Abstract: A method for manufacturing an optical device including at least one silicone elastomer optical waveguide includes the steps of providing a substantially rigid mold with a patterned surface, providing a core layer of a curable silicone elastomer, patterning the core layer by means of the patterned surface of the substantially rigid mold, curing the patterned core layer, and removing the substantially rigid mold from the patterned core layer. The method advantageously allows the manufacture of an optical device including at least one optical waveguide in a single step and in a reproducible manner.

Abstract: A tool for static or dynamic planning of a WDM network with dedicated protection. The WDM network is represented by a layered graph having image nodes for each node of the network and horizontal arcs for each link of the network, so as to replicate in each layer the topology of the network. A Bhandari algorithm is adapted for finding on the layered graph a working-spare pair of lightpaths for each connection request to be allocated.

Abstract: 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 (?1), S (?2), . . . , S (?n), received at its input ports and for transmitting the remaining optical signals through its output ports in the first and second interferometric arms.

Abstract: A device for crossing optical beams. At least a first input optical waveguide is directed along a first axis, a second optical waveguide is directed along a second axis inclined with respect to the first axis, and a photonic crystal having a regular periodicity in an optical crossing region at the intersection of said first and second axis has, opposite the first and second input waveguides, a first and a second output waveguide to provide for exit beams.

Abstract: In a process for producing a low polarization mode dispersion optical fiber, which comprises the steps of drawing a glass preform into an optical fiber and of spinning, during drawing, the optical fiber about an optical fiber axis, the spinning is imparted according to a bidirectional and substantially trapezoidal spin function, which includes zones (P) of substantially constant amplitude (plateau) and zones of transition (T) where inversion of the spin direction takes place, wherein the extension (p) of the zones of substantially constant amplitude is greater than the extension (t) of the zones of transition, and the number of inversions of the direction of spin in a length of fiber of 20 m is at most two.

Abstract: A wavelength converter device is provided for generating a converted radiation at frequency ?g through interaction between at least one signal radiation at frequency ?s and at least one pump radiation at frequency ?p, including an input for the at least one signal radiation at frequency ?s, a pump light source for generating the at least one pump radiation at frequency ?p, an output for taking out the converted radiation at frequency ?g, a structure for transmitting the signal radiation, including two optical resonators having a non-linear material, having an optical length of at least 40*?/2, ? being the wavelength of the pump radiation, and resonating at the pump, signal and converted frequencies ?p, ?s and ?g, wherein by propagating through the structure, the pump and signal radiation generate the converted radiation by non-linear interaction within the optical resonators.

Abstract: An optical communication line of a communication system has a first processing station and an amplifying station. The line has a first optical connection having at least partially compensated accumulated dispersion and is placed between the first processing station and the amplifying station. A second optical connection having at least partially compensated accumulated dispersion is connected to the output of the amplifying station. Portions of optical fiber leaving the processing station and the amplifying station are associated to respective first order chromatic dispersions which are of opposite signs and have absolute values lower than or equal to 13 ps2/Km.

Abstract: A polarization stabilizing device and method based on controlling the phase retardation of a pair of variable phase retarders with a controller such that the first of the variable retarders has its phase retardation switched between first and second values whenever the phase retardation of the second of the variable retarders reaches an upper or a lower limit. The upper and lower limits of the second retarder and the first and second values of the first retarder are chosen so that discontinuities in the power of the output optical signal are avoided when the first variable retarder is switched, thereby providing endless polarization stabilization using phase retarders that themselves have only limited retardation ranges.

Abstract: An optical cable having at least one element for the transmission of optical signals and a structure that is able to protect the at least one element. The structure is a multilayer structure and is arranged in a position radially external to the at least one element and has a) at least one first covering layer of polymeric material in a position radially external to the at least one element; b) at least one covering layer of foamed polymeric material in a position radially external to the at least one first covering layer, and c) at least one second covering layer of polymeric material in a position radially external to the at least one covering layer of foamed polymeric material. The foamed polymeric material has a density between 0.3 and 0.7 kg/dm3 and tensile modulus at 20° C. between 300 and 700 MPa.

Abstract: Waveguide bends are specially designed according to a matching condition in order to suppress mode distortion and other undesirable effects. The bend is structured having regard to its length and curvature to ensure that at its end the first and second bend modes are substantially in phase with each other having completed approximately an integer number of beats. By being in phase at the end of the bend, the two modes are able to properly reconstruct the first mode of the straight waveguide and propagate on with a minimum of distortion, whether it be into a straight section, a further curved section of arbitrary curvature, into a free space propagation region and the like. This approach suppresses mode distortion, transition losses and other negative effects of waveguide bends. Device applications include couplers, Y-branches and Mach-Zehnder interferometers, all of which include waveguide bends.

