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.

An optical device includes a first waveguide that includes a plurality of first portions coupled with regions doped with first dopants, and a plurality of second portions coupled with regions doped with second dopants, distinct from the first dopants, the plurality of first portions being interleaved with the plurality of second portions. And the optical device includes a second waveguide located adjacent to the first waveguide for coupling light from the first waveguide to the second waveguide. The second waveguide includes a third portion coupled with a third region doped with the first dopants and a fourth portion coupled with a fourth region doped with the second dopants, wherein the first portion is located adjacent to the third portion and the second portion is located adjacent to the fourth portion.

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

Multi-directional optical devices are disclosed. The optical device may employ a multiple input/multiple output optical coupling structure to determine propagation direction of received light (in receiver configuration), and/or control the propagation direction of transmitted light (in transmitter configuration). Propagation direction can be determined without the need for moving parts. In accordance with some embodiments, designs of solid-state photonic integrated circuits (PICs) are disclosed herein that utilize N×M star couplers to perform Fourier transformations to light traversing between the N ports and M ports such that light arriving at one or more of the N ports is distributed with a linear phase profile across the M ports. The slope of the linear phase profile is dependent on which of the N ports that light was received from. The light exits from waveguides coupled to the M ports at one or more propagation directions dependent on the linear phase profile.

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.

An optical coupler includes a first waveguide including a first multi-mode waveguide section having a cross-section characterized by a first height and a first width that is greater than the first height and a second waveguide including a second multi-mode waveguide section having a cross-section characterized by a second height and a second width that is greater than the second height. The first multi-mode waveguide section is positioned adjacent to the second multi-mode waveguide section at least partially above or below the second multi-mode waveguide so that light entering the first multi-mode waveguide section is coupled from the first multi-mode waveguide section to the second multi-mode waveguide section. Methods for coupling light between waveguides with the optical coupler and optical devices that include the optical coupler are also described.

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.

An optical communications system includes a laser transmitter to generate an optical signal and a first optical fiber network coupled to transmit the optical signal from the laser transmitter system. A first latchable, asymmetric coupler is disposed along the first optical fiber network to receive the optical signal, and has a first tap output that receives a selected and alterable first fraction of the optical signal. A second latchable, asymmetric coupler is disposed along the first optical fiber network to receive the optical signal from the first latchable asymmetric coupler and has a second tap output that receives a selected and alterable second fraction of the optical signal incident at the second latchable. In certain embodiments the first and second couplers are capable of operating at any of at least three tapping fractions.

Systems and methods for activation in an optical circuit in accordance with embodiments of the invention are illustrated. One embodiment includes an optical activation circuit, wherein the circuit comprises a directional coupler, an optical-to-electrical conversion circuit, a time delay element, a nonlinear signal conditioner, and a phase shifter. The directional coupler receives an optical input and provides a first portion to the optical-to-electrical conversion circuit and a second portion to the time delay element, the time delay element provides a delayed signal to the phase shifter, and the optical-to-electrical conversion circuit converts an optical signal from the directional coupler to an electrical signal used to activate the phase shifter to shift the phase of the delayed signal.

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.