Authors: Sylvain Girard, A. Boukenter, Y. Ouerdane, J.-P. Meunier
Abstract: We studied the defects at the origins of the permanent radiation-induced attenuation in four g-rays irradiated single-mode germanosilicate optical fibers (~1 MeV; 1.2 kGy; 0.3 Gy/s) in the spectral range 400 - 1700 nm. We determined the wavelength dependence of the following cladding codopant influences: germanium (0.3 %), phosphorus (0.3 %), fluorine (0.3 %) on the germanosilicate (13 %) fiber radiation responses. We identified some of the different color centers
produced by g-rays and we evaluated their localization in the fiber cross-section through the determination of the radial distribution of the radiation-induced absorption at 633 nm. We also evidenced the strong interactions between these three codopants. In particular, our results showed that the properties of the phosphorus-related color centers, which mainly determine the fiber infrared radiation sensitivity, are strongly influenced by the germanium- and fluorine-codoping.
329
Authors: Ki Tae Park, Woo Sang Lee, Bong Chul Joo, Yoon Koog Hwang
Abstract: In general, structures in service gradually lose their original performance-level over time
due to initial defects in design and construction, or exposure to unfavorable external conditions such
as repeated loading or deteriorating environment, and in extreme cases, may collapse. So, in order to
maintain the serviceability of structures at optimal level, advanced structure measuring system which
can inform optimal time point and method of maintenance is required in addition to accurate
prediction of residual life of the structure by periodic inspection. In Korea, the large-scale project for
the safety network integration for long-term smart monitoring systems for bridge structures started in
2007, and this is the second year of the project. In this system, various structure types such as bridge,
tunnels and cut slopes were considered with an emphasis on safety. The purpose of this system is to
integrate the operation centers for these structure types in order to control and evaluate the structure’s
real-time safety level through measured behavioral data. In this paper, the progress methodology for
this network system and the smart monitoring system installation techniques for each structure types
are briefly suggested.
49
Authors: Sandrine Lépinay, Guillaume Laffont, Giséle Volet, Véronique Wintgens, Pierre Ferdinand, Marie Claude Millot, Benjamin Carbonnier
Abstract: In this work, we demonstrate the possibility to use optical fiber incorporating photowritten tilted fiber Bragg gratings (TFBG) as optical detection system for the real time monitoring of interfacial adsorption events and biological recognition. For this purpose, immobilization of cyclodextrin polymers onto the surface of optical fiber was envisioned through the layer-by-layer self-assembly method with the aim of developing sensing layers with well-defined host properties. To develop a biological sensor, amphiphilic dextran, acting as intermediate layer between the polyelectrolyte multilayer assembly and the biological probe, was immobilized though inclusion complex formation. The dextran layer exhibit a dual functionality: (i) it prevents non-specific proteins adsorption and (ii) it allows covalent immobilization of anti-bovine serum albumine through activation of the hydroxyl groups with 1,1’-carbonyl diimidazole. To verify the feasibility of our strategy, fluorescence microscopy was applied to evidence the effective inclusion of fluorescent macromolecular – flurorescein labelled dextran bearing adamantane as side-grafts – species within the cyclodextrin cavities present onto the optical fiber interface and at the last layer to prove the grafting of anti bovin serum albumin onto the amphiphilic dextran by a capture of fluorescein bovin serum albumin by the antibody layer. In a further step, it was demonstrated that the elaboration of the multilayer assembly can be monitored in real time using the TFBG sensor.
45
Authors: Irina Severin, Rochdi El Abdi, Marcel Poulain, Mihai Caramihai
Abstract: The increased optical fiber development for a variety of physical and chemical measurements using smart structures and sensors leads to investigate the mechanical and chemical reliability of standard commercial acrylate polymer coated fibers. A comparison of mean failure strength of as-aged fibres to the water influence for similar exposure duration has revealed the highest sensitivity to dimethyl sulfoxide reagent (DMSO). SEM investigation revealed different damage levels in function of the aging conditions.
414
Abstract: Electrical overheating and fire are multiple faults in power system, optical fiber temperature measurement technology is better than the traditional temperature measurement device. It can test electrical system changes in temperature more effective and reliable, thus effectively contain similar accidents. This paper expounds the optical fiber temperature monitoring system warning the working principle, system constitution and its characteristics, discusses the practical application of optical fiber temperature warning monitoring system in power system.
1514
