Self-referencing techniques in photonics sensors and multiplexing

11 pages, 8 figures.-- Contributed to: "Photonic Materials, Devices, and Applications II", ed. by Serpengüzel, Ali; Badenes, Gonçal; Righini, Giancarlo C. (Maspalomas, Spain, May 2, 2007).A short review of self-reference techniques for remote fiber-optic intensity sensors and possible integration in multiplexing sensor networks is reported. Special focus is given to developments on radio-frequency (RF) source modulation techniques in interferometric configurations operating under incoherent regime. Experimental results on ring resonator (RR) configurations in transmission and reflection modes are included. Sensitivity, optimum insertion losses and robustness to intensity error fluctuations are reported. Sensors are interrogated at two sub carrier frequencies having a high rejection of interference from laser source intensity fluctuations and loss in the fiber lead. Dependence on source coherence is also analysed.Scalable self-referencing sensor networks with low insertion losses implemented in Coarse Wavelength Division Multiplexing (CWDM) technology are reported. The possibility of remote self-referenced measurements using a full-duplex fiber down-lead tenths of kilometers long with no need for optical amplification is also described. Fiber Bragg gratings (FBG) are used in the reflection configuration, thus increasing the sensitivity of the optical transducers. Low-cost off-the-shelf devices in CWDM and DWDM technology can be used to implement and scale the network.Applications to specific photonic sensors are also envisaged and these techniques can be used in networks of microfiber loop resonators, being the microfiber loop the sensing element itself.This work was partially supported by CICYT (TEC2006-13273-C03-03-MIC), COST299, EPhoton/One+(NoE-ISTEU), FENIS-CCG06-UC3M/TIC-0619, CAM (FACTOTEM-CM:S-0505/ESP/000417).Publicad

Reconfigurable optical multiplexer based on liquid crystals for polymer optical fiber networks

In this work, different novel 3×1 multiplexer structures for being used in polymer optical fiber networks are proposed. Designs are compact, scalable, and of low consumption, capable of operating in a large wavelength range simultaneously 660, 850, and 1300 nm, due to the use of nematic liquid crystal cells. Light that comes from each input port is handled independently and eight operation modes are possible. Control electronics has been made using a programmable integrated circuit. Electronic system makes available the managing of the optical stage using a computer. An additional four optical sensors have been included for allowing the optical status checking. Finally, a polarization independent multiplexer has been implemented and tested. Insertion losses less than 4 dB and isolation better than 23 dB have been measured. In addition, 30-ms and 15-ms setup and rise times have been obtained. The proposed multiplexer can be used in any polymer optical fiber network, even in perfluorinated graded index one, and it can be specially useful in optical sensor networks, or in coarse wavelength division multiplexing networks.Publicad

Desarrollo de un Sistema de Acceso para Parqueaderos y Cobro Tarifario Utilizando Reconocimiento de Patrones.

El trabajo de investigación de desarrollo de un sistema de accesos para parqueadero y cobro tarifario mediante reconocimiento de patrones tiene como objetivo automatizar y mejorar las condiciones de servicio de parqueaderos disminuyendo tiempos de registro y tarifando valores justos en la Facultad de Informática y Electrónica perteneciente a la Escuela Superior Politécnica de Chimborazo. Mediante análisis documental fueron evaluadas redes neuronales de aprendizaje supervisado y se escogió la red neuronal de retropropagación como más apta para el trabajo. El sistema se desarrolló bajo el sistema operativo Linux-Ubuntu, usando como compilador QT Creator y para visión artificial las librerías de OpenCV, el lenguaje de programación fue C++. Se codificó la red neuronal y se escogieron muestras para su entrenamiento. Se diseñó el sistema de segmentación y clasificación. Se construyó un modelo a escala de un parqueadero, donde se instalaron dos cámaras IP conectadas en red con el computador. Los resultados por el sistema de reconocimiento de siete caracteres obtenidos fueron favorables con un porcentaje de 99.256% clasificando caracteres de placas vehiculares. Así mismo el tiempo de procesamiento fue relativamente bajo con un valor medio de 156.21ms. Se concluye que la red de retropropagación posee un alto desempeño clasificando caracteres y manejando grandes volúmenes de datos. Se ven reducidos los tiempos de ingreso y salida del parqueadero mediante el sistema creado. Se recomienda a los investigadores de la Facultad de Informática y Electrónica que tomen este trabajo como referencia para trabajar con redes neuronales artificiales.This research is a development of an accessing system for parking and charging through recognizing prompts, It aims to automatize and better the conditions of service of parking, decreasing register time and charging the correct price in the Faculty of Informatics and Electronics at Superior Polytechnic of Chimborazo. Using documental analysis neuronal networks of supervising learning were assessed and the most appropriate neural network of Retro-propagation was chosen for work. The system took into consideration the operative system Linux-Ubuntu by using QT Creator as compiler and for artificial vision the bookstores of OpenCV, programming language was C++. Neural network was coded and samples were chosen for its entertainment. The system of segmentation and classification was designed. A scale model of parking was build including two cameras IP on line with the computer. The results were positive in 99.256% classifying license plates. Processing time was relatively low with a medium value of 156.21ms. It is also taken into account that retro-propagation network has a high development classifying characteristics and management of big data volumes. Entering and leaving parking time have been reduced because of the new system. It is recommended to researches of the Faculty of Informatics and Electronics to consider this work to keep studying neuronal artificial networks

