Abstract
A sensing head for simultaneous measurement of temperature and strain is presented and analyzed. The proposed configuration is based on the combination of two Bragg gratings, written in different fibres and with different reflectivities, to form a single signature with a reflected step spectrum profile. By measuring the changes in the peak wavelength and spectral width of this signature, resolutions of 0.65 degreesC/rootHz and +/- 2.55 muepsilon/rootHz were achieved for temperature and strain measurements, respectively.

Abstract
An optical fiber sensor for the measurement of oxygen in gaseous environments, which is based on the quenching of the fluorescence of a ruthenium complex, is presented. The sensing chemistry is immobilized in a sol-gel based solid matrix that is coated on a tapered optical fiber probe. Oxygen measurement is performed both by phase and fluorescence intensity spectroscopy. Experimental results show that the fluorescence intensity and the lifetime depend both on oxygen and temperature. A scheme for simultaneous determination of the temperature and the oxygen concentration is proposed. Temperature measurement is performed using the excitation radiation and an absorption long pass filter. Preliminary results are presented which show a temperature measurement independent of oxygen and of optical power level.

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.