2018 Session – Subwavelength, plasmonics & metamaterials

Water-loaded plasmonic stripe integrated with Si3N4 waveguide using gold and CMOS compatible metals

A. Manolis, G. Dabos, D. Ketzaki, E. Chatzianagnostou, N. Pleros, L. Markey, J.C. Weeber, A. Dereux, A.L. Giesecke, C. Porschatis, B. Chmielak and D. Tsiokos Department of Informatics – Center for Interdisciplinary Research and Innovation, Aristotle University of Thessaloniki, Greece
Tel: +302310990588, e-mail: dtsiokos@csd.auth.gr
Laboratoire Interdisciplinaire Carnot de Bourgogne, CNRS-Université de Bourgogne, Dijon, France 3AMO GmbH, Advanced Microelectronic Center Aachen (AMICA), Otto-Blumenthal-Strasse, Aachen, Germany

Abstract
In this work, we report the integration of low loss Si3N4 waveguides with water-loaded thin plasmonic stripes. Experimental measurements revealed a photonic to plasmonic insertion loss of 2.3dB per transition and a propagation length of 75μm at 1550nm when using gold as plasmonic metal. With the aid of numerical simulations we also demonstrate how CMOS compatible metals may be used to realize such structures at low cost. The proposed waveguide scheme holds promise as an optical transducer in future plasmonics-augmented biosensors.

Keywords: Surface plasmons, thin-film plasmonics, silicon nitride, photonic integrated circuits. CMOS metals.

Th.1.B.1 73-Regular Paper, Water-loaded plasmonic stripe integrated with Si3N4 waveguide using gold and CMOS compatible metals


Surface enhanced Raman spectroscopy via isolated plasmonic nanoantennas integrated on silicon nitride waveguides

Ali Raza, Javier Losada, Stephane Clemmen, Roel Baets, Amadeu Griol and Alejandro Martínez
Photonics Research Group, INTEC Department, Ghent University-imec, Technologiepark-Zwijnaarde, 9052 Ghent – Belgium 2 Center for Nano-and Biophotonics, Ghent University – Belgium
Nanophotonics Technology Center, Universitat Politècnica de València, Camino de Vera s/n, 46022, Valencia – Spain e-mail: amartinez@ntc.upv.es

Abstract
In this work, we demonstrate experimentally surface enhanced Raman spectroscopy (SERS) via bowtie metallic nanoantennas integrated in silicon nitride waveguides. Two different configurations are considered: nanoantenna on top of the waveguide and nanoantenna inside a gap created in the waveguide. Even though both configurations allow for observing the Raman peaks of 4-nitrothiophenol (NTP), the latter shows higher peaks as a result of a better coupling from the Raman active centres to the fundamental TE waveguide mode. Our results pave the way towards the realization of massive SERS detectors on silicon-compatible photonic chips.

Keywords: silicon photonics; SERS; nanoantennas; hybrid photonic circuits.

Th.1.B.2 80-Regular Paper, Surface enhanced Raman spectroscopy via isolated plasmonic nanoantennas integrated on silicon nitride waveguides


Subwavelength metamaterials structures for applications in silicon photonics

J. H. Schmid, P. Cheben, D. Melati, D.-X. Xu, S. Janz, J. Lapointe, S. Wang, M. Vachon, R. Halir, A. Ortega-Moñux, G. Wangüemert-Pérez, I. Molina-Fernández, A. Sánchez-Postigo, J.M. LuqueGonzalez, J.D. Sarmiento-Merenguel, Jiří Čtyroký
Advanced Electronics and Photonics Research Centre, National Research Council Canada, 1200 Montreal Road, Ottawa, Ontario, Canada
e-mail: jens.schmid@nrc-cnrc.gc.ca
Universidad de Málaga, Dpto. de Ingeniería Comunicaciones, ETSI Telecomunicación, Campus de Teatinos s/n, 29071 Málaga, Spain
Institute of Photonics and Electronics, CAS, Chaberská 57, 182 51 Prague, Czech Republic

Abstract
Subwavelength engineering in silicon photonic integrated circuits is a powerful design tool that allows one to adjust the waveguide core effective refractive index by periodically patterning the silicon waveguide layer at the subwavelength scale. This creates a new degree of freedom in photonic circuit design. In recent years, the subwavelength metamaterial concept has been demonstrated and applied to many silicon photonic devices such as fiber-chip couplers, waveguide crossings, microspectrometers, ultra-fast optical switches, athermal waveguides, evanescent field sensors, polarization rotators and colorless interference couplers. Here we report our advances in the development of subwavelength engineered dielectric metamaterial structures for silicon photonic devices with a special emphasis on the practical performance of fiber-chip coupling structures and the possibility to affect the spectral bandwidth of silicon photonic devices by subwavelength engineering. In particular, we will present our results in developing highly efficient and broadband fiber-chip and laser-chip couplers for silicon photonic wire waveguides using subwavelength engineered structures, a broadband prism assisted grating coupler, an ultra-broadband multi-mode interference (MMI) coupler device and narrow-band Bragg spectral filters in subwavelength grating (SWG) waveguides.

