Abstract: A method is described for the characterization of atmospheric particles by means of a lidar device. The method provides to send a laser pulse in the atmosphere, a part of which is directly backscattered by the particles in the atmosphere. A reflecting optical device is provided, that is positioned at a predetermined distance d from the lidar device, whereby a part of the laser pulse that directly reaches the reflecting device is backreflected and is later backscattered by the particles in the atmosphere thus generating a counterpropagating backscattering signal directed towards the reflecting device, which signal reaches the reflecting device and is backreflected towards the lidar device. The lidar device detects the direct backscattering and counterpropagating signals. The optical characteristics of the particles are determined on the basis of the direct backscattering signal and the counterpropagating backscattering signal.

Abstract: A photovoltaic device optical system for enhanced light harvesting with a transparent layer of dielectric material having on one side an array of micro-lenses and on the opposite side a metal reflective film with an array of openings. The micro-lenses focus direct sunlight impinging thereon through the openings, to separate direct sunlight and diffuse sunlight. The photovoltaic device has a first photovoltaic cell system for the exploitation of the direct sunlight located in the opposite hemi-space of the micro-lenses array with respect to the plane of the openings array and a second photovoltaic cell system for the exploitation of diffuse sunlight, located in the same hemi-space containing the micro-lenses array with respect to the plane of the openings array.

Abstract: A method is described for the characterization of atmospheric particles by means of a lidar device. The method provides to send a laser pulse in the atmosphere, a part of which is directly backscattered by the particles in the atmosphere. A reflecting optical device is provided, that is positioned at a predetermined distance d from the lidar device, whereby a part of the laser pulse that directly reaches the reflecting device is backreflected and is later backscattered by the particles in the atmosphere thus generating a counterpropagating backscattering signal directed towards the reflecting device, which signal reaches the reflecting device and is backreflected towards the lidar device. The lidar device detects the direct backscattering and counterpropagating signals. The optical characteristics of the particles are determined on the basis of the direct backscattering signal and the counterpropagating backscattering signal.

Abstract: A radiometer for measuring the total effective UV radiance of the type comprising, in an optical pathway sequence, a diffuser, an interference filter and a detector. Said interference filter comprises a plurality of alternating layers of magnesium fluoride and zirconium oxide, where the diffuser/interference filter/detector system has a spectral response equivalent to the erythema action curve CIE.

Abstract: An apparatus for determining the internal outline of a duct or cavity, comprises light-emitting means (71) suitable for generating a collimated light beam, an elongate probe element (51; 51?; 51?) suitable for being introduced into the duct and for guiding the collimated beam along a predetermined propagation direction, reflector means (52) supported by the probe element (51; 51?; 51?) and suitable for deflecting the collimated beam so as to illuminate the internal wall of the duct, and for deflecting the reflected or diffused light coming from an illuminated point (P) of the internal wall so as to guide it along the probe element (51; 51?; 51?), and detection means (76) suitable for receiving an image of the illuminated point (P), which image is correlated with the optical distance of the point from the detection means (76), and for providing a corresponding electrical signal. The image is formed by the light guided by the receiving reflector means (52).

Abstract: A method is for forming three-dimensional micro- and nanostructures, based on the structuring of a body of material by a mould having an impression area which reproduces the three-dimensional structure in negative form. This method includes providing a mould having a substrate of a material which can undergo isotropic chemical etching, in which the impression area is to be formed. An etching pattern is defined on (in) the substrate, having etching areas having zero-, uni- or bidimensional extension, which can be reached by an etching agent. A process of isotropic chemical etching of the substrate from the etching areas is carried out for a corresponding predetermined time, so as to produce cavities which in combination make up the impression area. The method is advantageously used in the fabrication of sets of microlenses with a convex three-dimensional structure, of the refractive or hybrid refractive/diffractive type, for forming images on different focal planes.

Abstract: A semiconductor laser comprises an active region (12) which, in response to a pumping energy applied thereto, can produce a stimulated emission of radiation with a central wavelength (?) in the far infrared region, and a confinement region (16, 18, 22) suitable for confining the radiation in the active region (12), and comprising at least one interface (16a, 16b, 22a) between adjacent layers that is capable of supporting surface plasmon modes generated by an interaction of the interface with the radiation. The confinement region (16, 18, 22) comprises a wave-guide layer (16) which is delimited on opposite sides by a first interface and by a second interface (16a, 16b).

Abstract: A method of manufacturing superconducting wires based on MgB2 is described and includes the steps of: production of a cylindrical wire comprising an MgB2 core surrounded by a metal covering, in which the core has a lattice structure formed by grains of the compound MgB2; rolling of the wire to produce a conductor in tape form; and subsequent heat treatment by heating to a temperature of between 800° C. to 870° C. This last step helps to increase the connection between the MgB2 grains whilst retaining the structural defects produced in the rolling step, thus producing a superconducting wire with greater current-transport capacity.

Abstract: A method of measuring properties of particles immersed in a body (B), comprising the performing of a series of instantaneous acquisitions by illumination of the body with a temporally coherent light beam (152) of predetermined width D and predetermined wavelength ? such as to generate scattered radiation (155) by scattering interaction of the light beam with the particles, and the detection of a plurality of values of the intensity of the total radiation (155, 156 155?,156?) coming from the body at a plurality of points simultaneously, the points being at a distance z from the body such that the points can receive the scattered radiation (155, 155?) which comes from substantially all of the directions in which the particles are capable of scattering, and that each of the points receives the scattered radiation (155, 155?) of a large number of particles, and processing (100) of the series of acquisitions in a manner such as to determine the properties of the particles.

Abstract: Optical system for detecting the concentration of combustion products operating in situ and at high temperature based on measurement of the optical absorption of a gaseous mixture of combustion products through a photodetecting sensor based on gallium nitride (GaN), aluminium nitride (AlN), indium nitride (InN) and corresponding alloys. The operating temperature of the sensor preferably lies between 500° C. and 700° C., but the resistance of the active material permits use at even higher temperatures. This system can be used to measure the concentration of chemical species present in combustion products directly at their outlet, where the high operating temperature makes it possible to avoid fouling of the sensor caused by carbonaceous and non-carbonaceous deposits. The rate of response of the system is less than or equal to 1 millisecond and makes it possible to adjust the parameters of an associated combustion process control system in real time.

Abstract: A method is described for the identification of a party authorised to have the benefit of a service delivered by a provider party via a telematics network, in which the provider party and each user party are connected to the network by means of a respective electronic communications and processing system (S, C), and the provider party requests a temporary password (PWD) identifying the user party to allow access to the services delivered.

Abstract: A device for aligning a trapped microscopic particle along a selected axis of alignment, comprises

Abstract: A silicon-based light-emitting device is described and comprises an active region, an excitation system which can bring about a condition of inversion of the population of carriers within the active region, and semi-reflective elements which can define a resonant optical structure in which the active region is inserted so as to bring about stimulated emission of coherent light,