A waveguide grating. The waveguide grating includes a rib composed of a first material. A first portion of the waveguide has a first layer on the rib, the first layer being composed of a second material; and a second layer on the first layer, the second layer being composed of a third material, the third material having a higher index of refraction than the first material.

A mode field adapter (MFA) is disclosed. The MFA is tapered and includes a passive core region and an active core region separated by a distance. Further, the passive core region includes first and second passive layers that are separated by another distance. The MFA is configured to receive an optical signal from a first waveguide, and alter, for transmission to a second waveguide, an optical mode of the optical signal. The optical mode is altered based on the distance between the first and second passive layers, the distance between the active and passive core regions, and the tapering of the MFA. The optical mode is altered such that an optical loss associated with the optical signal traversing from the first waveguide to the second waveguide by way of the MFA is within a tolerance limit.

An arrayed waveguide grating device includes an input coupler configured to receive a light signal and split the light signal into a plurality of output light signals. The device also includes a plurality of waveguides optically connected to the input coupler, each waveguide having a plurality of waveguide portions having respective sensitivities to variance in one or more parameters associated with operating of the optical arrayed grating device. Lengths of the respective portions are determined such that each waveguide applies a respective phase shift to the output light signal that propagates through the waveguide and the plurality of waveguides have at least substantially same change in phase shift with respective changes in the one or more parameters associated with operation of the device. An output coupler is optically connected to the plurality of waveguides to map respective light signals output from the plurality of waveguides to respective focal positions.

A photonic integrated device includes a first waveguide and a second waveguide. The first and second waveguides are mutually coupled at a junction region the includes a bulge region.

An optical waveguide includes a first waveguide core, a second waveguide core, a first subwavelength multilayer cladding, a second subwavelength multilayer cladding and a third subwavelength multilayer cladding. The first waveguide core and the second waveguide core have a width (w) and a height (h). The first waveguide core is disposed between the first subwavelength multilayer cladding and the second subwavelength multilayer cladding. The second waveguide core is disposed between the second subwavelength multilayer cladding and the third subwavelength multilayer cladding. Each subwavelength multilayer cladding has a number (TV) of alternating subwavelength ridges having a periodicy (A) and a filling fraction (p). A total coupling coefficient (|/c|) of the first waveguide core and the second waveguide core is from 10 to 0.

In order to provides an optical waveguide element and an optical modulator that can prevent the damage to the substrate and the deterioration of the properties of the substrate that may occur due to the stress, by reducing the influence of stress on the substrate by the buffer layer, the optical waveguide 1 is provided with a substrate 5 having an electro-optical effect; an optical waveguide 10 formed on the substrate 5; a first buffer layer 9a provided on the substrate 5; and a second buffer layer 9b provided under the substrate 5, wherein the first buffer layer 9a and the second buffer layer 9b are composed of substantially the same material and have substantially the same thickness, and the first buffer layer 9a and the second buffer layer 9b are formed to be in contact with an upper surface and lower surface of the substrate 5, respectively.

An optical circuit element capable of preventing stray light propagated through a part including a substrate of the optical circuit element from being emitted to the outside is provided. The optical circuit element has a substrate, an optical waveguide layer that is formed on one surface of the substrate, and a protective layer that is overlaid on the optical waveguide layer. The optical waveguide layer has an optical waveguide configured for light to be propagated therethrough. A groove portion, which reaches to a position deeper than the one surface from a surface of the protective layer toward the substrate, is formed. The optical circuit element further includes a light absorption layer that covers at least a bottom surface and a side surface of the groove portion.

Provided is an optical phase shifter. The optical phase shifter includes: a slab waveguide in which a first slab region doped into a first conductivity type and a second slab region doped into a second conductivity type are arranged side by side to form a PN junction; and a rib waveguide disposed on the slab waveguide such that one side of the rib waveguide makes contact with the first slab region, and an opposite side of the rib waveguide makes contact with the second slab region, wherein the rib waveguide includes first to third rib waveguide layers that are sequentially stacked, the first and third rib waveguide layers include silicon (Si), and the second rib waveguide layer includes silicon-germanium (SiGe).

A LIDAR system includes a LIDAR chip configured to output a LIDAR output signal. The LIDAR chip includes a redirection component and alternate waveguides. The redirection component receives an outgoing LIDAR signal from any one of multiple alternate waveguides. The LIDAR output signal includes light from the outgoing LIDAR signal. A direction that the LIDAR output signal travels away from the LIDAR chip is a function of the alternate waveguide from which the redirection component receives the outgoing LIDAR signal.

Techniques for enhancing the absorption of photons in semiconductors with the use of microstructures are described. The microstructures, such as pillars and/or holes, effectively increase the effective absorption length resulting in a greater absorption of the photons. Using microstructures for absorption enhancement for silicon photodiodes and silicon avalanche photodiodes can result in bandwidths in excess of 10 Gb/s at photons with wavelengths of 850 nm, and with quantum efficiencies of approximately 90% or more.