An optical grating coupler defining an axis and configured to couple light between a planar waveguide and an optical fiber, including first and second entry surfaces and a plurality of scattering regions symmetric to the axis and arranged such scattering strength presented to incoming light by the plurality of scattering regions changes from weak to strong along a beam path of the incoming light to match a Gaussian mode profile of the optical fiber.

A wavelength demultiplexing device configured so as to spatially distributing the spectral contributions of an incident light beam, when in use, and which includes a linear waveguide and a planar waveguide, formed in a coplanar way and adapted to be optically coupled with one another along a coupling line, by evanescent coupling. Such a device may further include diffraction gratings located in the planar waveguide, to extract light out of the latter.

A sensor system comprises a pulsed light source, and a passive sensor head chip in communication with the light source. The sensor head chip includes a first photonics substrate, a transmitting optical component on the first photonics substrate and configured to couple a pulse, transmitted through a first optical fiber from the light source, into a region of interest; and a receiving optical component on the first photonics substrate and configured to couple backscattered light, received from the region of interest, into a second optical fiber. A signal processing chip communicates with the sensor head chip and light source. The signal processing chip includes a second photonics substrate and comprises a passive optical filter array that receives the backscattered light from the second optical fiber. The filter array includes notch filters in communication with each other and operative for frequency selection; and optical detectors respectively coupled to the notch filters.

Holographic energy directing systems may include a waveguide array and a relay element. Disclosed calibration approaches allows for mapping of energy locations and mapping of energy locations to angular direction of energy as defined in a four-dimensional plenoptic system. Distortions due to the waveguide array and relay element may also be compensated.

Disclosed are apparatuses for optical coupling and a system for communication. In one embodiment, an apparatus for optical coupling including a substrate and a grating coupler is disclosed. The grating coupler is disposed on the substrate and includes a plurality of coupling gratings arranged along a first direction, wherein effective refractive indices of the plurality of coupling gratings gradually decrease along the first direction.

A wavelength demultiplexing device configured so as to spatially distributing the spectral contributions of an incident light beam, when in use, and which includes a linear waveguide and a planar waveguide, formed in a coplanar way and adapted to be optically coupled with one another along a coupling line, by evanescent coupling. Such a device may further include diffraction gratings located in the planar waveguide, to extract light out of the latter.

Holographic energy directing systems may include a waveguide array and a relay element. Disclosed calibration approaches allows for mapping of energy locations and mapping of energy locations to angular direction of energy as defined in a four-dimensional plenopic system. Distortions due to the waveguide array and relay element may also be compensated.

Disclosed are high-density energy directing devices and systems thereof for two-dimensional, stereoscopic, light field and holographic head-mounted displays. In general, the head-mounted display system includes one or more energy devices and one or more energy relay elements, each energy relay element having a first surface and a second surface. The first surface is disposed in energy propagation paths of the one or more energy devices and the second surface of each of the one or more energy relay elements is arranged to form a singular seamless energy surface. A separation between edges of any two adjacent second surfaces is less than a minimum perceptible contour as defined by the visual acuity of a human eye having better than 20/40 vision at a distance from the singular seamless energy surface, the distance being greater than the lesser of: half of a height of the singular seamless energy surface, or half of a width of the singular seamless energy surface.

Disclosed are transparent energy relay waveguide systems for the superimposition of holographic opacity modulation states for holographic, light field, virtual, augmented and mixed reality applications. The light field system may comprise one or more energy waveguide relay systems with one or more energy modulation elements, each energy modulation element configured to modulate energy passing therethrough, whereby the energy passing therethrough may be directed according to 4D plenoptic functions or inverses thereof.

Provided is a variable wavelength filter having a wide variable wavelength range. In the variable wavelength filter, a slab waveguide that is a component of an arrayed-waveguide grating has a groove into which a resin is inserted. The groove intersects with a plurality of line segments A joining a place of connection between an input light waveguide and the slab waveguide to places of connection between respective array waveguides and the slab waveguide. The groove is formed such that a total length LA of an intersection of the groove and each of the line segments A monotonously increases or decreases between the adjacent line segments A with a difference in the total length LA between the adjacent line segments A being constant.