Simultaneous interrogation of multiple fiber bragg grating sensors using an arrayed waveguide grating filter fabricated in SOI platform

A novel fiber Bragg grating (FBG) interrogator is demonstrated based on an optimized arrayed waveguide grating (AWG) filter. The AWG response is optimized to achieve large crosstalk between the output channels, which allows simultaneous detection of multiple FBG peaks, using centroid signal processing techniques, without constraints on the minimum FBG peak spectral width. The measured interrogator resolution is 2.5 pm, and the total measurement range is 50 nm. The device is fabricated in a silicon-on-insulator platform and has a footprint of only 2.2 x 1.5 mm. A novel approach to minimize the polarization dependence of the device is proposed and experimentally demonstrated

ESSenTIAL : EPIXfab services specifically targeting (SME) industrial takeup of advanced silicon photonics

ePIXfab brings silicon photonics within reach of European small and medium sized enterprises, thereby building on its track record and its integration into Europractice. To this end, ePIXfab offers affordable access to standardized active and passive silicon photonic IC and packaging technology, a path from design to manufacturing and hands-on training. Based on a consortium of major research institutes with silicon photonics expertise, ePIXfab reaches out to European industry and supports them to evaluate silicon photonics in the context of concrete applications and markets. In order to ensure low-cost, quick access and scalability to manufacturing, the maturity of silicon photonic IC technology is enhanced by setting up a library of generic devices, a level of process and device benchmarking and a well maintained design flow. For the first time, devices in a standard package are offered to facilitate measurements. Training programs on the IC and packaging services are also offered, including hands-on training in making designs. Maturity, standardization and sustainability are driven by a steadily growing worldwide user base

N.M.R.-studie van 1,2,3-triazolen

KULeuven Campusbibliotheek Exacte Wetenschappen / UCL - Université Catholique de LouvainSIGLEBEBelgiu

A short and efficient synthesis of (R,R)-2-methylcyclopropanecarboxylic acid

We report herein a short and efficient synthesis of (RR)-2methyleyclopropanecarboxylic acid via a Horner-Wadsworth-Emmons reaction involving commercially available (S)-propylene oxide and triethylphosphonoacetate (TEPA). The TEPA/ base/propylene oxide stoichiometry was found critical to achieve high yields. We therefore studied the TEPA anion formation and stability using in situ IR spectroscopy. The reaction yield is strongly influenced by the counterion and solvent, whereas high diastereoselectivities are always obtained. Under the best experimental conditions (HexLi/MeTHF/150 degrees C), crude (RR)2-methylcyclopropanecarboxylic acid is obtained in 85-90% yield with > 98% trans selectivity

Spectroscopic characterization of 4-methylamphetamine: formaldehyde adduct formation hindered the identification by mass spectrometry

A powder was submitted to the author’s laboratory for analysis on the presence of illegal drugs. Based on the structure elucidation performed by nuclear nuclear magnetic resonance spectroscopy and analysis of the trimethylsilyl and trifluoroacetyl derivatives with gas chromatography mass spectrometry, the powder was found to contain the designer drugs 4-methylamphetamine, besides amphetamine and caffeine. The electron impact mass spectrum of 4-methylamphetamine obtained from the analysis of a methanolic sample solution showed a base ion of m/z 56 rather than the expected m/z 44, therefore no hit was found with an electron impact mass spectrum present in the mass spectral library and literature. The increase of 12 atomic mass units was explained by formaldehyde-adduct formation