Fabrication of Polymer Optical Fiber Splitter Using Lapping Technique

This work involves in designing and developing a POF-based directional coupler/splitter using lapping technique and geometrical blocks. Two fiber strands were first tapered at the middle and they were attached to the geometrical blocks and lapped together. Design parameters that are used to develop this coupler/splitter are core diameter, Dc, etching length, Le, bending radius, Rc, coupling length, Lc and pressure, Fc. All the parameters were taken into account during characterization and analysis of the designed coupler in order to find the most optimum prototype coupler/splitter. Characterizations are done by experimental set-up to test the efficiency, splitting ratio, coupling ratio, excess loss and insertion loss for all the couplers/splitters. Through the characterization process and analysis, the optimized coupler with high splitting ratio and low excess loss were identified. Throughout the experimental process, some of the fibers were improved and renewed in order to realize the design and development of the coupler using this technique. The device can also be utilized as an optical tap and the applications of the device are not only limited in in-house network but also in automotive applications. By using a platform, several splitting ratio can be obtained by integrating different core-cladding thickness and bending radius in order to get the desired splitting ratio and excess loss

Polymer Optical Fiber Splitter Using Tapered Techniques for Green Technology

Polymer Optical Fiber is opted as the most suitable medium for short haul communication system since it has lower cost and low loss for limited distance of transmission compared to glass fiber. This topic aims to show an alternative, green-technology based, economic and user-oriented communication passive device specifically a directional coupler by lapping tapered-fibers technique. This developed device is using designed geometrical blocks with integration of tapering effect, Dc, macro-bending, Rc, force exertion unto the coupling region, Fc, and etching lengths of the cores, Le to gain different splitting ratios, i.e., 50:50 and 90:10 experimentally by using the designed geometrical blocks with varied bending radii that affects the radiation of evanescent wave and to relate the integration of Couple Mode Theory and Hertz’s Law to obtain optimum coupling efficiency. The development may be an option to current device that are less user-friendly and fragile. This device is developed as a green technology-based device as an option for higher speed communication devices since the materials using in the development is safe, harmless, and inexpensive

Advanced devices based on fibers, integrated optics and liquid crystals for WDM networks

The increment of bandwidth required for new services offered to users make necessary the use of optical fibres in data transmission. Glass optical fibres are widely used in long distance communications, and there are many devices implemented for using in these networks, but these technologies are sometimes expensive for their used in local loops. Different systems implemented over the established technology are used for increasing local loops bandwidth, but more services are demanded at home. Those applications require more bandwidth than the offered by the usual twisted copper pair. Multimode fibres (both silica and polymer) with larger core diameters and numerical aperture, allows for large tolerance on axial misalignments, which results in cheaper connectors as well as associated equipment, but with a bandwidth penalty with regards to their singlemode counterparts, mainly due to the introduction of modal dispersion. On the other hand, polymer optical fibre (POF) offers several advantages over conventional multimode optical fibre over short distances (ranging from 100m to 1000m) such as the even potential lower cost associated with its easiness of installation, splicing and connecting. This is due to the fact that POF is more flexible and ductile, making it easier to handle. Consequently, POF termination can be realized faster and cheaper than in the case of multimode silica fibre. Therefore, the number of applications that use POF is quickly increasing. POF is being used in video transmission in medical equipment, or in multimedia applications for civil aviation and high range cars, in-home and access networks, wireless LAN backbone or office LAN, and in intrinsic optical sensor networks among others. Even greater channel capacity can be available using a specific type of POF, perfluorinated Graded-Index POF (PF GIPOF), having low attenuation and large bandwidth from 650nm to 1300nm. Link lengths for in-building/home scenarios are short (less than 1 km), and thus the loss per unit length is of less importance. Transmission of 10Gbps data over 100m and transmission of 1.25Gbps Ethernet over 1 km have been experimentally demonstrated with PF GIPOF. On the other hand, combiners and multiplexers are basic elements in POF networks using Wavelength Division Multiplexing (WDM) and there are not that many already developed. It is important to have low losses devices and reconfiguration can be an additional feature in those networks. On the other hand, reconfigurable optical networks in critical applications demand devices able to have different functionalities, including switching. This work has focused in the development of different optical switches for a wide range of optical networks. Different switching technologies are available. Liquid crystals are widely used as displays, but they are also employed in telecommunications. Other common technology used in data routing is integrated optics. In this case, light propagates by means of a waveguide and the modification of its parameters makes possible switching operation. Micro-Electromechanical Mechanisms, MEMs, based in small mobile mirrors that can change the direction of the incident light when required are an important optical switching technology. The objective of the present work is the proposal of several optical switches using different technologies depending on the final application. Some of these structures have been experimentally tested whereas others have been simulated. Most of the presented switches use liquid crystals, having different functionalities and broadband operation range, so allowing wavelength division multiplexing. To these respect it has been developed an optical multiplexer/combiner and an advanced multifunctional optical switch (AMOS), both implemented with Nematic Liquid Crystal technology. It has also been developed a multiplexer/combiner based on Polymer Dispersed Liquid Crystals. The third kind of switches proposed are micro ring-resonators combined with liquid crystals. Micro ring-resonators consist of a circular waveguide attached to one or two straight waveguides acting like input and output ports. Light that passes through the structure can be filtered according to the ring resonator characteristics: ring length, coupling ratio, losses… The use of liquid crystal makes possible the tuning of the ring resonator filtering properties. The last proposed switch is made of a passive splitter and a Mach-Zehnder Interferometer. This kind of devices makes use of integrated optics and interference for switching purposes. The variation of the optical properties influencing the two light beam interference can be done in different ways: thermally, electrically… Finally, an automated optical characterization bench has been implemented in order to make easy the measurements. It is composed by a three axis translation stage with three actuators, several linear translation stages that allows the user to modify the bench structure for adapting it to his experiment, and different machinery for mounting the optics.The present research work has been supported by the following Spanish projects: TIC2003-038783 (DISFOTON), TEC2006-13273-C03-03-MIC (FOTOCOMIN) and TEC2009-14718-C03-03-MCI (DEDOS) of the Spanish Interministerial Commission on Science and Technology (CICYT), FACTOTEM-CM: S-005/ESP/000417, and FACTOTEM-II-CM: S2009/ESP-1781 and FENIS-CCG06-UC3M/TIC-619 of Comunidad Autónoma de Madrid. Additional financial support has been obtained form European Thematic Network SAMPA: Synclinic and Anticlinic Mesophases for Photonic Applications (HPRNCT- 2002-00202), carried out during the V Framework Program of the European Union, COST Action 299 FIDES: Optical Fibres Dedicated to Society, and from the European Network of Excellence: ePhoton/ONe+ (FP6-IST-027497), both carried out during the VI Framework Program of the European Union, and BONE: Building the Future Optical Network in Europe (FP7-ICT-216863) carried out during the VII Framework Program of the European Union

