DTE - GDAF - Capítulos de monografías

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Photo-termo-elastic behaviour of a PMMA-core POF
(Copy Red, S.A., 2013) Pérez Castellanos, José Luis; Sánchez Montero, David Ricardo; Vázquez García, María Carmen; Zahr Viñuela, Jorge Alonso
The use of fiber optic sensing systems of mechanical elements are based, among others, on light variations versus strain. This paper shows the results of tensile tests on a PMMA-core POF with simultaneous measurement of both optical intensity and temperature changes.
Multimode fibers in Millimeter-wave evolution for 5G cellular networks
(SPIE- The International Society for Optical Engineering, 2016-02) Vázquez García, María Carmen; Sánchez Montero, David Ricardo; Ponce Hernández, Wendy; Contreras Lallana, Pedro; Larrabeiti López, David; Montalvo García, Julio; Tapetado Moraleda, Alberto; Pinzón Castillo, Plinio Jesús
Small-cell and cloud-RAN systems along with the use of the millimeter-wave band have been considered as promising solutions to meet the capacity demand of the future wireless access networks. Radio over Multimode fibers (RoMMF) can play a role in the integrated optical-wireless access systems for next-generation wireless communications, mainly in within-building environments. The numerical results show the effectiveness of MMF to transmit at 60 GHz band with 7- GHz bandwidth for different link lengths and refractive index profiles under restricted mode launching and using narrow linewidth sources. The integration with optically powered remote antenna units is also proposed based on the large core effective area of MMF. Temperature impairments and graded index plastic optical fiber transmission are also discussed.
Monitoring techniques in broadband access networks
(IEEE . The Institute of Electrical and Electronics Engineers, Inc, 2015-07) Vázquez García, María Carmen; Sánchez Montero, David Ricardo; Montalvo García, Julio; Tapetado Moraleda, Alberto
Broadband access networks needs specific monitoring techniques at the physical layer to provide the quality of service required by the users. Similarities between sensor and access networks will be analysed to get best practices in both scenarios to provide novel monitoring and self-reference techniques.
Self-referenced temperature sensor based on a polymer optical fiber macro-bend
(SPIE- The International Society for Optical Engineering, 2014-06) Tapetado Moraleda, Alberto; Pinzón Castillo, Plinio Jesús; Zubía, Joseba; Pérez Garcilópez, Antonia Isabel; Vázquez García, María Carmen
The design and development of a plastic optical fiber (POF) macrobend temperature sensor is presented. The sensor has a linear response versus temperature at a fixed bend radius, with a sensitivity of 8.2 ∙ 10−4(ºC)−1 〖8.2.10〗^(-4) 〖(°C) 〗^(-1) and a 8% non-linearity full scale error. The sensor system uses the power variation between two discrete wavelengths for auto reference purposes. An analysis for selecting operation wavelengths has been carried out in order to optimize the response of the sensor. The proposed sensor can be used in harsh environment and has a low-cost
Experimental test of polymer optical fiber temperature sensor on different surrounding media
(Plastic Optical Fiber Trade Organization, 2013-09) Tapetado Moraleda, Alberto; Vázquez García, María Carmen; Zubia, Joseba; Sánchez Montero, David Ricardo; Lallana, Pedro C.
Influence of external media on a fiber-optic temperature sensor based on a macro-bend multimode Polymer Optical Fiber (POF) is analyzed. The sensor has a linear response with a sensitivity of 〖1.92.10〗^(-3) 〖(°C) 〗^(-1) at a fixed bend radius. 2.4 times sensitivity variations for different surrounding media are reported.
Temperature sensor based on fiber optic pyrometer in material removal processes
(SPIE- The International Society for Optical Engineering, 2012-10) Tapetado Moraleda, Alberto; Vázquez García, María Carmen; Soldani, Xavier; Miguélez Garrido, María Henar; Sánchez Montero, David Ricardo
In this work, different non-contact fiber-optic pyrometers have been developed for measuring localized temperatures on material removal area during mechanizing processes. Designs are developed for adaptation to the harsh measuring conditions on specific cutting tool machinery and using commercial optoelectronics and fiber-optic components for resolution enhancement. A 0.1 dB/ºC sensitivity at 300 ºC is obtained, and calibration curves at 1100 nm, 1300 nm, 1550 nm and 1610 nm are reported. Different reception circuits are used for testing resolution limits, higher bandwidths imply greater noise and worst results as expected.
