Patents by Inventor Aldo Righetti

Aldo Righetti has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20220136818
    Abstract: The present invention relates to an optical coherence tomography analysis method, comprising: Providing a Swept Source Optical Coherence Tomography system (SS-OCT), the SS-OCT system including: a light source, tunable over a spectral band, that generates a coherent light signal; an optical interferometer for dividing the coherent light signal into a reference arm leading to a reference reflector and a sample arm leading to a sample; an optical element to selectively direct a sample light signal exiting the sample arm to a specific portion of the sample, so that for each selection in the optical element a different specific portion of the sample is illuminated; an optical detector for detecting an interference signal generated by a combination of reference and sample returning signals from the reference arm and from the sample arm, reflected by the reference reflector and the sample, respectively; Wherein, for the same selection operated at the optical element level illuminating a specific portion of the
    Type: Application
    Filed: April 3, 2020
    Publication date: May 5, 2022
    Applicant: CENTRO INTERNAZIONALE DELLA FORONICA PER ENERGIA (CIFE) IN FORMAL ABBREVIATA "CIFE"
    Inventors: Aldo RIGHETTI, Maria Chiara UBALDI, Giorgio GRASSO
  • Publication number: 20220011087
    Abstract: 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: a cavity, the cavity including: a gain medium, an optical tunable filter, a first and a second mirrors, one of which is partially reflective, wherein the optical tunable filter includes: a first and a second electrodes, a liquid crystal, the method comprising: applying a voltage difference between the first and second electrodes to apply an electric field to the liquid crystal; wherein applying a voltage difference includes: applying the voltage difference for at least a driving time interval lasting less than 1 ?s; and varying the voltage difference applied between the first and second electrodes within the driving time interval so that a maximum applied voltage difference is reached and said maximum applied voltage is above 0.1 kV.
    Type: Application
    Filed: April 3, 2020
    Publication date: January 13, 2022
    Inventor: Aldo RIGHETTI
  • Patent number: 9640938
    Abstract: An optical amplifier (1), and a related optical amplification method, comprising an optical path (2) having an input end (3) and an output end (4), a first erbium doped optical fiber (5) placed along the optical path, a first gain flatting filter (6) placed along the optical path downstream the first erbium doped optical fiber, a second erbium doped optical fiber (7) placed along the optical path downstream the first gain flatting filter, a second gain flatting filter (8) placed along the optical path downstream the second erbium doped optical fiber, a third erbium doped optical fiber (9) placed along the optical path downstream the second gain flatting filter, and an optical pump (10) optically coupled to the optical path so as to optically pump at least the first and the third erbium doped optical fiber.
    Type: Grant
    Filed: May 4, 2015
    Date of Patent: May 2, 2017
    Assignee: PADTEC S.A.
    Inventors: Fausto Meli, Aldo Righetti, Giorgio Grasso
  • Patent number: 9419729
    Abstract: A branching unit (1) for an optical telecommunication link (100), the unit comprising a first (2), a second (3) and a third terminal (4) for termination of conductors of respective branch cables in use, a fourth terminal (5) for connection to a sea earth (6) in use, and a circuit (8) comprising a plurality of relays comprising at least a first, a second and a third relay associated to respectively the first, second and third terminal, the circuit being structured for connecting together two terminals out of the first, second and third terminal and for connecting the remaining terminal to the fourth terminal, depending on a sequence of power feeding at the first, second and third terminals, in use, wherein the circuit (8) comprises a sea earth circuit (9) terminated at one end to the fourth terminal and a bidirectional triode thyristor (13) placed along the sea earth circuit, a driving circuit (19) being provided for driving the bidirectional triode thyristor so as to trigger the bidirectional triode thyristor
    Type: Grant
    Filed: November 13, 2014
    Date of Patent: August 16, 2016
    Assignee: PADTEC S.A.
