Browsing by Author "Tatam, Ralph P."

Browsing by Author "Tatam, Ralph P."

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  • Novel highly sensitive protein sensors based on tapered optical fibres modified with Au-based nanocoatings 
    Urrutia, Aitor; Bojan, Kartheka; Marques, L.; Mullaney, Kevin; Goicoechea, Javier; James, Stephen W.; Clark, M.; Tatam, Ralph P.; Korposh, Sergiy (Hindawi Publishing Corporation, 2016-08-08)
    In this work, novel protein sensors based on tapered optical fibres modified with Au coatings deposited using two different procedures are proposed. Au based coatings are deposited onto a non-adiabatic tapered optical fibre ...
  • A novel laser diode wavelength stabilisation technique for use in high resolution spectroscopy 
    Asmari, Abdullah Shah (Cranfield University, 2015)
    Tuneable diode laser absorption spectroscopy (TDLAS) based gas sensors are widely used for trace gas detection for their high selectivity and sensitivity. The laser source used in TDLAS requires a narrow line width in ...
  • Objective speckle displacement resulting from the deformation of shaped objects 
    Charrett, Thomas O. H.; Tatam, Ralph P. (SPIE, 2015)
    This paper describes an extended theory of the displacement of the objective speckle pattern resulting from displacement and/or deformation of a coherently illuminated diffuse object where the influence of the surface shape ...
  • Objective speckle displacement: an extended theory for the small deformation of shaped objects 
    Charrett, Thomas O. H.; Tatam, Ralph P. (Optical Society of America, 2014-10-10)
    This paper describes an extended and improved theory of the displacement of the objective speckle pattern resulting from displacement and/or deformation of a coherently illuminated diffuse object. Using the theory developed ...
  • Objective speckle velocimetry for autonomous vehicle odometry 
    Francis, Daniel; Charrett, Thomas O. H.; Waugh, L.; Tatam, Ralph P. (Osa Optical Society of America, 2012-05-31)
    Speckle velocimetry is investigated as a means of determining odometry data with potential for application on autonomous robotic vehicles. The technique described here relies on the integration of translation measurements ...
  • On-line monitoring of multi-component strain development in a tufting needle using optical fibre Bragg grating sensors 
    Chehura, Edmon; Dell'Anno, Giuseppe; Huet, Tristan; Staines, Stephen E.; James, Stephen W.; Partridge, Ivana K.; Tatam, Ralph P. (Institute of Physics, 2014-05-20)
    Dynamic loadings induced on a tufting needle during the tufting of dry carbon fibre preform via a commercial robot-controlled tufting head were investigated in situ and in real-time using optical fibre Bragg grating (FBG) ...
  • Optical coherence tomography with a Fizeau interferometer configuration 
    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 ...
  • An optical fiber hydrogen sensor using a palladium-coated ball lens 
    Chowdhury, Sahar A.; Correia, Ricardo N.; Francis, Daniel; Brooks, Simon J.; Jones, Benjamin J. S.; Thompson, Alexander W. J.; Hodgkinson, Jane; Tatam, Ralph P. (Institute of Electrical and Electronics Engineers, 2015-06-15)
    A self-referenced optical fiber refractometer using a ball lens as a sensor head has been developed and characterized. A 350-μm ball lens created at the tip of a single mode fiber has been coated with a 40-nm optically ...
  • Optical fiber sensing based on reflection laser spectroscopy 
    Gagliardi, G.; Salza, M.; Ferraro, P.; Chehura, Edmon; Tatam, Ralph P.; Gangopadhyay, T. K.; Ballard, N.; Paz-Soldan, D.; Barnes, J. A.; Loock, H-P; Lam, TT-Y; Chow, J. H.; De Natale, P. (MDPI AG, 2010-03-05)
    An overview on high-resolution and fast interrogation of optical-fiber sensors relying on laser reflection spectroscopy is given. Fiber Bragg-gratings (FBGs) and FBG resonators built in fibers of different types are used ...
  • Optical fibre Fizeau-based OCT 
    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 ...