Diffraction grating-based demultiplexers for SI-POF networks
(Plastic Optical Fiber Trade Organization, 2013-09-11) Pinzón Castillo, Plinio Jesús; Hegartty, Kevin; Vázquez García, María Carmen; Pérez Garcilópez, Antonia Isabel
In this paper, the possibility of implementing low-loss demultiplexer devices based on diffractive elements for SI-POF networks is studied. Theoretical and experimental analyses of three different diffractive setups are reported. It is also presented a 3-channel demultiplexer proposal, based on a transmission diffraction grating, with experimental insertion loss from 3.6dB to 5.8dB and adjacent channel crosstalk from −16.4dB to −28.6dB. This proposal presents low losses and low crosstalk, and it is very easy to implement in a compact reflective setup.
Broadband 1x2 liquid crystal optical switch with low thermal dependence
(Plastic Optical Fiber Trade Organization, 2013-09) Pinzón Castillo, Plinio Jesús; Pérez Garcilópez, Antonia Isabel; Vázquez Rufino, Isabel; Sánchez-Pena, José Manuel
In this work, the optimized design of a broadband 1×2 liquid crystal (LC) optical switch (OS) is presented. The design is based on a polarization rotator (PR), which is composed of two nematic LC cells. The azimuth angle and thickness of each LC cell is obtained with a simple computational optimization approach, with performance comparable with more complex existing procedures. The LC-OS is capable to route, in a uniform way, optical signals in the visible spectral range (400 nm - 700 nm) with low thermal dependence in the range from 15ºC to 40ºC, making it ideal for wavelength division multiplexing applications in POF systems.
One photon and two photon spectroscopy in polymer optical fibres doped with conjugated polymer
(Plastic Optical Fiber Trade Organization, 2013-09) Ayesta, Igor; Illarramendi, María Asunción; Arrue, Jon; Jiménez, Felipe; Mateo, Javier; Vázquez García, María Carmen; Zubía, Joseba
In this work, we have compared the characteristics of the spectral emission of plastic optical fibers (POFs) doped with the conjugated polymer poly(9,9 dioctylfluorene)-alt-benzothiadiazole (F8BT), under oneand two-photon excitation. Measurements include evolutions of the fluorescence spectra with excitation wavelength and propagation distance, together with an analysis of the emission photostability.
Study of the photo-thermo-mechanical behaviour of PMMA-core POFs
(Plastic Optical Fiber Trade Organization, 2013-09) Sánchez Montero, David Ricardo; Torres Zafra, Juan Carlos; Pérez Castellanos, José Luis; Zahr Viñuela, Jorge Alonso; Vázquez García, María Carmen
In this work, we report the results obtained during the photo-thermo-mechanical characterization of a PMMA-core plastic optical fiber (POF) through tensile tests. Simultaneous measurements of the received optical power and temperature variation during the deformation process are also reported, analyzing its viability as an intensity-based sensing system.
Fault location in full-duplex plastic optical fiber links using synchronized decay time detection
(Plastic Optical Fiber Trade Organization, 2013-09-11) Sánchez Montero, David Ricardo; Pedreira Conchado, Pablo; Montalvo García, Julio; Vázquez García, María Carmen
In this work, a low cost fiber-fault location technique in full-duplex plastic optical fiber links is reported. The employed method consists of using real time measurements of overlaid optical supervision signals employed simultaneously at both ends of the plastic fiber link during operation, comparing the decay time detection at both ends of the link when a fiber fault occurs. The proposed technique is successfully demonstrated over Graded Index (GI) Plastic Optical Fiber (POF) links
Interrogation of Remote Intensity-Based Fiber-Optic Sensors Deploying Delay Lines in the Virtual Domain
(SPIE- The International Society for Optical Engineering, 2012-10-14) Sánchez Montero, David Ricardo; Vázquez García, María Carmen
In this work a self-referencing intensity-based fiber-optic sensor using virtual instrumentation is presented. The use of virtual delay lines along with novel self-referencing techniques minimizing resolution and using a single frequency avoids all-optical or electrical-based delay lines approaches at reception. This solution preserves the self-referencing and performance characteristics of the proposed optical sensing topology, and leads to a more compact solution with higher flexibility for the multiple interrogation of remote sensing points. Results are presented for a displacement sensor demonstrating the concept feasibility.
