A device includes a dielectric layer, a plurality of grating structures, and a dielectric material between the plurality of grating structures and on top of the plurality of grating structures. The grating structures are arranged on the dielectric layer and separated from each other, the plurality of grating structures each having a bottom portion and top portion, the top portion having a first width and the bottom portion having a second width, the second width being larger than the first width.

A device includes a dielectric layer, a plurality of grating structures, and a dielectric material between the plurality of grating structures and on top of the plurality of grating structures. The grating structures are arranged on the dielectric layer and separated from each other, the plurality of grating structures each having a bottom portion and top portion, the top portion having a first width and the bottom portion having a second width, the second width being larger than the first width.

An optical device includes a first waveguide extending in a first direction and a second waveguide connected to the first waveguide. The second waveguide includes a first mirror, a second mirror, and an optical waveguide layer. At least either the first waveguide or the second waveguide has one or more gratings in a part of a connection region in which the first mirror, the second mirror, and the first waveguide overlap one another when seen from an angle parallel with a direction perpendicular to a first reflecting surface of the first mirror. The one or more gratings is at a distance that is longer than at least either a thickness of the first mirror or a thickness of the second mirror in the first direction from an end of the first mirror or the second mirror that is in the connection region.

An optical device includes a first waveguide extending in a first direction and a second waveguide connected to the first waveguide. The second waveguide includes a first mirror, a second mirror, and an optical waveguide layer. At least either the first waveguide or the second waveguide has one or more gratings in a part of a connection region in which the first mirror, the second mirror, and the first waveguide overlap one another when seen from an angle parallel with a direction perpendicular to a first reflecting surface of the first mirror. The one or more gratings is at a distance that is longer than at least either a thickness of the first mirror or a thickness of the second mirror in the first direction from an end of the first mirror or the second mirror that is in the connection region.

A device for optical signal processing includes a first layer, a second layer and a waveguiding layer. A lens is disposed within the first layer and adjacent to a surface of the first layer. The second layer is underneath the first layer and adjacent to another surface of the first layer. The waveguiding layer is located underneath the second layer and configured to waveguide a light beam transmitted in the waveguiding layer. A grating coupler is disposed over the waveguiding layer. The lens is configured to receive, from one of the grating coupler or a light-guiding element, the light beam, and focus the light beam towards another one of the light-guiding element or the grating coupler.

A device for optical signal processing includes a first layer, a second layer and a waveguiding layer. A lens is disposed within the first layer and adjacent to a surface of the first layer. The second layer is underneath the first layer and adjacent to another surface of the first layer. The waveguiding layer is located underneath the second layer and configured to waveguide a light beam transmitted in the waveguiding layer. A grating coupler is disposed over the waveguiding layer. The lens is configured to receive, from one of the grating coupler or a light-guiding element, the light beam, and focus the light beam towards another one of the light-guiding element or the grating coupler.

A semiconductor package and a manufacturing method thereof are provided. A die stack in the semiconductor package includes a photonic die and an electronic die stacked on the photonic die by a face-to-face manner. A convex lens is disposed at a back surface of the electronic die, and is formed in an oval shape, such that optical beams can be collimated to have circular beam shape, as passing through the convex lens. In some embodiments, the semiconductor package includes more of the die stacks, and includes an interposer lying below the die stacks. In these embodiments, tilted reflectors are formed in the photonic dies and the interposer, to set up vertical optical paths between the interposer and the photonic dies, and lateral optical paths in the interposer. In this way, optical communication between the photonic dies can be established.

An integrated mode converter and multiplexer (/demultiplexer) combines a multimode interference coupler, at least one phase-shifter and a symmetrical Y-junction. The dispersion of the multimode interference coupler is engineered through subwavelength structures in order to achieve a very wide bandwidth. Several phase-shifter topologies for further bandwidth enhancement are disclosed, as well as architectures for multiplexing a greater number of optical modes.

An integrated mode converter and multiplexer (/demultiplexer) combines a multimode interference coupler, at least one phase-shifter and a symmetrical Y-junction. The dispersion of the multimode interference coupler is engineered through subwavelength structures in order to achieve a very wide bandwidth. Several phase-shifter topologies for further bandwidth enhancement are disclosed, as well as architectures for multiplexing a greater number of optical modes.

An optical ring resonator-based gyroscope includes a photonic integrated circuit (PIC) chip including a plurality of optical elements, the plurality of optical elements including a resonator ring; and a printed circuit board including a plurality of electrical components, the photonic integrated circuit being mounted on a surface of the printed circuit board, the photonic integrated circuit and the printed circuit board being electrically connected. A photonic integrated circuit (PIC) chip including a substrate; a dielectric layer; a first waveguide layer forming at least: a ring resonator and reflector portions; a second waveguide layer forming at least: vertical Bragg grating couplers disposed over one of the plurality of reflector portions, a chip waveguide; a magneto-optic layer encapsulated in the dielectric layer; and a metal layer forming a plurality of metal connection pads and a plurality of wire traces for electrically connecting the PIC chip to electronic components.