Browsing by Author "Ford, Helen D."

Browsing by Author "Ford, Helen D."

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  • Charrett, Thomas O. H.; Ford, Helen D.; Nobes, David S.; Tatam, Ralph P. (International Society for Optical Engineering; 1999, 2003-12-31)
    A Planar Doppler Velocimetry (PDV) illumination system has been designed which is able to generate two beams, separated in frequency by about 600 MHz. This allows a common-path imaging head to be constructed, using a ...
  • Ford, Helen D.; Tatam, Ralph P. (Iop Publishing Ltd, 2007-01-01)
    An imaging fibre bundle is incorporated into a full-field imaging OCT system, with the aim of eliminating the mechanical scanning currently required at the probe tip in endoscopic systems. Each fibre within the imaging ...
  • Ford, Helen D.; Tatam, Ralph P. (International Society for Optical Engineering; 1999, 2005-12-31)
    To eliminate mechanical scanning in the probe head of an endoscopic OCT system, we propose the use of an imaging fibre bundle for probe beam delivery. Each fibre in the bundle addresses a Fizeau interferometer formed ...
  • Ford, Helen D.; Tatam, Ralph P. (2006-12-31)
    An imaging fibre bundle is demonstrated for spatially-multiplexed probe beam delivery in OCT, with the aim of eliminating the mechanical scanning currently required at the probe tip in endoscopic systems. Each fibre in ...
  • Sarantavgas, G. F.; Ford, Helen D.; Tatam, Ralph P. (2008-03-05)
    An OCT system incorporating a coherent fibre imaging bundle is described. Fibres are accessed sequentially by a beam focused onto the input face of the bundle, allowing 2D or 3D images to be acquired using point detection. ...
  • Nobes, David S.; Ford, Helen D.; Tatam, Ralph P. (Springer Science Business Media, 2004-01-01)
    Abstract This paper describes a planar Doppler velocimetry (PDV) technique that is capable of measuring the three, instantaneous and time average components of velocity over two spatial dimensions using a single pair of ...
  • Balboa, Itziar; Ford, Helen D.; Tatam, Ralph P. (Iop Publishing Ltd, 2006-02-10)
    This paper describes the development of optical fibre low-coherence speckle interferometers capable of three-dimensional surface profiling with a resolution of 10–20 µm and a depth range of typically tens of centimetres. ...
  • Lu, Zenghai H.; Charrett, Tom O. H.; Ford, Helen D.; Tatam, Ralph P. (Springer, 2008)
    This paper describes the development of a Mach-Zehnder interferometric filter based planar Doppler velocimetry (MZI-PDV) flow measurement technique. The technique uses an unbalanced Mach-Zehnder interferometer (MZI) to ...
  • Casaubieilh, P.; Ford, Helen D.; James, Stephen W.; Tatam, Ralph P. (International Society for Optical Engineering; 1999, 2005-12-31)
    We report the investigation of a Fizeau interferometer-based OCT system. A secondary processing interferometer is necessary in this configuration, to compensate the optical path difference formed in the Fizeau ...
  • Casaubieilh, P.; Ford, Helen D.; Tatam, Ralph P. (SPIE - International Society for Optics and Photonics, 2004-06-09)
    An optical fibre, Fizeau configuration Optical Coherence Tomography (OCT) system is presented in this paper. The interferometer is formed between the distal end of the sample-arm fibre and the sample itself. This ensures ...
  • Ford, Helen D.; Tatam, Ralph P. (Iop Publishing Ltd, 2013-07-24)
    A passive, endoscopic optical coherence tomography (OCT) probe has been demonstrated, incorporating an imaging fibre bundle and 45° conical mirror, and with no electromechanical components at the probe tip. Circular scanning, ...
  • Ford, Helen D.; Tatam, Ralph P. (Optical Society of America, 2017-04-06)
    Duct-profiling in test samples up to 25 mm in diameter has been demonstrated using a passive, low-coherence probe head with a depth resolution of 7.8 μm, incorporating an optical-fibre-linked conical mirror addressed by ...
  • Nobes, David S.; Ford, Helen D.; Tatam, Ralph P. (SPIE - International Society for Optics and Photonics, 2003-08-03)
    The development of a planar Doppler velocimetry is described. The technique is capable of measuring the three, instantaneous components of velocity in two dimensions using a single pair of signal and reference cameras. ...
  • Charrett, Thomas O. H.; Ford, Helen D.; Tatam, Ralph P. (IOP Publishing, 2006)
    Two frequency planar Doppler Velocimetry (2ν-PDV) is a modification of the Planar Doppler Velocimetry (PDV) method that allows velocity measurements to be made, quickly and non intrusively, across a plane defined by a laser ...
  • Charrett, Thomas O. H.; Ford, Helen D.; Tatam, Ralph P. (AIAA, 2006)
    A modified Planar Doppler Velocimetry (PDV) technique, two frequency PDV (2v-PDV), is described that allows measurements of the velocity field over a plane defined by a laser light sheet using sequential illumination of ...
  • Charrett, Thomas O. H.; Ford, Helen D.; Tatam, Ralph P. (SPIE, 2005-12-31)
    3D planar flow-field measurements are made using multiple imaging fibre bundles to port different views of the measurement plane, defined by a laser light sheet, to a CCD camera. The Doppler frequency shifts of particles ...
  • Charrett, Thomas O. H.; Ford, Helen D.; Tatam, Ralph P. (International Society for Optical Engineering; 1999, 2005-12-31)
    The work presented here describes a method that allows three component velocity measurements to be made, quickly and non-intrusively, across a plane in a flow defined by a laser light sheet. The method, two frequency ...
  • Ford, Helen D.; Tatam, Ralph P. (Elsevier Science B.V., Amsterdam., 2013-04-15)
    Cross-correlation of optical coherence tomography (OCT) images has been applied to internal imaging of PVA and two-part epoxy adhesives during cure, providing information on relative viscosity at different positions within ...
  • Ford, Helen D.; Tatam, Ralph P. (2009-10-05)
    OCT probes for endoscopy typically use a single optical fibre to deliver light to the measurement region. 2D imaging is achieved using mechanical scanning components at the probe tip. We are investigating an OCT system ...