Tolerance analysis for efficient MMI devices in silicon photonics
(SPIE- The International Society for Optical Engineering, 2014-03) Vázquez García, María Carmen; Tapetado Moraleda, Alberto; Orcutt, J.; Meng, H. C.; Ram, R.
Silicon is considered a promising platform for photonic integrated circuits as they can be fabricated in state-of-the-art electronics foundaries with integrated CMOS electronics. While much of the existing work on CMOS photonics has used directional couplers for power splitting, multimode interference (MMI) devices may have relaxed fabrication requirements and smaller footprints, potentially energy efficient designs. They have already been used as 1x2 splitters, 2x1 combiners in Quadrature Phase Shift Keying modulators, and 3-dB couplers among others. In this work, 3-dB, butterfly and cross MMI couplers are realized on bulk CMOS technology. Footprints from around 40um2 to 200 um2 are obtained. MMI tolerances to manufacturing process and bandwidth are analyzed and tested showing the robustness of the MMI devices.
Localización de fallos en enlaces full-duplex de fibra óptica mediante detección sincronizada de tiempos de caída
(Fundación General de la Universidad de Alcalá de Henares, 2013) Sánchez Montero, David Ricardo; Pedreira Conchado, Pablo; Vázquez García, María Carmen; Montalvo García, Julio
En este trabajo, se muestran los resultados obtenidos durante la evaluación experimental de un método de localización de cortes en enlaces full-dúplex de fibra óptica, empleando un método alternativo a medidas con Reflectómetros Ópticos en el Dominio del Tiempo (OTDR). El método utilizado consiste en comparar los tiempos de caída en los dos extremos del enlace de manera sincronizada cuando se produce un corte de fibra. Se han evaluado dos tipos de tecnologías de fibra, multimodo y monomodo, analizando las prestaciones del método en cada caso y para varios tipos de rotura de cable, considerando y comparando la precisión de las medidas así como las máximas distancias soportadas.
Optimization of polarization rotators spectral response for broadband optical switching applications
(Fundación General de la Universidad de Alcalá de Henares, 2013) Pinzón Castillo, Plinio Jesús; Pérez Garcilópez, Antonia Isabel; Vázquez García, María Carmen; Sánchez-Pena, José Manuel
In this work, optimized designs of broadband polarization rotators based on cascaded nematic liquid crystal cells are presented. Visible spectral range (400 nm – 700 nm) is considered in the designs. A simple computational optimization approach, with performance comparable with more complex existing procedures, is used. Application of designed achromatic polarization rotators in the implementation of optical switches for wavelength division multiplexing in polymer optical fibers networks is also analyzed.
Temperature Impairment Characterization in Radio-Over-Multimode Fiber Systems
(SPIE- The International Society for Optical Engineering, 2012-01) Vázquez García, María Carmen; Sánchez Montero, David Ricardo
An emerging theme in next-generation access research includes seamless wireline-wireless convergence addressed by Radio-over-Fiber (RoF) technologies. Optical cabling solutions offer th e possibility for semi-transparent transport through the access network microwave to mm-wave radio carriers commonly employed for creating high-capacity picocell wireless networks, attending present demands from the wireless technologies, with portable/mobile devices converging with photonics. Advanced RoF techniques can efficiently generate and transport such carriers, and deliver them to simplified antenna stations or radio access points (RAPs). Thus, they can convey high data rates in comprehensive modulation formats on multiple-GHz carriers in MMF networks. Selective mode-launching schemes combined with the use of narrow linewidth optical sources are experimentally demonstrated to enable broadband RF, microwave and mm-wave transmission in short- and middle-reach distances over silica-based multimode optical fibers (MMFs); and are rev iewed in this pap er. However, arbitrary operating conditions, such as the temperature dependence in the fiber link, impose a great challenge for the extension of the RoMMF technology. Temperature impairment ch aracterization is analyzed over the broadband transmission bands that are present, under certain operating link conditions, in the frequency response performance of MMF to support multiple GHz carrier delivering schemes, thus contributing to fault link prevention.
