An optical system includes a silicon (Si) substrate, a buried oxide (BOX) layer formed on the substrate, a silicon nitride (SiN) layer formed above the BOX layer, and a SiN waveguide formed in the SiN layer. In some embodiments, the optical system may additionally include an interposer waveguide adiabatically coupled to the SiN waveguide to form a SiN-interposer adiabatic coupler that includes at least the tapered section of the SiN waveguide, the optical system further including at least one of: a cavity formed in the Si substrate at least beneath the SiN-interposer adiabatic coupler or an oxide overlay formed between a top of a SiN core of the SiN waveguide and a bottom of the interposer waveguide. Alternatively or additionally, the optical system may additionally include a multimode SiSiN adiabatic coupler that includes a SiN taper of a SiN waveguide and a Si taper of a Si waveguide.

The invention relates to an optoelectronic device for generation of a frequency comb comprising: a laser source (2); an optical micro-resonator (3), comprising a resonant ring (20); at least one waveguide (30) optically coupled to the resonant ring (20), having an effective index associated with a fundamental optical mode supported by the filtering guide (30) equal to an effective index associated with an optical higher order mode supported by the resonant ring (20).

Provided is a resin optical waveguide containing a core, under cladding and over cladding, in which the resin optical waveguide has portions having a core width varying along a light propagation direction, the maximum core width is 4 to 10 ?m, and the minimum core width of 1 ?m or more and less than 4 ?m, when the length of a portion S at which the core width is 1 ?m or more and less than 4?m is LS and the length of a portion at which the core width is 4 to 10 ?m is LL, the proportion of LS to the total length is 0.1 to 40%, and the portion S contains neither a certain bubble defect nor a certain defect inside the core and in a vicinity of a core-cladding interface.

A device and method are provided. The device includes a bus waveguide having a longitudinal axis, a lower waveguide disposed on a first side of the bus waveguide, and an upper waveguide disposed on a second side of the bus waveguide opposite to the first side of the bus waveguide, wherein the upper waveguide substantially matches a path of the lower waveguide. The method includes receiving a TE.sub.1 mode optical signal on a bus waveguide, receiving a TE.sub.0 mode optical signal on a lower waveguide disposed below the bus waveguide, mode multiplexing the TE.sub.1 mode optical signal and the TE.sub.0 mode optical signal without converting the TE.sub.0 mode optical signal or the TE.sub.1 mode optical signal to another mode, and outputting the TE.sub.0 mode optical signal and the TE.sub.1 mode optical signal on the bus waveguide.

The present invention relates to a composite optical waveguide (1) containing a polymer optical waveguide and a silicon optical waveguide adiabatically coupled to each other, in which the polymer optical waveguide and the silicon optical waveguide are coupled to each other by an adhesive layer in an adiabatic-coupling portion where a core of the polymer optical waveguide and a core of the silicon optical waveguide are disposed to face each other, the adhesive layer is formed by using a photocurable adhesive having a glass transition point Tg being 125 C. or higher after curing, and the adiabatic-coupling portion includes a region in which a spacing t between the core of the polymer optical waveguide and the silicon optical waveguide is 1.5 m or less.

The invention relates to an optical coupling device for coupling a first waveguide, for example a multi-mode waveguide, to a second waveguide, for example a single-mode waveguide. The device is formed in a core layer and comprises a focusing structure (SF) capable of converting a light beam from a target mode of the first waveguide to a target mode of the second waveguide. The focusing structure comprises a plurality of trenches (T1-T4) made in the core layer to create a pseudo graded refractive index, itself able to convert the light beam from the target mode of the first waveguide to the target mode of the second waveguide.

The scope of the invention extends to a photonic circuit comprising a single-mode waveguide, a multi-mode waveguide and a device according to the invention for coupling the single-mode waveguide to the multi-mode waveguide. The multi-mode waveguide can comprise a surface coupling network in order to allow for coupling with an optical fibre.

A sensing cable includes a first optical fiber, a second optical fiber that extends along the first optical fiber and that is spaced from the first optical fiber, and a transmitting material that includes an intervention portion present between the first optical fiber and the second optical fiber, the transmitting material being configured to transmit light from the first optical fiber to the second optical fiber through the intervention portion.

A guided light source that comprises: at least one quantum box associated with a discoid wave guide to achieve cylindrical propagation of a wave front emitted by the at least one quantum box in the discoid wave guide; an annular wave guide surrounding the discoid wave guide and having a grating coupler formed on its internal periphery to receive the wave front in normal incidence; an output wave guide optically coupled to the annular wave guide, in which the wave front is guided. The invention includes the method of fabrication of such a source, and its use for emission of a sequence of single photons.

An optical system includes a silicon (Si) substrate, a buried oxide (BOX) layer formed on the substrate, a silicon nitride (SiN) layer formed above the BOX layer, and a SiN waveguide formed in the SiN layer. In some embodiments, the optical system may additionally include an interposer waveguide adiabatically coupled to the SiN waveguide to form a SiN-interposer adiabatic coupler that includes at least the tapered section of the SiN waveguide, the optical system further including at least one of: a cavity formed in the Si substrate at least beneath the SiN-interposer adiabatic coupler or an oxide overlay formed between a top of a SiN core of the SiN waveguide and a bottom of the interposer waveguide. Alternatively or additionally, the optical system may additionally include a multimode SiSiN adiabatic coupler that includes a SiN taper of a SiN waveguide and a Si taper of a Si waveguide.

In the examples provided herein, an apparatus has a mode converter coupled to a first waveguide to convert light propagating in a first set of spatial modes along the first waveguide to a second set of spatial modes. The apparatus also has a second waveguide coupled to the mode converter, where the second set of spatial modes propagate along the second waveguide in a first direction away from the mode converter. Further, the apparatus includes a coupler to couple a portion of the light propagating in the second set of spatial modes out of the second waveguide. Additionally, the second waveguide has an end facet away from the mode converter to reduce back reflection of the light not coupled out of the second waveguide to the first waveguide.