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Michel LeBlanc

Bio: Michel LeBlanc is an academic researcher from Halliburton. The author has contributed to research in topics: Optical fiber & Fiber Bragg grating. The author has an hindex of 26, co-authored 152 publications receiving 5692 citations. Previous affiliations of Michel LeBlanc include United States Department of the Navy & University of Maine.


Papers
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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: In this article, a distributed strain sensing technique using a fiber optic Bragg grating has been developed and tested, and three different demodulation approaches are reviewed indicating a trade-off between a relatively simple measurement process for selected types of strain profile and a more complete measurement process that is suitable for any strain profile.
Abstract: A new distributed strain sensing technique using a fiber optic Bragg grating has been developed and tested. This is the first `true' distributed strain sensor, to the authors' knowledge, with a high spatial resolution of about 1 mm. Since gratings can be made with a length of tens of centimeters, this new fiber optic measurement technique could have broad applications to smart materials and structures where monitoring of a continuous strain profile over a length of millimeters to tens of centimeters is needed. In this paper three different demodulation approaches are reviewed indicating a trade-off between a relatively simple measurement process for selected types of strain profile and a more complete measurement process that is suitable for any strain profile. Experimental results with different approaches are presented.

135 citations

Journal ArticleDOI
TL;DR: It is confirmed that intracore Bragg gratings can be used to evaluate strain gradients and can be thought of as quasi-distributed strain sensors and provides a warning of any sensor/host debonding.
Abstract: Fiber-optic intracore Bragg gratings have been of interest for a variety of sensing applications,1,3 especially for smart structures.4 In most smart structures applications, the strain along a fiber grating sensor is uniform and the strain is measured by the shift of the reflective wavelength of the grating. However, in some situations such as near a fiber debonding zone or near a structural damage point, strong local strain gradients are produced. Under such strain fields, the grating spectrum will not only be shifted but also distorted due to the chirp induced in the grating period by the imposed strain gradient. Based on this spectrum distortion, it is possible to use Bragg gratings as quasi-distributed sensors to sense strain gradients over a small region (sub-centimeter). We have calculated the reflection spectrum of nonuniform Bragg gratings by using the T-matrix method. This has enabled us to determine the effects of strain gradients on the spectrum. Experiments have verified these theoretical results.

124 citations

Journal ArticleDOI
TL;DR: A method of extracting the strain profile along a fiber Bragg grating from the intensity reflection spectrum is described, based on a filter synthesis theory that relates the aperiodicity of a grating with its reflection spectrum.
Abstract: A method of extracting the strain profile along a fiber Bragg grating from the intensity reflection spectrum is described The procedure is based on a filter synthesis theory that relates the aperiodicity of a grating with its reflection spectrum To illustrate the approach, we measured the strain profile near a hole in a plate and obtained a strain resolution of 80 μ∊ The spatial resolution depends on the strain gradient; ie, the higher the gradient, the better the resolution A resolution of 08 mm was achieved for a 5-mm grating with a gradient of 250 μ∊/mm

121 citations

Journal ArticleDOI
TL;DR: The birefringence of a pi -phase-shifted fiber Bragg grating can be determined with high accuracy by measurement of the polarization-induced spectral splitting of its narrow central transmission window by means of a distributed force resolution.
Abstract: The birefringence of a pi -phase-shifted fiber Bragg grating can be determined with high accuracy by measurement of the polarization-induced spectral splitting of its narrow central transmission window. The use of this feature for sensing of a load applied in the direction transverse to the optical fiber is demonstrated. A distributed force resolution of 1.4x10(-3) N/mm was obtained, which corresponds to a difference in the principal strains of the fiber core of 0.5mu? . We also show that the transverse load response of the sensor is insensitive to temperature.

98 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: This article reviews the recent progress in optical biosensors that use the label-free detection protocol, in which biomolecules are unlabeled or unmodified, and are detected in their natural forms, and focuses on the optical biosENSors that utilize the refractive index change as the sensing transduction signal.

2,060 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
TL;DR: In this paper, the authors reviewed recent research on fiber optic long-period gratings (LPGs) with emphasis placed upon the characteristics of LPGs that make them attractive for applications in sensing strain, temperature, bend radius and external index of refraction.
Abstract: Recent research on fibre optic long-period gratings (LPGs) is reviewed with emphasis placed upon the characteristics of LPGs that make them attractive for applications in sensing strain, temperature, bend radius and external index of refraction. The prospect of the development of multi-parameter sensors, capable of simultaneously monitoring a number of these measurands will be discussed.

1,203 citations

Book ChapterDOI
01 Jan 2009
TL;DR: In this paper, the magnetic properties of magnetic nanoparticles have been investigated and a number of methods for nanoparticle synthesis including the preparation of metallic magnetic particles have been described in the literature, including the control of particle size, shape, and monodispersity as well as their stability towards oxidation.
Abstract: As compared to bulk materials, magnetic nanoparticles possess distinct magnetic properties and attempts have been made to exploit their beneficial properties for technical and biomedical applications, e.g. for magnetic fluids, high-density magnetic recording, or biomedical diagnosis and therapy. Early magnetic fluids (MFs) were produced by grinding magnetite with heptane or long chain hydrocarbon and a grinding agent, e.g. oleic acid [152]. Later procedures for MFs precipitated Fe 3+/Fe 2+ of an aqueous solution with a base, coated the particles by oleic acid, and dispersed them in carrier liquid [161]. However, besides the elemental composition and crystal structure of the applied magnetic particles, particle size and particle size distribution determine the properties of the resulting MF. Many methods for nanoparticle synthesis including the preparation of metallic magnetic particles have been described in the literature. However, there still remain important questions, e.g. concerning control of particle size, shape, and monodispersity as well as their stability towards oxidation. Moreover, peptization by suitable surfactants or polymers into stable MFs is an important issue since each application in engineering or biomedicine needs special MFs with properties adjusted to the requirements of the system.

980 citations