Abstract
A novel in-fiber modal interferometer is presented that is based on a nonadiabatic biconical fused taper that couples light between the cladding and the core, combined with the Fresnel reflection at the fiber end. It is observed that the returned light from this fiber structure shows a channeled spectrum similar to that of a two-wave Michelson interferometer. The application of this device as a fiber optic flowmeter sensor is demonstrated. 2007 (c) Optical Society of America.

Abstract
A novel Mach-Zehnder interferometer based on a fiber multimode interference structure combined with a long-period fiber grating (LPG) is proposed. The multimode interference is achieved through the use of a MMF section spliced between two single-mode fibers, with a length adjusted to couple a fraction of light into the cladding modes. A LPG placed after the MMF couples light back into the fiber core, completing the Mach-Zehnder interferometer. This novel configuration was demonstrated as a bending sensor. (c) 2007 Optical Society ofAmerica.

Abstract
A micrometric Fabry-Perot refractometer based on an end-of-fiber polymer tip is proposed. The fiber tip, with a length of 36 mu m, was fabricated by self-guiding photopolymerization. The two-wave interferometric operation was achieved by combining the light waves generated at the interface between the single-mode fiber and the polymer tip, and at the fiber tip end (Fresnel reflection). The Fabry-Perot interferometer is coherence addressed and heterodyne interrogated, resulting into a liquid refractive index resolution of approximate to 7.5 x 10(-4). (C) 2009 Optical Society of America

Abstract
Fiber Bragg Gratings are structures with remarkable characteristics that have induced new qualitative developments in the broad field of optical fiber technology, most notably in optical communications and in optical sensing. When these devices are applied for sensing, the underlying concept is the modulation of the grating Bragg wavelength by the measured and, therefore, a central issue is the sensitive and accurate conversion of the resonant wavelength into a proportional electrical signal with the adequate format for further processing. This topic is broadly known as Fiber Bragg Grating interrogation and is the subject of the present chapter. It is organized in two parts: in the first one, the techniques developed by the scientific community looking for this functionality are reviewed, with emphasis on the identification of general conceptual classes where they fit; in the second part, illustrative and state-of-the-art commercial Fiber Bragg Grating interrogation systems are described.

Abstract
The electrocatalytic oxidation of D-sorbitol on a polycrystalline platinum electrode, in perchloric aqueous medium, was studied by cyclic voltammetry under varying sweep rate, potential limits, stirring, temperature, pH and concentration of D-sorbitol. A value of about 50 kJ mol(-1) was obtained for the apparent activation enthalpy of the oxidation reaction at 0.1 V vs. sme. The experimental rate equation is i = kC(D-sorb)(0.4) C-H+(-0.3).exp[0.4 FE/RT], valid for [D-sorbitol] < 0.1 mol dm(-3) and pH < 1.

Abstract
Interferometric sensors based on source coherence synthesis have been reported for measurement of quasistatic parameters. An absolute sensing technique has been demonstrated based on fringe visibility modulation using a frequency modulated laser. In this Letter, a technique is described which allows to perform absolute displacement measurements in the range from tens to several hundreds of micrometers. It is based on dynamical spectral filtering of a superluminescent source which provides frequency modulation amplitudes up to 3000 GHz. The principle is described and experimentally verified for displacement measurement