Abstract
Fiber Bragg grating sensors were attached to the surface of a rechargeable lithium battery in order to monitor its thermal and strain fluctuations through charge and different discharge C rates. During the discharge process above 1C, it were observed, a temperature and strain fluctuations of a 4.12 +/- 0.67 degrees C and 24.64 +/- 6.02 mu epsilon, respectively. In the regular charge process, a temperature and strain variation of 1.03 +/- 0.67 degrees C and 15.86 +/- 6.02 mu epsilon, were detected.

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
In this work, a hybrid Fabry-Perot interferometer based on a novel four-bridge microstructured fiber is presented and characterized. The characterization of this cavity is performed in the L-band using two different instruments: an optical spectrum analyzer and an optical backscatter reflectometer. The Fabry-Perot output signal presents linear variation with temperature changes (sensitivity 9.8-11.9 pm/°C), variation with the polarization states of light and high stability. © 2014 SPIE.

Abstract
In this work a strain sensor based on a suspended core fiber is proposed. The sensor comprises a suspended core PCF between SMFs and is based on the multimode interference generated in these transitions. A strain sensitivity study for different sensing heads and stage separation lengths was carried out showing a sensitivity of -2.42 pm/mu epsilon for the best case. Also the sensing head was tested for curvature and temperature, showing in the first case that it is insensitive to curvature effects, and secondly, that for small sensor lengths it was insensitive to temperature variations.

Abstract
A multimodal interferometer based on a new microstructured fiber tip is proposed for detection of the evaporation process of acetone. The new geometry consists of a capillary tube in which an offset Ge-doped core is fused and spliced at the end of a single-mode fiber. The fiber tip sensor structure was immersed in liquid acetone and the evaporation process of acetone was monitored in real time. Due to the refractive index variation of the external medium with increasing temperature, a short detection time of similar to 1 s was achieved. (C) 2014 Society of Photo-Optical Instrumentation Engineers (SPIE)

Abstract
Surface Plasmon Resonance (SPR) is the base for some of the most sensitive label free optical fiber biosensors. However, most solutions presented to date require the use of fragile fiber optic structure such as adiabatic tapers or side polished fibers. On the other hand, long-period fiber gratings (LPG) present themselves as an interesting solution to attain an evanescent wave refractive index sensor platform while preserving the optical fiber integrity. The combination of these two approaches constitute a powerful platform that can potentially reach the highest sensitivities as it was recently demonstrated by detailed theoretical study [1, 2]. In this work, a LPG-SPR platform is explored in different configurations (metal coating between two LPG - symmetric and asymmetric) operating in the telecom band (around 1550 nm). For this purpose LPGs with period of 396 mu m are combined with tailor made metallic thin films. In particular, the sensing regions were coated with 2 nm of chromium to improve the adhesion to the fiber and 16 nm of gold followed by a 100 nm thick layer of TiO2 dielectric material strategically chosen to attain plasmon resonance in the desired wavelength range. The obtained refractometric platforms were then validated as a biosensor. For this purpose the detection of thrombin using an aptamer based probe was used as a model system for protein detection. The surface of the sensing fibers were cleaned with isopropanol and dried with N-2 and then the aminated thrombin aptamer (5'-[NH2]-GGTTGGTGTGGTTGG-3') was immobilized by physisorption using Poly-L-Lysine (PLL) as cationic polymer. Preliminary results indicate the viability of the LPFG-SPR-APTAMER as a flexible platforms point of care diagnostic biosensors.