Abstract: A method for inputting commands to a holographic input system, includes the steps of generating a virtual image of an input device by illuminating a hologram of the input device by means of a corresponding reference beam, the hologram being prerecorded on a holographic support; optically detecting a position of at least one actuator for operating the input device with respect to the virtual image of the input device; and issuing at least one command signal corresponding to the position of that at least one actuator as optically detected.

Abstract: A method and an apparatus for reading passive tags affixed to objects to be identified and tracked by a radio frequency identification system are disclosed. An interrogating station sends radio-frequency inquiry signals toward the passive tags through an antenna array and receives the response signals from the tags through the same array. Electronic circuitry for processing such response signals has a phase conjugator submitting each received signal to phase conjugation, and the phase-conjugated signals are back transmitted to the passive tags. Retrodirectivity of the antenna array obtained through the phase conjugation allows a precise object identification and tracking also at relatively long distances.

Abstract: A method for inputting commands to a holographic input system, includes the steps of generating a virtual image of an input device by illuminating a hologram of the input device by means of a corresponding reference beam, the hologram being prerecorded on a holographic support; optically detecting a position of at least one actuator for operating the input device with respect to the virtual image of the input device; and issuing at least one command signal corresponding to the position of that at least one actuator as optically detected.

Abstract: A method and an apparatus for reading passive tags affixed to objects to be identified and tracked by a radio frequency identification system are disclosed. An interrogating station sends radio-frequency inquiry signals toward the passive tags through an antenna array and receives the response signals from the tags through the same array. Electronic circuitry for processing such response signals has a phase conjugator submitting each received signal to phase conjugation, and the phase-conjugated signals are back transmitted to the passive tags. Retrodirectivity of the antenna array obtained through the phase conjugation allows a precise object identification and tracking also at relatively long distances.

Abstract: A controlled area (A) is configured as a telecommunications cellular system location area, connection of cellular system mobile terminals (T) to such location area (A) is checked. A detected connection indicates that the bearer of the terminal (T) accessed the controlled area, which information can thus be used both to prevent unauthorized access and to certify and document authorized access also by interrogation through the system. The fact that terminal (T) has been kept switched on inside the controlled area despite this being interdicted can also be detected and such behavior can be debited to the terminal (T) involved and/or the terminal can be inhibited by means of temporary deactivation of the terminal (T).

Abstract: The present invention relates to a portable apparatus for the vision of images comprising a supporting structure (11) to be applied on a user's head substantially in the form of eyeglasses, a display device (13a, 13b) fitted on said structure having a display surface (51-58) on which spatial distributions of light emissions arc generated and a control unit (30) capable of driving the display device (13a, 13b) in order to generate on the display surface (51-58), positioned before the eye, centered on its optical axis at a distance substantially equal to the focal distance of the cornea-lens system, a spatial distribution of light emissions, substantially corresponding to the Fourier transform of the image to be made visible.

Abstract: A mobile communication network (N) comprises at least one base transceiver station (BTS) configured to communicate with mobile terminals (T) connected to a corresponding coverage cell. The possibility of communication, which is obtained by means of first communication channels (C), is integrated with the implementation of at least one second communication channel (C′) of the Bluetooth® type. According to the arrangement, said at least one second Bluetooth communication channel (C′) can permit the communication between said base transceiver station (BTS) and said mobile terminals (T) even if none of said first communication channels (C) is available. Preferential application is in the context of shopping centres, airports, railway stations, stadiums, bus stops, underground train stations, etc., and in general in situations characterised by high possible variations in the traffic level depending on time.

Abstract: A method for transmitting signals, and digital signals in particular, from a given point such as a base station (BS) to a terminal such as a mobile communications network terminal (T) envisages that said terminal (T) generates pulse signals at determined instants. The base station (BS) detects the received waveforms, which have been altered as a result of phenomena such as multipath propagation, for example. The waveforms thus detected are subjected to phase conjugation, e.g., in the form of time reversal. Transmission form the base station (BS) to the terminal (T) takes place using waveforms corresponding to the phase conjugated waveforms thus obtained. In this way, a waveform corresponding to that of the aforesaid pulse signals can be reconstituted at terminal (T).

Abstract: Controlled area (A) is configured as a telecommunications cellular system location area, by checking connection of cellular system mobile terminals (T) to such location area (A). Connection corresponds to terminal (T) bearer access to the controlled area and can thus be used both to prevent unauthorized access and to certify and document authorized access also by interrogation through the system. The fact that terminal (T) has been kept switched on inside the controlled area despite denial can also be detected and such behavior debited to the terminal (T) involve and/or inhibited by means of temporary denial of the terminal (T)'s activation.

