Abstract: Disclosed are edge couplers having a high coupling efficiency and low polarization dependent loss, and methods of making the edge couplers. In one embodiment, a semiconductor device for optical coupling is disclosed. The semiconductor device includes: a substrate; an optical waveguide over the substrate; and a plurality of layers over the optical waveguide. The plurality of layers includes a plurality of coupling pillars disposed at an edge of the semiconductor device. The plurality of coupling pillars form an edge coupler configured for optically coupling the optical waveguide to an optical fiber placed at the edge of the semiconductor device.

Abstract: Methods of fabricating optical devices with high refractive index materials are disclosed. The method includes forming a first oxide layer on a substrate and forming a patterned template layer with first and second trenches on the first oxide layer. A material of the patterned template layer has a first refractive index. The method further includes forming a first portion of a waveguide and a first portion of an optical coupler within the first and second trenches, respectively, forming a second portion of the waveguide and a second portion of the optical coupler on a top surface of the patterned template layer, and depositing a cladding layer on the second portions of the waveguide and optical coupler. The waveguide and the optical coupler include materials with a second refractive index that is greater than the first refractive index.

Abstract: Integrated optical devices and methods of forming the same are disclosed. A method of forming an integrated optical device includes the following steps. A substrate is provided. The substrate includes, from bottom to top, a first semiconductor layer, an insulating layer and a second semiconductor layer. The second semiconductor layer is patterned to form a waveguide pattern. A surface smoothing treatment is performed to the waveguide pattern until a surface roughness Rz of the waveguide pattern is equal to or less than a desired value. A cladding layer is formed over the waveguide pattern.

Abstract: In some embodiments, the present disclosure relates to a device having a first waveguide and a second waveguide arranged over a substrate. The first waveguide has a first input terminal and a first output terminal, wherein the first input terminal is configured to receive light. The second waveguide is arranged laterally beside the first waveguide and has a second input terminal and a second output terminal. The second input terminal of the second waveguide is configured to receive light. The first waveguide further includes a first portion that has a different structure than surrounding portions of the first waveguide. The second waveguide further includes a second portion that has a different structure than surrounding portions of the second waveguide. The first waveguide is spaced apart at a maximum distance from the second waveguide at the first portion and the second portion.

Abstract: Disclosed are edge couplers having a high coupling efficiency and low polarization dependent loss, and methods of making the edge couplers. In one embodiment, a semiconductor device for optical coupling is disclosed. The semiconductor device includes: a substrate; an optical waveguide over the substrate; and a plurality of layers over the optical waveguide. The plurality of layers includes a plurality of coupling pillars disposed at an edge of the semiconductor device. The plurality of coupling pillars form an edge coupler configured for optically coupling the optical waveguide to an optical fiber placed at the edge of the semiconductor device.

Abstract: An optical modulator includes a carrier and a waveguide disposed on the carrier. The waveguide includes a first optical coupling region, a second optical coupling region, first regions, and second regions. The first optical coupling region is doped with first dopants. The second optical coupling region abuts the first optical coupling region and is doped with second dopants. The first dopants and the second dopants are of different conductivity type. The first regions are doped with the first dopants and are arrange adjacent to the first optical coupling region. The first regions have respective increasing doping concentrations as distances of the first regions increase from the first optical coupling region. The second regions are doped with the second dopants and are arranged adjacent to the second optical coupling region. The second regions have respective increasing doping concentrations as distances of the second regions increase from the second optical coupling region.

Abstract: A photonic structure is provided. The photonic structure includes an oxide structure surrounded by a semiconductor substrate, a buried oxide layer over the semiconductor substrate, and an optical coupling region over the buried oxide layer. The oxide structure has a first side surface and a second side surface opposite to the first side surface. In a plan view, the optical coupling region is tapered from the first side surface of the oxide structure to the second side surface of the oxide structure.

Abstract: An optical attenuating structure is provided. The optical attenuating structure includes a substrate, a waveguide, doping regions, an optical attenuating member, and a dielectric layer. The waveguide is extended over the substrate. The doping regions are disposed over the substrate, and include a first doping region, a second doping region opposite to the first doping region and separated from the first doping region by the waveguide, a first electrode extended over the substrate and in the first doping region, and a second electrode extended over the substrate and in the second doping region. The first optical attenuating member is coupled with the waveguide and disposed between the waveguide and the first electrode. The dielectric layer is disposed over the substrate and covers the waveguide, the doping regions and the first optical attenuating member.

Abstract: A photonic structure is provided. The photonic structure includes a semiconductor substrate, and an oxide structure embedded in the semiconductor substrate, and an optical coupling region directly above the buried oxide layer. A side surface of the oxide structure is exposed from an edge of the semiconductor substrate. The optical coupling region is tapered to a terminus of the optical coupling region at the edge of the semiconductor substrate.

Abstract: An optical system with different optical coupling device configurations and a method of fabricating the same are disclosed. An optical system includes a substrate, a waveguide disposed on the substrate, an optical fiber optically coupled to the waveguide, and an optical coupling device disposed between the optical fiber and the waveguide. The optical coupling device configured to optically couple the optical fiber to the waveguide. The optical coupling device includes a dielectric layer disposed on the substrate, a semiconductor tapered structure disposed in a first horizontal plane within the dielectric layer, and a multi-tip dielectric structure disposed in a second horizontal plane within the dielectric layer. The first and second horizontal planes are different from each other.

