Pirelli Cavi S.p.a.

Cisco Technology, Inc.

Societa Cavi Pirelli S.p.a.

Google Inc.

Pirelli Cavi E Sistemi S.p.a.

Cisco Photonics Italy S.r.l.

Padtec S.a.

Telecom Italia

Politecnico Di Milano

Pirelli & C. S. P. A.

Advanced Digital Broadcast S.a.

Pirelli General Plc

Corning O.t.i. Inc.

Fondazione Centro Internazionale Della Fotonica Per Energia

Giorgio Grasso

Aldo Righetti

Fausto Meli

Mario Tamburello

Flavio Fontana

Marco Romagnoli

Pierluigi Franco

Roberta Castagnetti

Paul L Scrivener

Fabrizio Di Pasquale

Marcos Antonio Brand&atilde;o Sanches

Matjaz Vidmar

Maria Chiara Ubaldi

Andrea Ivano Melloni

Luciano Socci

Pierpaolo Boffi

Gianmario Lanfranconi

Giovanni Sacchi

Lucia Marazzi

Enrico Dotti

Silvia Ghidini

Paola Galli

Silvia Maria Pietralunga

Paola Parolari

Claudio Zammarchi

Francesco Morichetti

Lorenzo Bolla

Francesco Maria Tassone

Eleanor Joan Tarbox

Paolo Ottolenghi

Mauro Robba

Fabio Donati

Emilio Casaccia

Andrew P Appleyard

Roberto Aldeghi

Giovanni Tamiri

The present invention relates to a method to tune a wavelength of a coherent light signal emitted by a tunable laser, the tunable laser comprising:

Tunable laser and method to tune a wavelength of a light emitted by the laser

In a telecommunication network, a modular expandable gateway connects a local area network to a wide area network and includes a base module and a plurality of add-on modules arranged in one or more stacks, the base module and the add-on modules including respective encryption/decryption engines to exchange secure information with each other, thus frustrating any possible fraudulent interception of the information at the module interconnections.

Method for secure signal transmission in a telecommunication network, in particular in a local area network

An optical amplifier (), and a related optical amplification method, comprising an optical path () having an input end () and an output end (), a first erbium doped optical fiber () placed along the optical path, a first gain flatting filter () placed along the optical path downstream the first erbium doped optical fiber, a second erbium doped optical fiber () placed along the optical path downstream the first gain flatting filter, a second gain flatting filter () placed along the optical path downstream the second erbium doped optical fiber, a third erbium doped optical fiber () placed along the optical path downstream the second gain flatting filter, and an optical pump () optically coupled to the optical path so as to optically pump at least the first and the third erbium doped optical fiber.

Optical amplifier and related method

Optical amplification stage () for OTDR monitoring, comprising a first () and a second optical signal path (), a first () and a second optical amplifier (), a first optical coupler () placed along the first optical signal path downstream the first optical amplifier, a second optical coupler () placed along the second optical signal path downstream the second optical amplifier, an optical by-pass path () optically connecting the first and the second optical coupler, a first () and a second optical reflector () optically connected to respectively the first and second optical coupler, and an optical filter () placed along the optical by-pass path which has attenuation high on the whole WDM band and low at the OTDR wavelength(s).

Optical amplification stage for OTDR monitoring and related method and system for OTDR monitoring of an optical communication link

A solar concentrator () having a longitudinal axis of extension () and a cross-section at right angles to the longitudinal axis substantially equal for a continuum of cross-sections, and comprising a reflective system () and a refractive system (), the reflective system forming an optical inlet () and an optical outlet () and comprising two semi-portions positioned specularly relative to the plane of symmetry, where the cross-section profile of the refractive system is a triangle () having a base () at the optical outlet () and apex () on the axis of symmetry (), where the cross-section profile of each semi-portion of the reflective system comprises a segment () in the shape of a parabola having an axis () forming with the axis of symmetry an acceptance angle (&#x3b8;0) greater than zero and a focus (F) on the axis of symmetry, and where the focus falls inside the triangle.

Solar concentrator for photovoltaic systems

A method of filtering an optical signal includes operating an optical filter having resonators, each having a respective free spectral range and a respective resonance falling within a first frequency band, first tuning at least one resonator with respect to at least another resonator to obtain a separation between any resonance of at least one resonator falling within an optical bandwidth with respect to a resonance of at least another resonator nearest to the any resonance, second tuning all the resonators of the optical filter so as to move all respective resonances by a respective frequency interval greater than a frequency spacing, and third tuning the at least one resonator and the at least another resonator such that a further respective resonance of each one of the resonators falls within a second frequency band, different from the first frequency band.

