Telecom Italia S.p.a.

Cselt-centro Studi E Laboratori Telecomunicazioni S.p.a.

Diego Roccato

Renato Caponi

Riccardo Calvani

Giorgio Grego

Francesco Cisternino

Marco Schiano

Marcello Potenza

Claudio Naddeo

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. The optical detection operation further includes providing at least one actuation hologram corresponding to the at least one actuator being placed at a specified position with respect to the virtual image of the input device, illuminating the at least one actuator with a beam, in order to obtain scattering into a corresponding object beam interacting with one actuation hologram through the corresponding object beam; generating a respective actuation detection beam through the interaction; and detecting the respective actuation detection beam to issue the command signal.

Inputting information using holographic techniques

The present invention relates to a new model for interpreting interferometric measurements, able to lead to a new method, system () and device () for measuring the PMD (Polarisation Mode Dispersion) of an optical fibre (). The model, which is based on the theory of propagation of the optical signal as can be determined according to the socalled Prindpal States of Polarisation (PSPs) of the fibre, leads to a new interpretation of the interferogram generated with the interferometric measurements and is characterized in that it identifies in said interferogram a central peak and two side lobes. Thanks to this new model, it is possible to determine the PMD of the fibre based on the information content associated to at least one of the two side lobes identified in the interferogram.

Method and apparatus for measuring the polarization mode dispersion of an optical fiber

A train of transform-limited optical pulses with wavelength close to the zero-dispersion wavelength of the fiber and high and variable peak power, such as to give rise to self-phase modulation, is sent into a fiber. The spectral broadening of the signal exiting the fiber is measured for a number of values of the peak power of the pulses and the nonlinear refractive index is obtained from the angular coefficient of the straight line representing spectral broadening versus peak power.

Method of and device for measuring the nonlinear refractive index in a

Ultra-short transform-limited optical pulses, to be utilized for high bit-rate transmission systems, are obtained through direct modulation of a semiconductor laser by pulses of such duration as to excite only the first peak of the relaxation oscillations of the cavity of laser, tuned to such a length that the pulse portions that overlap inside the cavity interfere constructively. The pulses emitted by the laser then pass upon a fiber with high negative dispersion to compensate for the phase effect due to the chirp.

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Turin, Italy

Diego Roccato