Abstract
An optical fiber interferometer for measuring the d(33) coefficient of piezoelectric samples is described. Its configuration is based on the Mach-Zehnder interferometer, and a double incidence on the thin-film samples successfully suppresses the undesirable bending effect of the substrate. Detection of the small displacement is based on an active homodyne scheme. Results are reported for a bulk piezoelectric transducer (PZT) sample and a PZT thin-film incorporated in a microactuator. (C) 2002 American Institute of Physics.

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 simulation characterization with FEM was made, showing that the HiBi fibre was sensitive to different applied load angles. As such, the experimental data for transversal strain was assessed and the obtained sensibility values were in accordance with the simulation results. The collected data enable the complete characterization of the HiBi FBG, showing its capability to be used as a multiparameter sensor.

Abstract
A new scheme is presented for simultaneous measurement of strain and temperature using a sampled fibre Bragg grating based on a long period structure written using the electric are technique. The temperature and strain measurement resolutions are estimated to be +/-0.50degreesC/rootHz and +/-3.38 muepsilon/rootHz, respectively.

Abstract
We report the use of the electric arc technique to apodise Fibre Bragg Gratings (FBG). Electric arc discharges applied at the ends of the grating produce a smoothing of the refractive index modulation profile which reduces the side lobes at longer wavelengths. Using this technique, a FBG was apodised with a side lobe reduction of 17 dB.

Abstract
We present and demonstrate a 20 nm tunable L-band fiber ring laser. Tunability is achieved by curving a simple taper which controls the intra-cavity loss.