An optical switch structure includes a substrate, a first electrical contact, a first material having a first conductivity type electrically connected to the first electrical contact, a second material having a second conductivity type coupled to the first material, and a second electrical contact electrically connected to the second material. The optical switch structure also includes a waveguide structure disposed between the first electrical contact and the second electrical contact and comprising a waveguide core coupled to the substrate and including a first material characterized by a first index of refraction and a first electro-optic coefficient and a waveguide cladding at least partially surrounding the waveguide core and including a second material characterized by a second index of refraction and a second electro-optic. The first index of refraction is greater than the second index of refraction the first electro-optic coefficient is less than the second electro-optic coefficient

The optical switch 10 comprises a first waveguide 11, a second waveguide 12, and an exchanger 13. The first waveguide 11 comprises a first end E1 and a second end E2. The second waveguide 12 comprises a third end E3 and a fourth end E4, respectively located on the first end E1 side and the second end E2 side as viewed from the center of the first waveguide 11. The exchanger 13 comprises: a first waveguide section 21 configuring a directional coupler together with the first waveguide 11 and including a phase changing material 23; and a second waveguide section 22 configuring a directional coupler together with the second waveguide 12 and including a phase change material 24. The exchanger 13 inputs electromagnetic waves, input from the first end E1 and output from the first waveguide section 21, to the third end E3 side of the second waveguide section 22. The exchanger 13 inputs electromagnetic waves, input from the third end E3 and output from the second waveguide section 22, to the second end E2 side of the first waveguide section 21.

Embodiments of the disclosure provide an emitter array for an optical sensing system. The emitter array may include a waveguide including a plurality of waveguide branches. The emitter array may also include a plurality of grating switches positioned along each of the plurality of waveguide branches and configured to selectively turn on or off the corresponding waveguide branch for transmitting light. In certain aspects, a grating switch may include an upper grating structure configured to couple to a waveguide branch when the grating switch is activated to allow the light to emit from the waveguide branch.

Circuits for generating a pair of qudits in a maximally entangled state and methods of operating such circuits are disclosed. The circuits can be photonic circuits that use a combination of beam splitters, phase shifters, and detectors to produce an entangled pair of d-dimensional qudits from an input set of 4d photons. In a case where d equals 2, a pair of qubits in a Bell state can be generated.

The invention relates to a method for homogenization of the output beam profile of a multimode optical waveguide (10). The method comprises the following method steps: splitting input radiation (2) of coherent light over two or more beam paths (I-IV), modulating the radiation in at least one of the beam paths (I-IV), combining the beam paths (I-IV) by superimposing the modulated radiation onto the input (9) of the multimode waveguide (10), where the radiation forms a temporally variable interference pattern, and propagating the radiation using the multimode waveguide (10). The invention furthermore relates to a device for carrying out the method. At least one splitting device (14) which is designed to split input radiation (2) over two or more beam paths (I-IV), at least one modulator (16) which is designed for modulating the radiation in at least one of the beam paths (I-IV), and at least one superimposition device which is designed for combining the beam paths (I-IV) by superimposing the modulated radiation and for directing the superimposed radiation onto the input (9) of the multimode optical waveguide (10), are components of a photonic integrated circuit (3) according to an embodiment of the device.

An optical switch device includes a first semiconductor structure configured to operate as a first waveguide and a second semiconductor structure configured to operate as a second waveguide. The second semiconductor structure is located above or below the first semiconductor structure and separated from the first semiconductor structure. The second semiconductor structure includes a portion of a first doped region doped with dopants of a first type and a portion of a second doped region doped with dopants of a second type that is different from the dopants of the first type.

A vertical directional coupler or switch comprising a lower and an upper waveguide, integrated with an optical phase change material disposed between the lower and upper waveguides to control a directional of optical coupling between the lower and upper waveguides.

A ring resonator electro-optical device includes a first silicon nitride waveguide and a second annular silicon waveguide that comprises a first section running under a second section of the first waveguide. The second waveguide also includes an annular silicon strip having a cross-section increasing in the first section from a minimum cross-section located under the second section.

Described embodiments include photonic integrated circuits and systems with photonic devices, including thermal isolation regions for the photonic devices. Methods of fabricating such circuits and systems are also described.

An integrated-optics MEMS-actuated beam-steering system is disclosed, wherein the beam-steering system includes a lens and a programmable vertical coupler array having a switching network and an array of vertical couplers, where the switching network can energize of the vertical couplers such that it efficiently emits the light into free-space. The lens collimates the light received from the energized vertical coupler and directs the output beam along a propagation direction determined by the position of the energized vertical coupler within the vertical-coupler array. In some embodiments, the vertical coupler is configured to correct an aberration of the lens. In some embodiments, more than one vertical coupler can be energized to enable steering of multiple output beams. In some embodiments, the switching network is non-blocking.