Box 217, Enschede, 7500 AE, The Netherlands

Introduction: The main conventional method to analyse ionic content in water is ion chromatography. Though this method works very well the time required for a sample to be collected and analysed is long (>1day). Also this method requires experts and an analytical lab.


AlGaAs nanowires for phase-matched SHG in the telecom range

Natalia MORAIS, Fares CHOUCHANE, Marco RAVARO, Maurizio DE ROSA, Iolanda RICCIARDI, Aristide LEMAITRE, Ivan FAVERO, and Giuseppe LEO
Laboratoire Matériaux et Phénomènes Quantiques, UMR 7162, Université Paris Diderot – CNRS, Paris, France
INO – CNR, Istituto Nazionale di Ottica, Via Campi Flegrei 34, I-80078 Pozzuoli (NA), Italy
Alcatel-Thales III-V Lab, Palaiseau, France

Phase-matched three-wave mixing is possible in optically isotropic zinc-blende materials, thanks to quasi-phase matching occurring when the interacting fields propagate along a curved path about a principal dielectric axis. Following this scheme, efficient Second Harmonic Generation (SHG) was recently demonstrated in GaAs and AlGaAs microdisks, and it was predicted in curved waveguides.


Influence of Thermo-mechanical Effects induced by 3D Assembly on Silicon Microring Resonator

STMicroelectronics, 850 rue Jean Monnet, Crolles, 38926, France
GeePs, UMR CNRS 8507, CentraleSupélec, 3 rue Joliot Curie,
Gif-sur-Yvette, 91192, France

Silicon photonics is considered as a prime technology for communication and high-speed computing applications. Ring resonator modulators are one of the key components, especially for next-generation high data-rate and high density interconnects. Indeed ring-based transceivers have been proposed to implement energy-efficient optical links in order to meet power and bandwidth datacoms standard. The design of such a transceiver requires a careful integration between photonic and CMOS chips. The hybrid solution employed in consists of a flip-chip integration and is often preferred thanks to separated design and process technology optimisation for the best performance of each circuit. However the introduction of micro copper-pillars to connect both chips can induce thermo-mechanical stresses on silicon waveguides. This issue is not without consequence for the optical properties which will be discussed in the following, after the quantification of 3D assembly-induced stress.


Polarization properties of second harmonic signal from monolithic AlGaAs nanoantennas

Valerio Flavio GILI, Lavinia GHIRARDINI, Luca CARLETTI, Giovanni PELLEGRINI, Lamberto DUO’, Marco FINAZZI, Davide ROCCO, Andrea LOCATELLI, Ivan FAVERO, Marco RAVARO, Aristide LEMAITRE, Michele CELEBRANO, Costantino DE ANGELIS, and Giuseppe LEO
Matériaux et Phénomènes Quantiques, Université Paris Diderot, 10 rue A. Domon et L. Duquet, 75013 Paris, France
Department of Physics, Politecnico di Milano, Piazza Leonardo Da Vinci 32, 20133 Milano, Italy
Department of Information Engineering, University of Brescia, Via Branze 38, 25123 Brescia, Italy
Centre de Nanosciences et de Nanotechnologies, CNRS, Route de Nozay, 91460 Marcoussis, France
corresponding author e-mail: giuseppe.leo@univ-paris-diderot.fr

Metal-less nanophotonics has recently raised an increasing interest because the optical response of high-permittivity dielectric nanoparticles exhibits negligible dissipative losses and strong magnetic multipole resonances in the visible and near-IR. Here we propose all-dielectric Al0.18Ga0.82As-on-AlOx nanodiskrs, on which we measure second harmonic generation (SHG) with conversion efficiency up to 10-5 for a 1.6 GW/cm2 pump in the optical telecom wavelength range. Our samples were fabricated from a [100] non-intentionally doped GaAs wafer, with a 400nm layer of Al0.18Ga0.82As on top of an aluminum-rich substrate. We first patterned circles with a scanning electron microscope (SEM) lithography system, followed by ICP-RIE dry etching. Finally the sample was selectively oxidized at 390°C for 30 min. The result is an array of nanoantennas on an aluminum-oxide (AlOx) substrate, as shown in Fig. 1(a).


Chalcogenides photonic integrated circuits for near- and mid-infrared applications

F-22305 Lannion Cedex, France
ISCR, UMR-CNRS 6226, Glass and Ceramics Team, 35042 Rennes, France
loic.bodiou@univ-rennes1.fr, joel.charrier@univ-rennes1.fr

Chalcogenide glasses are an important class of amorphous semiconductors that contain at least one of the chalcogen elements from group 6a of the periodic table (S, Se and Te but excluding oxygen) as major constituent. These elements are covalently bonded to network formers such as As, Ge, Sb, Ga, Si or P. The unique optical properties of these glasses are motivating intense research towards the development of a wide range of photonic applications. In particular, all-optical signal processing in near-infrared (IR) telecommunications window is taking advantage of their high optical nonlinearities. These glasses also exhibit low maximum phonon energies (values range from 350-425 cm-1 for sulphide, 250-300 cm-1 for selenide and 150-200 cm-1 for telluride) which yields a broad transparency in the mid-IR, independently of the exact glass composition. MidIR trace molecules sensing platforms could therefore also benefit from the development of these materials. For both applications (telecommunication and sensing), the current trend is directed toward minimizing device footprints and cost by implementing integrated optical components.


