Embodiments of the disclosure provide an optical antenna for a photonic integrated circuit (PIC). The optical antenna includes a semiconductor waveguide on a semiconductor layer. The semiconductor waveguide includes a first vertical sidewall over the semiconductor layer over the semiconductor layer. A plurality of grating protrusions extends horizontally from the first vertical sidewall of the semiconductor waveguide.

Structures for an optical coupler and methods of fabricating a structure for an optical coupler. The structure includes a first waveguide core having a first tapered section and a second waveguide core having a second tapered section positioned adjacent to the first tapered section of the first waveguide core. The second tapered section is positioned with a lateral offset in a lateral direction relative to the first tapered section. The second tapered section is positioned with a vertical offset in a vertical direction relative to the first tapered section.

A grating coupler having first and second ends for coupling a light beam to a waveguide of a chip includes a substrate configured to receive the light beam from the first end and transmit the light beam through the second end, the substrate having a first refractive index n1, a grating structure having curved grating lines arranged on the substrate, the grating structure having a second refractive index n1, wherein the curved grating lines have line width w and height d and are arranged by a pitch Λ, wherein the second refractive index n2 is less than first refractive index n1, and a cladding layer configured to cover the grating structure, wherein the cladding layer has a third refractive index n3. The curves of the grating lines are constructed such that the emitting beam is shaped for efficient coupling to another optical component. The curves can also be tilted to reduce coupling back into the waveguide.

A grating coupler having first and second ends for coupling a light beam to a waveguide of a chip includes a substrate configured to receive the light beam from the first end and transmit the light beam through the second end, the substrate having a first refractive index n1, a grating structure having curved grating lines arranged on the substrate, the grating structure having a second refractive index n1, wherein the curved grating lines have line width w and height d and are arranged by a pitch Λ, wherein the second refractive index n2 is less than first refractive index n1, and a cladding layer configured to cover the grating structure, wherein the cladding layer has a third refractive index n3. The curves of the grating lines are constructed such that the emitting beam is shaped for efficient coupling to another optical component. The curves can also be tilted to reduce coupling back into the waveguide.

The invention relates to a waveguide and a polarisation splitter based on said waveguide, in which a rotation of an angle greater than zero is applied to a plurality of sections of a core material and a plurality of sections of a covering material, thereby achieving an independent control of the refractive indices of a zero-order transverse electric mode and a zero-order transverse magnetic mode. This document also describes a manufacturing method of said waveguide which allows the birefringence of the light that passes through the waveguide.

A device includes a light source, a waveguide layer, and a light director layer. The light source emits illumination light. The waveguide layer includes a cladding layer and an optical waveguide. The cladding layer provides a top planar surface of the waveguide layer and the optical waveguide is immersed in the cladding layer and includes a light input coupler. The light director layer includes a bottom planar surface that is disposed on the top planar surface of the waveguide layer. The light director layer also includes a light director that receives and directs the illumination light to the light input coupler as shaped light. The light director is configured to tilt the illumination light to give the shaped light a tilt angle with respect to the light input coupler.

Eyewear including a frame, a projector supported by the frame, and a lens supported by the frame. The lens has a first surface facing an eye of the user and a second surface facing away from the eye of the user when the frame is worn. The lens also includes a waveguide defined by the first and second surfaces to receive light from the projector. An input light coupler and an output light coupler are on the first surface of the lens and at least one reflector is positioned on a second surface of the lens to redirect light received from the input coupler and/or the output coupler to redirect light having an angle of incidence with respect to the second surface of the lens that would result in that portion of the light exiting the waveguide through the second surface in the absence of the at least one reflector.

An optical waveguide includes a core layer which extends along a longitudinal direction and through which light can propagate; and a protective film that is formed on at least a portion of a surface of the core layer and has a smaller refractive index than the core layer. At least a portion of the protective film is provided in a manner allowing contact with a gas or a liquid. In a cross-section of at least a portion perpendicular to a longitudinal direction of the core layer, the protective film is formed around the entire surface of the core layer.

A grating device includes a supporting body having a first main face and a second main face, an under clad layer provided on the first main face of the supporting body, an optical material layer provided on the under clad layer, and a back face layer provided on the second main face of the supporting body. The under clad layer is composed of g a material having a refractive index of 1.69 or lower. The optical material layer is composed of a metal oxide having a refractive index of 1.70 or higher and 3.50 or lower and includes a Bragg grating. The back face layer is composed of a material having a refractive index of 1.69 or lower or a metal oxide having a refractive index of 1.70 or higher and 3.50 or lower.

A light flux diameter expanding element includes a light guiding plate with a light input face and a light output face, and with a thickness of 0.2 mm to 0.8 mm; a diffraction grating on the input side; and a diffraction grating on the output side, and is provided so as to have the same grating period as that of the diffraction grating on the input side, in which a forming region of the diffraction grating on the input side is smaller than that of the output side, and a grating period of the diffraction grating on the input side is a period in which a small diffraction angle in diffraction angles of +1-st order diffracted light and −1-st order diffracted light, which are diffracted in the diffraction grating on the input side, in the light guiding plate becomes larger than a critical angle of the light guiding plate.