An optical waveguide in which a grating coupler is formed, a first pattern region arranged to surround the grating coupler, and a second pattern region arranged to surround the grating coupler are included. The first pattern region and the second pattern region are arranged adjacently. In a periphery of the grating coupler, the first pattern region is formed in a region continuous in a circumferential direction. Similarly, in the periphery of the grating coupler, the second pattern region is formed in a region continuous in the circumferential direction.

An optical waveguide in which a grating coupler is formed, a first pattern region arranged to surround the grating coupler, and a second pattern region arranged to surround the grating coupler are included. The first pattern region and the second pattern region are arranged adjacently. In a periphery of the grating coupler, the first pattern region is formed in a region continuous in a circumferential direction. Similarly, in the periphery of the grating coupler, the second pattern region is formed in a region continuous in the circumferential direction.

A grating coupled laser (GCL) includes an active section and a passive section. The passive section is butt coupled to the active section to form a butt joint with the active section. The active section includes an active waveguide. The passive section includes a passive waveguide, a transmit grating coupler, and a top cladding. The passive waveguide is optically coupled end to end with the active waveguide and includes a first portion and a second portion. The first portion of the passive waveguide is positioned between the second portion of the passive waveguide and the active waveguide. The transmit grating coupler is optically coupled to the passive waveguide and includes grating teeth that extend upward from the second portion of the passive waveguide. The top cladding is positioned directly above the first portion of the passive waveguide and is absent directly above at least some of the transmit grating coupler.

Aspects of the disclosure relate to apparatus for the fabrication of waveguides. In one example, an angled ion source is utilized to project ions toward a substrate to form a waveguide which includes angled gratings. In another example, an angled electron beam source is utilized to project electrons toward a substrate to form a waveguide which includes angled gratings. Further aspects of the disclosure provide for methods of forming angled gratings on waveguides utilizing an angled ion beam source and an angled electron beam source.

A master oscillator power amplifier comprises a semiconductor laser formed on a substrate and configured to output an optical signal, and a semiconductor optical amplifier (SOA) formed on the substrate. The SOA comprises an optical waveguide having an optically active region, wherein the optical waveguide is configured to expand a mode size of the optical signal along at least two dimensions.

A graded-index optical element may include a nanovoided material including a first surface and a second surface opposite the first surface. The nanovoided material may be transparent between the first surface and the second surface. Additionally, the nanovoided material may have a predefined change in effective refractive index in at least one axis due to a change in at least one of nanovoid size or nanovoid distribution along the at least one axis. Various other elements, devices, systems, materials, and methods are also disclosed.

A pupil replication waveguide for a projector display includes a slab of transparent material for propagating display light in the slab via total internal reflection. A diffraction grating is supported by the slab. The diffraction grating includes a plurality of tapered slanted fringes in a substrate for out-coupling the display light from the slab by diffraction into a blazed diffraction order. A greater portion of the display light is out-coupled into the blazed diffraction order, and a smaller portion of the display light is out-coupled into a non-blazed diffraction order. The tapered fringes result in the duty cycle of the diffraction grating varying along the thickness direction of the diffraction grating, to facilitate suppressing the portion of the display light out-coupled into the non-blazed diffraction order.

A device includes a grating coupler with a grating constant, two light sources, and a planar waveguide, which are configured to couple light with two different wavelengths λ.sub.1, λ.sub.2 into the waveguide. The waveguide has a waveguiding layer disposed adjacent to a substrate layer and a cover layer. The waveguiding layer has a thickness d and effective refractive indices of N(λ.sub.k, j.sub.k), wherein λ.sub.k is one of the wavelengths and j.sub.k is an order of a waveguide mode, wherein the coupled light of the wavelength λ.sub.k has a coupling angle α.sub.k into the waveguide, and wherein an amount of difference between the coupling angles is a divergence angle Δα. Guiding of waveguide modes of the order j.sub.k>0 is possible for a wavelength of the coupled light. The waveguiding layer is arranged to couple the light via the grating coupler under a divergence angle of Δα<6.

Various embodiments of silicon photonic (SiP) chips are provided that are configured for backside or frontside optical fiber coupling. An SiP chip includes a photonic integrated circuit formed on a first surface of a first substrate. The photonic integrated circuit includes at least one optical component and at least one coupling element. The at least one optical component is configured to propagate an optical signal therethrough in a waveguide propagation direction that is substantially parallel to a plane defined by the first surface. The at least one coupling element is configured to couple an optical signal propagating along an optical path transverse to the waveguide propagation direction into the at least one optical component to enable the backside or frontside coupling of an optical fiber to the SiP chip.

The present disclosure relates to semiconductor structures and, more particularly, to spiral waveguide absorbers and methods of manufacture. The structure includes: a photonics component; and a waveguide absorber with a grating pattern coupled to a node of the photonics component.