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A. B. Lobo Ribeiro

Bio: A. B. Lobo Ribeiro is an academic researcher from University of Porto. The author has contributed to research in topics: Fiber Bragg grating & Optical fiber. The author has an hindex of 13, co-authored 32 publications receiving 846 citations. Previous affiliations of A. B. Lobo Ribeiro include Health Science University & Fernando Pessoa University.

Papers
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Journal ArticleDOI
TL;DR: A new approach for the interrogation of a large number of fiber-optic grating sensors is proposed and demonstrated for a small number of sensors in which signal recovery is achieved by matching a receiving grating to its corresponding sensor.
Abstract: A new approach for the interrogation of a large number of fiber-optic grating sensors is proposed and demonstrated for a small number of sensors in which signal recovery is achieved by matching a receiving grating to its corresponding sensor. This technique is demonstrated for both quasi-static and periodic measurands, and the resolution achieved for a single sensor–receiving grating pair for quasi-static strain is 4.12 μ∊.

217 citations

Journal ArticleDOI
TL;DR: Numerical and experimental results show that there is an optimum Bragg wavelength difference between the two FBG's that maximizes the sensitivity for this demodulation technique.
Abstract: A technique for the demodulation of fiber Bragg grating (FBG) sensors based on the use of a second wavelength-matched FBG receiver to track wavelength shifts from the FBG sensor is analyzed, particularly regarding its sensitivity as determined by primary noise sources. Numerical and experimental results show that there is an optimum Bragg wavelength difference between the two FBG’s that maximizes the sensitivity for this demodulation technique.

106 citations

Journal ArticleDOI
TL;DR: In this article, a passive self-referencing all-fibre technique for Bragg wavelength shift detection using a biconical fiber filter is described, which exhibits a periodic spectral power dependence.
Abstract: A passive self-referencing all-fibre technique for Bragg wavelength shift detection using a biconical fibre filter is described. This filter, basically a tapered depressed-cladding fibre, exhibits a periodic spectral power dependence which permits direct tracking of wavelength shifts in a 20 nm unambiguous range. Dynamic strain resolution of 1.5 µstrain/√Hz has been achieved.

78 citations

Journal ArticleDOI
TL;DR: A combined spatial- and time-division-multiplexing topology with drift-compensated high-resolution wavelength-shift detection is reported for fiber Bragg grating sensors.
Abstract: A combined spatial- and time-division-multiplexing topology with drift-compensated high-resolution wavelength-shift detection is reported for fiber Bragg grating sensors. An eight-element grating sensor array is demonstrated based on this topology. A resolution of ~1.2 μe over a range of ~1.5 me with a measurement bandwidth of 30 Hz (~0.22 μɛ/Hz) has been achieved for quasi-static strain measurement.

73 citations

Journal ArticleDOI
TL;DR: In this article, a multipoint fiber-optic temperature sensor network integrated inside a power transformer for continuous monitoring of hot-spots on windings, cellulose insulations, and oil, is demonstrated and tested.
Abstract: A multipoint fiber-optic temperature sensor network integrated inside a power transformer for continuous monitoring of hot-spots on windings, cellulose insulations, and oil, is demonstrated and tested. The temperature sensors are based on proprietary encapsulated fiber Bragg grating (FBG) sensors and the optical interrogation unit uses a special designed narrowband high power broadband fiber source. The fiber-optic sensing network is integrated into a 20 MVA, 345/radic3 kV -20 kV power transformer (CORE type) having 12 temperature sensing points, distributed over several physical locations inside the transformer (windings, cellulose insulators, magnetic circuit, and cooling oil entrance and exit).

67 citations


Cited by
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Journal ArticleDOI
TL;DR: In this paper, the authors review the recent developments in the area of optical fiber grating sensors, including quasi-distributed strain sensing using Bragg gratings, systems based on chirped gratings and intragrating sensing concepts.
Abstract: We review the recent developments in the area of optical fiber grating sensors, including quasi-distributed strain sensing using Bragg gratings, systems based on chirped gratings, intragrating sensing concepts, long period-based grating sensors, fiber grating laser-based systems, and interferometric sensor systems based on grating reflectors.

3,665 citations

Journal ArticleDOI
TL;DR: Among the various fiber-optic sensor technologies, especially, technologies such as fiber grating sensors, fiber- Optic gyroscopes, and fiber-Optic current sensors are discussed with emphasis on the principles and current status.

1,610 citations

Journal ArticleDOI
Yun-Jiang Rao1
TL;DR: In-fibre Bragg grating (FBG) sensors are one of the most exciting developments in the field of optical fiber sensors in recent years as discussed by the authors, and significant progress has been made in applications to strain and temperature measurements.
Abstract: In-fibre Bragg grating (FBG) sensors are one of the most exciting developments in the field of optical fibre sensors in recent years. Compared with conventional fibre-optic sensors, FBG sensors have a number of distinguishing advantages. Significant progress has been made in applications to strain and temperature measurements. FBG sensors prove to be one of the most promising candidates for fibre-optic smart structures. This article presents a comprehensive and systematic overview of FBG sensor technology regarding many aspects including sensing principles, properties, fabrication, interrogation and multiplexing of FBG sensors. It is anticipated that FBG sensor systems will be commercialized and widely applied in practice in the near future due to the maturity of economical production of FBGs and the availability of cost effective interrogation and multiplexing techniques.

1,170 citations

Book
01 Jan 1999
TL;DR: The most common fabrication techniques (interferometric, phase mask, and point by point) are examined in detail with reference to the advantages and disadvantages in utilizing them for inscribing Bragg gratings as mentioned in this paper.
Abstract: Since the discovery of photosensitivity in optical fibers there has been great interest in the fabrication of Bragg gratings within the core of a fiber. The ability to inscribe intracore Bragg gratings in these photosensitive fibers has revolutionized the field of telecommunications and optical fiber based sensor technology. Over the last few years, the number of researchers investigating fundamental, as well as application aspects of these gratings has increased dramatically. This article reviews the technology of Bragg gratings in optical fibers. It introduces the phenomenon of photosensitivity in optical fibers, examines the properties of Bragg gratings, and presents some of the important developments in devices and applications. The most common fabrication techniques (interferometric, phase mask, and point by point) are examined in detail with reference to the advantages and the disadvantages in utilizing them for inscribing Bragg gratings. Reflectivity, bandwidth, temperature, and strain sensitivity of the Bragg reflectors are examined and novel and special Bragg grating structures such as chirped gratings, blazed gratings, phase-shifted gratings, and superimposed multiple gratings are discussed. A formalism for calculating the spectral response of Bragg grating structures is described. Finally, devices and applications for telecommunication and fiber-optic sensors are described, and the impact of this technology on the future of the above areas is discussed.

1,089 citations

Journal ArticleDOI
TL;DR: The recent research and development activities in structural health monitoring using FBG sensors have been critically reviewed, highlighting the areas where further work is needed.
Abstract: In-service structural health monitoring (SHM) of engineering structures has assumed a significant role in assessing their safety and integrity. Fibre Bragg grating (FBG) sensors have emerged as a reliable, in situ, non-destructive tool for monitoring, diagnostics and control in civil structures. The versatility of FBG sensors represents a key advantage over other technologies in the structural sensing field. In this article, the recent research and development activities in structural health monitoring using FBG sensors have been critically reviewed, highlighting the areas where further work is needed. A few packaging schemes for FBG strain sensors are also discussed. Finally a few limitations and market barriers associated with the use of these sensors have been addressed.

858 citations