The Experts below are selected from a list of 237 Experts worldwide ranked by ideXlab platform

Jayantha Katupitiya - One of the best experts on this subject based on the ideXlab platform.

  • experimental determination of optimum parameters for nano grinding of optical Fibre End faces
    International Journal of Machine Tools & Manufacture, 2004
    Co-Authors: Yousef A Gharbia, Jayantha Katupitiya
    Abstract:

    This study presents detailed experimental results that help to determine the optimal grit size, speed and in-feed rate for grinding End faces of optical Fibres on a nano-grinding machine. The determination of these parameters was based on surface roughness, material removal rate and the surface and sub-surface damage investigations. The observations consisted of qualitative as well as quantitative evaluations. Qualitative assessment of surface quality was carried out using an optical microscope. The quantitative measurement of surface roughness was carried out using atomic force microscopy (AFM). The material removal rates were determined using feed rates of the nano-grinding machine. Using a focussed ion beam (FIB), the ground surfaces were milled to expose their cross sections. The ground surfaces and the cross sections were examined using scanning electron microscopy (SEM) for surface or sub-surface damage.

  • loose abrasive blasting as an alternative to slurry polishing of optical Fibre End faces
    International Journal of Machine Tools & Manufacture, 2003
    Co-Authors: Yousef A Gharbia, Jayantha Katupitiya
    Abstract:

    Abstract A novel method of polishing the End face of an optical Fibre by blasting it with loose dry abrasive grit travelling at high speeds is presented. The method, called loose abrasive blasting (LAB), is specifically designed to improve the surface quality of micro-lenses ground at the tips of optical Fibres. Thus, the method described is suitable for polishing non-flat surfaces. Blasting is carried out by immersing the Fibre tip in a stream of high kinetic energy abrasive grit. The surface finish attainable using LAB is compared with that of cleaved, ground and slurry polished Fibre End faces. Optical microscopy photographs are presented as a qualitative comparison. The surface roughnesses are measured using atomic force microscopy (AFM). For cleaved Fibres, the surface roughness improved by a factor of 2 and 6 for slurry polished and dry diamond blasted Fibres, respectively.

Yousef A Gharbia - One of the best experts on this subject based on the ideXlab platform.

  • experimental determination of optimum parameters for nano grinding of optical Fibre End faces
    International Journal of Machine Tools & Manufacture, 2004
    Co-Authors: Yousef A Gharbia, Jayantha Katupitiya
    Abstract:

    This study presents detailed experimental results that help to determine the optimal grit size, speed and in-feed rate for grinding End faces of optical Fibres on a nano-grinding machine. The determination of these parameters was based on surface roughness, material removal rate and the surface and sub-surface damage investigations. The observations consisted of qualitative as well as quantitative evaluations. Qualitative assessment of surface quality was carried out using an optical microscope. The quantitative measurement of surface roughness was carried out using atomic force microscopy (AFM). The material removal rates were determined using feed rates of the nano-grinding machine. Using a focussed ion beam (FIB), the ground surfaces were milled to expose their cross sections. The ground surfaces and the cross sections were examined using scanning electron microscopy (SEM) for surface or sub-surface damage.

  • loose abrasive blasting as an alternative to slurry polishing of optical Fibre End faces
    International Journal of Machine Tools & Manufacture, 2003
    Co-Authors: Yousef A Gharbia, Jayantha Katupitiya
    Abstract:

    Abstract A novel method of polishing the End face of an optical Fibre by blasting it with loose dry abrasive grit travelling at high speeds is presented. The method, called loose abrasive blasting (LAB), is specifically designed to improve the surface quality of micro-lenses ground at the tips of optical Fibres. Thus, the method described is suitable for polishing non-flat surfaces. Blasting is carried out by immersing the Fibre tip in a stream of high kinetic energy abrasive grit. The surface finish attainable using LAB is compared with that of cleaved, ground and slurry polished Fibre End faces. Optical microscopy photographs are presented as a qualitative comparison. The surface roughnesses are measured using atomic force microscopy (AFM). For cleaved Fibres, the surface roughness improved by a factor of 2 and 6 for slurry polished and dry diamond blasted Fibres, respectively.

Manuel B. Marques - One of the best experts on this subject based on the ideXlab platform.

Michel Leblanc - One of the best experts on this subject based on the ideXlab platform.