Multiplexer and variable optical attenuator based on PDLC for polymer optical fiber networks

In this work, a combination of a multiplexer and a variable optical attenuator in the same device (VMUX) for use in Polymer Optical Fiber is proposed. Polymer Dispersed Liquid Crystals (PDLC) are polarization independent, have high contrast and gray scale capability. For these reasons, PDLC cells with pixels can be used as switching elements in the device. Characterization of the PDLC has been carried out at two wavelengths. VMUX Complete switching is reached for driving voltages of 20 Vrms, with insertion losses less than 1.6 dB, attenuation larger than 31 dB, rise time less than 2.6 ms and decay time better than 12.4 ms have been obtained.This work was supported in part by CICYT (TIC2003-03783 and TEC2006-13273-C03-03-MIC), in part by UC3M (FAVICOBIS), in part by CAM (FACTOTEM-CM:S-0505/ESP/000417), and in part by COST 299.Publicad

Modal liquid crystal temperature sensor

Proceeding of: 2014 IEEE SENSORS proceedings: Valencia, Spain, November 2-5, 2014.In this work, a novel liquid crystal temperature sensor is proposed. This sensor is composed by only two electrodes. A simple and easily scalable structure uses the temperature dependence of the liquid crystal permittivity as the sensing magnitude. The sensor has a high sensitivity, low voltage control, low power consumption and high linearity. The analytical modelling allows an optimization of the structure, in terms of sensitivity. Several liquid crystal has been investigated. The response improves the characteristics of previous LC sensors and even some commercial sensors (e.g. 60 mV/°C for 10 V rms of applied voltage, six times more than of most silicon temperature sensors).This work was supported in part by the Ministerio de Ciencia e Innovación of Spain (grant no.TEC2009-13991-C02-01) and the Comunidad de Madrid (grant no. FACTOTEM2 S2009/ESP-1781)

Remote optical powering using fiber optics in hazardous environments

Potential niches for a power-over-fiber (PoF) technique can be found in hazardous areas that require controlling unauthorized access to risk areas and integration of multiple sensors, in scenarios avoiding electromagnetic interference, and the presence of ignition factors. This paper develops a PoF system that provides galvanic isolation between two ends of a fiber for remotely powering a proximity sensor as a proof of concept of the proposed technology. We analyze scalability issues for remotely powering multiple sensors in a specific application for the hazardous environment. The maximum number of remote sensors that can be optically powered and the limiting factors are also studied; considering different types of multimode optical fibers, span lengths, and wavelengths. We finally address the fiber mode field diameter effect as a factor that limits the maximum power to be injected into the fiber. This analysis shows the advantages of using step-index versus graded-index fibers.This work was supported in part by the Spanish Ministerio de Economía, Industria y Competitividad, Comunidad de Madrid and H2020 European Union Programme under Grants TEC2015-63826-C3-2-R and S2013/MIT-2790, in part by FSE, and in part by 5G PPP BlueSpace Project under Grant 762055.Publicad

