Pirelli & C. S. P. A.

Google Inc.

Mosaid Technologies Corporation

Pirelli Cavi E Sistemi S.p.a.

Cambridge Enterprise Limited

Other

Cisco Technology, Inc.

Pgt Photonics, S.p.a

Consorzio Nazionale Interuniversitario Per Le Telecomunicazioni (cnit)

Consorzio Nazionale Interuniversitario Per Le Telecomunicazioni

Consorzio Nazionale Interuniversitario Per Le Telecomunicazione

Fondazione Istituto Italiano Di Tecnologia

Marco Romagnoli

Luciano Socci

Paola Galli

Silvia Ghidini

Maurizio Tormen

Giacomo Gorni

Lorenzo Bolla

Giorgio Grasso

Pierluigi Franco

Michele Midrio

Camilla Bonati

Andrea Carlo Ferrari

Francesco Maria Tassone

Vito Sorianello

Aldo Righetti

Matteo Cherchi

Pierpaolo Boffi

Lucia Marazzi

Paola Parolari

Raffaele Corsini

Marco Piazza

Attilio Bragheri

Gaia Cevini

Alberto Montanaro

Glulia Pietra

Fabrizio Carbone

Daniele Faccio

Roberto Aldeghi

Stefano Lorenzotti

Giovanni Tamiri

Daniele Franco Faccio

Marco Angelo Giambra

Vaidotas Miseikis

A Wavelength Division Multiplexing (WDM) for an optical fibre comprising a set of optical inputs, one for each wavelength of a WDM optical signal to be transmitted, a graphene electro-absorption modulator (EAM) for each optical input to modulate light from the optical input, and one or more drivers to drive each graphene electro-absorption modulator. The drivers have a data input, a low pass filter to low-pass filter data from the data input to provide low pass filtered data, and an output to drive each graphene electro-absorption modulator with a combination of the low pass filtered data and a bias voltage. The bias voltage is configured to bias the graphene EAM into a region in which, e.g., when the transmission of the graphene electro-absorption modulator increases the effective refractive index for the modulated light decreases and vice-versa to pre-chirp to the modulated light to compensate for dispersion in the fibre.

Optical transmitter

An RF transmitter comprising an optical source configured to generate a pair of optical lines separated by an RF carrier frequency. The transmitter may comprise a graphene photodetector having at least two electrical contacts; a transmit antenna coupled to a first of the electrical contacts; and an electrical data signal input connected to a second of the electrical contacts. The graphene photodetector is illuminated by the optical source; it may comprise a graphene photo-thermal effect (PTE) photodetector or a bolometric photodetector. A corresponding receiver is also described.

Transmitters and receivers

In an integrated polarization splitting and rotating photonic device comprising at least one first waveguide; a second waveguide, both said waveguides extending from an input section to an output section; a top cladding; a bottom cladding and a symmetry-breaking layer so as to form an optical guiding structure in a wafer chip, said top and bottom claddings extending throughout the whole optical guiding structure sandwiching said waveguides therebetween, said symmetry-breaking layer extends in the optical guiding structure at least over the whole guiding structure length, and, at the input section, the at least one first waveguide core has a predetermined width through the optical guiding structure to the output section, receiving an input light signal, and further, the second waveguide core, both at the input and the output section, has a width narrower than said predetermined width of the first waveguide core; so that the optical guiding structure guides a first mode substantially confined within said at least one first waveguide core and a second mode substantially confined within said second semiconductor waveguide core said first and said second modes having the same polarization at the output section.

Integrated photonic polarisation rotator and splitter and related method

An optical device includes an optical splitter having an input port, a first output port and a second output port and is adapted to receive at said input port a WDM optical signal including a plurality of channels equally spaced by a frequency spacing and occupying an optical bandwidth, and wherein the optical splitter is adapted to output at the first and second output ports, respectively, a first and a second portion of the optical signal; an optical combiner having a respective first and second input ports and a respective output port; a first optical path optically connecting the first output port of the optical splitter to the first input port of the optical combiner; a second optical path optically connecting the second output port of the optical splitter to the second input port of the optical combiner, a first optical filter optically coupled along the first optical path, and a second optical filter optically coupled to the second optical path and the free spectral range of both the first and the second optical filter is equal to an odd multiple of the frequency spacing and greater than half of the optical bandwidth.

Method and system for tunable optical filtering

An optical communication system and method of use are described. The system comprises an optical source adapted to receive a digitally encoded data signal comprising sequences of data at a data rate (B) and comprising two signal levels representing a first state and a second state of the data signal, the optical source being adapted to produce an optical signal substantially frequency modulated with frequency excursion &#x394;&#x3bd; comprising a first instantaneous frequency (&#x3bd;) associated to the first state and a second instantaneous frequency (&#x3bd;) associated to the second state; an optical converter adapted to receive the substantially frequency modulated optical signal, the optical converter having an optical transfer function varying with frequency and including at least one pass band, the at least one pass band having a peak transmittance and at least a low-transmittance region.

