摘要:
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 λz within the first optical band, a phase delay of 2πm.
摘要:
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%)λx(0-0-100%)λy type, wherein λx is a wavelength with the first optical band and λy 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 λz within the first optical band, a phase delay Δφ of 2πm.
摘要:
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%)λx(0-0-100%)λy type, wherein λx is a wavelength with the first optical band and λy 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 λz within the first optical band, a phase delay Δφ of 2πm.
摘要:
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. The coupling portion has a terminal waveguide core rib portion having a second width lower than the first width and terminating in a facet, and a transition waveguide core rib portion optically joining to each other the circuit waveguide portion and the terminal waveguide portion, the transition waveguide core rib portion being laterally tapered so that a width thereof decreases from the first width to the second width. The waveguide structure allows an integrated optical device designer satisfying optical circuits needs and, at the same time, ensuring a satisfactory coupling efficiency with an external field.
摘要:
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 λz within the first optical band, a phase delay of 2πm.
摘要:
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.
摘要:
A hybrid waveguide structure having a combination of buried waveguide sections and ridge waveguide sections on the same substrate, share a common core layer. The buried waveguide sections provide the low index contrast desirable for couplers and other device components. The ridge waveguide sections provide the high index contrast needed for efficient low-loss tightly curved waveguides. The devices are fabricated starting from a low index contrast buried waveguide. Cladding material is then selectively removed by etching down from an upper surface either side of the waveguide core to a lower surface. This forms an enhanced index contrast ridge section of the waveguide. The other sections of the waveguide core remain buried and thus retain lower index contrast. Using this approach, a variety of optical devices, such as add/drop or add-after-drop multiplexers for WDM applications based on microrings or Mach-Zehnder interferometers, can be made with large feature sizes of several microns using silica-on-glass or silica-on-silicon technology, for example, and without having to use nanofabricated semiconductor structures.
摘要:
An optical communication system has a transmitter generating a phase-modulated optical signal (Sa, Sb, . . . , Sk); a receiver for receiving the phase-modulated optical signal; an optical communication link between the transmitter section and the receiver section. The optical communication link is a dispersion-managed optical communication link having dispersion-compensating elements propagating the phase-modulated optical signal at substantially constant optical power. The receiver has a dispersive element having a prescribed dispersion, the dispersive element receiving and converting the phase-modulated optical signal into a corresponding intensity-modulated optical signal, and an optical intensity detector fed with the intensity-modulated optical signal.
摘要:
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. The at least one among the first and second optical couplers further includes a second optical input port and a third optical input port, and the at least one among the first and second optical couplers implements an optical power coupling such that optical power received at either one of the first or second optical input ports is coupled, the first fraction into each of the first optical output ports, and the second fraction into the second optical output port, whereas optical power received at the third optical input port is coupled, a third fraction into each of the first optical output ports, and a fourth fraction into the second optical output port, wherein the first fraction is different from the third fraction.
摘要:
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.