Abstract
An interferometric tip sensor based on the post-process of a special design double-cladding optical fiber is proposed. Due to the sensing head design, it is sensitive to environmental variations. In order to analyze this effect, the sensing head is subjected to temperature variations both in liquid and gas (at 1 atm). Comparing the two signals, it is possible to discriminate the contribution of the liquid refractive index variation with temperature. Not only the amplitude of the signal varies with the surrounding medium, but also the phase of the interferometric pattern alters. This is due to the presence of a thin diaphragm at the end face of the fiber structure turning the sensing head in a three wave interferometric device. An indirect measurement of the water refractive index is performed, by subjecting the sensing head to temperature variations in air and water. Even though the sensitivities obtained are lower than the ones reported in the literature, it should be highlighted that there is no core exposition of the fiber to the external medium. The sensor is easy to fabricate, robust, and reproducible.

Abstract
The recent burst of R&D activity in Plasmonics, associated with the possibility of materials nanostructuring which enables the access to metamaterials, has been strongly impacting many branches of optics such as imaging, data recording and sensing. This talk details the factors that turned the combination Plasmonics and Metamaterials a huge opportunity to optical sensing.© OSA 2014.

Abstract
A Fabry-Pérot microcavity tip sensor based on the post-process of a special design double-cladding optical fiber is proposed. The sensor is subjected to temperature variations in both air and water. © OSA 2013.

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
A Fabry-Perot microcavity tip sensor fabricated by post-processing of a special design double-cladding optical fiber is proposed. The produced fiber has a pure silica core, an outer cladding, and an inner silica cladding surrounding the core doped with phosphorous. When subjected to chemical etching post-processing, the whole ring region is removed and light is guided in the core region. The sensing head is created by splicing this fiber to single mode fiber and applying chemical etching to the fiber end. The core is forming a tip and it is thus surrounded by air. The Fabry-Perot microcavity tip sensor is subjected to temperature, and a sensitivity of 15.5 pm/degrees C is obtained.

Abstract
This work discusses remote fiber sensors enabled by optical amplification. Continuous wave numerical modeling based on the propagation of pumps and signal lasers coupled to optical fibers explores Raman amplification schemes to predict the sensor's behavior. Experimental analyses report the results to a temperature remote optical sensor with 50 km distance between the central unit and the sensor head. An electrical interrogation scheme is used due to their low cost and good time response. Different architectures in remote sensor systems are evaluated, where diffraction gratings are the sensor element. A validation of calculated results is performed by experimental analyses and, as an application, the noise generated by Raman amplification in the remote sensors systems is simulated applying such numerical modeling. The analyses of sensors systems based on diffraction gratings requires optical broadband sources to interrogate the optical sensor unit, mainly in long period gratings that shows a characteristic rejection band. Therefore, the sensor distance is limited to a few kilometers due to the attenuation in optical fibers. Additional attenuation is introduced by the sensor element. Hence, to extend the distance in the optical sensor system, the optical amplification system is needed to compensate the losses in the optical fibers. The Raman amplification technology was selected mainly due to the flexibility in the gain bandwidth. The modeling can be applied to sensor systems that monitor sites located at long distances, or in places that the access is restricted due to harsh environment conditions in such cases conventional sensors are relatively fast deteriorated.