People to feel more and more attention to health, the pursuit of high quality of life, biomedical sensing is one of the development of technology, person to understand the current state of health, currently known as blood sugar and blood pressure monitors, to track health status of the instrument is obvious too inadequate, usually go to the hospital for examination, but it is quite time-consuming, ranging from a waste of time, so the immediate biomedical optical fiber sensor to do direction. Evanescent wave ways to do research for my use of the sensing material-specific dye, sensing agent in different situations will be absorbed to change the situation, the use of sol-gel method (Sol-Gel) to coated with the specific dye, to make our fiber clothes (cladding), when the light in optical fibers, through the specific dye to change the energy of light in optical fibers.

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This thesis investigates the generation and radio-over-fibre (RoF) transport of unlicensed 60 GHz millimetre-wave (mm-wave) frequency band. The investigated benefits of transmission schemes applicable for the mm-wave generation include optical carrier suppression (OCS), optical frequency multiplication (OFM) and remote heterodyne detection (RHD). For the in-door cabling of the mm-wave transmission, a low-cost polymer optical fibre (POF) along with bend-insensitive single mode fibre (BI-SMF) has been investigated for short-range networks. Transporting mm-wave generated signals over POF and BI-SMF cables based on OCS scheme showed results with the highest spectral efficiency and least inter-symbol interference over a 2.5 Gbit/s data delivery. Based on this thesis analysis, OCS simulation of POF showed the most reliable power penalty performance and receiver sensitivity at 30-m whilst the BI-SMF fiber produced equal observations at 150-m and more. In observing the free space links of delivering the RoF signal, the attenuation on the received signal power for both POF and BI-SMF was insignificant but expected, as the simulation assumed complete and total collimation of the light beams onto the aperture of the photodetector. OCS scheme for mm-wave generation and transport was explored based on the cost effectiveness of using one external modulator compared to other generation schemes that utilised more than one external modulator. OFM scheme was simulated to transport LTE and Wi-Fi signals along with 60 GHz RF band through both SMF and MMF-POF/BI-SMF cables. OFM transport scheme produced the highest attenuation on LTE, Wi-Fi and mm-wave signals carrying 100 Mbit/s data as simulated POF lengths increased. The best performance POF length was observed at 10-m. The application of offset launch technique at the coupling of SMF and POF showed insignificant improvement on signal bandwidth. The free space OFM transmission also demonstrated negligible change to the received signal power. This reinforces the attributes of deploying OWC system in an in-door environment. In other investigation, the simulated successful delivery of mm-wave signal using RHD scheme modulated and transported 10 Gbit/s data signal over POF and BI-SMF cables. Additional observed unrecorded result also showed BI-SMF cable maintained a 2% reduction of received power for 450-m fiber cable from 150-m. The attributes to RHD includes its low operating power system application and delivery of localised 60 GHz signal for uplink RoF transmission. The conceptualised design of Gigabit data delivery for indoor customer applications either through POF or BI-SMF cable, transporting various wireless channels has been presented in this thesis for the design of a robust next generation Broadband access network to reinforce the fiber-inside-the-home (FiTH) deployment.

The fiber-optics communication device with a plastic optical fiber (POF) has become a technology of increasing interests. The attenuation of commercial available POF has been improved to tens of decibels per kilometer. Due to its flexibility and high alignment efficiency, it has been widely used in many areas. In this study, different end shapes of POF have been proposed to increase the coupling efficiency of a POF from a surface emitting LED. Both the experiments and a ray tracing simulation are performed to investigate the coupling scheme. Experimental results also illustrate the feasibility of using ray tracing model in POF end shapes design. The effect of ball fiber lens on coupling efficiency is studied first. Lens material is EPO-TEK 353ND two parts epoxy. The result indicates that the ball fiber lens can improve the coupling efficiency significantly. A more impact end shape modified from the ball fiber lens is proposed in this study, i.e. a thin tip-rounded fiber lens. Numerical and experimental results show the tip can work as good as a ball fiber lens does. A reflection-styled end shape has also been proposed in this thesis, i.e. a taper-ended POF. In this design, the taper edge serves as a reflector to bend the rays incident on it by total internal reflection. The maximum efficiency achieves a great improvement from the previous design. Further study on the various fiber types with different sizes and numerical apertures have also been studied by the ray tracing model.