Development of Inverted p-Substrate InP/AlGaInAs Lasers for Vertical Integration with Multiple Passive or Active Intrinsic Regions

Shane P. DUGGAN, Niall P. KELLY, Ludovic CARO, Mohamad DERNAIKA, Maryam SHAYESTEH, Justin K. ALEXANDER, Hua YANG, Padraic E. MORRISSEY, Agnieszka GOCALINSKA, Kevin K. THOMAS,
Emanuele PELUCCHI and Frank H. PETERS
Integrated Photonics Group, Tyndall National Institute,
Dyke Parade, Cork, T12R5CP, Ireland
Physics Department, University College Cork,
College Road, Cork, T12YN60, Ireland
Electrical and Electronic Engineering Department, University College Cork,
College Road, Cork, T12YN60, Ireland
Epitaxy and Physics of Nanostructures Group, Tyndall National Institute,
Dyke Parade, Cork, T12R5CP, Ireland

Photonic integrated circuits (PICs) often require separate active and passive optoelectronic devices on a single chip. Active devices generate and amplify light while passive devices are for lossless guiding and manipulation. Integration of the two types of optoelectronic devices is challenging as each requires different material. Monolithic vertical integration of passive and active devices allows separate material to be grown one above the other, while tapering of the different layers allows transitions between the now integrated devices.


Ridge waveguide lasers based on fs-laser writing on rare-earth doped crystals

J. Martínez de Mendívil, G. Lifante, E. Cantelar, J. del Hoyo, J. Solís, M.C. Pujol, M. Aguiló and F. Díaz
Departamento de Tratamiento de la Señal y Comunicaciones, Universidad de Mondragón, Arrasate-Mondragón, 20500, Gipuzkoa, Spain
Dept. de Física de Materiales, Universidad Autónoma de Madrid, Madrid, Spain
Laser Processing Group, Instituto de Óptica, CSIC, Madrid, Spain
Física i Cristalografia de Materials i Nanomaterials (FiCMA-FiCNA), Universitat Rovira i Virgili, Tarragona, Spain

The fs-laser writing technique is an interesting and versatile approach to fabricate ridge optical structures in dielectrics, defining the so-called type-IV direct written waveguides. The fs-laser ablation is used to remove the selected parts of the planar waveguide surface, constructing thus the ridges. This technology does not require the use of clean room facilities, and allows rapid prototyping of integrated photonic devices because it is a mask-less technology. Among other integrated photonic devices, waveguide lasers in crystalline media are attractive to be used as miniaturized laser sources. In particular doubles tungstates (KYW) and lithium niobate (LiNbO3) are good candidates for laser hosts when doped with active rare earths, such as Yb or Nd, operating around 1 µm wavelength.


PIC Fabrication Platforms for SOI and Si3N4 in a Flexible Photonic Foundry Concept

AMO GmbH, Otto-Blumenthal-Str. 25, Aachen, 52074, Germany

We provide unique highly flexible fabrication platforms for integrated photonic circuits based on SOI and Si3N4 from design to fabrication and characterization of the manufactured devices. The schematic in Fig. 1 depicts different options of our technology platforms. The accessibility of both platforms permits applications from telecom wavelengths to the NIR and visible range, hence the devices are suitable for communication as well as for sensing. AMO has been developing the SOI platform for photonic applications for more than one decade. Waveguide losses and grating couplers have been optimized for both telecom wavelength ranges around 1310 nm and 1550 nm. Critical passive structures such as directional couplers and ring resonators can be fabricated with high precision (Fig. 2b), g)). The passive platform is completed with efficient grating couplers (Fig. a)) (2.5 dB loss) and edge coupling through spot-size converters. In order to maximize the yield of our SOI-based photonic devices fabrication tolerances have been intensively studied and device design as well as processes both for the lithographic definition and for the pattern transfer via reactive ion etching have been optimized accordingly.


