Abstract
In this paper an optofluidic chip for simultaneous determination of refractive index and acquisition of absorption or fluorescent spectra is described. The system comprises a microfluidic channel with multiple inlet/outlet for sample handling and a dual fiber optic probe, standing face to face across the channel, for the optical measurements. An FBG based Fabry Perot cavity, and a Braggmeter, allow for interferometric measurement of the refractive index while external illumination and a multimode fiber enable acquisition of the absorption/fluorescence spectra with a CCD spectrometer. Preliminary results showing the viability of simultaneous measurement are obtained from the characterization of mixed samples with distinct refractive index and dye concentrations.

Abstract
In this work a magnetic field sensor based on an FBG coated with a thin film of Terfenol-D is presented. The sensor was tested with two optical interrogation systems: one, a scanning laser system with a 1 pm resolution, and the other a differential white light interferometer (WLI). The results obtained in the magnetic field range of 20 mT to 100 mT, show the possibility of increasing the magnetic field measurement resolution, with temperature fluctuations invariance, by a factor of 4.5 when using the WLI system.

Abstract
A high-birefringent fiber (HBF) was tapered as adiabatic in sequence steps by utilizing a CO2 laser and its birefringence was measured in fiber loop mirror (FLM) setup. The birefringence of tapered section and total sensor was obtained to be -8.02x10(-2), and 2.46x10(-4), respectively. Then, refractive index (RI) sensitivity increased and temperature sensitivity of the tapered Hi-Bi fiber (THBF) decreased. The sensitivity of the proposed FLM interferometer for RI changes in the range from 1.3380 to 1.3470 was measured to be 389.85 nm/RIU. The temperature sensitivity in the range from 50 degrees C to 90 degrees C was measured to be -1.19nm/degrees C.

Abstract
In this work, fiber in-line Mach-Zehnder Interferometer (MZI) based on triangular-shape suspended core fibers (SCFs) is investigated. The sensitivity of the sensing head was determined for pressure and temperature, respectively. The sensitivities are 0.4 pm/psi and 13 pm/psi for longitudinal and radial pressure, respectively. The sensing head was also subjected to temperature and presented very low sensitivity.

Abstract
A brief review on biconical tapered fiber sensors for biosensing applications is presented. A variety of configurations and formats of this sensor have been devised for label free biosensing based on measuring small refractive index changes. The biconical nonadiabatic tapered optical fiber offers a number of favorable properties for optical sensing, which have been exploited in several biosensing applications, including cell, protein, and DNA sensors. The types of these sensors present a low-cost fiber biosensor featuring a miniature sensing probe, label-free direct detection, and high sensitivity. © The Author(s) 2012.

Abstract
A system to interrogate optical fiber interferometric sensors with digital control is presented. The system is based on a receiving white light Mach-Zehnder interferometer and is capable of operating with four distinct synthetic and pseudo-heterodyne signal detection schemes. A differential phase detection scheme was implemented and system performance with the different processing schemes was compared using fiber Bragg grating based Fabry-Perot cavity strain sensors. With a lock-in time constant of 1 s, most digital techniques were able to nearly match the performance of a standard hardware system, demonstrating the feasibility of low-cost high-resolution interferometric systems operated with virtual instrumentation.