A beam steering apparatus includes a substrate; at least one light source provided on the substrate; a first waveguide configured to transmit a first light beam radiated from the at least one light source; at least one beam splitter configured to split the first light beam transmitted by the first waveguide to obtain a second light beam; a second waveguide configured to receive the second light beam; and a quantum dot optical amplifier provided on the second waveguide and comprising a barrier layer, a quantum dot layer, and a wetting layer, the quantum dot optical amplifier being configured to modulate a phase of the second light beam, and to amplify an intensity of the second light beam.

Implementations disclosed herein provide for devices and methods for obtaining parity time (PT) symmetric directional couplers through improved phase tuning, along with separate optical gain and optical loss tuning. The present disclosure integrates phase tuning and optical gain/loss tuning structures into waveguides of directional couplers disclosed herein. In some examples, directional couplers disclosed herein integrate one or more hybrid metal-oxide-semiconductor capacitors (MOSCAPs) formed by a dielectric layer between two semiconductor layers that provide for phase tuning via plasma dispersion and/or carrier accumulation depending on voltage bias polarity, and one or more optically active medium that provide for optical gain or loss tuning depending on voltage bias polarity.

A method of providing electrical isolation between subsections in a waveguide structure for a photonic integrated device, the structure comprising a substrate, a buffer layer and a core layer, the buffer layer being located between the substrate and the core and comprising a dopant of a first type, the first type being either n-type or p- type, the method comprising the steps of prior to adding any layer to a side of the core layer opposite to the buffer layer: selecting at least one area to be an electrical isolation region, applying a dielectric mask to a surface of the core layer opposite to the buffer layer, with a window in the mask exposing an area of the surface corresponding to the selected electrical isolation region, implementing diffusion of a dopant of a second type, the second type being of opposite polarity to the first type, and allowing the dopant of the second type to penetrate to the substrate to form a blocking junction.

An optoelectronic device and an array comprising a plurality of the same. The device(s) comprising: an optically active region with an electrode arrangement for applying an electric field across the optically active region; a first curved waveguide, arranged to guide light into the optically active region; and a second curved waveguide, arranged to guide light out of the optically active region; wherein the first curved waveguide and the second curved waveguide are formed of a material having a different band-gap from a band-gap of the optically active region, and wherein the overall guided path formed by the first curved waveguide, the optically active region and the second curved waveguide is U-shaped.

An optical modulating device may include a plurality of quantum dot (QD)-containing layers having QDs and a plurality of refractive index change layers. The QD-containing layers may be disposed between the refractive index change layers, respectively. The optical modulating device may be configured to modulate light-emission characteristics of the plurality of QD-containing layers. At least two of the QD-containing layers may have different central emission wavelengths. At least two of the plurality of refractive index change layers may include different materials or have different carrier densities.

A method of fabricating an optoelectronic component within a silicon-on-insulator substrate, the method comprising: providing a silicon-on-insulator (SOI) substrate, the SOI substrate comprising a silicon base layer, a buried oxide (BOX) layer on top of the base layer, and a silicon device layer on top of the BOX layer; etching a first cavity region into the SOI substrate and etching a second cavity region into the SOI substrate, the first cavity region having a first depth and the second cavity region having a second depth, the second depth being greater than the first depth; depositing a multistack epi layer into the first and the second cavity regions simultaneously, the multistack epi layer comprising a first multistack portion comprising a first active region and a second multistack portion comprising a second active region.

In an embodiment, a phase shifter includes: a light input end; a light output end; a p-type semiconductor material, and an n-type semiconductor material contacting the p-type semiconductor material along a boundary area, wherein the boundary area is greater than a length from the light input end to the light output end multiplied by a core width of the phase shifter.

A method for manufacturing a semiconductor optical device includes the steps of forming a first semiconductor layer on a substrate; forming a mask on the first semiconductor layer; forming a first mesa from the first semiconductor layer using the mask; forming an embedding layer on a portion of the first semiconductor layer that is exposed from the mask such that the first mesa is embedded in the embedding layer; and forming a second mesa from the first mesa.

Photonic devices having Al.sub.1-xSc.sub.xN and Al.sub.yGa.sub.1-yN materials, where Al is Aluminum, Sc is Scandium, Ga is Gallium, and N is Nitrogen and where 0<x0.45 and 0y1.

A device, such as an electroabsorption modulator, can modulate a light intensity by controllably absorbing a selectable fraction of the light. The device can include a substrate. A waveguide positioned on the substrate can guide light. An active region positioned on the waveguide can receive guided light from the waveguide, absorb a fraction of the received light, and return a complementary fraction of the received light to the waveguide. Such absorption produces heat, mostly at an input portion of the active region. The input portion of the active region can be thermally coupled to the substrate, which can dissipate heat from the input portion, and can help avoid thermal runaway of the device. The active region can be thermally isolated from the substrate away from the input portion, which can maintain a relatively low thermal mass for the active region, and can increase efficiency when heating the active region.