Staff publications (SoE)

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Browsing Staff publications (SoE) by Author "Antonello, Cutolo"

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    Laser-frequency locking techniques for high-sensitivity strain measurements by high-birefringence fiber Bragg gratings and resonators
    (International Society for Optical Engineering; 1999, 2007-12-31T00:00:00Z) Salza, M.; Gagliardi, G.; Di Maio, A.; Ferraro, P.; De Natale, P.; Chehura, Edmon; Tatam, Ralph P.; Antonello, Cutolo; Brian, Culshaw; José, Miguel López-Higuera
    A new approach to simultaneously interrogate orthogonal axes of single Fiber- Bragg-Gratings (FBGs) and FBG-FabryPerot resonator sensors fabricated in linearly highly birefringent (HiBi) fibre is presented. Novel interrogation techniquesof single Fiber-Bragg-Gratings (FBGs) and FBG-resonator sensors are presented. For a single FBG, we combined alaser-modulation technique to an electronic feedback loop that keeps the source always frequency locked to one peak ofthe sensor's reflected spectrum. Two different lasers, with orthogonally- polarized states, were adopted to monitorsimultaneously both the "fast" and "slow" FBG peaks. The corresponding correction signals from the servo-loop outputscan be interpreted as strain or temperature induced on the FBG. Detection limits ranging from 1 nε/√Hz to 100 nε/√Hz,for axial dynamic and static deformations, respectively, and of 0.025 °C/√Hz for temperature variations, are expected. Asimilar approach was developed for sub-pϵ resolution interrogation of an optical resonator made of a high-reflectivityFBG-pair, using the Pound- Drever-Hall (PDH) stabilizati
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    Nested long period grating interferometers
    (International Society for Optical Engineering; 1999, 2007-12-31T00:00:00Z) Murphy, Richard P.; James, Stephen W.; Tatam, Ralph P.; Antonello, Cutolo; Brian, Culshaw; Jos, Miguel Lpez-Higuera
    The concept of nested fibre optic long period grating (LPG) based interferometers is introduced. A number of in-series, identical LPGs may be used to form a set of nested, multiplexed Mach-Zehnder interferometers that may demodulated and demultiplexed by virtue of a Fourier analysis of the optical spectrum. The concept is demonstrated by the use of three LPGs to form a nested set of interferometers.
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    Simultaneous, independent measurement of temperature and strain using a tilted fibre Bragg grating
    (International Society for Optical Engineering; 1999, 2007-12-31T00:00:00Z) Chehura, Edmon; James, Stephen W.; Tatam, Ralph P.; Antonello, Cutolo; Brian, Culshaw; Jos, Miguel Lpez-Higuera
    A single fibre Bragg grating is used to discriminate between temperature and strain by exploiting the core-cladding mode coupling of a tilted fibre Bragg grating (TFBG). The core and cladding modes exhibit different thermal sensivities, while the strain sensivities are approximately equal. Monitoring the core-core mode coupling resonance and the core-cladding mode coupling resonance within the spectrum of a single TFBG allows the separation of the temperature and strain induced wavelength shifts.