2017 Poster Session MP1

1 × 2 Wavefront Control Type Wavelength-Selective Switch by Silicon Waveguides

Fumi NAKAMURA, Keijiro SUZUKI, Ken TANIZAWA, Minoru OHTSUKA, Nobuyuki YOKOYAMA, Kazuyuki MATSUMARO, Miyoshi SEKI, Keiji KOSHINO, Kazuhiro IKEDA, Shu NAMIKI, Hitoshi KAWASHIMA, Hiroyuki TSUDA
Faculty of Science and Technology, Keio University, 3-14-1, Hiyoshi, Kohoku-ku, Yokohama, Kanagawa, 223-0061, Japan
National Institute of Advanced Industrial Science and Technology (AIST), 16-1 Onogawa, Tsukuba, Ibaraki, 305-8569, Japan f_nakamura@tsud.elec.keio.ac.jp

A wavelength-selective switch (WSS) can route each of the input wavelength division multiplexed (WDM) signal to any one of the output ports. A WSS is the key device of an optical node in the optical network system. We previously proposed a 1 × 2 wavefront control type WSS [1], [2]. This WSS has no waveguide crossing; therefore the crosstalk between channels and the variation in loss among channels can be reduced. In this paper, we demonstrate successful switching operations with this WSS.


Frequency Tuning of Symmetric Colliding Pulse ModeLocked Laser through Asymmetric Biasing IntraCavity Phase Modulators

Mu-Chieh Lo, Robinson Guzmán, Carlos Gordón, Muhsin Ali,
Guillermo Carpintero
Departamento de Tecnología Electrónica, Universidad Carlos III de Madrid, Leganés, Madrid, 28911, Spain

In this paper we report a multimode interference reflector (MIR)-based linear cavity mode-locked laser (MLL) operating in the telecom C-band with a repetition rate of 30 GHz as shown in Fig. 1. A pair of intra-cavity electro-optic phase modulators (EOPM) enables spectral tuning of the optical and the photo-detected RF spectrum. As an asymmetric bias voltage increases up to 6 V, the RF frequency shift reaches 3 MHz. This photonic integrated circuit (PIC) was rapidly prototyped using generic photonic integration technology platform via industrial Multi-Project Wafer (MPW) run.


Integrated Dual-Mode Interferometer with Differential Single-Mode Outputs

Niklas HOPPE, Philipp DIERSING, Thomas FÖHN, Mathias KASCHEL, Thomas POLDER, Wolfgang VOGEL, Lotte RATHGEBER, Maria FELIX ROSA,
Institute of Electrical and Optical Communications,
University of Stuttgart, 70569, Stuttgart, Germany
Institut für Mikroelektronik Stuttgart (IMS CHIPS)
70569, Stuttgart, Germany

Abstract: We present for the first time the realization of an integrated dual-mode interferometer containing two differential single-mode outputs. The structure realized in a 250 nm silicon-on-insulator platform enables the monitoring of total optical output power. Hence, the estimation of phase relation becomes tolerant to input power fluctuations and can be realized by a single-wavelength operation even when the optical input power is unknown.


Full field Group Velocity Dispersion characterization of 300nm film height Silicon Nitride waveguides

Luis A. BRU, Gloria MICÓ, Daniel PASTOR, David DOMENECH, Ana M. SÁNCHEZ, Josep M. CIRERA, Javier SANCHEZ, Carlos DOMÍNGUEZ and Pascual MUÑOZ
Photonic-IC group @ Photonic Research Labs, Universitat Politècnica de Valencia, Spain
VLC Photonics S.L., Ed9B-UPV, c/ Camino de Vera s/n, Valencia, Spain
IMB-CNM-CSIC, Campus Belaterra UAB, Barcelona, Spain

Optical Frequency Domain Reflectometry (OFDR) allows retrieving amplitude and phase features from optical devices in the time and frequency domains. Characterization of the propagation features in new photonics platforms and waveguide designs is essential in different applications where dispersion tailoring and birefringence need to be controlled over a wide wavelength range. In this paper we present the full-field Group Velocity Dispersion (GVD) assessment of Si3N4 waveguides employing the time resolved features of OFDR techniques. The devices were fabricated on a 100mm Si wafer, composed of a SiO2 buffer (2.5μm thick, n=1.464) grown by thermal, following a LPCVD Si3N4 layer with thickness 300nm (n= 2.01) and a 2.0μm thick SiO2 (n=1.45) deposited by PECVD. A set of test of ring resonators (RRs), Fig. 1(a), was deployed for strip waveguides of width 1.0m. The bend radius was set to 150μm for which no significant additional loss was expected.