    Inventors: Daniele Androni, Aldo Righetti
  • Publication number: 20150340832
    Abstract: An optical amplifier (1), and a related optical amplification method, comprising an optical path (2) having an input end (3) and an output end (4), a first erbium doped optical fiber (5) placed along the optical path, a first gain flatting filter (6) placed along the optical path downstream the first erbium doped optical fiber, a second erbium doped optical fiber (7) placed along the optical path downstream the first gain flatting filter, a second gain flatting filter (8) placed along the optical path downstream the second erbium doped optical fiber, a third erbium doped optical fiber (9) placed along the optical path downstream the second gain flatting filter, and an optical pump (10) optically coupled to the optical path so as to optically pump at least the first and the third erbium doped optical fiber.
    Type: Application
    Filed: May 4, 2015
    Publication date: November 26, 2015
    Inventors: FAUSTO MELI, ALDO RIGHETTI, GIORGIO GRASSO
  • Patent number: 9124362
    Abstract: Optical amplification stage (1) for OTDR monitoring, comprising a first (2a) and a second optical signal path (2b), a first (3a) and a second optical amplifier (3b), a first optical coupler (4a) placed along the first optical signal path downstream the first optical amplifier, a second optical coupler (4b) placed along the second optical signal path downstream the second optical amplifier, an optical by-pass path (5) optically connecting the first and the second optical coupler, a first (11a) and a second optical reflector (11b) optically connected to respectively the first and second optical coupler, and an optical filter (10) placed along the optical by-pass path which has attenuation high on the whole WDM band and low at the OTDR wavelength(s).
    Type: Grant
    Filed: October 9, 2013
    Date of Patent: September 1, 2015
    Assignee: PADTEC S.A.
    Inventors: Giorgio Grasso, Andrea Melloni, Aldo Righetti, Fausto Meli
  • Publication number: 20150131191
    Abstract: A branching unit (1) for an optical telecommunication link (100), the unit comprising a first (2), a second (3) and a third terminal (4) for termination of conductors of respective branch cables in use, a fourth terminal (5) for connection to a sea earth (6) in use, and a circuit (8) comprising a plurality of relays comprising at least a first, a second and a third relay associated to respectively the first, second and third terminal, the circuit being structured for connecting together two terminals out of the first, second and third terminal and for connecting the remaining terminal to the fourth terminal, depending on a sequence of power feeding at the first, second and third terminals, in use, wherein the circuit (8) comprises a sea earth circuit (9) terminated at one end to the fourth terminal and a bidirectional triode thyristor (13) placed along the sea earth circuit, a driving circuit (19) being provided for driving the bidirectional triode thyristor so as to trigger the bidirectional triode thyristor
    Type: Application
    Filed: November 13, 2014
    Publication date: May 14, 2015
    Inventors: DANIELE ANDRONI, ALDO RIGHETTI
  • Patent number: 8975508
    Abstract: A solar concentrator (1) having a longitudinal axis of extension (3) and a cross-section at right angles to the longitudinal axis substantially equal for a continuum of cross-sections, and comprising a reflective system (6) and a refractive system (7), the reflective system forming an optical inlet (8) and an optical outlet (9) 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 (11) having a base (12) at the optical outlet (9) and apex (13) on the axis of symmetry (5), where the cross-section profile of each semi-portion of the reflective system comprises a segment (18) in the shape of a parabola having an axis (20) forming with the axis of symmetry an acceptance angle (?0) greater than zero and a focus (F) on the axis of symmetry, and where the focus falls inside the triangle.
    Type: Grant
    Filed: August 22, 2012
    Date of Patent: March 10, 2015
    Assignee: Fondazione Centro Internazionale Della Fotonica per Energia
    Inventors: Giorgio Grasso, Francesco Morichetti, Silvia Maria Pietralunga, Aldo Righetti, Maria Chiara Ubaldi
  • Publication number: 20140209148
    Abstract: A solar concentrator (1) having a longitudinal axis of extension (3) and a cross-section at right angles to the longitudinal axis substantially equal for a continuum of cross-sections, and comprising a reflective system (6) and a refractive system (7), the reflective system forming an optical inlet (8) and an optical outlet (9) 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 (11) having a base (12) at the optical outlet (9) and apex (13) on the axis of symmetry (5), where the cross-section profile of each semi-portion of the reflective system comprises a segment (18) in the shape of a parabola having an axis (20) forming with the axis of symmetry an acceptance angle (?0) greater than zero and a focus (F) on the axis of symmetry, and where the focus falls inside the triangle.
