A graded-index polymer waveguide (30) and a manufacturing method thereof are provided. The method includes providing a waveguide substrate (1); manufacturing a waveguide lower cladding layer (2) on a surface of the waveguide substrate (1); coating a material of a waveguide core layer (3) having UV photosensitivity on a surface of the waveguide lower cladding layer (2) away from the waveguide substrate (1); performing a hot imprinting process for the material of the waveguide core layer by means of a flexible transfer film mold and forming a waveguide core layer (3) having an imprinted waveguide link structure; performing a heat treatment process for the waveguide core layer (3); performing a pre-exposure process for the waveguide core layer; coating a waveguide upper cladding layer on a surface of a waveguide core layer (3); and curing the waveguide core layer (3) and the waveguide upper cladding layer (4).

Disclosed is a polymeric waveguide for propagating light therein along width and length dimensions of the polymeric waveguide. The polymeric waveguide has a first curved surface on one side thereof and a second curved surface on an opposite second side thereof, and a refractive index spatially varying through a thickness thereof between the first curved surface and the second curved surface. The polymeric waveguide is curved in a cross-section comprising at least one of the width and length dimensions.

Disclosed is a polymeric waveguide for propagating light therein along width and length dimensions of the polymeric waveguide. The polymeric waveguide has a first curved surface on one side thereof and a second curved surface on an opposite second side thereof, and a refractive index spatially varying through a thickness thereof between the first curved surface and the second curved surface. The polymeric waveguide is curved in a cross-section comprising at least one of the width and length dimensions.

Thermal isolation elements are provided in wafer-bonded silicon photonics that include a photonic platform, including a heating element and an optical waveguide that are disposed between a first surface and a second surface (opposite to the first surface) of the photonic platform; a substrate, including a third surface and a fourth surface (opposite to the third surface); wherein the first surface of the photonic platform is bonded to the third surface of the substrate; and wherein a cavity is defined by a trench in one or more of: the first surface and extending towards, but not reaching, the second surface, and the third surface and extending towards, but not reaching, the fourth surface; wherein the cavity is filled with a gas of a known composition at a predefined pressure; and wherein the cavity is aligned with the optical waveguide and the heating element.

Thermal isolation elements are provided in wafer-bonded silicon photonics that include a photonic platform, including a heating element and an optical waveguide that are disposed between a first surface and a second surface (opposite to the first surface) of the photonic platform; a substrate, including a third surface and a fourth surface (opposite to the third surface); wherein the first surface of the photonic platform is bonded to the third surface of the substrate; and wherein a cavity is defined by a trench in one or more of: the first surface and extending towards, but not reaching, the second surface, and the third surface and extending towards, but not reaching, the fourth surface; wherein the cavity is filled with a gas of a known composition at a predefined pressure; and wherein the cavity is aligned with the optical waveguide and the heating element.

Methods for fabricating an optical waveguide and a display device and a photomask used therein is provided. Firstly, a photomask is provided, wherein the photomask has light blocking structures regularly distributed. A first light curing resin layer is formed on a first transparent substrate. Next, the photomask is placed on the first light curing resin layer. The first light curing resin layer is irradiated and cured with incident light through the photomask and the light blocking structures to have a first curing level and a first refractive index. The first curing level and the first refractive index, corresponding to each other, are periodically distributed. Finally, the photomask is removed from the first light curing resin layer to form an optical waveguide with the first light curing resin layer having the first curing level that is periodically distributed and the first transparent substrate.

An optical coupler is provided. The optical coupler includes: a first optical structure, and a second optical structure disposed over the first optical structure. The first optical structure includes: a first substrate, a first cladding layer disposed on the first substrate, and a first waveguide disposed on the first cladding layer. The first waveguide includes a first coupling portion, and the first coupling portion including a first taper part. The second optical structure includes: a second substrate, a dielectric layer disposed on the second substrate; and a second waveguide disposed on the dielectric layer. The second waveguide includes a second coupling portion, and the second coupling portion including a second taper part. The second taper part is disposed on and optically coupled with the first taper part, and a taper direction of the first taper part is the same as a taper direction of the second taper part.

An optical waveguide at least includes: a lower clad layer; a core that is disposed on the lower clad layer and includes an entrance plane and an emission plane; and an optical path converting mirror including an inclined surface that is neither in parallel with nor orthogonal to a plane formed by the lower clad layer. The core includes a restriction release plane. When one of two portions obtained by dividing the core in two at the restriction release plane that is on the side of the entrance plane is defined as a first core pattern portion and remaining one of the two portions on the side of the emission plane is defined as a second core pattern portion, the optical path converting mirror is disposed on an optical path of the first core pattern portion or an extension of the optical path. At least a part of the light that has entered through the entrance plane is reflected by the optical path converting mirror to have an optical path converted. At least a part of light with an optical path not converted to be in a substantially orthogonal direction is emitted from the emission plane.

An optical coupler is provided. The optical coupler includes: a first optical structure, and a second optical structure disposed over the first optical structure. The first optical structure includes: a first substrate, a first cladding layer disposed on the first substrate, and a first waveguide disposed on the first cladding layer. The first waveguide includes a first coupling portion, and the first coupling portion including a first taper part. The second optical structure includes: a second substrate, a dielectric layer disposed on the second substrate; and a second waveguide disposed on the dielectric layer. The second waveguide includes a second coupling portion, and the second coupling portion including a second taper part. The second taper part is disposed on and optically coupled with the first taper part, and a taper direction of the first taper part is the same as a taper direction of the second taper part.

Provided is a resin composition for optical waveguide cores, the resin composition including liquid epoxy resin, and solid epoxy resin, in which a coefficient of variation calculated from a weighted average value of a refractive index of the liquid epoxy resin and a refractive index of the solid epoxy resin is 2.10% or less.