Simplified colorless characterization scheme for coherent receivers in DWDM scenarios using a single interferer

Intradyne coherent receivers, capable of detecting an individual wavelength-division multiplexed channel just by tuning the local oscillator frequency, is of great interest for the development of high-capacity flexible optical networks. Nevertheless, the unavoidable amplitude imbalances inherent to any realistic coherent receiver induce an interference contribution from the self-beating of the coincident channels present at its input. The charac- terization of this degraded colorless reception operation is of fundamental importance, but it usually requires the use of rather complex experimental setups, especially when the effects of tens of interference channels should be evaluated. In this work we propose a novel experimental setup that only requires the use of a single intense interferer to emulate those coincident channels, thus drastically simplifying the characterization process. In addition, we develop a general expression for the signal-to-noise ratio of the system that theoretically justifies the intended setup and demonstrate by massive numerical simulations its accuracy in different scenarios. We believe that the proposed approach may contribute to facilitate the experimental characterization of high-performance colorless coherent receiversFunding for open access charge: Universidad de Málaga / CBU

Subwavelength gratings for sensing and polarization management

Sub-wavelength grating (SWGs) structures are becoming important building blocks in planar waveguide photonic devices [1]. SWG structures have been successfully applied in the design of a range of devices with remarkable performance by using refractive index engineering and dispersion engineering techniques [2]. In this work we explore two new promising applications of these structures, namely in evanescent field waveguide sensing and polarization management. For the evanescent waveguide sensing devices, we show that sub- wavelength patterning of silicon wires can be used to control the delocalization of the waveguide mode and therefore enhance both bulk and surface sensitivities (Fig. 1). We will also discuss the implementation of subwavelength structures in efficient polarization splitter and rotator (PSR) devices [3]. PSR devices based on asymmetrical directional couplers typically exhibit stringent fabrication tolerances. We show that by implementing SWG structures in PSR design both the effective mode index and its derivatives with respect to critical dimensions can be controlled, which significantly improves tolerance to fabrication errors (Fig. 2).Universidad de Málaga, Campus de Excelencia Internacional Andalucía Tech

Silicon-on-insulator polarization controller with relaxed fabrication tolerances

Polarization control is essential in applications ranging from optical communications to interferometric sensors. The implementation of in- tegrated polarization controllers is challenging as they require polariza- tion rotating waveguides with stringent fabrication tolerances. Here, we present a fully integrated polarization controller scheme that signi cantly relaxes the requirements on the rotating waveguides, alleviating fabri- cation tolerances. We analytically establish a technology-independent, easily measurable tolerance condition for the rotating waveguides. Po- larization control in the presence of waveguide width errors of 25% is shown through full vectorial simulation.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Mode Converter and Multiplexer with a Subwavelength Phase Shifter for Extended Broadband Operation

4 pags., 3 figs., 1 tab.On-chip mode converters and multiplexers are fundamental components to scale the capacity of silicon optical interconnects by using different spatial modes of waveguides. Recently, we proposed a low loss and compact mode converter and multiplexer consisting of a subwavelength-engineered multimode interference coupler, tapered waveguides as phase shifter and a symmetric Y-junction. However, the narrow spectral response of the tapered phase shifter limited the device crosstalk performance. In this work, we demonstrate that the use of a subwavelength grating phase shifter with low phase-shift errors substantially reduces the crosstalk and expands the operational bandwidth. A complete multiplexer-demultiplexer link consisting of two devices in back-to-back configuration was fabricated in a 220-nm silicon-on-insulator platform. Experimental measurements of the complete link show insertion loss below 2 dB and crosstalk less than -17 dB over a bandwidth of 245 nm (1427 - 1672 nm).is work was supported in part by the Spanish Ministry of Science and Innovation (MICINN) under grants RTI2018- 097957-B-C33, RED2018-102768-T, TEC2015-71127-C2-1-R (FPI BES- 2016-077798) and NEOTEC-CDTI-SNEO20181232 (Alcyon Photonics S.L.); and the Community of Madrid – FEDER funds (S2018/NMT-4326). This project has received funding from the Horizon 2020 research and innovation program under Marie Sklodowska-Curie grant No. 73433

Broadband 2 × 2 multimode interference coupler for mid-infrared wavelengths

Versión aceptada del artículo publicado en Optics Letters (https://doi.org/10.1364/OL.439985).Beam splitters are core components of photonic integrated circuits and are often implemented with multimode interference couplers. While these devices offer high performance, their operational bandwidth is still restrictive for sensing applications in the mid-infrared wavelength range. Here we experimentally demonstrate a subwavelength-structured 2×2 multimode interference coupler with high performance in the 3.1−3.7µm range, doubling the bandwidth of a conventional device