  • Optical Fibre Grating Refractometers for Resin Cure Monitoring. 
    Buggy, Stephen J.; Chehura, Edmon; James, Stephen W.; Tatam, Ralph P. (Institute of Physics, 2007-06-01)
    The use of fibre grating refractometers as a means of monitoring the cure of a UVcured epoxy resin is presented. The wavelength shift of the attenuation bands of a long period grating and the spectral response of a tilted ...
  • Optical fibre long period grating based selective vapour sensing of volatile organic compounds 
    Topliss, Stephen M.; James, Stephen W.; Davis, Frank; Higson, Seamus P. J.; Tatam, Ralph P. (Elsevier Science B.V., Amsterdam., 2010-01-07)
    The chemical sensing capabilities of an optical fibre long period grating (LPG) coated with a functional material are explored. The LPG period and coating thickness are chosen such that the mode transition region, ...
  • Optical fibre long period grating gas sensor modified with metal organic framework thin films 
    Hromadka, Jiri; Tokay, Begum; James, Stephen W.; Tatam, Ralph P.; Korposh, Sergiy (Elsevier, 2015-07-09)
    An optical fibre long period grating (LPG) modified with a thin film of ZIF-8, a zeolitic immidazol framework material and a subgroup of metal organic framework family, was employed for the detection of organic vapours. ...
  • Optical fibre long period grating sensors with nanostructured coatings 
    Topliss, Stephen M. (Cranfield University, 2011-06)
    The dual resonant response of long period fibre gratings (LPG) operating near the phase matching turning point to the deposition of nanostructured coatings is explored. A broad range of LPGs have been fabricated with grating ...
  • Optical fibre pressure sensing using a frequency modulated laser-based signal processing technique 
    Barrington, James; James, Stephen; Kissinger, Thomas; Staines, Stephen; Prince, Simon; Alcusa Saez, Erica; Lawson, Nicholas J.; Tatam, Ralph P. (IOP Publishing, 2023-04-21)
    Range resolved interferometry (RRI) applied to the interrogation of an extrinsic Fabry–Perot based pressure sensor in laboratory and wind tunnel environments is presented. A simple, compact sensor head design was fabricated ...
  • Optical fibre wavelength filters and multiplexers 
    Ford, Helen D. (Cranfield University, 1994-03)
    Polarisation-based wavelength-division multi-/demulti-plexers (WDMs) and filters have been designed, constructed and evaluated. These are compact devices made from single-mode optical fibre possessing high linear ...
  • Optical fibre-coupled displacement and angle measurements using range-resolved interferometry 
    Wiseman, Kieran B.; Kissinger, Thomas; Tatam, Ralph P. (euspen, 2021-07-10)
    A novel approach to displacement and angle measurements that uses range-resolved interferometry to interrogate multiple interferometers is presented. Spatially offset beams are multiplexed onto the same delivery fibre ...
  • Optical frequency shifter using stimulated Brillouin scattering in fibre optic ring resonators. 
    Khan, Omer Shahab (Cranfield University, 1994-02)
    A fibre optic frequency shifter has been developed which generates a heterodyne frequency that is used to facilitate electronic demodulation of optical information. The operation of this device is analogous to an ...
  • Optical gas sensing: a review 
    Hodgkinson, Jane; Tatam, Ralph P. (Iop Publishing Ltd, 2013-01-31)
    The detection and measurement of gas concentrations using the characteristic optical absorption of the gas species is important for both understanding and monitoring a variety of phenomena from industrial processes to ...
  • Optical Gas Sensor Fabrication Based on Porphyrin-Anchored Electrostatic Self-Assembly onto Tapered Optical Fibers 
    Jarzebinska, Renata; Korposh, Sergiy; James, Stephen W.; Batty, William J.; Tatam, Ralph P.; Lee, Seung-Woo (Taylor & Francis, 2012-07-31)
    Tapered optical fibers with nano-assembled coatings of thicknesses of order tens of nanometres were used for the detection of ammonia gas. The film coating was composed of alternate layers of tetrakis-(4-sulfophenyl) ...