An integrated circuit comprises: at least one photonic layer that includes one or more optical waveguides; a first optical coupler that couples at least a first optical mode outside of the photonic layer to a first waveguide in the photonic layer; a photonic device that includes one or more ports in the photonic layer; a first multi-port optical coupler that includes three or more ports in the photonic layer, including a first port optically coupled to the first optical coupler, a second port optically coupled to a first port of the photonic device, and a third port optically coupled to a first optical reflector configured to send substantially all optical power emitted from the third port of the first multi-port optical coupler back to the third port of the first multi-port optical coupler.

Structures that include a distributed Bragg reflector and methods of fabricating a structure that includes a distributed Bragg reflector. The structure includes a substrate, an optical component, and a distributed Bragg reflector positioned between the optical component and the substrate. The distributed Bragg reflector includes airgaps and silicon layers that alternate in a vertical direction with the airgaps to define a plurality of periods.

Structures for a grating coupler and methods of fabricating a structure for a grating coupler. The structure includes a grating coupler having a central portion and edge portions. The central portion and the edge portions define a sidewall, and the central portion and the edge portions have a first longitudinal axis along which the edge portions are arranged in a spaced relationship. Each edge portion projects from the sidewall at an angle relative to the first longitudinal axis. A waveguide core is optically coupled to the grating coupler. The first longitudinal axis is aligned in a first direction, and the waveguide core has a second longitudinal axis that is aligned in a second direction different from the first direction.

Structures for a grating coupler and methods of fabricating a structure for a grating coupler. The structure includes a grating coupler having a central portion and edge portions. The central portion and the edge portions define a sidewall, and the central portion and the edge portions have a first longitudinal axis along which the edge portions are arranged in a spaced relationship. Each edge portion projects from the sidewall at an angle relative to the first longitudinal axis. A waveguide core is optically coupled to the grating coupler. The first longitudinal axis is aligned in a first direction, and the waveguide core has a second longitudinal axis that is aligned in a second direction different from the first direction.

An illuminator for a display panel includes a light source for providing a light beam and a lightguide coupled to the light source for receiving and propagating the light beam along the substrate. The lightguide includes an array of out-coupling gratings that runs parallel to the array of pixels for out-coupling portions of the light beam from the lightguide such that the out-coupled light beam portions propagate through the substrate and produce an array of optical power density peaks at the array of pixels due to Talbot effect. A period of the array of peaks is an integer multiple of a pitch of the array of pixels.

An illuminator for a display panel includes a light source for providing a light beam and a lightguide coupled to the light source for receiving and propagating the light beam along the substrate. The lightguide includes an array of out-coupling gratings that runs parallel to the array of pixels for out-coupling portions of the light beam from the lightguide such that the out-coupled light beam portions propagate through the substrate and produce an array of optical power density peaks at the array of pixels due to Talbot effect. A period of the array of peaks is an integer multiple of a pitch of the array of pixels.

A photoacoustic apparatus, comprising: at least one optical amplifier, configured to produce light; at least one photonic integrated circuit, configured as a tunable light filter; light guiding means, wherein the at least one optical amplifier, at least one photonic integrated circuit and light guiding means are configured as an optical cavity to produce laser light having an optical path within the optical cavity; and at least one acoustic sensor configured to detect sound produced by analyte introduced into the optical path of the laser light.

An optical waveguide comprises at least two TIR surface and contains a grating. Input TIR light with a first angular range along a first propagation direction undergoes at least two diffractions at the grating. Each diffraction directs light into a unique TIR angular range along a second propagation direction.

An optical waveguide comprises at least two TIR surface and contains a grating. Input TIR light with a first angular range along a first propagation direction undergoes at least two diffractions at the grating. Each diffraction directs light into a unique TIR angular range along a second propagation direction.

A LIDAR system includes a LIDAR chip configured to output a LIDAR output signal. The LIDAR chip includes a redirection component and alternate waveguides. The redirection component receives an outgoing LIDAR signal from any one of multiple alternate waveguides. The LIDAR output signal includes light from the outgoing LIDAR signal. A direction that the LIDAR output signal travels away from the LIDAR chip is a function of the alternate waveguide from which the redirection component receives the outgoing LIDAR signal.