Mutual Injection Locking of Lasers in a Photonic Integrated Circuit

Alison H. PERROTT, Ludovic CARO, Mohamad DERNAIKA, Niall P. KELLY, Padraic E. MORRISSEY, Frank H. PETERS
Physics Department, University College Cork,
College Road, Cork, Ireland, T12 YN60
Tyndall National Institute, Lee Maltings, Dyke Parade, Cork, Ireland, T12 R5CP
Engineering Department, University College Cork,
College Road, Cork, Ireland, T12 YN60

Photonic integrated circuits (PICs) offer many advantages in the area of photonics. In particular, complex optical systems which were once restricted to large table top setups are now finding their way onto integrated devices. Not only does this vastly decrease the size of these systems, it allows for lower power consumption and reduced cost.
We are interested in examining the stable regime of mutually injection locked lasers, which will be applied to the creation of optical superchannels for high bandwidth communications. The monolithic integration of multiple Slotted Fabry-Pérot (SFP) lasers onto a single PIC has been investigated [3]. Injection locking of such a system is highly complex, due to mutual feedback between the lasers. Yet, stable optical-phase locking between two SFP lasers on-chip has been demonstrated for the case where one laser, the master, is much higher powered than the other laser, the slave. In this paper, we investigate the mutual injection locking of two integrated, identical, equally powered SFP lasers while varying the coupling ratio between them


Temperature-immune readout of an integrated optical wavelength meter based on microring resonators

Caterina TABALLIONE, Temitope AGBANA, Gleb VDOVINE, Marcel HOEKMAN, Lennart WEVERS, Jeroen KALKMAN, Michel VERHAEGEN, Peter J.M. VAN DER SLOT and Klaus-Jochen BOLLER
University of Twente, P.O. Box 217, 7500 AE Enschede,
University of Delft, P.O. Box 5, 2600 AA Delft,
LioniX International BV, P.O. Box 456, 7500 AL Enschede
E-mail: c.taballione@utwente.nl

Wavelength meters are central for many applications such as in telecommunication systems or laser monitoring. The primary function of a wavelength meter is to provide an output signal that changes sensitively with the wavelength of the input light. Of central importance is the reproducibility of the output signal even in the presence of external perturbations, e.g., temperature changes causing thermal drift. Various different methods are usually applied to improve reproducibility, e.g., thermal stabilization or repeated calibration with an additional reference light source of well-known and stable wavelength.


Strip-loaded horizontal slot waveguide: confinement with negligible losses

Matthieu ROUSSEY, Ségolène PELISSET, Leila Ahmadi, Markku KUITTINEN, and Seppo HONKANEN
Institute of Photonics, University of Eastern Finland, P.O. BOX 111, 80101 Joensuu, Finland

From optical computing to data storage, from bio-sensing to quantum applications, integrated photonic nano-structures in waveguides are widely used. However, an ideal platform is still to be found to provide, at the same time, an easy fabrication, a low power consumption, low losses, and wavelength scalable devices. A promising solution is presented here.


Design and Optimization of a High Speed Slow-Light Silicon Modulator in the O-Band

Andrea ZANZI, Pablo SANCHIS, Javier MARTI, Antoine BRIMONT
Valencia Nanophotonics Technology Center, Universitat Politècnica de València Building 8F | 1st Floor, Camino de Vera, s/n, 46022 Valencia, Spain anzan@ntc.upv.es

The ever-growing increase in global internet traffic imposes significant challenges in data centre (DC) operators equipment manufacturers. These modern DCs utilized hundreds of thousands of servers in several hierarchy layers, which require an efficient interconnection network that have to be both low-cost and energy-efficient. This is precisely where silicon photonics can play a key role. Indeed, Silicon-on insulator (SOI) technologies is currently considered as one of the most promising platforms to achieve high density levels of integration of photonic devices at low cost, owing to its high-index contrast and compatibility with mature complementary metal-oxide semi-conductor (CMOS) fabrication process.