Abstract: Disclosed are edge couplers having a high coupling efficiency and low polarization dependent loss, and methods of making the edge couplers. In one embodiment, a semiconductor device for optical coupling is disclosed. The semiconductor device includes: a substrate; an optical waveguide over the substrate; and a plurality of layers over the optical waveguide. The plurality of layers includes a plurality of coupling pillars disposed at an edge of the semiconductor device. The plurality of coupling pillars form an edge coupler configured for optically coupling the optical waveguide to an optical fiber placed at the edge of the semiconductor device.

Abstract: Disclosed are apparatus and methods for optical coupling in optical communications. In one embodiment, an apparatus for optical coupling is disclosed. The apparatus includes: a planar layer; an array of scattering elements arranged in the planar layer at a plurality of intersections of a first set of concentric elliptical curves crossing with a second set of concentric elliptical curves rotated proximately 90 degrees to form a two-dimensional (2D) grating; a first taper structure formed in the planar layer connecting a first convex side of the 2D grating to a first waveguide; and a second taper structure formed in the planar layer connecting a second convex side of the 2D grating to a second waveguide. Each scattering element is a pillar into the planar layer. The pillar has a top surface whose shape is a concave polygon having at least 6 corners.

Abstract: Integrated optical devices and methods of forming the same are disclosed. A method of forming an integrated optical device includes the following steps. A substrate is provided. The substrate includes, from bottom to top, a first semiconductor layer, an insulating layer and a second semiconductor layer. The second semiconductor layer is patterned to form a waveguide pattern. A surface smoothing treatment is performed to the waveguide pattern until a surface roughness Rz of the waveguide pattern is equal to or less than a desired value. A cladding layer is formed over the waveguide pattern.

Abstract: The present disclosure provides a photo sensing device and a method for forming a photo sensing device. The photo sensing device includes a substrate, a photosensitive member, a superlattice layer and a diffusion barrier structure. The substrate includes a silicon layer at a front surface. The photosensitive member extends into and at least partially surrounded by the silicon layer, wherein an upper portion of the photosensitive member protruding from the silicon layer has a top surface and a facet tapering toward the top surface. The superlattice layer is disposed between the photosensitive member and the silicon layer. The diffusion barrier structure is disposed at a first side of the photosensitive member and a bottom of the diffusion barrier structure is at a level below a top surface of the silicon layer, wherein at least a portion of the diffusion barrier structure is laterally surrounded by the silicon layer.

Abstract: Disclosed are apparatus and methods for optical coupling in optical communications. In one embodiment, an apparatus for optical coupling is disclosed. The apparatus includes: a planar layer; an array of scattering elements arranged in the planar layer at a plurality of intersections of a first set of concentric elliptical curves crossing with a second set of concentric elliptical curves rotated proximately 90 degrees to form a two-dimensional (2D) grating; a first taper structure formed in the planar layer connecting a first convex side of the 2D grating to a first waveguide; and a second taper structure formed in the planar layer connecting a second convex side of the 2D grating to a second waveguide. Each scattering element is a pillar into the planar layer. The pillar has a top surface whose shape is a concave polygon having at least 6 corners.

Abstract: Disclosed are edge couplers having a high coupling efficiency and low polarization dependent loss, and methods of making the edge couplers. In one embodiment, a semiconductor device for optical coupling is disclosed. The semiconductor device includes: a substrate; an optical waveguide over the substrate; and a plurality of layers over the optical waveguide. The plurality of layers includes a plurality of coupling pillars disposed at an edge of the semiconductor device. The plurality of coupling pillars form an edge coupler configured for optically coupling the optical waveguide to an optical fiber placed at the edge of the semiconductor device.

Abstract: An optical modulator includes a dielectric layer and a waveguide. The waveguide is disposed on the dielectric layer. The waveguide includes an electrical coupling portion, a slab portion, and an optical coupling portion. The slab portion is directly in contact with both of the electrical coupling portion and the optical coupling portion. The slab portion has a first sub-portion and a second sub-portion connected to the first sub-portion. A top surface of the electrical coupling portion, a top surface of the first sub-portion, and a top surface of the second sub-portion are located at different level heights.

Abstract: An optical device for coupling light propagating between a waveguide and an optical transmission component is provided. The optical device includes a taper portion and a grating portion. The taper portion is disposed between the grating portion and the waveguide. The grating portion includes rows of grating patterns. A first size of a first grating pattern in a first row of grating patterns is larger than a second size of a second grating pattern in a second row of grating patterns. A first distance between the first row of grating patterns and the waveguide is less than a second distance between the second row of grating patterns and the waveguide.

Abstract: The present disclosure provides a photo sensing device, the photo sensing device includes a substrate, including a silicon layer at a front surface, a photosensitive member extending into and at least partially surrounded by the silicon layer, a first doped region having a first conductivity type at a first side of the photosensitive member, wherein the first doped region is in the silicon layer, and a second doped region having a second conductivity type different from the first conductivity type at a second side of the photosensitive member opposite to the first side, wherein the second doped region is in the silicon layer, and the first doped region is apart from the second doped region, and a superlattice layer disposed between the photosensitive member and the silicon layer, wherein the superlattice layer includes a first material and a second material different from the first material.

Abstract: Integrated optical devices and methods of forming the same are disclosed. A method of forming an integrated optical device includes the following steps. A substrate is provided. The substrate includes, from bottom to top, a first semiconductor layer, an insulating layer and a second semiconductor layer. The second semiconductor layer is patterned to form a waveguide pattern. A surface smoothing treatment is performed to the waveguide pattern until a surface roughness Rz of the waveguide pattern is equal to or less than a desired value. A cladding layer is formed over the waveguide pattern.