Spectral and spatial characterization of perfluorinated graded-index polymer optical fibers for the distribution of optical wireless communication cells

In this paper, the characterization of a perfluorinated graded-index polymer optical fiber (PF-GIPOF) for a high-bitrate indoor optical wireless system is reported. PF-GIPOF is used here to interconnect different optical wireless access points that distribute optical free-space high-bitrate wireless communication cells. The PF-GIPOF channel is first studied in terms of transmission attenuation and frequency response and, in a second step, the spatial power profile distribution at the fiber output is analyzed. Both characterizations are performed under varying restricted mode launch conditions, enabling us to assess the transmission channel performance subject to potential connectorization errors within an environment where the end users may intervene by themselves on the home network infrastructure.This work has been partially supported by the Collège Doctoral International/Université Européenne de Bretagne (CDI/UEB) and “Conseil Régional de Bretagne” and by the Spanish Ministry of Economía y Competitividad under the grant TEC2012-37983- C03-02.Publicad

Modelling and electro-optical testing of suspended particle devices

Some smart windows make use of suspended particle devices (SPDs) which are made of charged rod-shape particles that change their orientation in an applied electric field, thereby allowing transmittance control. In this work, the electro-optical behaviour of a commercial SPD is analyzed. Impedance analysis shows characteristics similar to those of a Randles circuit, and a modified equivalent circuit is proposed and experimentally validated. Intermediate levels of transmittance are obtained using a customized field programmable gate array (FPGA)-based electrical circuit. Finally, measurements are taken to check the applicability of the SPD device and control system in smart glazing or photonic applications.Universidad Carlos III de MadridThis research was partially supported by funds from the Spanish Ministry of Science and Technology (Project PTR95-0940.01.OP), and by Comunidad de Madrid (Project FACTOTEMCM:S-0505/ESP/000417).Publicad

Formalización de transformaciones de refinamiento de componentes

En el proceso de desarrollo de software dirigido por modelos es posible encontrar situaciones en las que las transformaciones entre modelos de distintos niveles de abstracción necesitan un tratamiento previo que facilite la transformación, sobre todo cuando se dispone de varios modelos especificas de la plataforma. En este documento se propone como solución la realización de una transformación de refinamiento, previa a la obtención del modelo especifico de la plataforma.Centro Universitario de la Defensa. Escuela de Turismo de Cartagena. Escuela Técnica Superior de Ingeniería Industrial UPCT. Escuela Técnica Superior de Ingeniería de Telecomunicación (ETSIT). Escuela de Ingeniería de Caminos y Minas (EICM). Escuela de Arquitectura e Ingeniería de Edificación (ARQ&IDE). Parque Tecnológico de Fuente Álamo. Navantia. Campus Mare Nostru

Una herramienta libre para la docencia de sistemas domóticos

[SPA]En este artículo se presenta una herramienta libre y gratuita pensada principalmente para mejorar los métodos de enseñanza en el desarrollo de sistemas domóticos. Esta herramienta permite a los estudiantes comprender las principales propiedades de un sistema domóticos y los conceptos genéricos, así como modelar una aplicación real de una forma más fácil e intuitiva. Este artículo no sólo se centra en la herramienta también se presenta la metodología que deben seguir profesores y estudiantes. Además siguiendo con las pautas marcadas por Bolonia en cuanto a auto estudio y trabajo en casa, se han incorporado tareas que los estudiantes son capaces de desarrollar como parte de su trabajo en casa y sin necesidad de realizar inversiones en licencias de herramientas comerciales. [ENG]This paper presents a free tool that can be used to improve the teaching methods of smart home systems development. This tool allows students to undestand the main properties and the generic concepts of home automation systems. In addition, students can use the tool to develop home automation systems in a more easy and intuitive way. The article is not only concerned with the description of the tool but also with the methodology to be followed by teachers and students. Furthermore, according to the guidelines of Bolonia Declaration with regard to autonomous-learning and homework, tasks have been incorporated that can be developed by studens as part of their homework without the need of commercial tool licenses.Campus Mare Nostrum, Universidad Politécnica de Cartagena, Universidad de Murcia, Región de Murci