Modeling of gold circular sub-wavelength apertures on a fiber endface for refractive index sensing

A finite-difference time-domain approach was used to investigate the excitation of surface plasmons of the circular sub-wavelength apertures on an optical fiber endface. This phenomenon provided the basis of a sensitive liquid refractive index sensor. The proposed sensor is compact and has the potential to be used in biomedical applications, having a sensitivity of (373 ± 16) nm per refractive index unit (RIU) as found through the variation of a reflection minimum with the wavelength

How to compare arc-annotated sequences: The alignment hierarchy

International audienceWe describe a new unifying framework to express comparison of arc-annotated sequences, which we call alignment of arc-annotated sequences. We first prove that this framework encompasses main existing models, which allows us to deduce complexity results for several cases from the literature. We also show that this framework gives rise to new relevant problems that have not been studied yet. We provide a thorough analysis of these novel cases by proposing two polynomial time algorithms and an NP-completeness proof. This leads to an almost exhaustive study of alignment of arc-annotated sequences

Targeted Automatic Integer Overflow Discovery Using Goal-Directed Conditional Branch Enforcement

We present a new technique and system, DIODE, for auto- matically generating inputs that trigger overflows at memory allocation sites. DIODE is designed to identify relevant sanity checks that inputs must satisfy to trigger overflows at target memory allocation sites, then generate inputs that satisfy these sanity checks to successfully trigger the overflow. DIODE works with off-the-shelf, production x86 binaries. Our results show that, for our benchmark set of applications, and for every target memory allocation site exercised by our seed inputs (which the applications process correctly with no overflows), either 1) DIODE is able to generate an input that triggers an overflow at that site or 2) there is no input that would trigger an overflow for the observed target expression at that site.United States. Defense Advanced Research Projects Agency (Grant FA8650-11-C-7192

Multiplexing of fibre optic reflective sensors using Bragg gratings

A multiplexing method for a fibre optic refractive index sensor is presented that is potentially capable of simultaneous measurement from many sensor heads, each of which is a cleaved fibre end. Associated with each sensor head are two fibre couplers and an optical fibre Bragg grating having a unique Bragg wavelength. Experimental characterization of the sensor network through the use of liquids with different refractive indices showed excellent agreement with numerical analysis and a precision of 0.002 RIU and resolution of the order of 10−3 RIU

Multipoint refractive index sensor for liquids based on optical fiber Bragg-gratings

Proceedings of SPIE (International Society for Optical Engineering) volume 7503