Re-inventing Multimode Interference Couplers Using Subwavelength Gratings

We use the concept of subwavelength grating (SWG) refractive-index-engineering to propose and experimentally demonstrate a reduced size, slotted 2x2 MMI coupler. We also present an ultra-broadband 2x2 MMI coupler which is based on SWG dispersion engineering.This work was supported in part by the Spanish Ministerio de Ciencia (project TEC2009-10152), a Formación del Profesorado Universitario scholarship (AP-2006-03355), the European Mirthe project (FP7-2010-257980) and “Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Subwavelength Index Engineering for SOI Waveguides

Photonic structures with a sub-wavelength pitch, small enough to suppress diffraction, can behave as equivalent homogenous materials that can be engineered to exhibit a specific refractive index and dispersion. Here we discuss the design of a variety of integrated photonic devices, ranging from grating couplers to multimode interference couplers, for which the use of sub-wavelength structures enables unique characteristics. We will place special emphasis on the design and experimental demonstration of multi-mode interference couplers with an unprecedented bandwidth beyond 200nm at telecom wavelengths.Universidad de Málaga.Campus de Excelencia Internacional Andalucía Tech. Ministerio de Economía y Competitividad, "Programa Estatal de Investigación, Desarrollo e Innovación Orientada a los Retos de la Sociedad (cofinanciado FEDER)", Proyecto TEC2013-46917-C2-1-

Subwavelength silicon photonics: keynote presentation

2020 Photonics North (PN), Niagara Falls, ON, Canada, 26-28 May 2020Subwavelength structures are enabling a host of high-performances devices in the silicon photonic platform. Here we review our progress in the field, with an emphasis on the auspicious anisotropic properties of these structures for applications ranging from broadband on-chip GRIN-lenses, to zero-birefringence waveguides and polarization splitters

Research and development project assessment and social impact

Nowadays, organisations increasingly need to adapt to the fast evolution of markets and societies in our globalised world in order to be competitive. Therefore, it is essential to take the right decisions when it comes to invest in research and development (R & D) projects. However, an issue that has not been given much attention is how to measure the social impact (or return) of R & D projects. In this exploratory study, the findings of an analysis of how R & D projects are assessed and selected, including this social perspective, are presented. The methodology which has been used in this research includes both interviews and analysis of the data obtained through them. The major finding is that in the current situation the social impact is not taken into account, but is growing the awareness of this perspective among different types of organizations dealing with R & D activities.(undefined)info:eu-repo/semantics/publishedVersio

Silicon photonic mode multiplexers based on subwavelength metamaterials and on-chip beam forming

4 pags., 1 fig. -- Event: SPIE OPTO, 2023, San Francisco, California, United StatesIntegration of photonic circuits on silicon offers a unique opportunity to address the scaling of inter- and intra-chip communications in an energy-efficient and cost-effective manner. Mode-division multiplexing (MDM) is deemed as one of the most promising technologies to increase aggregated data bandwidth and avoid a communication capacity crunch. In this invited talk, we review our latest advances on integrated silicon mode multiplexers, including new topologies based on subwavelength grating (SWG) metamaterials for extended broadband operation and higher-order mode support. Specifically, we report on an ultra-broadband multiplexer based on a phase shifter and a multimode interference (MMI) coupler both engineered with subwavelength metamaterials. Experimental measurements of a complete multiplexer-demultiplexer link show losses lower than 2 dB and crosstalk below -17 dB over a bandwidth of 245 nm (1427 – 1672 nm).This work has been funded in part by the French Industry Ministry (Nano2022 project under IPCEI program); the Agence Nationale de la Recherche (ANR-MIRSPEC-17- CE09-0041); the European Union’s Horizon Europe (Marie SklodowskaCurie grant agreement Nº 101062518); the Spanish Ministry of Science and Innovation (MICINN) under grants RTI2018-097957-B-C33 and PID2020-115353RA-I00; the Spanish State Research Agency under grant MCIN/AEI/10.13039/501100011033 (PTQ2021-011974); the Community of Madrid – FEDER funds (S2018/NMT4326); the European Union – NextGenerationEU through the Recovery, Transformation and Resilience Plan (DIN2020-011488). The fabrication of the device was performed at the Plateforme de Micro-NanoTechnologie/C2N, which is partially funded by the Conseil General de l’Essonne. This work was partly supported by the French RENATECH network.Peer reviewe