Google Inc.

Pirelli Cavi E Sistemi S.p.a.

Mosaid Technologies Corporation

Politecnico Di Milano

Pgt Photonics, S.p.a

Corning O.t.i. Inc.

Optical Technologies Italia Spa

Pierpaolo Boffi

Mario Martinelli

Lucia Marazzi

Paola Parolari

Aldo Righetti

Paolo Martelli

Davide Piccinin

Livio Paradiso

Rocco Siano

Giorgio Grasso

Marco Romagnoli

Guido Alberto Maier

Riccardo Belli

Stefano Avanzi

Giovanni Tamiri

Andrea Tonini

Diego Mottarella

A method of phase modulating optical radiation by the steps of phase modulating the optical radiation by using a modulator having an extinction ratio in order to provide a multilevel phase shift key signal, and applying to each optical pulse a phase-shift having an absolute value depending on the extinction ratio and a sign depending, for each of the optical pulses, on the respective optical phase value. An apparatus implementing the method is also disclosed.

Method and apparatus for optical phase modulation

A filter for an optical fibre temperature sensor comprising at least one first and one second optical filter for filtering an optical pulse reflected by said optical fibre, characterised in that said at least one first and one second optical filter comprise standard commercial filters complying with ITU specifications, said optical pulse lying within the range from 1570 nm to 1580 nm.

Filter for an optical fibre temperature sensor

An optical communication system () comprises at least a transmitter () apt to emit a differential phase shift keying (DPSK) optical signal having a bit-rate equal to R, at least a receiving system () for receiving the differential phase shift keying optical signal; and an optical link () optically connecting the transmitter and the receiving system for transmitting the DPSK optical signal from the transmitter to the receiving system, wherein the receiving system comprises a coherent optical receiving device () apt to coherently receive the propagated DPSK optical signal and to emit at least one electrical signal (I) related to the received DPSK optical signal, and wherein the receiving system further comprises at least one electrical filter () for filtering the at least one electrical signal and having &#x2212;3 dB double-side bandwidth greater than or equal to 0.44 R and lower than or equal to 0.68 R, and at least one squarer () for squaring the at least one filtered electrical signal. A related method for optical communication is also disclosed.

System and method for coherent detection of optical signals

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

A device and method for stabilizing the state of polarization of polarization multiplexed optical radiation including an identified channel is disclosed. The device and method comprise providing to the polarization multiplexed optical radiation a first controllable polarization transformation to generate a first transformed optical radiation; detecting a first state of polarization of a first polarized portion with respect to a first polarization parameter; controlling the first controllable polarization transformation so that the first polarization parameter has a predetermined value independent of a polarization state of the polarization multiplexed optical radiation; providing to the first transformed optical radiation a second controllable polarization transformation to generate a second transformed optical radiation; detecting a second state of polarization of a second polarized portion; and controlling the second controllable polarization transformation so that the second state of polarization has a predefined value.

Method and device for stabilizing the state of polarization of a polarization multiplexed optical radiation

A device and method for stabilizing the polarization of polarization multiplexed optical radiation includes an identified channel which is provided with a pilot signal. The device and method are based on providing to the polarization multiplexed optical radiation a controllable polarization transformation; measuring the optical power of a polarized portion of the identified channel downstream the polarization transformation; controlling, responsively to the optical power, the controllable polarization transformation so that the identified channel downstream the polarization transformation has a predefined polarization azimuth; providing to the optical radiation downstream the polarization transformation a further controllable polarization transformation; measuring the optical power of a polarized portion of the identified channel downstream the further controllable polarization transformation; and controlling, responsively to the optical power, the further controllable polarization transformation so that the identified channel downstream the further controllable polarization transformation has a predefined state of polarization.

An optical window signal generator which begins generation of an optical output signal in response to an optical activation pulse, and terminates generation of the optical output signal in response to an optical deactivation pulse. The rise time of the optical output signal is equal to the rise time of the optical activation pulse, and its fall time is equal to the rise time of the optical deactivation pulse.

Optical window signal generator

An optical device having a first input for at least one input optical signal having a random state of polarization and a first optical element capable of dividing, in space, the input optical signal into a pair of optical signals which are substantially parallel and have a predetermined state of polarization perpendicular to each another. The optical device also having a first crystal element for propagation, in free space, of at least the pair of optical signals coming from the first optical element, and the first crystal element being devoid of internal separation planes, and having electro-optical properties and being associated with electrodes so as to apply a voltage in a direction substantially perpendicular to the direction of propagation, along the first crystal element, of the at least one pair of optical signals. The optical device also having an optical control element for supplying at least one optical control beam, having a predetermined power, to the first crystal element, the at least one optical control beam being superimposed on the at least one pair of optical signals and having a direction of propagation which along the first crystal element is substantially perpendicular to the direction of application of the voltage, the at least one optical control beam being capable of causing to rotate through a predetermined angle the state of polarization of the at least one pair of optical signals in the first crystal element. The optical device also having a second optical element capable of combining the at least one pair of optical signals coming from the first crystal element in a single output signal and a first output for the output signal.

Optical system having optical control beam

An optical device is provided for processing a digital optical signal in parallel and in free space. A device consistent with the invention provides for inputting a digital optical signal in guided propagation, converting the digital optical signal to n digital optical signals in guided propagation, and converting the n digital optical signals to n digital optical signals in free space. In addition, the invention provides for selecting a bit preselected from the at least one temporal series of n bits of each of the n digital optical signals, modifying optically, at least one bit of the spatial figure of the n bits, and outputting the at least one bit of the spatial figure of n bits.

Optical device and a method of processing a digital optical signal in parallel and in free space

An optical device to perform an asynchronous and parallel processing of a N bits serial stream of an optical digital signal comprises a) a serial to parallel converter which converts the serial stream of N bits into a first parallel pattern of N bits carrying the same information as the serial stream of N bits; b) an optical system to produce, from the parallel pattern of N bits, a first two-dimensional (2-D) image made of N rows and M columns (N&times;M) of bits, each column being associated to the digital optical signal by a predetermined relationship; c) a logic device to perform logic operations on the bits of the first 2-D image; and d) a device to send to an output the results of the logic operations.

Optical device for processing an optical digital signal

There is provided an optical wavelength converter which allows the rapid and efficient shifting of information modulated on a light signal of one wavelength to a light signal of a second wavelength without the negative effects of noise and other disturbances which have proven to be problems in the prior art. The device splits a CW probe signal of a first wavelength into two components, which propagate with opposite orientations through a Kerr leg. Also propagating in the Kerr leg is a modulated drive signal at a second wavelength. These signals interact in the Kerr leg, and are recombined at an output coupler so as to create interference between the two probe components. An intensity modulated probe signal is output.

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Voghera, Italy

Pierpaolo Boffi