An optical modulator includes a dielectric layer and a waveguide. The waveguide is disposed on the dielectric layer. The waveguide includes an electrical coupling portion, a slab portion, and an optical coupling portion. The slab portion is directly in contact with both of the electrical coupling portion and the optical coupling portion. The slab portion has a first sub-portion and a second sub-portion connected to the first sub-portion. A top surface of the electrical coupling portion, a top surface of the first sub-portion, and a top surface of the second sub-portion are located at different level heights.

A multi core optical fiber that includes a plurality of cores disposed in a cladding. The plurality of cores include a first core and a second core. The first core has a first propagation constant β.sub.1, the second core has a second propagation constant β.sub.2, the cladding has a cladding propagation constant β.sub.0, and (I).

An optical device includes a first substrate having a first surface, a second substrate having a second surface, at least one optical waveguide, and a plurality of spacers, disposed on at least either the first surface or the second surface, that include a first portion and a second portion. The first portion of the plurality of elastic spacers is at least one elastic spacer located in a region between the first substrate and the second substrate in which the first substrate and the second substrate overlap each other as seen from an angle parallel with a direction perpendicular to the first surface. The second portion of the plurality of elastic spacers is at least one elastic spacer located in a region in which the first substrate and the second substrate do not overlap each other as seen from an angle parallel with the direction perpendicular to the first surface.

An integrated optical beam steering device includes a planar dielectric lens that collimates beams from different inputs in different directions within the lens plane. It also includes an output coupler, such as a grating or photonic crystal, that guides the collimated beams in different directions out of the lens plane. A switch matrix controls which input port is illuminated and hence the in-plane propagation direction of the collimated beam. And a tunable light source changes the wavelength to control the angle at which the collimated beam leaves the plane of the substrate. The device is very efficient, in part because the input port (and thus in-plane propagation direction) can be changed by actuating only log.sub.2 N of the N switches in the switch matrix. It can also be much simpler, smaller, and cheaper because it needs fewer control lines than a conventional optical phased array with the same resolution.

Structures including a grating coupler and methods of forming a structure that includes a grating coupler. The grating coupler includes segments that are positioned with a spaced relationship on a slab layer. The segments contain an active material configured to have a first state with a first refractive index and a second state with a second refractive index in response to an applied stimulus. The first and second states may be produced by applying different sets of bias voltages to the segments as the applied stimulus.

Techniques disclosed herein relate to photon sources with high spectral purity and high brightness. In one embodiment, a photon-pair source includes a pump waveguide, a first resonator coupled to the pump waveguide to couple pump photons from the pump waveguide into the first resonator, a second resonator coupled to the first resonator, and an output waveguide coupled to the second resonator. The second resonator is configured to convert the pump photons into photon pairs. The second resonator and the first resonator are configured to cause a coupling-induced resonance splitting in the second resonator or the first resonator. The second resonator and the output waveguide are configured to couple the photon pairs from the second resonator into the output waveguide. In some embodiments, the photo-pair source includes one or more tuners for tuning at least one of the first resonator or the second resonator.

A Liquid Crystal Waveguide (LCW) system can provide sub-aperture incoupling or outcoupling of light having an input wavelength and input beamsize defining an aperture characteristic of the system. A Liquid Crystal Waveguide (LCW) can include a generally planar LCW core to receive light via a light input zone for communication toward a light output zone. Sub-aperture interfacial light couplers can be planarly arranged in or parallel to the planar LCW core in the light input zone or the light output zone. Sub-aperture interfacial light couplers can include teeth, prisms, or facets, a photonic crystal metasurface, or a geometric-phased holograph (GPH)). Overall LCW thickness can be reduced, which can be helpful in space-limited applications or for reducing material costs.

An optical modulator includes a dielectric layer and a waveguide. The waveguide is disposed on the dielectric layer. The waveguide includes an electrical coupling portion, a slab portion, and an optical coupling portion. The slab portion is directly in contact with both of the electrical coupling portion and the optical coupling portion. The slab portion has a first sub-portion and a second sub-portion connected to the first sub-portion. A top surface of the electrical coupling portion, a top surface of the first sub-portion, and a top surface of the second sub-portion are located at different level heights.

Provided are systems and methods for photonic-electronic neural network computation. In an embodiment, arrays of input data are processed in an optical domain and applied through a plurality of photonic-electronic neuron layers, such as in a neural network. The data may be passed through one or more convolution cells, training layers, and classification layers to generate output information. In embodiments, various types of input data, e.g., audio, video, speech, analog, digital, etc., may be directly processed in the optical domain and applied to any numbers of layers and neurons in various neural network configurations. Such systems and methods may also be integrated with one or more photonic-electronic systems, including but not limited to 3D imagers, optical phased arrays, photonic assisted microwave imagers, high data-rate photonic links, and photonic neural networks.

An optical beam scanning semiconductor device includes 1×N electrically controlled, integrated optical switch matrix and specifically designed integrated optical grating output couplers at each of N output waveguides of 1×N switch. By selecting one of the N outputs of the 1×N switch as the output of the input optical signal, an optical output beam scans in free space. Variation in the grating output coupler design enables a smart scanning device with multiple controllable beam characteristics.