Rapid, reliable and low cost techniques to fabricate biosensors is a hot topic nowadays. Here, we present a BIO-grating fabricated by means of local, selective denaturing of molecules using UV radiation. A phase-mask is used to generate an interferometric pattern of 1420 nm pitch that, when illuminating a biolayer of BSA molecules lead to its periodic deactivation. After the biorecognition of the specific antibody, aBSA, a BIO-grating is generated due to the height difference between the protein, and the complex protein + antibody. We present the optimization of the fabrication of the BIO- gratings and their AFM characterization. Also, the biosensor performance in terms of limit of detection and limit of quantification will be presented.

The development or the improvement of production processes are necessary aspects, in order to enhance the quality and efficiency in optical manufacturing. This paper presents an approach to manufacture fine grinding tools in a very flexible and efficient way. A new filament composed of polyamide, ZrO2 particles and diamond grains is developed and used in an additive manufacturing process for tool fabrication. The resulting tools are successfully applied in an ultra-fine grinding process on fused silica samples.

We report experimental results of a frequency shifted digital holography setup for spatially resolved vibrometry. A spatially homogeneous artificial phase modulation is used as a reference to correct for speckle noise. Furthermore, when superimposed upon the object vibration with slightly different frequency, the resulting beat can be evaluated. The beat frequency is invariant under relative motion between the object and interferometer, providing robustness in presence of parasitic low frequency vibrations. In addition, the ‘working point’ is raised out of the noise floor, providing the opportunity to enhance the sensitivity at small vibration displacements. The method is demonstrated by measurements on a vibrating clarinet reed.

Long-chain hydrocarbons, petroleum and diesel, have long been used as source of energy for locomotives. Unlike it’s short-chain counterpart petroleum, diesel fuel is considered dirtier due to black soot particulates it emits that poses greater health hazard. Here, we attempt to measure the absorbance spectra of premium diesel fuels, neat and adulterated, using terahertz (THz) frequency domain spectroscopy to determine the level of impurities that can further exacerbate its emission. Two broad absorption peaks at 6.42 THz and 7.75 THz as well as narrow peaks at 13.07 THz, 13.88 THz, and in the range of 16-17 THz, characterized the premium diesel. These spectral features are well identifiable in the adulterated samples but their intensities vary depending on the type of impurities. Decrease in the absorbance is observed with water contaminant, increase in isopropanol, while sulfur and methanol contaminants did not influence the absorbance spectra. This technique demonstrates initial but promising results in probing adulteration in petrochemical products.

Stable isotopic compositions of carbon and oxygen (δ13C et δ18O) measured from carbonates are used in geology to reconstruct paleotemperatures and to learn about the evolution of the biogeochemical carbon cycle. The standard technique used since the middle of the XXth century to measure isotopic ratios is based on a wet chemical protocol which CO2 is evolved from the acidic dissolution of carbonates followed by quantification of CO2 molecules isotopologues using mass spectrometer or infrared spectroscopy. This is a lengthy protocol that necessitate to manipulate acid solution and numerous gas phases purification steps before isotopic measurements. Our new preparation technique aims at offering an alternative to the wet chemical preparation of the samples by using a direct extraction of CO2 via a laser-induced calcination process. In addition to save time, this method allows to consider spatially resolved and automated in-situ measurements and does not necessitate further purification steps of the evolved CO2 during calcination.