Abstract: An ADD/DROP filter and an optical add/drop multiplexer are disclosed. An ADD/DROP filter includes an input port, an output port, an add port connecting to a modulator, and a drop port. The modulator is configured to load a pilot signal to a first optical signal to obtain a second optical signal, and transmit the second optical signal to the add port. A third optical signal is input to the input port. A wavelength difference between the second optical signal and the third optical signal is an integral multiple of a free spectral range. A power detector is connected to the output port and/or the drop port. The power detector is configured to obtain an output optical signal from the output port or the drop port and detect an optical power of the output optical signal.

Abstract: An optical delay method, and related system, includes propagating an optical signal along an optical delay device (10) with a first stage (11) having a variable input coupler (20) and a delay element. An intermediate stage (12) has a variable intermediate coupler (30) and a delay element. An output stage (13) includes a variable output coupler (40). The method sets a coupling ratio of the input (20) and output couplers (40) equal to a value K1 selected among a plurality of at least three values. A coupling ratio of the intermediate coupler (30) is set equal to a value K2, wherein K1=sin2(?) & K2=sin2(A*?) with ? greater than or equal to zero and less than or equal to ?/2 and A greater than or equal to 1.5 and less than or equal to 2.5.

Abstract: An ADD/DROP filter and an optical add/drop multiplexer are disclosed. An ADD/DROP filter includes an input port, an output port, an add port connecting to a modulator, and a drop port. The modulator is configured to load a pilot signal to a first optical signal to obtain a second optical signal, and transmit the second optical signal to the add port. A third optical signal is input to the input port. A wavelength difference between the second optical signal and the third optical signal is an integral multiple of a free spectral range. A power detector is connected to the output port and/or the drop port. The power detector is configured to obtain an output optical signal from the output port or the drop port and detect an optical power of the output optical signal.

Abstract: An optical delay method, and related system, includes propagating an optical signal along an optical delay device (10) with a first stage (11) having a variable input coupler (20) and a delay element. An intermediate stage (12) has a variable intermediate coupler (30) and a delay element. An output stage (13) includes a variable output coupler (40). The method sets a coupling ratio of the input (20) and output couplers (40) equal to a value K1 selected among a plurality of at least three values. A coupling ratio of the intermediate coupler (30) is set equal to a value K2, wherein K1=sin2(?)çK2=sin2(A*?) with ? greater than or equal to zero and less than or equal to ?/2 and A greater than or equal to 1.5 and less than or equal to 2.5.

Abstract: An optical radiation detection system (100) comprising: an optical medium (1) structured to define a region (5) suitable for transmitting an optical radiation and being associated to at least one electric parameter varying as a function of the optical radiation concerning said region; at least one electrode (2, 3) electrically coupled to the optical medium (1), and spaced from said region (5), an electric power generator (4) connected to said at least one electrode (2) and structured to provide an electric signal (Se) to be applied to the optical medium. Further, the system comprises an electric measuring circuit (50) connected to said at least one electrode (2) and structured to provide a measuring electric signal (SM) representing a variation of said at least one electric parameter.

Abstract: An optical radiation detection system (100) comprising: an optical medium (1) structured to define a region (5) suitable for transmitting an optical radiation and being associated to at least one electric parameter varying as a function of the optical radiation concerning said region; at least one electrode (2, 3) electrically coupled to the optical medium (1), and spaced from said region (5), an electric power generator (4) connected to said at least one electrode (2) and structured to provide an electric signal (Se) to be applied to the optical medium. Further, the system comprises an electric measuring circuit (50) connected to said at least one electrode (2) and structured to provide a measuring electric signal (SM) representing a variation of said at least one electric parameter.

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).

Abstract: In a photonic waveguide, there is provided an undercladding layer and a waveguide core, having a cross-sectional height and width, that is disposed on the undercladding layer. The waveguide core comprises a waveguide core material having a thermo-optic coefficient. A refractive index tuning cladding layer is disposed on top of the waveguide core. The refractive index tuning cladding layer comprises a refractive index tuning cladding material having an adjustable refractive index and an absorption length at a refractive index tuning radiation wavelength. A thermo-optic coefficient compensation cladding layer is disposed on top of the refractive index tuning cladding layer. The thermo-optic coefficient compensation cladding layer comprises a thermo-optic coefficient compensation material having a thermo-optic coefficient that is of opposite sign to the thermo-optic coefficient of the waveguide core material.