Keywords: Silicon photonics, subwavelength structures, metamaterials, Bragg gratings

Th.1.B.3 12-Invited Paper, Jens Schmid (National Research Council, Canada), “Silicon photonics and subwavelength photonic structures-metamaterials”


High performance and small footprint spot size converters based on SWG metamaterial lenses

José Manuel Luque-González, Alejandro Ortega-Moñux, Robert Halir, Iñigo Molina-Fernández, J. Gonzalo Wangüemert-Pérez, Jens H. Schmid
and Pavel Cheben
Universidad de Málaga, Dept. de Ingeniería de Comunicaciones, ETSI Telecomunicación, Campus de Teatinos s/n, 29071 Málaga, España 2 National Research Council Canada, 1200 Montreal Road, Bldg. M50, Ottawa K1A 0R6, Canada *Corresponding author: jmlg@ic.uma.es

Abstract
Spot size converters with high expansion ratio are required in a variety of situations. This is the case of nonfocusing Silicon on Insulator (SOI) fiber-to-chip grating couplers, which typically require long adiabatic tapers (Ltaper >100µm) from the narrow single-mode waveguides (WSi-wire ~ 500nm) to the wide grating region (Wgrating ~ 15µm). Here, we explore the potential of subwavelength grating (SWG) dielectric metamaterials to implement integrated GRaded INdex (GRIN) lenses to expand the mode field. Our designs achieve the desired Beam Expansion (BE) with insertion losses below 1dB over a distance of only LBE ~ 17µm.

Keywords: Subwavelength grating, Graded Index, Beam expander, Silicon-On-Insulator, Grating coupler.

Th.1.B.4 53-Regular Paper, High performance and small footprint spot size converters based on SWG metamaterial lenses


Coherent control of the absorption and scattering of an isolated plasmonic nanoantenna integrated in a silicon waveguide

Alba Espinosa-Soria, Amadeu Griol and Alejandro Martínez
Nanophotonics Technology Center, Universitat Politècnica de València, Camino de Vera s/n, 46022, Valencia – Spain e-mail: amartinez@nrtc.upv.es

Abstract
In this paper, we use an on-chip approach to experimentally demonstrate that the absorption and scattering of a subwavelength plasmonic nanoantenna can be manipulated by using coherent illumination. To do so, we integrate the nanoantenna in a gap separating two silicon photonic waveguides so that it can be illuminated from its both sides by two coherent beams with controlled amplitude and phase. We show experimentally that scattering can be modulated by about one order of magnitude, whilst higher values could be obtained by further optimization. This finding paves the way towards coherent all-optical data processing in subwavelength devices integrated on silicon-compatible chips.

Keywords: silicon photonics; coherent perfect absorption; nanoantennas; hybrid photonic circuits.

Th.1.B.5 121-Regular Paper, Coherent control of the absorption and scattering of an isolated plasmonic nanoantenna integrated in a silicon waveguide


Plasmonics for integrated optics

Pierre Berini
School of Electrical Engineering and Computer Science, University of Ottawa, 25 Templeton St., Ottawa, Ontario K1N 6N5, Canada
e-mail: berini@eecs.uottawa.ca
Department of Physics, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada 3 Centre for Research in Photonics at the University of Ottawa, Ottawa, Ontario K1N 6N5, Canada

Abstract
We review work on integrated optical components and devices operating with surface plasmons. The properties of long-range surface plasmon waveguides are discussed, followed by their application to elements such as Sbends, Y-junction splitters, couplers and Mach-Zehnder interferometers. Such passive elements are then used to underpin advanced active devices, such as surface-plasmon amplifiers, lasers and biosensors.

Keywords: Surface plasmon waveguides, passive components, active devices, lasers, amplifiers, biosensors.

Th.1.B.6 19-Invited Paper, Pierre Berini (Univ. Ottawa), “Plasmonics for Integrated Optics”