50 research outputs found
The relevance of point defects in studying silica-based materials from bulk to nanosystems
The macroscopic properties of silica can be modified by the presence of local microscopic modifications at the scale of the basic molecular units (point defects). Such defects can be generated during the production of glass, devices, or by the environments where the latter have to operate, impacting on the devices’ performance. For these reasons, the identification of defects, their generation processes, and the knowledge of their electrical and optical features are relevant for microelectronics and optoelectronics. The aim of this manuscript is to report some examples of how defects can be generated, how they can impact device performance, and how a defect species or a physical phenomenon that is a disadvantage in some fields can be used as an advantage in others
Optical absorption in commercial single mode optical fibres for the LHC machine
The optical absorption of light at 1310 nm and 1550 nm in various commercially available Single Mode (SM) fibres samples has been studied. The absorption was measured as a function of dose, dose rate, temperature and light power. The samples were irradiated with gamma rays from a 60Co source and exposed to a complex radiation field from high energy physics. One fibre sample with an F-doped core exhibits extreme low absorption of light at 1310 nm during irradiation up to doses of at least 100 kGy
From the HINDAS Project : Excitation Functions for Residual Nuclide Production by Proton-Induced ReactionsÂ
peer reviewe
Design and test of the optical fiber assemblies for the scalar magnetic field sensor aboard the JUICE mission
A set of optical fiber assemblies has been developed and successfully qualified for its use on a European space science mission to the icy moons of Jupiter (Jupiter Icy Moons Explorer, JUICE), to be launched in 2022. The paper gives an overview of the design challenges, the test methods used for failure detection and screening of the optical fiber cable assemblies as well as the further testing performed in the frame of a lot acceptance qualification
Influence of coating material, cladding thickness, and core material on gamma radiation sensitivity of pure silica core-step-index fibres
We investigated the influence of core material, cladding thickness, drawing speed, and coating material on the radiation sensitivity of pure silica core step-index fibers with high OH-content. The gamma radiation-induced attenuation at 660 nm and 850 nm of fibers by different manufacturers are compared
Radiation hard optical fibers
Meanwhile there exist fibers of nearly all types that show sufficient radiation hardness in lengths necessary for the respective application. Hydrogen loading or treatment and thermal or photo bleaching can harden certain fibers or fiber links
High radiation hardness of a hollow core photonic bandgap fibre
A 19-cell hollow core photonic bandgap fiber with a core diameter of 20 µm and an attenuation minimum of about 11dB/km at 1590 nm was exposed to continuous 60Co gamma radiation and pulsed electrons up to dose values of 10 Exp4 Gy and 100 Gy, respectively. The attenuation increase during continuous or after pulsed irradiation was at least 30 times or 100 times lower, respectively, than observed with the best conventional single-mode fibers. Furthermore a slight reduction of the width of the transmission band after a total gamma dose of 1.4 × 10 Exp5 Gy was observed
Influence of manufacturing parameters and temperature on the radiation sensivity of fiber Bragg gratings
For the first time the radiation sensitivity of Bragg gratings was investigated as a function of hydrogen loading pressure before and fiber tension during grating inscription, of the recoating procedure, and of the grating temperature. At -50°C the radiation-induced Bragg wavelength shift was about two times higher than at room temperature. This should be considered when selecting Bragg gratings e.g., for certain space applications