Configurations for a one by four light splitting device are disclosed. The light splitting device may include a primary waveguide, a first coupling waveguide, and a second coupling waveguide. The primary waveguide may couple light from the primary waveguide into both the first and second coupling waveguides. Due to the manipulation of the coupling modes, a fundamental mode of light may be input and four fundamental modes of light may be output. In some examples, the primary waveguide may input a fundamental mode of light that may be converted into a first hybrid mode, which may be a four lobe mode. The first and second coupling waveguides may be tapered and separated by a gap such that the first hybrid mode may be converted into two second hybrid modes, which may then be converted back into four fundamental modes of output light.

An optical waveguide connection structure connects a Si waveguide and an optical fiber to each other with a bonding layer interposed therebetween. The Si waveguide has a core whose cross-sectional area in the direction perpendicular to the direction of propagation of light decreases toward the optical fiber, and a cladding that covers the core. The optical fiber has a fiber core, a fiber cladding that covers the fiber core, and a recess formed in an end face opposed to the Si waveguide. The bonding layer fills a gap between the end face of the Si waveguide and the end face of the optical fiber and the recess, and the bonding layer has a refractive index greater than the refractive index of the fiber core of the optical fiber.

A method for fabricating an integrated structure, using a fabrication system having a CMOS line and a photonics line, includes the steps of: in the photonics line, fabricating a first photonics component in a silicon wafer; transferring the wafer from the photonics line to the CMOS line; and in the CMOS line, fabricating a CMOS component in the silicon wafer. Additionally, a monolithic integrated structure includes a silicon wafer with a waveguide and a CMOS component formed therein, wherein the waveguide structure includes a ridge extending away from the upper surface of the silicon wafer. A monolithic integrated structure is also provided which has a photonics component and a CMOS component formed therein, the photonics component including a waveguide having a width of 0.5 μm to 13 μm.

A semiconductor structure is disclosed. The semiconductor structure includes: a substrate and a gate element over the substrate. The gate element includes: a gate dielectric layer over the substrate; a gate electrode over the gate dielectric layer; and a waveguide passing through the gate electrode from a top surface of the gate electrode to a bottom surface of the gate electrode. A manufacturing method of the same is also disclosed.

The present disclosure provides a light detecting device. The light detecting devices includes an insulating layer, a silicon layer, a light detecting layer, N first doped regions and M second doped regions. The silicon layer is disposed over the insulating layer. The light detecting layer is disposed over the silicon layer and extends within at least a portion of the silicon layer. The first doped regions have a first dopant type and are disposed within the light detecting layer. The second doped regions have a second dopant type and are disposed within the light detecting layer. The first doped regions and the second doped regions are alternatingly arranged. M and N are integers equal to or greater than 2.

An optical fiber adapter and method of fabricating the same from a wafer including a double silicon-on-insulator layer structure. The optical fiber adapter may include a mode converter, a trench, and a V-groove, the V-groove and the trench operating as passive alignment features for an optical fiber, in the transverse translational and rotational degrees of freedom, and in the longitudinal translational degree of freedom, respectively. The mode converter may include a buried tapered waveguide.

A 90-degree optical hybrid includes two optical splitters that respectively split inputted light into two beams, two optical combiners that respectively combine two beams of inputted light and thereby output two beams of interfering light respectively, and four arm waveguides that input light splitted by any of the two optical splitters into any of the two optical combiners. Each of the four arm waveguides has a bend waveguide arranged at its center and a plurality of optical waveguides including a tapered waveguide having a width that decreases toward the bend waveguide. Both ends of each of the plurality of optical waveguides are respectively in contact with a end surface of any one of the two optical splitter, the two optical combiners, the bend waveguide and the other of the plurality of optical waveguides, and each of the plurality of waveguides is the tapered waveguide or a linear waveguide.

A method for fabricating an integrated structure, using a fabrication system having a CMOS line and a photonics line, includes the steps of: in the photonics line, fabricating a first photonics component in a silicon wafer; transferring the wafer from the photonics line to the CMOS line; and in the CMOS line, fabricating a CMOS component in the silicon wafer. Additionally, a monolithic integrated structure includes a silicon wafer with a waveguide and a CMOS component formed therein, wherein the waveguide structure includes a ridge extending away from the upper surface of the silicon wafer. A monolithic integrated structure is also provided which has a photonics component and a CMOS component formed therein, the photonics component including a waveguide having a width of 0.5 μm to 13 μm.

Disclosed are grating couplers having a high coupling efficiency for optical communications. In one embodiment, an apparatus for optical coupling is disclosed. The apparatus includes: a substrate; a grating coupler comprising a plurality of coupling gratings over the substrate, wherein each of the plurality of coupling gratings extends in a first lateral direction and has a cross-section having a middle-raised shape in a second lateral direction, wherein the first and second lateral directions are parallel to a surface of the substrate and perpendicular to each other in a grating plane; and a cladding layer comprising an optical medium, wherein the cladding layer is filled in over the grating coupler.

Integrated passive/active modulator units, integrated passive/active modulators comprising one or more units, and corresponding methods of fabrication and use are provided. In an example embodiment, a unit comprises an upstream passive portion comprising a passive waveguide; a downstream passive portion comprising a continuation of the passive waveguide; and an active portion between the upstream passive portion and the downstream passive portion. The active portion comprises an active waveguide and electrical contacts in electrical communication with the active waveguide. The active waveguide comprises an upstream taper and/or a downstream taper. The upstream taper is configured to optically couple the active waveguide to the passive waveguide of the upstream portion and the downstream taper is configured to optically couple the active waveguide to the continuation of the passive waveguide of the downstream portion.