High-Q Al2O3 Microring Resonator for Sensing Applications

Optical Sciences Group, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands m.degoede@utwente.nl

Waveguide based microring resonators (MRRs) are particularly suitable for on-chip integrated optical sensors. Their spectra contain resonance notches that shift due to the probing of the evanescent modal field of local dielectric variations. Sensors based on this shift have already been reported in the Si, Si3N4 and SiON technologies. The Al2O3 technology has the prospect of very high quality (Q) factors due to its low propagation loss. Furthermore, doping it with rare-earth ions enables the realization of on-chip laser based sensors for ease of detection. Here, a high Q Al2O3 waveguide MRR sensor is presented as alternative to the traditional MRR technologies with the prospect of developing lasing-based Al2O3 MRR sensors.


A single-frequency integrated ring laser for gyro applications

Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw, Poland
SMART Photonics B.V., Horsten 1, 5612 AX Eindhoven, the Netherlands

Inertial measurement unit (IMU) is an essential part of modern aircrafts, drones spacecrafts, ships, missiles and others. A typical IMU comprises a set of accelerometers and gyroscopes providing signals which enable accurate and reliable navigation. The application determines detailed requirements, however in any case high speed and accuracy, compact and robust design combined with low power consumption are strongly demanded. Optical gyroscopes, either interferometric or ring laser based devices, seem to be the most suitable for these applications. However, so far an integrated optical gyroscope has not been implemented on the market. In our previous paper we demonstrated the initial results of our research on multi-mode integrated ring lasers for gyro application, while in this work we present a system, based on a single-frequency integrated ring laser, which could be used as an optical gyro sensor.


Analysis of the sensitivity of Mach-Zehnder interferometer filter to fabrication tolerances through elementary effect test

Abi WAQAS, Daniele MELATI and Andrea MELLONI
Dipartimento di Elettronica, Informazione e Bioingegneria,
Politecnico di Milano, 20133, Italy
Department of Telecommunication,
Mehran University of Engineering and Technology, Pakistan

Abstract: Sensitivity analysis method is applied to the Mach-Zehnder interferometer filter to assess how the fabrication processes variations of some geometrical parameters can influence the performance of the photonics devices.


 Low-voltage Optical Switching by a Four-waveguide Directional Coupler

Tianran LIU, Francesco PAGLIANO, Andrea FIORE
Department of Applied Physics and Institute for Photonic Integration, Eindhoven University of Technology,
P.O. Box 513, 5600MB Eindhoven, The Netherlands

Optical switches base on electrostatic movable micro-mirrors have been developed since nineties of the last century for their low power consumption and high optical performance. As nano-fabrication technology advances, it is recently possible to build optical switches with other optical devices on a single chip. To reach higher level of integration, moving waveguides rather than mirrors to steer light is a better option since it involves less free-space alignment. Several works have been done in this direction in the recent years. However, most of these devices require a high actuation voltage from 14V to 50V and the switching frequency is below 1MHz, which limit their diversity in application.


Linear and non-linear propagation properties of state of the art Silicon Nitride waveguides

Pascual MUÑOZ, Gloria MICÓ, Luis BRU, Daniel PASTOR, David DOMENECH
Photonic-IC group @ Photonic Research Labs,
Universitat Politècnica de Valencia, Spain
VLC Photonics S.L., Ed9B-UPV, c/ Camino de Vera s/n, Valencia, Spain

Among the materials for silicon based photonics, Silicon Nitride (Si3N4) has received considerable interest for non-linear photonics, due to its larger band gap with negligible two photon absorption. Each of the non-linear applications requires a suitable dispersion.


