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Surface plasmon resonance containing amorphous As2S3 film is proposed as a chemical sensor to highlight several liquid hydrocarbons. Method is label-free and is based on detection of small changes in the refractive index. As2S3 operates as plasmonic waveguide which confines the probing beam to the interface with liquid hydrocarbons. The method can easily distinguish hydrocarbons with very close refractive indices. The film thicknesses were optimized to obtain the best sensitivity and resolving power. Minimum reflectance of SPR less than 1 % was found for optimal calculated film thicknesses, the sensitivity to the refractive index changes being 2·10-5. [ABSTRACT FROM AUTHOR]

The high sensitivity of chalcogenide surface plasmon resonance (SPR) structures with chalcogenide films is fructified to elaborate the salinity sensor for the seawater. A four layers configuration was taken into consideration, comprising a BK7 prism, a gold thin film, a chalcogenide As2S3 film and the ambient medium, which is the ß-Galactosidase solution. The transfer matrix formalism was used in our study to determine the reflectances characterizing the plasmonic structure. The two polarization modes (TE and TM) were taken into consideration, in order to determine the best configuration that allows an optimal sensitivity. The structure used as optical sensor has a high sensitivity. A 0.05 % change in concentration causes an 18-arc seconds change in plasmonic resonance incident angle and it can be resolved. [ABSTRACT FROM AUTHOR]

The article presents a practical application of lasers, for reconstruction of the road transversal profiles in dynamic regime. The method uses a laser source and a video area scan camera placed at a determined distance behind the laser for the contactless measurement of the height above the pavement surface. The laser source projects a planar beam which is perpendicular on a road horizontal plane and oriented on its transversal direction to cover an entire road transversal section. The intersection of the planar beam with pavement surface represents the road profile. The main advantage of the proposed method is that it is cheaper than ultrasonic or laser sensors methods. [ABSTRACT FROM AUTHOR]

The proposed system provides fast geographic positioning of some objectives or of some of their components where these objectives are situated at great distances from the roadways (buildings, land markings) or they are inaccessible in a direct mode (dams, bridges, heaps of debris). The system includes a laboratory vehicle whose position angles and geographical coordinates are determined in real time using a GPS receiver for precise positioning that is supported by an inertial navigation system and an Internet connection to a national network of stations providing basic type Real Time Kinematic differential corrections, while the receiver antenna is located next to a camera on a platform disposed on the vehicle hood assembly lab camera with the lens pointed at one side vehicle under a fixed angle, accurately determined. The system assures an accurate geo-referencing of the off-road objective characteristics, an important problem for the infrastructure management at the level of public works administration. [ABSTRACT FROM AUTHOR]

Arrays of microlenses have been created on the surface of thin amorphous films of As2S3by localized photoexpansion induced by femtosecond laser pulses. The profile of a typical microlens has been mathematically described. Ray-tracing analysis has been performed to determine the focal points in the red and near-infrared spectrum of electromagnetic radiation. These lie at distances of 1.21 μm atλ = 650 nm and 1.33 μm atλ = 1.5 μm above the top of the microlens. It is suggested that the microlenses could be used in two-dimensional optoelectronic circuits or in fibre optics. [ABSTRACT FROM AUTHOR]