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

Abstract

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 have studied the effect of gamma radiation on Long Period Fiber Grating (LPFG) temperature sensors fabricated in a pure-silica fiber, using the arc discharge technique. The temperature sensitivity of the LPFGs remains unchanged by the irradiation.

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.