Double Al2O3 Microring Resonator for Self-Referenced Sensing Applications 

Optical Sciences Group, MESA+ Institute for Nanotechnology,
University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands

Microring resonators (MRRs) find many applications for on-chip integrated optical sensors. Their operation is based on the spectral shift of resonance notches due to the probing of the evanescent modal field of local dielectric variations. MRR sensors are sensitive to any environmental perturbations, including temperature fluctuations and bulk refractive index variations, making it difficult to de-embed these from the actual analyte signal. By using a double MRR and by recording the differential spectral shift of the resonance notches of both a signal and a reference MRR the effect of the environment can be minimized [1]. Here, an Al2O3 double MRR with high quality factor Q=1.5e5 is demonstrated that is insensitive to both temperature and bulk refractive index changes. This system can be used for self-referenced and stable biosensing applications by functionalizing one of the two MRRs. Then, a change in differential resonance wavelength shift arises only due to the attachment of analytes to the sensing MRR surface, eliminating the environmental variations.


Simulation and Experimental Evaluation of Optical Chirp Modulation for Bimodal Waveguide Interferometer Biosensors

Daniel GRAJALES, Jose Ramón SENDRA, Laura M. LECHUGA
Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and the Barcelona Institute of Science and Technology, and CIBER-BBN.
Campus UAB. Barcelona, Spain.
IUMA, Institute for Applied Microelectronics, University of Las Palmas GC, Campus de Tafira, Las Palmas, Gran Canaria, Spain.

We report the simulation and implementation of an optical chirp modulation system for interferometric optical waveguides operating in the visible range to explore the sensor response to different wavelengths in order to ensure the maximum sensitivity.

Optical interferometers are powerful and sensitive tools for detecting small changes at nanometric scale. When working as biosensor devices they can provide the highest sensitivities for real-time and label-free biomolecular detection, without the need of additional amplification steps. Our group proposed a Bimodal Waveguide Interferometer (BiMW) as a high performance biosensor, which is an elegant, robust, simple yet powerful and sensitive device. Nonetheless, due to the nature of the interferometric signals, sensitivity fades or signal ambiguities can be present. To overcome such difficulties we proposed an all-optical phase modulation. However, this technique required the individual analysis of the visibility (signal amplitude) inherent to each BiMW sensor, previously to any experiment, in order to ensure that we can get the maximum sensitivity. As a replacement, we propose a chirp modulation as an exploratory mechanism previous to the detection.


Widely tunable mid-IR monolithic coherent source

Alice BERNARD, Marco RAVARO, Jean-Michel GERARD, Olivier PARILLAUD, Bruno GERARD, Ivan FAVERO, and Giuseppe LEO
Laboratoire Matériaux et Phénomènes Quantiques, UMR 7162, Université Paris Diderot – CNRS, Paris, France
CEA-CNRS-UJF groupe Nanophysique et Semiconducteurs, CEA, INAC, SP2M, Grenoble, France
III-V Lab, Thales Research and Technology, Route départementale 128,
91767 Palaiseau, France

InGaAsP lattice-matched to InP is widely used for optoelectronic components such as lasers, detectors and modulators. For the design of these devices, knowledge of refractive index is critical. While it has been well described up to 1.55 µm1-4, only one publication offers its measurement at longer wavelengths5, with limited precision. We have performed an accurate characterization of the refractive index up to 3.14 µm, lengthening the wavelength range and offering a significant increase in precision. This data is exploited to design a tunable source in the mid-IR range, through spontaneous downconversion (SPDC) of a laser beam at 1.55 µm.


A multi-channel photonic integrated transmitter driven by an application specific integrated circuit

Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw, Poland
SMART Photonics B.V., Horsten 1, 5612 AX Eindhoven, the Netherlands

The dynamically developing market of modern fiber-optic access networks calls for highspeed, multi-channel photonic transmitters and receivers, technologically suitable for volume production at low cost. Such devices can be potentially developed using cuttingedge photonic integration technologies. At present, one of the major obstacles for broad implementation of photonic integrated circuits on the market are packaging constraints, especially related to providing many electrical RF interfaces. In this work we demonstrate and discuss a concept of hybrid integration of a multi-channel photonic integrated transmitter driven by an electronic application specific integrated circuit (ASIC). The two circuits will be bonded using a standard flip-chip technology. Such a hybrid integration scheme can provide an efficient method of driving multi-channel photonic integrated devices at high speed. To the best knowledge of the authors, such a concept is presented for the first time.