    Type: Application
    Filed: August 22, 2012
    Publication date: July 31, 2014
    Applicant: FONDAZIONE CENTRO INTERNAZIONALE DELLA FOTONICA PER ENERGIA
    Inventors: Giorgio Grasso, Francesco Morichetti, Silvia Maria Pietralunga, Aldo Righetti, Maria Chiara Ubaldi
  • Publication number: 20140105595
    Abstract: Optical amplification stage (1) for OTDR monitoring, comprising a first (2a) and a second optical signal path (2b), a first (3a) and a second optical amplifier (3b), a first optical coupler (4a) placed along the first optical signal path downstream the first optical amplifier, a second optical coupler (4b) placed along the second optical signal path downstream the second optical amplifier, an optical by-pass path (5) optically connecting the first and the second optical coupler, a first (11a) and a second optical reflector (11b) optically connected to respectively the first and second optical coupler, and an optical filter (10) placed along the optical by-pass path which has attenuation high on the whole WDM band and low at the OTDR wavelength(s).
    Type: Application
    Filed: October 9, 2013
    Publication date: April 17, 2014
    Applicant: PADTEC S.A.
    Inventors: GIORGIO GRASSO, ANDREA MELLONI, ALDO RIGHETTI, FAUSTO MELI
  • Patent number: 8437645
    Abstract: An optical communication system (100; 2300) comprises at least a transmitter (110) apt to emit a differential phase shift keying (DPSK) optical signal having a bit-rate equal to R, at least a receiving system (1200) for receiving the differential phase shift keying optical signal; and an optical link (130) 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 (1205) 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 (270) for filtering the at least one electrical signal and having ?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 (280) for squaring the at least one filtered electrical signal.
    Type: Grant
    Filed: December 6, 2007
    Date of Patent: May 7, 2013
    Assignee: Google Inc.
    Inventors: Pierpaolo Boffi, Lucia Marazzi, Paolo Martelli, Paola Parolari, Aldo Righetti
  • Patent number: 8380076
    Abstract: 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.
    Type: Grant
    Filed: December 27, 2006
    Date of Patent: February 19, 2013
    Assignee: Google Inc.
    Inventors: Pierpaolo Boffi, Giorgio Grasso, Lucia Marazzi, Paola Parolari, Aldo Righetti, Marco Romagnoli, Giovanni Tamiri
  • Patent number: 8311411
    Abstract: A method of stabilizing the state of polarization of an optical radiation comprises: 1) applying sequentially to the optical radiation a first and a second controllable phase retardation; 2) detecting an optical power of at least a first polarized portion of the optical radiation obtained after step 1; 3) applying sequentially to the optical radiation obtained after step 1 a third and a fourth controllable phase retardation; 4) detecting an optical power of a further polarized portion of the optical radiation obtained after step 3; 5) controlling, responsive to the optical power of said first polarized portion, the second controllable phase retardation so as to maintain the polarization state of the optical radiation obtained after step 1 at a defined great circle r on a Poincare sphere; 6) in case the second controllable phase retardation reaches a first limit value, commuting the first controllable phase retardation between first and second values; 7) controlling, responsive to the optical power of said fur
    Type: Grant
    Filed: December 21, 2007
    Date of Patent: November 13, 2012
    Assignee: Google Inc.
    Inventors: Paolo Martelli, Mario Martinelli, Aldo Righetti
  • Patent number: 8200087
    Abstract: A device and method for stabilizing the state of polarization of polarization multiplexed optical radiation including an identified channel is disclosed.
    Type: Grant
    Filed: March 2, 2011
    Date of Patent: June 12, 2012
    Assignee: Google Inc.
    Inventors: Pierpaolo Boffi, Lucia Marazzi, Paolo Martelli, Mario Martinelli, Aldo Righetti, Rocco Siano
  • Publication number: 20110170870
    Abstract: A device and method for stabilizing the state of polarization of polarization multiplexed optical radiation including an identified channel is disclosed.