Dispersion tolerant optical system and method

The method for filtering an optical signal comprising a plurality of channels lying on a grid of optical frequencies equally spaced by a frequency spacing and occupying an optical bandwidth, comprises: a) operating an optical filter comprising a plurality of resonators, wherein a first resonator of the plurality is optically coupled to the optical signal and the remaining resonators are optically coupled in series to the first resonator, so that a respective resonance of each one of the plurality of resonators falls within a first frequency band having bandwidth less than or equal to 15 GHz; b) operating the optical filter so as to obtain a separation between said respective resonance of at least one resonator with respect to said respective resonance of at least another different resonator, the separation being greater than or equal to 25 GHz; c) operating the optical filter so that said respective resonance of each one of the plurality of resonators falls within a second frequency band, different from the first frequency band, having bandwidth less than or equal to 15 GHz, wherein during the procedure from step a) to step c), at least one among said respective resonance of the at least one resonator and said respective resonance of the at least another different resonator is moved also outside a frequency region spanning between, and including, the first and the second frequency band. A corresponding device for filtering an optical signal is disclosed.

Method and device for hitless tunable optical filtering

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.

An optical mode transformer comprises a first waveguide including a first core, a first cladding and an end facet configured to be coupled to an optical fiber. A second waveguide comprises a second core and a second cladding, and is arranged with respect to the first waveguide so as to realize an evanescent optical coupling with the first waveguide. The second core comprises a tapered region, in at least a portion of which the evanescent coupling takes place. The first core and the second core are separated by a gap. A first refractive index contrast of the first waveguide is less than a second refractive index contrast of the second waveguide.

Optical mode transformer, in particular for coupling an optical fiber and a high-index contrast waveguide

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

An optical mode transformer comprises a first waveguide including a first core, a first cladding and an end facet configured to be coupled to an optical fiber. The transformer further includes a second waveguide comprising a second core, a second cladding and an end directly coupled to an end of the first waveguide. A third waveguide comprises a third core and a third cladding, and is arranged with respect to the second waveguide so as to realize an evanescent optical coupling with the second waveguide. The third core includes a tapered region wherein evanescent coupling takes place, and wherein a refractive index contrast of the first waveguide is less than a refractive index contrast of the second waveguide, the refractive index contrast of the second waveguide is less than a refractive index contrast of the third waveguide, and the refractive index contrast of the third waveguide is not less than 18%.

An optical device includes an optical splitter having an input port, a first output port, a second output port and a resonant structure including at least a resonator, the optical splitter being adapted to receive at the input port a WDM optical signal and to output at the first and second output ports, respectively, a first and a second portion of the optical signal, the second portion including the channels lying on a sub-grid of optical frequencies spaced by an integer multiple of the WDM frequency spacing; an optical combiner having a first input port, a second input port, an output port and adapted to receive at the first and second input ports, respectively, the first and the second portions and adapted to output them at said output port; a first optical path optically connecting the first output port of the optical splitter to the first input port of the optical combiner so as to propagate the first portion; a second optical path optically connecting the second output port of the optical splitter to the second input port of the optical combiner so as to propagate the second portion; and an optical filter optically coupled to the second optical path, wherein the optical combiner includes at least one resonant structure including at least a resonator.

Method and device for tunable optical filtering

A method for switching from a first optical path optically coupled to an optical processing device to a second optical path, the first and second optical paths optically connecting, in parallel configuration, a first optical switch to a second optical switch, according to the following steps: directing optical radiation comprising at least a fast operating wavelength through the first optical path to the optical processing device, which is tuned to the first operating wavelength; tuning a resonant all-pass filter optically coupled to the second optical path so as to match, at least at a wavelength adjacent to the first operating wavelength, a phase distortion introduced by the optical processing device on the optical radiation; synchronously actuating the first and the second optical switch so as to switch the optical radiation from the first optical path to the second optical path.

Method and system for hitless tunable optical processing

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

An integrated optical add/drop device having switching function for use in wavelength division multiplexing optical communication systems, has first and second optical couplers between which first and second interferometric arms of an interferometer are extended. The integrated optical add/drop device has an optical filter having first and second input ports connected to first portions of the first and second interferometric arms and first and second output ports connected to second portions of the first and second interferometric arms. The optical filter acts as a selective switch exchanger for exchanging between one interferometric arm and the other at least one of a plurality of optical signals S (&#x3bb;), S (&#x3bb;), . . . , S (&#x3bb;n), received at its input ports and for transmitting the remaining optical signals through its output ports in the first and second interferometric arms. The integrated optical add/drop device also has at least first and second optical shifters located on opposite sides of the optical filter.

Integrated optical add/drop device having switching function

Growing community of inventors

Milan, Italy

Marco Romagnoli