Noise Tolerance in Integrated-Optic Recognition Circuit for Optical 16QAM Codes

Tokushima University, 2-1 Minamijosanjima-cho, Tokushima, 770-8506, Japan

In photonic label routers, various optical signal processing functions are required, which include optical label extraction, recognition of the label, optical switching and buffering controlled by signals based on the label information and network routing tables, and label rewriting. Among these functions, we focus on photonic label recognition. We have proposed two kinds of optical waveguide circuits to recognize 16 quadrature amplitude modulation (QAM) codes.


Design of a Multiple-reference Time-domain Optical Coherence Tomography System

B. Imran Akca
Biomedical Engineering & Physics, Academic Medical Center,
University of Amsterdam, 1100 DE Amsterdam, The Netherlands

Optical coherence tomography (OCT) is a non-invasive, three-dimensional imaging technique that offers close-to-histology-level image quality [1]. In conventional timedomain (TD)-OCT systems depth scanning is achieved by modifying the relative optical path length difference of the reference and the sample arms in a sequential way using mechanical scanners. Due to the moving reference mirror TD-OCT systems require an inherently long acquisition time. To overcome this problem non-moving part solutions have been proposed such however, each solution has its own drawbacks.


Fabrication of Monolithic Optofluidic Evanescent Probing Device for Sensing Applications

CAP – Centre for Applied Photonics, INESC TEC,
Rua Dr. Roberto Frias, Porto, 4200-465, Portugal
Department of Physics, University of Trás-os-Montes e Alto Douro,
Quinta de Prados, Vila Real, 5000-801, Portugal
Department of Physics and Astronomy, Faculty of Sciences of University of Porto, Rua do Campo Alegre, Porto, 4169-007, Portugal joaomaia93@hotmail.com

Micromachining with femtosecond (fs) laser can be exploited to monolithically integrate optical components and microfluidic channels in pure fused silica substrates, due to internal modification of the glass properties that are induced by the laser beam. In this paper, the optimization of the fabrication of microfluidic channels, was conducted by examining etch rate and surface roughness as a function of the irradiation conditions, namely scanning speed, scanning depth, pulse energy, beam polarisation and scan lines separation. Moreover, careful positioning of an optical layer relative to the microchannel was performed by analysing in real-time the channel etching reaction. This latter feature enables precise control of the optical interaction between the two structures, which can be of use in optofluidic devices for sensing applications.


Dispersion controlling in strained silicon waveguides using sub-wavelength grating metamaterials

Daniel Benedikovic, Carlos Alonso-Ramos, Mathias Berciano, Xavier Le Roux, Eric Cassan, Delphine Marris-Morini, and Laurent Vivien
Centre for Nanoscience and Nanotechnology, CNRS, Univ. Paris-Sud, Université Paris-Saclay, C2N – Orsay, 91405 Orsay Cedex, France daniel.benedikovic@u-psud.fr

We report on controlling of the group velocity dispersion in silicon (Si) strip waveguides, with refractive index engineered sub-wavelength grating (SWG) metamaterials, covered by silicon nitride (Si3N4) layer. This waveguide geometry is utilized for breaking the centrosymmetric nature of silicon and opening the route for second-order nonlinearities in the silicon-on-insulator technology. We show by calculations that attractive waveguide dispersion profiles over a broad spectral range can be flexibly tailored by proper control of transversal dimensions and appropriate refractive index engineering. Both normal and anomalous dispersion regimes can be obtained, being one important parameter for various nonlinear applications in photonics.


Photonic Integrated Circuits for Data Center Interconnects

Benjamin WOHLFEIL, Danish RAFIQUE, Michael EISELT
ADVA Optical Networking SE, Märzenquelle, Meiningen, 98617, Germany

Optical transceivers for data center interconnects (DCI) are projected to become a multibillion dollar market by the end of this decade [1]. Due to the increasing demand for high data rates driven by cloud and mobile applications, next-generation DCIs will not only require higher capacity but also an improvement in bandwidth density, power efficiency and cost. Following the electronics industry’s example, where a high level of integration has provided for these goals, the DCI market may also benefit from integration of optical functionality in so called photonic integrated circuits (PIC). In this paper we discuss PIC based solutions for DCIs and explore the challenges for deployment of PICs in DCIs.