A package assembly includes a package substrate including a first die that includes a photonic integrated circuit, a second die located on the first die, the second die including an electronic integrated circuit electrically connected to the photonic integrated circuit, and an interposer module on the package substrate, at least a portion of the interposer module being located on the first die and electrically connected to the photonic integrated circuit.

A resonant waveguide grating includes a waveguiding layer and a plurality of subwavelength structures. The waveguiding layer, being in optical proximity to the plurality of subwavelength structures, is configured to guide at most ten wave-guided light modes. The plurality of subwavelength structures includes at least two adjacent grooves having a subwavelength distance between their groove centers being different than the subwavelength distance between the centers of two adjacent ridges. The plurality of subwavelength structures is configured to couple out of the waveguiding layer resonantly by diffraction, an outcoupled fraction of an incoupled portion of incident light. The outcoupled fraction is a diffracted part of an incident light beam. A diffractive optical combiner and a diffractive optical coupler, both include the resonant waveguide grating of the invention. A near-eye display apparatus includes at least the resonant waveguide grating of the invention.

A LIDAR system includes a demultiplexer that separates an outgoing LIDAR signal into multiple LIDAR output signals that each carries a different channel and the different channels are each at a different wavelength. The system also includes a beam distributor that receives each of the LIDAR output signals. The beam distributor directs the received LIDAR output signals such that different LIDAR output signals travel away from the beam distributor in different directions.

A LIDAR system includes a demultiplexer that separates an outgoing LIDAR signal into multiple LIDAR output signals that each carries a different channel and the different channels are each at a different wavelength. The system also includes a beam distributor that receives each of the LIDAR output signals. The beam distributor directs the received LIDAR output signals such that different LIDAR output signals travel away from the beam distributor in different directions.

An optical coupler includes a substrate, a mirror layer, a plurality of coupling gratings, a plurality of waveguides, and an oxide layer. The substrate includes a first surface, a second surface opposite to the first surface, and a concave portion exposed from the first surface. The mirror layer is disposed in the concave portion. The coupling gratings are disposed above the mirror layer. The waveguides are laterally aligned with the coupling gratings. The concave portion faces both the coupling gratings and the waveguides. The oxide layer is bonded on the first surface. The coupling gratings and the waveguides are disposed on the oxide layer.

An optical coupler includes a substrate, a mirror layer, a plurality of coupling gratings, a plurality of waveguides, and an oxide layer. The substrate includes a first surface, a second surface opposite to the first surface, and a concave portion exposed from the first surface. The mirror layer is disposed in the concave portion. The coupling gratings are disposed above the mirror layer. The waveguides are laterally aligned with the coupling gratings. The concave portion faces both the coupling gratings and the waveguides. The oxide layer is bonded on the first surface. The coupling gratings and the waveguides are disposed on the oxide layer.

An optical phased array (OPA) photonic integrated chip includes a plurality of array elements, a plurality of phase shifters, a plurality of combiners, and an edge coupler configured to couple to a single mode waveguide. The plurality of phase shifters includes a layer of phase shifters that has a phase shifter connected to each array element in the plurality of array elements. The plurality of combiners is configured to connect the plurality of phase shifters to the edge coupler. The plurality of combiners includes a first combiner that has a first output that is connected to a second combiner or the edge coupler, and a second output of the first combiner is connected to a photodetector. An in-phase light portion at the first combiner is output through the first output, and an out-of-phase light portion at the first combiner is output through the second output.

An optical phased array (OPA) photonic integrated chip includes a plurality of array elements, a plurality of phase shifters, a plurality of combiners, and an edge coupler configured to couple to a single mode waveguide. The plurality of phase shifters includes a layer of phase shifters that has a phase shifter connected to each array element in the plurality of array elements. The plurality of combiners is configured to connect the plurality of phase shifters to the edge coupler. The plurality of combiners includes a first combiner that has a first output that is connected to a second combiner or the edge coupler, and a second output of the first combiner is connected to a photodetector. An in-phase light portion at the first combiner is output through the first output, and an out-of-phase light portion at the first combiner is output through the second output.

A planar optical waveguide based on two-dimensional grating includes an optical waveguide substrate which is a transparent plane-parallel plate, and a functional grating element which includes a two-dimensional grating having two grating directions with an angle of 60° in between. The two-dimensional grating is either protruded or recessed into the top surface of the optical waveguide substrate. The output image from a micro-projector can enter the optical waveguide and then gets projected to cover the entire area of the functional grating element, enabling a human eye to view the output image across a large eye-box.

A planar optical waveguide based on two-dimensional grating includes an optical waveguide substrate which is a transparent plane-parallel plate, and a functional grating element which includes a two-dimensional grating having two grating directions with an angle of 60° in between. The two-dimensional grating is either protruded or recessed into the top surface of the optical waveguide substrate. The output image from a micro-projector can enter the optical waveguide and then gets projected to cover the entire area of the functional grating element, enabling a human eye to view the output image across a large eye-box.