Abstract
The objective of this work was to study, understand and evaluate the effect of different geometric configurations of carbon plies, in the reflected wavelength spectrum of Bragg grating structure together with the effect of the recoating process of the sensor. The different possibilities depend upon the orientation and location of the optical fibre relative to the composite reinforcement orientation and the presence/absence of recoating. The material stacking sequence and the cure conditions were are also studied and the influence of the different possibilities was considered. The optical spectrum response obtained by the interaction of the optical fibre with the host material is shown.

Abstract
A smart laminated composite with a simple geometry was produced with embedded fiber Bragg grating sensors. The smart structure is composed of two Bragg gratings located in regions of different thicknesses of the laminated composite. Although one of the Bragg gratings is embedded between two layers, the other is embedded in jour layers. When the strain is applied to the smart composite, different response is obtained. Because of this characteristic it is possible to discriminate strain and temperature using a traditional matrix method. To reduce the inherent error, an artificial neural network approach is proposed that will improve the strain and temperature measurement discrimination when using this new configuration. These instrumented carbon fiber laminates can be used for monitoring of reinforcement and protection of structures. (C) 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 235-239, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23990

Abstract
It is reported a LPG dynamic interrogation technique based on the modulation of fibre Bragg gratings located in the readout unit that permits to attenuate the effect of the 1/f noise of the electronics in the resolution of the LPG-based sensing head. The concept is tested to detect variations of the external refractive index and a resolution of 2.0x10 (4) NIR was achieved without system optimization. Additionally, the effect in the sensor resolution when introducing Erbium and Raman optical amplification is experimentally investigated.

Abstract
This presentation gives a review of the main concepts behind fibre optic sensing networks. Some important application areas are mentioned, such as the monitoring of oil fields, of large Civil Engineering structures, as well as of natural environments. Then, it will be addressed the potential relevance of this technology in domains of increasingly social importance, such as Health and Elderly Care, particularly in the development of Personal Health Systems.

Abstract
It is reported a long-period grating (LPG) dynamic interrogation technique based on the modulation of fiber Bragg gratings located in the readout unit of the system. It permits to attenuate the effect of the 1/f noise of the electronics in the resolution of the LPG-based sensing head. The concept is tested to detect variations of the external refractive index and a resolution of 2.0 x 10(-4) NIR was achieved without system optimization. Additionally, the effect in the sensor resolution when introducing Erbium and Raman optical amplification is experimentally investigated.

Abstract
In recent years the need to monitor different parameters has led to the development of several architectures able to make real time, un-attended measurements. Particularly in regard to environmental issues, it is very important that the equipment and measuring systems be small and light to avoid maximum interference of the ecosystems Studied. In this context, optical fibre sensors have become extremely attractive for use in natural environments to monitor different parameters of biological interest, due to their intrinsic small weight and size and low reactivity to chemical and biological parameters. In this paper we present an innovative and technologically advanced system for the simultaneous measurement of temperature and salinity based on optical fibre Bragg grating sensors and on an optical sensing cable especially designed for large-scale and distributed or quasi-distributed measurements. A prototype of this optical cable was installed in the Mira Channel at Ria de Aveiro, Portugal. Temperature variation during three weeks from 4 to 23 June 2002 is investigated and presented here.