  • study of interfacial interaction of an optical Fibre embedded in a host material by in situ measurement of Fibre End displacement part 2 experiments
    Smart Materials and Structures, 2005
    Co-Authors: Michel Leblanc
    Abstract:

    This paper describes the experimental approach and the experimental results of a new technique for the characterization of host-to-sensor interaction based on the measurement of the embedded Fibre End face displacement. The method consists of monitoring the reflected signal from the Fabry–Perot cavity formed at the End of an embedded Fibre while the test sample is under increasing axial load. The curve of displacement versus applied strain in the host is analysed to describe the quality of the strain transfer and the condition of the interfacial region. Results on a test configuration consisting of an optical Fibre surrounded by epoxy in an aluminium matrix are presented. In this configuration, the epoxy acts as the Fibre coating and the aluminium is the host material. The results show that for this configuration the mode of failure of the interfacial region is by plastic deformation of the epoxy material. The results also make evident the visco-elastic and visco-plastic response of the epoxy.

Kyriacos Kalli - One of the best experts on this subject based on the ideXlab platform.

  • Femtosecond laser processing of optical Fibres for novel sensor development
    2017 25th Optical Fiber Sensors Conference (OFS), 2017
    Co-Authors: Kyriacos Kalli, Andreas Ioannou, Andreas Theodosiou, Amedee Lacraz
    Abstract:

    We present results of recent research where we have utilized a femtosecond laser to micro-structure silica and polymer optical Fibres in order to realize versatile optical components such as diffractive optical elements on the Fibre End face, the inscription of integrated waveguide circuits in the Fibre cladding and novel optical Fibre sensors designs based on Bragg gratings in the core. A major hurdle in tailoring or modifying the properties of optical Fibres is the development of an inscription method that can prove to be a flexible and reliable process that is generally applicable to all optical Fibre types; this requires careful matching of the laser parameters and optics in order to examine the spatial limits of direct laser writing, whether the application is structuring at the surface of the optical Fibre or inscription in the core and cladding of the Fibre. We demonstrate a variety of optical components such as two-dimensional grating structures, Bessel, Airy and vortex beam generators; moreover, optical bridging waveguides inscribed in the cladding of single-mode Fibre as a means to selectively couple light from single-core to multi-core optical Fibres, and demonstrate a grating based sensor; finally, we have developed a novel femtosecond laser inscription method for the precise inscription of tailored Bragg grating sensors in silica and polymer optical Fibres. We also show that this novel Fibre Bragg grating inscription technique can be used to modify and add versatility to an existing, encapsulated optical Fibre pressure sensor.

  • beam shaping via femtosecond laser modified optical Fibre End faces
    Proceedings of SPIE, 2016
    Co-Authors: Andreas Ioannou, Michael Polis, Amedee Lacraz, Andreas Theodosiou, Kyriacos Kalli
    Abstract:

    We present the results of investigations regarding laser micro-structuring of single mode optical Fibres by direct access of the Fibre End face and compare this with inscription in planar samples. We combine a high numerical aperture objective and femtosecond laser radiation at visible wavelengths to examine the spatial limits of direct writing and structuring at the surface of the optical Fibre. We realise a number of interesting devices from one- and two-dimensional grating structures, to Bessel, Airy and vortex beam generators. We show the versatility of this simple but effective inscription method, where we demonstrate classic multiple slit diffraction patterns and patterns for non-diffracting beams, confirming that the flexible direct write method using femtosecond lasers can be to produce binary masks that can lead to beam shaping using a method that is applicable to all types of planar samples and through fine control of laser parameters to multi-mode and singlemode optical Fibres.

  • Femtosecond laser microstructuring through optical Fibre End faces: inscription of surface gratings and sub-surface splitters
    OFS2012 22nd International Conference on Optical Fiber Sensors, 2012
    Co-Authors: Kyriacos Kalli, Charalambos Koutsides, Michael Komodromos, Kate Sugden
    Abstract:

    We present the results of femtosecond laser microstructuring of optical Fibres by direct access of the Fibre End face, both at the surface and several hundred microns into the Fibre, to realise one-and two-dimensional grating structures and optical Fibre splitters, respectively. We show the versatility of this simple but effective inscription method, where we demonstrate classic multiple slit diffraction patterns and show the potential for coarse wavelength division multiplexing for sensor signals. A key advantage for the Fibre splitter is that the inscription method avoids the use of oil immersion that compensate for the Fibre curvature in the standard side writing method.