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 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: 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 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.

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 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.