Abstract: To manufacture polarization-maintaining optical fibers, a fiber is directly and continuously irradiated with at least one beam of UV radiation during drawing and before application of external coatings.

Abstract: To determine the polymerization profile of a layer of polymeric material, particular a coating of an optical waveguide, a source sends a light radiation towards the layer under test at different angles of incidence, and both the portion of radiation reflected by the layer and the portion transmitted by the layer are converted into electrical signals. The electrical signals are supplied to devices for measuring their intensity, and a processing system processes the intensity values to obtain a value of the refractive index at a different depth inside the layer and to obtain the degree of polymerization at each depth by comparison with the values of the refractive index of a precursor of the polymer and of the fully polymerized material.

Abstract: A method and device are provided for measuring the viscoelastic characteristics of polymeric coatings of optical fibers directed on a coated fiber. The ends of the fiber are inserted into a pair of clamps which are shaped in such a way as to hold the coating without tearing it and to allow it to slide longitudinally over the fiber. The clamps impart a relative oscillating motion to the coating creating a longitudinal tensile stress of periodically varying intensity. The clamps and their support are part of a rheometer which measures the opposing stress and processes the stress data to give the desired characteristics.

Abstract: The radiation to be analyzed is sent onto an interference filter which selects different portions of the radiation spectrum in correspondence with different incidence angles. The intensity values of the radiation outgoing from the element are stored by a measuring and data processing unit which processes such values with the transfer function of the element to obtain the information on the spectrum.

Abstract: An optical spectroscopy system, wherein a pulse of a radiation to be analyzed is sent to a diffractive element presenting high temporal chromatic dispersion, and information relevant to the radiation spectrum is obtained from pulse broadening in the time domain.

Abstract: The system uses a monochromatic radiation source (1) and an acousto-optic modulator (2), which acts as a Bragg modulator and is driven by a frequency which is caused to periodically vary. The modulator emits a first beam having the same wavelength as the source and a second beam, whose wavelength and emission direction vary with the modulating frequency and which is collimated. For measuring angular displacements, the collimated beam is recombined with the first beam after traversing a plate (5) with parallel and plane faces integral for the rotation with a moving device, and a photodetector (12) generates a beat signal whose frequency depends on the angular position of the plate (5). For measuring linear displacements, the two beams are directly sent onto a detector (12) integral with the moving device.

Abstract: A device for the correlation between optical beams having spatially modulated intensities has an active glass window, which on one side is illuminated at the same time by a reading and a pumping beam through one or a plurality of semitransparent mirrors. The reading beam has radiations with a wavelength equal to that of a transition between an intermediate and fundamental energy level. The pump beam has radiations with a wavelength corresponding to the energy of the highest power level of the material forming the active glass, obtaining on the other side of the window a light beam representing the correlation betwen the pumping and reading beams.

Abstract: An electrooptic deflector composed of a plate made of a material with a refractive index which can be modified by the application of an electrical field, whereinto a collimated optical beam can be injected in direction parallel to the electrodes deposited on a plate face. Said electrodes are parallel to one another, equally-spaced and separately connected to voltage sources apt to increase the refractive index in the material passing from an electrode to the next. The emerging optical beam is deflected in the direction wherein the refractive index increases.

Abstract: The method of measuring viscosity of a glass body, such as an optical preform related to at least its softening temperature, exploits the scattering effects the body introduces into a substantially monochromatic radiation passing through it; more particularly, the width of the spectral line due to Brillouin scattering is measured. The temperature of the body can also be determined by measuring the width of the line generated by Rayleigh scattering. The method is of particular interest for measurements on glasses.

Abstract: The distributed temperature sensor employs an optical fiber as sensing element located in an ambient or near a body of which the temperature is to be monitored or measured. A source of light pulses sends into the fiber, pulses of predetermined duration. The backscattered radiation is collected for each pulse and the frequency spectrum variations in the backscattered radiation with respect to the incident radiation are analyzed. A computer obtains the temperature from said variations. The source and the spectrum variation analyzer are part of an optical time domain reflectometer which allows the temperature information to be associated with the information on the position of the backscattering point along the fiber.

Abstract: A static interferometric ellipsometer, wherein a source (3) generates a coherent light-beam with two monochromatic radiations at slightly different frequencies. A first photodetector (6) generates a first beat between the two radiations, to be used as reference. A second photodetector (9) generates a second beat between the two radiations, after they have been polarized in perpendicular planes and separated so that one of them is reflected onto the photodetector (9) by the sample under test (1,2). A measuring and computing system (11) determines the optical properties of said sample starting from the intensity of the second beat and from the relative phase between the two beats.