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).

Abstract: In a photonic waveguide, there is provided an undercladding layer and a waveguide core, having a cross-sectional height and width, that is disposed on the undercladding layer. The waveguide core comprises a waveguide core material having a thermo-optic coefficient. A refractive index tuning cladding layer is disposed on top of the waveguide core. The refractive index tuning cladding layer comprises a refractive index tuning cladding material having an adjustable refractive index and an absorption length at a refractive index tuning radiation wavelength. A thermo-optic coefficient compensation cladding layer is disposed on top of the refractive index tuning cladding layer. The thermo-optic coefficient compensation cladding layer comprises a thermo-optic coefficient compensation material having a thermo-optic coefficient that is of opposite sign to the thermo-optic coefficient of the waveguide core material.

Abstract: A three-arm-Mach-Zehnder interferometer for splitting/combining first and second wavelength bands is provided, wherein the optical device includes first and second optical splitting/combining elements; a differential optical delay device comprising first, second and third optical paths; the first, second and third optical paths of the differential optical delay device are configured to introduce, at a wavelength ?z within the first optical band, a phase delay of 2?m.

Abstract: A three-arm-Mach-Zehnder interferometer for splitting/combining first and second wavelength bands is provided, wherein the optical device includes first and second optical splitting/combining elements; a differential optical delay device comprising first, second and third optical paths; the first, second and third optical paths of the differential optical delay device are configured to introduce, at a wavelength ?z within the first optical band, a phase delay of 2?m.

Abstract: A three-arm-Mach-Zehnder interferometer for splitting/combining a first and a second wavelength band, wherein the optical device includes: a first and second optical splitting/combining element; a differential optical delay device comprising a first, a second and a third optical path; each of the first and second optical splitting/combining elements, is of the (25-50-25%)?x(0-0-100%)?y type, wherein ?x is a wavelength with the first optical band and ?y is a wavelength with the second optical band, and the first, second and third optical paths of the differential optical delay device are configured to introduce, at a wavelength ?z within the first optical band, a phase delay ?? of 2?m.

Abstract: A three-arm-Mach-Zehnder interferometer for splitting/combining a first and a second wavelength band, wherein the optical device includes: a first and second optical splitting/combining element; a differential optical delay device comprising a first, a second and a third optical path; each of the first and second optical splitting/combining elements, is of the (25-50-25%)?x(0-0-100%)?y type, wherein ?x is a wavelength with the first optical band and ?y is a wavelength with the second optical band, and the first, second and third optical paths of the differential optical delay device are configured to introduce, at a wavelength ?z within the first optical band, a phase delay ?? of 2?m.

Abstract: An optical device includes an interferometer having a first optical coupler, a second optical coupler and at least three arms optically coupling the first optical coupler to the second optical coupler; and a phase-shifting arrangement associated with the arms, at least one among the first and second optical couplers including a first optical input port, two first optical output ports and a second optical output port. An optical power coupling is implemented such that optical power received at the first optical input port is coupled, a first fraction into each of the first optical output ports, and a second fraction into the second optical output port.

Abstract: An optical switching system includes a two-dimensional arrangement of a plurality of switching elements. Each switching element includes an optical guiding structure which includes two pairs of waveguides; a driving arrangement for individually moving the switching elements between at least a first and a second position; and a first and a second input and a second output. When a generic switching element is moved in the first position, the first pair of waveguides connects a first input with a first output, and a second input with a second output; when a generic switching element is moved in the second position, the second pair of waveguides connects the first input with the second output, and the second input with the first output. In a first embodiment, the waveguides are provided on a disc shaped carrier and lie in the same plane, which disc is rotated. In a second embodiment, the two pairs of waveguides lie in different planes and the waveguide carrier plate is moved up and down for switching.

Abstract: An integrated optical waveguide structure having a waveguide core for guiding an optical field, formed on a lower cladding layer. The waveguide core has a waveguide core layer substantially coextensive to the lower cladding layer and having a substantially uniform thickness, and a waveguide core rib of a substantially uniform height protruding from a surface of the waveguide core layer opposite to a surface thereof facing the lower cladding layer. A layout of the waveguide core rib defines a path for the guided optical field. The integrated optical waveguide structure has a circuit waveguide portion in which the waveguide core layer has a first width, adapted for guiding the optical field through an optical circuit, and at least one coupling waveguide portion adapted for coupling the circuit waveguide portion to an external optical field.

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: 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.