Abstract
In this work an all optical hot-wire flowmeter based on a silver coated fibre incorporating a long period grating and a Bragg grating is demonstrated. Optical energy at 1480 nm propagating down the fibre is coupled by the long period grating into the fibre cladding and absorbed by the metallic coating deposited on the fibre surface over the Bragg grating position. This absorption acts like a hot-wire raising locally the fibre temperature, which is effectively detected by the FBG resonance shift. The temperature raise depends on the flow speed of the surrounding air that has the effect to cool the fibre. In this way, the FBG Bragg wavelength shift can be related with the flow speed. Results obtained demonstrate the working principle and a flow speed resolution of 0.08 m/s is demonstrated.

Abstract
In this work, a Brillouin fibre laser sensor for strain and temperature discrimination is presented. The fibre laser sensor consists in a Fabry-Pérot cavity with 20 meters of optical fibre between two Bragg gratings. © 2006 OSA/OFS 2006.

Abstract
A fiber sensing system is presented that allows simultaneous measurement of both refractive index and temperature while providing passive referencing to intensity fluctuations. © 2006 OSA/OFS 2006.

Abstract
A theoretical and experimental study of the self-referencing resonant fiber optic intensity sensors based respectively on Michelson and Mach-Zehnder configurations is conducted. Sensor linearity and sensitivity are addressed, being also considered sensors design and optimization.

Abstract
A novel self-referencing parameter for electro-optical WDM networks in reflective configuration for remote fiber-optic intensity sensors is reported and experimentally tested. In this configuration electrical delay lines are deployed at the processing unit, instead of long delay fiber coils in each measuring point; providing a more compact sensor-head and an easy-reconfigurable operation point. The measurement parameter is defined as the ratio between voltage values at the reception stage for different electrical phase-shifts and it is analyzed following the Z-transform formalism. Measurements validating the theoretical model are reported and self-referencing and crosstalk properties of the network are analyzed. © 2009 SPIE.

Abstract
A Fabry-Perot (FP) cavity of simple design and based on a pure silica diaphragm-free hollow tube is proposed. Its operation is based on a first reflection of light at the end of the single-mode fiber that illuminates the silica rod and in a second reflection that takes place at the end of the rod. The FP cavity is characterized for high temperature, pressure and refractive index sensing, showing useful characteristics for the measurement of these three parameters. The diaphragm-free configuration simplifies the measurement of the refractive index of fluids. (C) 2011 Optical Society of America