Steady increases in the bandwidth requirements of access networks and local area networks have created a need for short-reach links supporting data rates of 10 Gb/s and larger. Server applications and data center applications too require such links. The primary challenge for these links lies in the reduction of the cost while retaining or improving the performance. Traditionally, multimode fiber (MMF) has satisfied these needs because of its low installation cost resulting from the alignment tolerance associated with the large core size. However, in view of the ever-increasing performance requirements, extraction of the best performance requires a holistic view of the channel that involves global optimization of transmitter, fiber, receiver performance and signaling strategies. The optimization results in a channel impairment mitigation technique that is a combination of optical, opto-electronic, and electronic methods. Both glass and plastic MMF links have been addressed in this work and many of the advances apply equally to both media. One example that applies strictly to glass MMF is the use of Raman amplification to not only combat attenuation but to reduce intersymbol interference (ISI). Raman amplification was demonstrated as an optical channel impairment mitigation technique enabling multi-km, multi-Gb/s transmission over glass-MMF. We demonstrated both numerically and experimentally that a power penalty reduction of 1.4 dBo can be achieved for 10 Gb/s transmission over 9 km of 62 micron glass MMF with a Raman pump power 250 mW. In recent years, plastic optical fiber (POF) has emerged as a potentially lower cost alternative to glass-MMF in enabling high performance links. The primary objective of this research is to explore the possibilities and develop low-cost, short-reach, high-data-rate POF-links. Using a comprehensive multimode fiber model, we showed that strong mode coupling, together with a reasonably accurate refractive index profile enables 40 Gb/s transmission over 200 m of graded-index POF. We experimentally demonstrated 40 Gb/s error-free transmission over 100 m of graded index perfluorinated POF (GI-PF-POF). We also demonstrated that even larger core (120 micron) GI-PF-POF can support >10 Gb/s over 100 m length. We numerically computed and experimentally measured the differential modal delay of GI-PF-POF to demonstrate that the available bandwidth is nearly independent of the launch conditions. Therefore, the alignment tolerance at the transmitter is increased resulting in a dramatically reduced packaging cost at the transmitter. However, the large-core POF increases the difficultly in capturing of the light efficiently onto a detector and results in optical power penalty and associated modal noise. To solve this, we have designed and developed a 10 Gb/s photoreceiver consisting of a large (100 micron diameter) GaAs PIN photodetector and a regulated cascade input based transimpedance amplifier (TIA) with low input impedance. Thus, a low-cost, alignment-tolerant, high-data-rate link is realized that uses a high-power, high-speed vertical cavity surface emitting laser (VCSEL) transmitter, large-core, high-speed GI-PF-POF, and the developed receiver.

Plastic optical fiber (POF) for use in automotive applications is not a new concept and has been used in some vehicles for infotainment media distribution within the Media Oriented Systems Transport protocol. However, the use of POF for the control network’s physical layer is a concept that has not been implemented in automotive applications. Many aspects of a vehicle can be improved by implementing POF as the physical backbone for the control network. Currently, the Controller Area Network (CAN) is used as the primary backbone control network protocol for most automobiles as it is inexpensive and reliable. However, CAN is limited to 500 kbps in most vehicles and is easily accessible. Ethernet may provide the improvements of speed and security needed in today’s feature rich and connected vehicles. The feasibility of implementing Ethernet over POF as the control network for automotive applications is the topic of this research investigation.