Visible WDM System Design for Multi-Gbit/s Transmission over SI-POF
(SPIE- The International Society for Optical Engineering, 2015-01) Vázquez García, María Carmen; Pinzón Castillo, Plinio Jesús; Pérez Garcilópez, Antonia Isabel
In order to increase the data rates of Multi-Gbit/s links based on large core step index (SI) plastic optical fibers (POF), different modulation scenes have been proposed. Another option is to use multiple optical carriers for parallel transmission of communication channels over the same fiber. Some designs to reach data rates of 14.77 Gb/s in 50 m, with 4 channels have been developed by off line processing. In this work, designs to test the potential of real Multi- Gbit/s transmission systems using commercial products are reported. Special care in designing low insertion loss multiplexers and demultiplexers is carried out to allow for greener solutions in terms of power consumption.
Effects of elongation on polymer optical fiber power losses for sensing purposes
(SPIE- The International Society for Optical Engineering, 2014-06) Sánchez Montero, David Ricardo; Torres Zafra, Juan Carlos; Zahr Viñuela, Jorge Alonso; Pérez Castellanos, José Luis; Vázquez García, María Carmen
In this work, we explore the variation of power losses of PMMA-core plastic optical fiber through tensile tests. Experimental results of received optical power during elastic and plastic deformation process demonstrate the feasibility of POFs as simple intensity-based fiber-optic sensors for Structural Health Monitoring applications beyond complex schemes. A theoretical approach of the POF behavior versus strain is also provided.
Low power consumption silicon photonics tuning filters based on compound microring resonators
(SPIE- The International Society for Optical Engineering, 2013-02) Vázquez García, María Carmen; Contreras Lallana, Pedro; Vargas Palma, Salvador Elías
Scalable integrated optics platforms based on silicon-on-insulator allow to develop optics and electronics functions on the same chip. Developments in this area are fostered by its potential as an I/O technology that can meet the throughputs demand of future many-core processors. Most of the optical interconnect designs rely on small footprint and high power efficiency microring resonators. They are used to filter out individual channels from a shared bus guide. Second-order microring filters enable denser channel packing by having sharper pass-band to stop-band slopes. Taking advantage of using a single physical ring with clockwise and counter-clockwise propagation, we implement second order filters with lower tuning energy consumption as being more resilient to some fabrication errors. Cascade ability, remote stabilization potential, energy efficiency along with simple design equations on coupling coefficients are described. We design second-order filters with FWHM from 45 GHz to 20 GHz, crosstalk between channels from -40 dB to -20 dB for different channel spacing at a specific FSR, with energy efficiencies of single ring configurations and compatible with silicon-on-insulator (SOI) state of the art platforms.
WDM sensor network approach: Bridging the gap towards POF-based photonic sensing
(IEEE, 2014) Tapetado Moraleda, Alberto; Sánchez Montero, David Ricardo; Vázquez García, María Carmen; Webb, David J.
In this work a self-referenced technique for fiberoptic intensity sensors using virtual lock-in amplifiers is proposed and discussed. The topology is compatible with WDM networks so multiple remote sensors can simultaneously be interrogated. A hybrid approach combining both silica fiber Bragg gratings and polymer optical fiber Bragg gratings is analyzed. The feasibility of the proposed solution for potential medical environments and biomedical applications is shown and tested using a selfreferenced configuration based on a power ratio parameter.

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