Abstract: A tuneable grating assisted directional optical coupler to couple a transmission signal has a first waveguide including a first core and a first cladding, the first waveguide having a first effective refractive index. The coupler also has a second waveguide including a second core and a second cladding, the second waveguide having a second effective refractive index different from the first effective index and being in substantially close proximity to the first waveguide in a predetermined region to provide coupling therebetween. A periodic perturbation is positioned in the coupling region to cause the coupling to be wavelength selective for one given wavelength function of the first and/or the second effective refractive index. Additionally, the second cladding of the second waveguide has a tuneable material and the first cladding of the first waveguide has a non-tuneable material.

Abstract: A communication network includes a plurality of antennas and includes among the antennas at least one reconfigurable antenna adapted to serve communication traffic in a respective coverage area, the reconfigurable antenna having a radiation diagram exhibiting a plurality of selectively adjustable gain values for a set of directions, each direction in the set defining a propagation path between the antenna and a portion of the coverage area, determining, for each direction in the set, at least one value of communication traffic and at least one attenuation value over the propagation path, and selectively and independently alloting to each direction in the set a respective gain value as a function of at least one of the value of communication traffic and the attenuation value determined for that direction. The arrangement is adapted for use in communication networks such as second and third generation mobile communication networks employing electrically controllable antennas.

Abstract: An optical waveguide has a core layer made by a film containing a cross-linked polyamide based on a repeating unit of general formula (I) and a method for the production thereof.

Abstract: A method of evaluating the Polarization Mode Dispersion (PMD) of an optical fiber by arranging the optical fiber at substantially zero tension on a surface, propagating prescribed evaluation optical signals along the optical fiber, measuring fiber Differential Group Delay (DGD) values in response to the evaluation optical signals, repeating at least once the acts of propagating and measuring, each time preliminarily inducing a change in a mode coupling of the fiber, and determining the fiber PMD on the basis of a calculated DGD average value. Changes in the polarization mode coupling of the fiber are induced by, moving at least a section of the fiber substantially orthogonally to the surface.

Abstract: A process for manufacturing an electric cable. In particular, the process includes the steps of: a) feeding a conductor at a predetermined feeding speed; b) extruding a thermoplastic insulating layer in a position radially external to the conductor; c) cooling the extruded insulating layer; and d) forming a circumferentially closed metal shield around the extruded insulating layer. The process according to the invention is carried out continuously, i.e., the time occurring between the end of the cooling step and the beginning of the shield forming step is inversely proportional to the feeding speed of the conductor.

Abstract: A Raman amplifier having at least a first and a second optical Raman-active fiber disposed in series with each other is disclosed. 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 the first and second group of frequencies extends over a pump frequency range having a width of at least 40% of the Raman shift. The minimum and the maximum frequency in each of the first and second group of frequencies differ from each other by at most 70% of the Raman shift.

Abstract: Bidirectional isolating devices including non-reciprocal rotators (i.e. Faraday rotators) and wavelength selective reciprocal polarization rotators are disclosed. Each wavelength selective rotator behaves like a half-wave retarder in a first frequency range and behaves like a full-wave retarder in a second frequency range, according to a substantially periodic transfer function. The rotation has a predetermined number of birefringent elements (e.g. waveplates), the thickness and the orientation of which are chosen so as to obtain a transition between the half-wave retarder behavior and the full-wave retarder behavior in a frequency range lower than or equal to 40% of the period of the transfer function. In order to satisfy such a requirement, a relatively high number of birefringent elements is required, i.e. at least the five birefringent elements. Advantageously, the isolating device may comply with any allocation scheme for the opposite propagating signals.

Abstract: A method for shielding the magnetic field generated by an electrical power transmission line having at least one electrical cable. A magnetic shield is provided in a position radially external to at least one electrical cable. The magnetic shield has at least one pair of shielding layers made from different ferromagnetic materials, radially superimposed and having their maximum relative magnetic permeability increasing in a radial direction from the inside toward the outside of the magnetic shield. An electrical power transmission line provided with multiple-layer magnetic shield and a multiple-layer magnetic shield.

Abstract: The radiation characteristics of an antenna are made configurable including in the antenna a plurality of radiating elements and associating to each of said radiating elements a respective chain for processing the signal in transmission and/or reception with a module for weighting digital signals capable of applying to a digital signal at least a respective weighting coefficient and an antenna conversion set interposed between the module for weighting digital signals and one of the radiating elements of the antenna. The antenna conversion set operates on a digital signal on the side of the signal weighting module and on an analogue signal distributed on the processing chains associated to each radiating element of the antenna propagates (in transmission and/or reception), while respective weight coefficients are applied to said digital signal weighting modules. The weighting coefficients determine the radiation diagram of the antenna.