[ES] Las fibras ópticas son dispositivos muy utilizados en el campo de las telecomunicaciones desde su descubrimiento. En las últimas décadas, las fibras ópticas comenzaron a utilizarse como sensores fotónicos. Los primeros trabajos se centraron en la medición de unas dimensiones físicas en un punto específico. Posteriormente, surgió la posibilidad de medir las propiedades de la fibra óptica en diferentes puntos a lo largo de la fibra. Este tipo de sensores se definen como sensores distribuidos. Los componentes optoelectrónicos fueron desarrollados e investigados para telecomunicaciones. Los avances en las telecomunicaciones hicieron posible el desarrollo de sistemas de interrogación para sensores de fibra óptica, creciendo en paralelo con los avances de las telecomunicaciones. Se desarrollaron sistemas de interrogación de fibra óptica que permiten el uso de una única fibra óptica monomodo estándar como sensor que puede monitorear decenas de miles de puntos de detección al mismo tiempo. Los métodos que extraen la información de detección de la señal reflejada en la fibra óptica son los más empleados debido a la facilidad de acceso al sensor y la flexibilidad de estos sistemas. Los más estudiados son la reflectometría en dominios de tiempo y frecuencia. La reflectometría óptica en el dominio del tiempo (OTDR) fue la primera técnica utilizada para detectar la posición de los fallos en las redes de comunica-ción de fibra óptica. El OTDR sensible a la fase hizo posible detectar la elongación y la temperatura en una posición específica. Paralelamente, los gratings de Bragg (FBG) se convirtieron en los dispositivos más utilizados para implementar sensores en fibra óptica discretos. Se desarrollaron técnicas de multiplexación para realizar la detección en múltiples puntos utilizando FGBs. La reflectometría realizada interrogando arrays de FBG débiles demuestra que mejora el rendimiento del sistema en comparación al uso de una fibra monomodo. Los sistemas de interrogatorio actuales tienen algunos inconvenientes. Algunos de ellos son velocidad de interrogatorio limitada, grandes dimensiones y alto costo. En esta tesis doctoral se desarrollaron nuevos sistemas de interrogación y sensores de fibra óptica para superar algunos de estos inconvenientes. Los sensores de fibra óptica de plástico demuestran ser una plataforma innovadora para desarrollar nuevos sensores y sistemas de interrogación de bajo costo y fáciles de implementar para fibras de plástico comerciales. Se investigó la reflectometría en el dominio del tiempo y las técnicas fotónicas de microondas para la interrogación de una matriz de rejillas débiles que permitieron simplificar el sistema de interrogación para la detección de temperatura y vibración. / [CA] Les fibres òptiques són dispositius molt utilitzats en el camp de les telecomunica-cions des del seu descobriment. En les últimes dècades, les fibres òptiques van començar a utilitzar-se com a sensors fotònics. Els primers treballs es van centrar en el mesurament d'unes dimensions físiques en un punt específic. Posteriorment, va sorgir la possibilitat de mesurar les propietats de la fibra òptica en diferents punts al llarg de la fibra. Aquest tipus de sensors es defineixen com a sensors distribüits. Els components optoelectrònics van ser desenvolupats i investigats per a telecomunicacions. Els avanços en les telecomunicacions van fer possi-ble el desenvolupament de sistemes d'interrogació per a sensors de fibra òptica, creixent en paral·lel amb els avanços de les telecomunicacions. Es van desenvolupar sistemes d'interrogació de fibra òptica que permeten l'ús d'una única fibra òptica monomodo estàndard com a sensor que pot monitorar desenes de milers de punts de detecció al mateix temps. Els mètodes que extreuen la informació de detecció del senyal reflectit en la fibra òptica són els més utilitzats a causa de la facilitat d'accés al sensor i la flexibilitat d'aquests sistemes. Els més estudiats són la reflectometría en dominis de temps i freqüència. La reflectometría òptica en el domini del temps (OTDR) va ser la primera tècnica utilitzada per a detectar la posició de les fallades en les xarxes de comunicació de fibra òptica. El OTDR sensible a la fase va fer possible detectar l'elongació i la temperatura en una posició específica. Paral·lelament, els gratings de Bragg (FBG) es van convertir en els dispositius més utilitzats per a implementar sensors en fibra òptica discrets. Es van desenvolupar tècniques de multiplexació per a realitzar la detecció en múltiples punts utilitzant FGBs. La reflectometría realitzada interrogant arrays de FBG febles demostra que millora el rendiment del sistema en comparació a l'ús d'una fibra monomodo. Els sistemes d'interrogatori actuals tenen alguns inconvenients. Alguns d'ells són velocitat d'interrogatori limitada, voluminositat i alt cost. En aquesta tesi doctoral es van desenvolupar nous sistemes d'interrogació i sensors de fibra òptica per a superar alguns d'aquests inconvenients. Els sensors de fibra òptica de plàstic demostren ser una plataforma innovadora per a desenvolupar nous sensors i siste-mes d'interrogació de baix cost i fàcils d'implementar per a fibres de plàstic comercials. Es va investigar la reflectometría en el domini del temps i les tècniques fotòniques de microones per a la interrogació d'una matriu de reixetes febles que van permetre simplificar el sistema d'interrogació per a la detecció de temperatura i vibració. / [EN] Optical fibers are devices largely used in telecommunication field since their discovery. In the last decades, optical fibers started to be used as photonic sensors. The first works were focused on the measurement of physical dimensions to a specific point. Afterward, emerged the possibility to measure the optical fiber properties at different locations along the fiber. These kinds of sensors are defined as distributed sensors. The optoelectronic components were developed and investigated for telecommunications. The progress in telecommunication made possible the development of optical fiber sensors interrogation systems, growing in parallel with the advances of telecommunications. Optical fiber interrogation systems were developed to use a single standard monomode optical fiber as a sensor that can monitor tens of thousands of sensing points at the same time. The methods that extract the sensing information from the backscattered signal in the optical fiber are widely employed because of the easiness of access to the sensor element and the flexibility of these systems. The most studied are the reflectometry in time and frequency domains. The optical time domain reflectometry (OTDR) was the first technique used to detect the position of the failures in the optical fiber communication networks. Using phase sensitive OTDR it is possible to sense strain and temperature at a specific position. In parallel, fiber Bragg gratings (FBGs) became the most widely used devices to implement discrete optical fiber sensors. Multiplexing techniques were developed to perform multi points sensing using these gratings. The reflectometry performed interrogating weak FBGs arrays demonstrate to improve the performance of the system employing a single mode fiber. The interrogation systems nowadays have some drawbacks. Some of them are limited speed of interrogation, bulkiness, and high cost. New interrogation systems and optical fiber sensors were developed in this doctoral thesis to overcome some of these drawbacks. Plastic optical fiber sensors demonstrate to be an innovative platform to develop both new sensors and low cost, easy to implement interrogation systems for commercial plastic fibers. Reflectometry in time domain and microwave photonic techniques were investigated for the interrogation of weak gratings array allowed to simplify the interrogation system for the sensing of temperature and vibration. / I would like to greatly thank the European Union’s Horizon 2020 Research and Innovation Program that funded the research described in this thesis under the Marie Sklodowska-Curie Action Grant Agreement 722509. / Sartiano, D. (2021). Design of optical fiber sensors and interrogation schemes [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/161357