Abstract: An optical communication system and method of use are described. The system comprisesan 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 ?? comprising a first instantaneous frequency (?0) associated to the first state and a second instantaneous frequency (?1) 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.

Abstract: 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 ?? comprising a first instantaneous frequency (?0) associated to the first state and a second instantaneous frequency (?1) 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.

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.

Abstract: An optical assembly includes an optical package having a wall with an aperture and includes a laser device capable of emitting a laser beam through the aperture and a collimator including a sleeve defining a first and a second end, the collimator including a terminating portion of an optical fiber. In addition, the assembly includes a joint element having a first and a second surface, the first surface contacting the wall around the aperture in a first contact area, and the second surface including a convex surface contacting a portion of the surface of the sleeve in correspondence of its first end in a second contact area, the convex surface being at least partially inserted in the sleeve, so that the collimator is aligned with respect to the laser beam.

Abstract: A method of fabricating a turning mirror for an optical device includes the steps of depositing on a substrate, which defines a plane in which an optical signal propagates in a propagating direction, a photoresist layer sensitive to electrons and to UV radiation. The material in which the photoresist layer is formed, has a contrast not larger than 3. A first portion of the photoresist layer is exposed to an electron beam, wherein the electron dose of the electron beam exposure is varied within the first portion according to a selected pattern, and wherein the electron does to which a given region in the photoresist is exposed, depends on the resulting photoresist height in the given region after development. A second portion of the photoresist layer is exposed to UV radiation; the first and the second portions are overlapped at least in a third portion.

Abstract: The present invention relates to an external-cavity laser module comprising a thermoelectric cooler (TEC) including an upper carrier plate having an upper surface, said TEC being configured to stabilize the temperature of the upper surface at a substantially constant temperature. The laser module further comprises a laser assembly mounted on an optical bench, which is in thermal coupling with said upper surface, said laser assembly comprising a gain medium for emitting an optical beam into the external cavity and an end mirror.

Abstract: An optical device for splitting/combining a first and a second continuous optical wavelength bands, each wider than 10 nm, has a first, a second, a third, a fourth and a fifth optical splitting devices optically coupled in cascade and a first, a second, a third and a fourth optical differential delay devices optically coupled to, and interleaved between, the optical splitting devices. A suitable choice of the coupling angles of the splitting devices and of the differential delays of the optical differential delay devices gives to the structure flattened passbands and stopbands and makes the optical device tolerant to fluctuations of the structural parameters. An apparatus includes the optical device for use in fiber-to-the-premises networks.

Abstract: A Raman amplifier comprises at least a first and a second optical Raman-active fiber disposed in series with each other. A first pump source is connected to the first Raman-active fiber, and is adapted for emitting and coupling into the first Raman-active fiber a first pump radiation including a first group of frequencies. A second pump source is connected to the second Raman-active fiber, and is adapted for emitting and coupling into the second Raman-active fiber a second pump radiation including a second group of frequencies. The whole of said first and second group of frequencies extends over a pump frequency range having a width of at least the 40% of the Raman shift. The minimum and the maximum frequency in each of said first and second group of frequencies differ with each other of at most the 70% of said Raman shift.

Abstract: An optical communication system and method of use are described.

Abstract: A method of controlling an external-cavity tuneable laser which has a wavelength-elective tuneable mirror, in which wavelength selectivity is achieved by an electrical signal provided by an alternating voltage. The tuneable mirror has a liquid crystal material, a diffraction grating and a planar waveguide optically interacting with the grating. The diffraction grating and the waveguide form a resonant structure that reflects only a selected resonance wavelength from among all the other wavelengths impinging thereon. Depending on the amplitude of the voltage applied to the tunable mirror, the tuneable mirror reflects radiation only at a given wavelength. The lasing output wavelength of the laser is selected to correspond to the resonance wavelength of the tuneable mirror. Accurate selection of the emission wavelength (frequency) of the tuneable laser by the tuneable mirror can be derived from the analysis of the signal modulation induced by the AC voltage applied to the tuneable mirror.

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.