Energy consumption study of reverse-biased modulators in monolithic electronic-photonic technology

S. Hosseini, M. Cătuneanu, R. Henker, F. Ellinger, K. Jamshidi
Integrated Photonic Devices Lab, Technische Universität Dresden, 01069 Dresden, Germany
Chair of Circuit Design and Network Theory,
Technische Universität Dresden, Germany

Electronic Photonic Integrated Circuits (EPIC) technology can be used to realize integrated photonic devices alongside with conventional electronic technology such as CMOS or BiCMOS. There is an alternative approach where photonic and electronic components are fabricated separately and then connected to each other using technologies such as wire bonding, flip-chip bump bonding or through silicon vias (TSV). The main challenge for the realization of high-speed devices is to realize energy-efficient devices. In this paper, the energy consumption of optical modulators as one of the main components of optical transceiver systems based on both pure photonic technology and EPIC technology are studied and compared.


Soft-proton exchange on Lithium Niobate substrates doped with Magnesium-oxide: route toward efficient and powerresistant nonlinear converters.

Tommaso LUNGHI, Florent DOUTRE, Guillaume LEGOFF, Getachew AYENEW, Hervé TRONCHE, Sébastien TANZILLI, Pascal BALDI and Marc DE MICHELI
Université Côte d’Azur, CNRS, Institut de Physique de Nice, France

Wavelength nonlinear conversion is an attractive approach to coherently shift the wavelength of an optical beam in regions of the spectrum where sources, optical components and detectors are more reliable and practical. Among the different nonlinear materials congruent Lithium Niobate (CLN) is one of the most widely used thanks to its large nonlinear coefficient. Through quasi-phasematching technique, a wide set of threewave mixing process can be addressed. In addition during these years several techniques have been developed in order to fabricate optical waveguide inside the substrate. However CLN suffers from Photo-Refractive Damage (PRD). The resistance to PRD can be improved by doping the lithium-niobate substrates with several dopants and Mangnesium-Oxide doped Lithium-Niobate substrates are the most accessible. Unfortunately, these substrates are less suitable for waveguide fabrication: the titanium indiffused process strongly reduces the benefit of Mg doping, while Annealed Proton Exchange (APE) waveguides show a nonlinear conversion less efficient than that of CLN. Several studies reported that the crystallographic structure of Mg-doped LN crystals is more severely affected by the proton exchange than that of CLN.


Mid-Infrared chemical sensing using a chalcogenide integrated transducer

F-22305 Lannion Cedex, France
ISCR, UMR-CNRS 6226, Glass and Ceramics Team, 35042 Rennes, France

Mid-Infrared (2-20 µm) spectroscopic techniques are widely used to identify chemicals substances, allowing quantitative real-time measurements in gases, liquids and solids. The current trend heads to the miniaturization of optical sensors, replacing bulky laboratory instruments (FTIR, monochromators, ATR etc..) by lab-on-chip devices providing portability, mechanical stability, immunity to electromagnetic noise and the potential for batch production. In recent years, optical integrated devices have been fabricated using different technologies such as GaAs, Si, Si3N4 and Ge. Chalcogenide glasses have also emerged as good candidates to manufacture Mid-Infrared photonic integrated circuits thanks to their ability to be deposited as thin films, their broad transparency (up to 20 µm), their potential to be doped with rare earth ions and their refractive index tunability obtained by varying glass composition.


Improving thermal performance of a UTC photodetector in the IMOS platform

Jorn P. VAN ENGELEN, Longfei SHEN, Yuqing JIAO, Meint K. SMIT,
Photonic Integration Research Group, Eindhoven University of Technology, The Netherlands

Recently a uni-traveling carrier photodetector (UTC-PD) with a 3 dB bandwidth beyond 67 GHz was presented. The device shows good performance up to 3 mA of photocurrent but experiences thermal failure (see Fig. 1a) at higher currents due to the poor heat extraction in membrane-type devices. Improvements to the thermal design are proposed that promise to double the possible photocurrent before thermal failure, which makes the performance comparable with state-of-the-art SOI UTC-PDs.


Proton Exchanged Waveguides on Congruent Lithium Tantalate and MgO-doped Lithium Tantalate

Getachew T. AYENEW, Pascal BALDI, Hervé TRONCHE, Florent DOUTRE, Marc DE MICHELI, Hoda KIANIRAD, Fredrik LAURELL
Université Côte d’Azur, CNRS, Institut de Physique de Nice, Parc Valrose, Nice, 06100, France
Applied Physics Department, KTH, AlbaNova, Roslagstullsbacken 21, Stockholm, 106 91, Sweden

Introduction : Lithium Tantalate (LT) has a shorter cut-off wavelength than Lithium Niob ate (LN) which makes the material attractive for UV generation through nonlinear processes. While congruent LT (CLT) suffers strongly from photorefractive damage, MgOdoped LT (MgO:LT) is an interesting alternative as it was shown on LN that MgO reduces the photorefractive effects. On the other hand, fabricating highly confining, low-loss optical waveguides on LT while preserving its nonlinear properties is still an issue, as it was previously shown that the index variation obtained using proton exchange is one order of magnitude lower than that on LN and that direct Proton Exchange (PE) erases both nonlinear coefficient and periodic domains organization as on LN.