Abstract
Optical fiber sensors based on the phenomenon of plasmonic resonance can be interrogated applying different methods, the most common one being the spectral approach where the measurand information is derived from the reading of the wavelength resonance dip. In principle, a far better performance can be achieved considering the reading of the phase of the light at a specific wavelength located within the spectral plasmonic resonance. This approach is investigated in this work for fiber optic SPR sensors with overlays which are combinations of metallic and dielectric thin films, permitting not only to tune the wavelength of the SPR resonance but also the sensitivity associated with the phase interrogation of the sensors.

Abstract
We present a new method for coupling light to high-Q silica whispering gallery mode resonators (WGMs) that is based on long period fiber gratings (LPGs) written in silica fibers. An LPG allows selective excitation of high-order azimuthally symmetric cladding modes in a fiber. Coupling of these cladding modes to WGMs in silica resonators is possible when partial tapering of the fiber is also implemented in order to reduce the optical field size and increase its external evanescent portion. Importantly, the taper size is about one order of magnitude larger than that of a standard fiber taper coupler. The suggested approach is therefore much more robust and useful especially for practical applications. We demonstrate coupling to high-Q silica microspheres and microbubbles detecting the transmission dip at the fiber output when crossing a resonance. An additional feature of this approach is that by cascading LPGs with different periods, a wavelength selective addressing of different resonators along the same fiber is also possible. (C) 2014 Optical Society of America

Abstract
A review in fiber post-processing for sensing applications is presented. The review is divided in three parts. Tapers devices, chemical etching for Fabry-Perot cavities and focused ion beam (FIB) as post-processing applied in optical fibers are considered. The most recent results as sensing elements are shown. © 2014 OSA.

Abstract
The measurement of refractive index (RI) is an important tool for label free biosensing in biomedical applications [1,2]. In this work, a LPG based fiber optic interferometric probe is used for thrombin detection. The aptamer raised against the thrombin was immobilized through an electrostatic immobilization method, using poly-L-lysine as cationic polymer. The functionalized probe was characterized and tested against thrombin. The system was validated with the detection of thrombin using an aptamer based probe (5'-[ amine]GGTTGGTGTGGTTGG-3') as a model system for protein detection. The shift corresponding to the affinity-assay between TBA and the thrombin was of about 56 pm. A differential readout interferometer based on a white light Mach-Zehnder configuration, with pseudo-heterodyne phase modulation is described. The system can be used to interrogate two similar LPGs based interferometers in a differential scheme. Considering the configuration where both devices are functionalized being one active (sensor) and the other one passive ( reference) it is possible to accurately measure the behavior of the analyte of interest independent of non-specific binding events, bulk refractive index changes and temperature. Signal processing with low cost digital instrumentation developed in Labview environment allows a detectable change in refractive index of Delta n approximate to 2x10(6) [3]. Coupling the sensing probe together with a passively functionalized reference probe in a differential system will enable pseudo-heterodyne interrogation and extremely sensitive phase detection of biological species.

Abstract
Despite the socio-economic importance of mining in Douro Coalfield, the coal exploitation and utilization originated impacts on the environment. From these stands out the S. Pedro da Cova waste pile which is self-burning since 2005. The potential environmental impacts associated with this coal waste pile include: air pollution caused by the gaseous emissions and dispersion of solid particles; pollution of soils, surface and groundwater caused by mobilization of solid particles, leaching of hazardous elements, dissolution of neoformed and deposition of solid particles; landslides and mass movements also caused the weathering agents, and deterioration of vegetation that may also be due to the acid drainage. The main objective of this work is the combustion temperature monitoring in S. Pedro da Cova waste pile using the infrared thermography technique. The acquired results during the temperature monitoring campaigns allow the study of the dynamics and evolutionary scenarios of the self-burning process in the coal waste pile, contributing to a precise definition of the risks to the environment and human health. © 2014, LNEG – Laboratório Nacional de Geologia e Energia IP.

Abstract
An optical fiber sensor based on arrays of silica microspheres is proposed. The microspheres are produced separately using a fusion splicer and then also connected in series by fusion splicing. Three different sensors are presented, differing by the number of microspheres. Due to the geometry of the structures, different behaviors are obtained in strain measurements. Sensors with an odd number of microspheres are more sensitive to strain than the ones with an even number of microspheres. Additionally, the sensing heads are subjected to temperature where a sensitivity of 20.3 pm/degrees C is obtained in a range of 200 degrees C. (C) 2014 Optical Society of America