    Type: Application
    Filed: March 2, 2011
    Publication date: July 14, 2011
    Inventors: Pierpaolo Boffi, Lucia Marazzi, Paolo Martelli, Mario Martinelli, Aldo Righetti, Rocco Siano
  • Patent number: 7917031
    Abstract: A device and method for stabilizing the polarization of polarization multiplexed optical radiation includes an identified channel which is provided with a pilot signal.
    Type: Grant
    Filed: October 22, 2004
    Date of Patent: March 29, 2011
    Assignee: PGT Photonics S.p.A.
    Inventors: Pierpaolo Boffi, Lucia Marazzi, Paolo Martelli, Mario Martinelli, Aldo Righetti, Rocco Siano
  • Publication number: 20100277798
    Abstract: A method of stabilizing the state of polarization of an optical radiation comprises: 1) applying sequentially to the optical radiation a first and a second controllable phase retardation; 2) detecting an optical power of at least a first polarized portion of the optical radiation obtained after step 1; 3) applying sequentially to the optical radiation obtained after step 1 a third and a fourth controllable phase retardation; 4) detecting an optical power of a further polarized portion of the optical radiation obtained after step 3; 5) controlling, responsive to the optical power of said first polarized portion, the second controllable phase retardation so as to maintain the polarization state of the optical radiation obtained after step 1 at a defined great circle r on a Poincare sphere; 6) in case the second controllable phase retardation reaches a first limit value, commuting the first controllable phase retardation between first and second values; 7) controlling, responsive to the optical power of said fur
    Type: Application
    Filed: December 21, 2007
    Publication date: November 4, 2010
    Inventors: Paolo Martelli, Mario Martinelli, Aldo Righetti
  • Publication number: 20100266291
    Abstract: An optical communication system (100; 2300) comprises at least a transmitter (110) apt to emit a differential phase shift keying (DPSK) optical signal having a bit-rate equal to R, at least a receiving system (1200) for receiving the differential phase shift keying optical signal; and an optical link (130) 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 (1205) 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 (270) for filtering the at least one electrical signal and having ?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 (280) for squaring the at least one filtered electrical signal.
    Type: Application
    Filed: December 6, 2007
    Publication date: October 21, 2010
    Inventors: Pierpaolo Boffi, Lucia Marazzi, Paolo Martelli, Paola Parolari, Aldo Righetti
  • Publication number: 20100232802
    Abstract: Optical transmission system (200) comprising: an optical source (210) adapted to generate a modulated optical signal having an optical spectrum and a dispersion robustness; an optical dispersion compensation filter (250) optically connected to the optical source, comprising at least two cascaded optical resonators and having a periodic transfer function that is rigidly translatable in the frequency spectrum and characterized by a free spectral range (FSR); a control system (270; 280; 260) adapted to act on the optical compensation filter in order rigidly to translate said transfer function along the frequency spectrum in a first and in a second position in such a way that: in a first position in the frequency spectrum of said transfer function, the mean chromatic dispersion weighted over said optical spectrum of the modulated signal is greater, in absolute value, than the value of dispersion robustness; in a second position in the frequency spectrum of said transfer function, the mean chromatic dispersion wei
    Type: Application
    Filed: December 27, 2006
    Publication date: September 16, 2010
    Applicant: PGT PHOTONICS S.P.A.
    Inventors: Pierpaolo Boffi, Giorgio Grasso, Lucia Marazzi, Paola Parolari, Aldo Righetti, Marco Romagnoli, Giovanni Tamiri
  • Patent number: 7528360
    Abstract: A polarization stabilizing device and method based on controlling the phase retardations of a pair of variable rotators with an optically interposed quarter-wave plate, with a controller such that the first of the variable rotators has its phase retardation switched between first and second values whenever the phase retardation of the second of the variable rotators reaches an upper or a lower limit. The upper and lower limits of the second rotator and the first and second values of the first rotator are chosen so that discontinuities in the power of the output optical radiation are avoided when the first variable rotator is switched, thereby providing endless polarization stabilization using rotators that themselves may have limited retardation ranges.
    Type: Grant
    Filed: September 6, 2005
    Date of Patent: May 5, 2009
    Assignee: PGT Photonics S.p.A.
    Inventors: Mario Martinelli, Paolo Martelli, Silvia Maria Pietralunga, Aldo Righetti