Method and device for hitless tunable optical filtering

An optical transmission system having an optical source, an optical dispersion compensation filter optically connected to the optical source, and a control system. The optical source generates a modulated optical signal having an optical spectrum and a value of dispersion robustness. The optical dispersion compensation filter has at least two cascaded optical resonators and a periodic transfer function rigidly translatable in the frequency spectrum to obtain translation in frequency of the transfer function without a substantial change in shape, and characterized by a free spectral range. The control system acts on the optical dispersion compensation filter in order to rigidly translate the transfer function along the frequency spectrum in first and second positions in the frequency spectrum. The translation of the transfer function between the first and the second positions is smaller than the free spectral range.

Optical transmission system with optical chromatic dispersion compensator

Systems and methods for generating spectrally efficient modulated optical signals are provided. Capacity of WDM optical communication links may be increased dramatically without changing the WDM channel plan thus minimizing modifications to optical amplifiers and passive optical components. A vestigial sideband (VSB) optical signal may be generated by filtering an amplitude modulated (AM) signal using a filter having a center frequency locked to the transmission frequency of a laser.

VSB transmitter using locked filter

Point-to-point link for the transmission of digital signals includes two opto-electronic conversion apparatuses and an optical cable including at least one optical fiber having two terminal portions, each opto-electronic conversion apparatus including an opto-electronic device optically coupled to a respective terminal portion between the two terminal portions of the at least one optical fiber, wherein at least one of the two opto-electronic conversion apparatuses is adapted to keep the respective terminal portion of the optical fiber in bent position with a bending radius R, where 1.5 mm&#x2266;R&#x2266;2.5 mm, and to keep the respective opto-electronic device optically coupled to the bent terminal portion in order to allow the transmission of the digital signals between the optical fiber and the at least one of the two opto-electronic conversion apparatuses; and at least the bent terminal portion of the at least one optical fiber is such as to satisfy the following relationship r/R&#x3c;0.07*n/(35+n), where n is the stress corrosion susceptibility factor and r is the radius of the cladding of the optical fiber.

Point-to-point optical fibre link

At a receiver a 20 Gbit/s soliton bit stream () is demultiplexed into two 10 Gbit/s bit streams () using a 2-way splitter (), a clock extraction circuit (), and a pair of polarization insensitive amplitude modulators () exhibiting positive chirp. The outputs of the modulators are fed to detectors () via lengths () of optical fiber exhibiting normal dispersion thereby producing bit streams () with increased mark/space ratio and reduced timing jitter.

System and method of high-speed transmission and appropriate transmission apparatus

An amplification architecture for WDM receiver systems. The WDM channel grid is divided into groups of adjacent channels. A separate optical amplifier is provided for each channel with a single pump being shared among the channels of each group. The gain experienced by channels of a given group may be adjusted by varying the power of the group's pump. This approach allows equalization of received channel power such that all channels fall within the desired dynamic range. The amplification architecture may be implemented in a space-efficient manner at low cost.

Shared variable gain amplifier for WDM channel equalization

An approach for automatic Raman gain and tilt control for a WDM (Wavelength Division Multiplexing) optical communication systems is disclosed. An optical fiber carries a plurality of optical signals, in which at least one of the optical signals are reference signals. An optical gain unit (e.g., Raman pump unit) couples to the optical fiber and adjusts the reference signals to compensate, in part, for losses associated with the optical fiber and gain tilt accumulation. Upon detecting and analyzing the reference signals, a controller controls the optical gain unit and outputs a control signal to the optical gain unit based upon the analyzed reference signals. An optical amplifier is connected to the optical fiber and amplifies the optical signals. The optical gain unit provides a nearly constant power per channel at an input of the optical amplifier. Under this approach, a Raman gain control mechanism, combined with the use of gain controlled EDFA (Erbium Doped Fiber Amplifier), allows high transmission capacity over ultra-long distances without optical regeneration and with high flexibility.

Automatic raman gain and tilt control for ultra-long-distance dense WDM optical communication system

Soliton or soliton-like optical pulses with characteristics adapted to propagation in an optical line for RZ type transmission are generated by modulating a continuous optical signal () by means of a modulator () which is substantially devoid of chirping, in which the modulator drive signal comprises at least one frequency () and one harmonic () thereof superimposed on each other (). A high-speed optical transmission system is rendered independent of the type of transmitter or of signals sent to it if it comprises an adaptation unit () receiving the original optical pulses () and capable of generating corresponding pulsed signals () of RZ type.

Systems and methods for ameliorating double Rayleigh backscattering induced impairments are provided. Raman amplification is divided among two or more stages. Optical energy from a single counter-propagating pump may traverse multiple stages while optical energy at the frequency of the signal to be amplified is permitted to propagate in the forward direction only. In this way the pump power can be effectively distributed over the entire amplifier length. The scheme may be implemented in a simple configuration employing a closed circulator and a fiber Bragg grating. Multiple wavelength pump operation may be accommodated as well as either discrete or distributed Raman amplification.

Suppression of double rayleigh backscattering and pump reuse in a raman amplifier

Growing community of inventors

Monza, Italy

Giorgio Grasso