Browsing by Author "Tatam, Ralph P."

Browsing by Author "Tatam, Ralph P."

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  • A fibre optic angle sensing tape for applications in robotics and automation 
    Pillai, Sivaji; Charrett, Thomas O. H.; Kissinger, Thomas; James, Stephen W.; Tatam, Ralph P. (SPIE, 2023-08-15)
    A dual-fibre single-plane angle-sensing tape that utilizes optical Fibre Segment Interferometry and Range- Resolved Interferometry (RRI) for angle sensing is presented. The sensing tape facilitates the multiplexing of an ...
  • Fibre optic fizeau intererometer for optical coherence tomography 
    Casaubieilh, P. (Cranfield University, 2006)
    The aim of the project was to develop the Fizeau interferometer configuration to take advantage of the benefits derived from its “downlead insensitivity” to temperature and polarisation fading. This sensing interferometer ...
  • Fibre optic hydrogen sensing for long term use in explosive environments 
    Chowdhury, S. A. (Cranfield University, 2015-09)
    Hydrogen is an explosive and flammable gas with a lower explosive limit of just 4% volume in air. It is important to monitor the concentration of hydrogen in a potentially hazardous environment where hydrogen may be ...
  • Fibre optic sensors with biologically active coatings for the detection of cells. 
    Rendon Romero, Antonio (Cranfield UniversitySATM, 2019-05)
    The purpose of this thesis is to develop a rapid, sensitive and selective optical sensor for Campylobacter jejuni detection as it is the most common cause of foodborne illness in humans. The optical sensor platform was ...
  • Fibre Optic Sensors with Nano-Structured Coatings. 
    James, Stephen W.; Tatam, Ralph P. (Institute of Physics, 2006-07-01)
    A review of optical fibre devices employing nano-structured coatings is presented. Active and passive coatings, deposited using the Langmuirâ  Blodgett and electro-static self-assembly techniques, have been utilised ...
  • Fibre segment interferometry for dynamic strain measurements 
    Kissinger, Thomas; Correia, Ricardo N.; Charrett, Thomas O. H.; James, Stephen W.; Tatam, Ralph P. (Institute of Electrical and Electronics Engineers, 2016-02-18)
    Using a novel range-resolved interferometric signal processing technique based on the sinusoidal optical frequency modulation of a cost-effective laser diode, a fibre sensing approach termed fibre segment interferometry ...
  • Fibre segment interferometry using code-division multiplexed optical signal processing for strain sensing applications 
    Kissinger, Thomas; Charrett, Thomas O. H.; Tatam, Ralph P. (Iop Publishing Ltd, 2013-09-30)
    A novel optical signal processing scheme for multiplexing fibre segment interferometers is proposed. The continuous-wave, homodyne technique combines code-division multiplexing with single-sideband modulation. It uses only ...
  • Fibre-coupled, multiplexed methane detection using range-resolved interferometry 
    Bremner, James; Kissinger, Thomas; Hodgkinson, Jane; Tatam, Ralph P. (Institute of Physics, 2021-02-08)
    We describe the first use of range-resolved interferometric signal processing for measurement of spectral transmission. This was applied to gas sensing using tunable diode laser spectroscopy, allowing the simultaneous and ...
  • Fibre-optic long period gratings for sensing applications 
    Khaliq, Sarfraz (Cranfield University, 2003-03)
    Long period gratings (LPGs) are formed by inducing a permanent periodic modulation of the refractive index (RI) of the core of an optical fibre. The transmission spectrum of the LPG contains a series of attenuation bands ...
  • Fibre-optic measurement of strain and shape on a helicopter rotor blade during a ground run: 2. Measurement of shape 
    Kissinger, Thomas; James, Stephen W.; Weber, Simone; Mullaney, Kevin; Chehura, Edmond; Pekmezci, Huseyin H.; Barrington, James; Staines, Stephen E.; Charrett, Thomas O. H.; Lawson, Nicholas J.; Lone, Mudassir; Atack, Richard; Tatam, Ralph P. (IOP Publishing, 2022-06-08)
    Optical fibre strain and shape measurement sensors were deployed on a rotor blade during a full-speed helicopter ground run, with real-time data wirelessly streamed from rotor hub-mounted sensor interrogators. In part 2 ...
  • Fibre-optic sensors with molecular coatings 
    Partridge, Matthew (Cranfield University, 2012-12)
    The intrinsic stability of fibre optic based sensing systems offer a platform that is suited to hazardous waste detection in a wide range of environments. Over the last few years Cranfield University has been working on ...
  • Finding minimum spanning trees more efficiently for tile-based phase unwrapping. 
    Al-Sawaf, Firas; Tatam, Ralph P. (Iop Publishing Ltd, 2006-06-06)
    The tile-based phase unwrapping method employs an algorithm for finding the minimum spanning tree (MST) in each tile. We first examine the properties of a tile's representation from a graph theory viewpoint, observing that ...
  • Formaldehyde sensor using non-dispersive UV spectroscopy at 340nm 
    Davenport, John; Hodgkinson, Jane; Saffell, John R.; Tatam, Ralph P. (International Society for Optical Engineering; 1999, 2014-05-22)
    Formaldehyde is a volatile organic compound that exists as a gas at room temperature. It is hazardous to human health causing irritation of the eyes, nose and throat, headaches, limited pulmonary function and is a potential ...
  • Frequency division multiplexing for interferometric planar Doppler velocimetry 
    Charrett, Thomas O. H.; Bledowski, Ian A.; James, Stephen W.; Tatam, Ralph P. (Optical Society of America, 2014-05-30)
    A new method of acquiring simultaneously the signal and reference channels used for interferometric planar Doppler velocimetry is proposed and demonstrated. The technique uses frequency division multiplexing (FDM) to ...
  • Frequency-division multiplexing for multicomponent shearography 
    Bledowski, Ian A.; Charrett, Thomas O. H.; Francis, Daniel; James, Stephen W.; Tatam, Ralph P. (Osa Optical Society of America, 2013-01-20)
    A new method of multiplexing the speckle patterns needed in multicomponent digital shearography systems is presented. Frequency-division multiplexing (FDM) of the measurement channels is achieved by recording speckle ...
  • Frequency-division-multiplexing technique for imaging metrology 
    Bledowski, Ian A. (Cranfield University, 2014)
    An algorithm to multiplex multiple image captures simultaneously onto a single image sensor at full frame resolution was developed for imaging metrology. Parseval’s theorem was used to obtain the image intensity from image ...
  • Full surface strain measurement using shearography 
    Groves, Roger M.; James, Stephen W.; Tatam, Ralph P. (International Society for Optical Engineering; 1999, 2001-12-31)
    Shearography is a full-field optical technique usually used for the determination of surface strain. Correlation of interferometric speckle patterns recorded before and after the object deformation yields fringes sensitive ...
  • Full-field interferometry using infinity corrected optics 
    Charrett, Thomas O. H.; Tatam, Ralph P. (IOP Publishing, 2015-12-01)
    In this paper the construction of full-field (imaging) interferometers using infinity corrected optics commonly used in microscopy is discussed, with an emphasis on self-mixing interferometry configurations where the ...
  • Full-field optical coherence tomography 
    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 ...
  • Full-field optical coherence tomography using a fibre imaging bundle 
    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 ...