Novel Specialty Optical Fibers and Applications

Novel Specialty Optical Fibers and Applications focuses on the latest developments in specialty fiber technology and its applications. The aim of this reprint is to provide an overview of specialty optical fibers in terms of their technological developments and applications. Contributions include:1. Specialty fibers composed of special materials for new functionalities and applications in new spectral windows.2. Hollow-core fiber-based applications.3. Functionalized fibers.4. Structurally engineered fibers.5. Specialty fibers for distributed fiber sensors.6. Specialty fibers for communications

Integrated polymer photonics : fabrication, design, characterization and applications

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Enabling Technology in Optical Fiber Communications: From Device, System to Networking

This book explores the enabling technology in optical fiber communications. It focuses on the state-of-the-art advances from fundamental theories, devices, and subsystems to networking applications as well as future perspectives of optical fiber communications. The topics cover include integrated photonics, fiber optics, fiber and free-space optical communications, and optical networking

Optimising the plastic optical fibre evanescent field biofilm sensor

This thesis describes the development, characterisation and application of large diameter multimode plastic optical fibre (POF) sensors using evanescent field modulation. The exposed polymethylmethacrylate (PMMA) core of the POF fibre forms the sensor interface that detects refractive index changes of a measurand acting as the cladding. When a liquid measurand is used, the sensor can detect changes in refractive index, absorption and suspended particulates. It is this simple mechanism by which the evanescent field POF sensor operates. The evanescent field POF sensor has been characterised for refractive index of surrounding liquid from 1.33 to 1.49. The sensor demonstrated accuracy of ± 7x 10-3 refractive index units below 1.4 and ±2x 10-3 refractive index units above 1.4. Components have been selected and designed for this project to ruggedise the sensor, to make the sensor more self-contained and cheaper. The original design of the test conditions did not allow for optimum deployment of the sensor as it stripped out the very modes of light that were required for sensing purposes. The system was also operating under pressure, not reflecting the real conditions under which the sensor would be operating. The re-design of test conditions holds the sensor without straining the POF and operates under normal atmospheric pressure. The POF sensor was demonstrated reacting to a real measurand eg biofilm in which initial growth affects the optical properties at the core cladding interface by refractive index modulation. This sensor was capable of measuring biofouling and scaling at water interfaces. The sensor was trialled in a European Commission funded project (CLOOPT) to study biofouling and scaling in closed loop water systems such as heat exchangers in the cooling tower of an electric power plant, and as an interface sensor for water quality monitoring (AQUA-STEW) involving biofilm removal and surface cleansing with a new application for contact lens protein removal systems. Tapering multimode POF was a desirable goal as this increases the proportion of light coupled into the core available for sensing purposes, to achieve a more sensitive evanescent field POF sensor. Optically clear and consistent smooth tapering of ends and mid-lengths of POF fibre were achieved through chemical removal of material. The tapered POF sensor was characterised with a range of refractive indices, and it exhibited two distinct regions; the water/alcohol region below 1.4 refractive index units, and the oil region above 1.4 suggesting the sensor's use as an oil-in-water, or water-in-oil sensor. From 95% confidence limits, the accuracy of the POF was ±O.006 refractive index units (to 2 standard deviations) for fluids of refractive indices above 1.4. Tapered POF is sensitive to refractive index providing a cheap, easy to handle and rugged throwaway sensor for water and beverage process and quality monitoring