Abstract
The development of fiber optical sensor in which the sensing head comprises a long period fiber grating (LPG) whose attenuation peak varies as function of its bending was investigated. Various arc-induced LPGs were fabricated in the spectral region of the optical source. The spectral power evolution was taken from a streched to a bending position with the optical spectrum analyzer. The developed fiber optical sensor demonstrated its capability of micro-displacement measurement.

Abstract
A novel microbend optical fiber sensing head embedded in Carbon Fiber Reinforced Plastic (CFRP) was developed. The sensor demonstrated its capability of measuring applied pressure up to 750 kPa.

Abstract
A bulk interferometric configuration for electrical current remote sensing in high voltage environments based on the Faraday effect is described. The combination of Sagnac's reciprocal properties with a Mach-Zehnder processing interferometer in the same sensing head is used to implement serrodyne processing for current sensing. A theoretical analysis based on the Jones matrix is presented. Experimental results that validate the exploited concept are obtained, showing linearity up to 1800 A(rms) and waveform. reproduction at 50 Hz. The possibility of using the proposed interferometric concept to simultaneously fulfil the requirements associated with metering and relaying applications is also addressed.

Abstract
A sensor for measurement of refractive index in oils was discussed. The sensor comprised a fiber based-device sensing head placed in a self-referenced fiber optic intensity sensor. The sensing head works on the principle of change of the refractive index of the medium that surrounds the unclad portion of multimode fiber. This results in different attenuation of the guided modes that propagate in the fiber. The injection current of the optical source was swept in frequency to obtain the transfer function.

Abstract
Two self-referenced intensity based optical fiber sensors supported on a Michelson sensing head configuration with and without optical feedback are described. Theoretical and experimental studies that demonstrate both sensors are discussed.

Abstract
We present a new sensor configuration based on the intrinsic bend sensitivity of Bragg gratings written in D-type fibres. This sensor can be embedded in any layer of a composite material to evaluate curvature in a way independent of axial strain or temperature. It can also be used to measure other parameters such as acceleration, angle or acoustic pressure.