Abstract: Structures for a directional coupler and methods of fabricating a structure for a directional coupler. A first waveguide core has a first section, a second waveguide core has a second section laterally adjacent to the first section, a third waveguide core has a first taper, a second taper, and a third section longitudinally positioned between the first taper and the second taper, and a fourth waveguide core has a first taper, a second taper, and a fourth section longitudinally positioned between the first taper and the second taper. The fourth section is laterally adjacent to the third section, and the third section and the fourth section are positioned either over or under the first section and the second section.

Abstract: A coupling structure includes a single mode active device and a planar optical waveguide. Specifically, the planar optical waveguide includes a silica waveguide for transmitting an optical signal, where the silica waveguide includes a coupling section and a conduction section; the coupling section is of a regular trapezoidal structure or an inverted trapezoidal structure, where a surface of the coupling section coupled to the single mode active device is a trapezoid top, and a surface of the coupling section connected with the conduction section is a trapezoid bottom; and a coupling gap is preset between the single mode active device and the planar optical waveguide.

Abstract: An optical semiconductor device includes a semiconductor substrate, a first semiconductor layer provided on the semiconductor substrate, and a mesa waveguide provided on the principal surface of the first semiconductor layer. The semiconductor device also includes a buried layer covering the upper surface of the first semiconductor layer. Part of the upper surface of the first semiconductor layer is exposed. A mesa structure provided at the boundary between a part of the first semiconductor layer is covered with the buried layer and a part of the first semiconductor layer is exposed. One side of the mesa structure is covered with the buried layer, and the other side is exposed. The optical semiconductor device can reduce the generation of stress in the buried layer, for example, to suppress the occurrence of cracks in the buried layer and enhance the reliability.

Abstract: 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 log2 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.

Abstract: A light projection apparatus is provided comprising: a source of light; a switchable grating on a first substrate; and a diffractive optical element. Light is diffracted at least once by the switchable grating and is diffracted at least once by the DOE.

Abstract: A waveguide display includes a substrate transparent to visible light and a projector configured to generate display light for an image, where the display light includes display light for a first field of view (FOV) of the image and display light for a second FOV of the image. The waveguide display also includes a first input coupler configured to couple the display light for the first FOV into the substrate, a first set of gratings configured to couple the display light for the first FOV out of the substrate at a first two-dimensional array of locations of the substrate, a second input coupler configured to couple the display light for the second FOV into the substrate, and a second set of gratings configured to couple the display light for the second FOV out of the substrate at a second two-dimensional array of locations of the substrate.

Abstract: A multi-clad optical fiber design is described in order to provide low optical loss, a high numerical aperture (NA), and high optical gain for the fundamental propagating mode, the linearly polarized (LP) 01 mode in the UV and visible portion of the optical spectrum. The optical fiber design may contain dopants in order to simultaneously increase the optical gain in the core region while avoiding additional losses during the fiber fabrication process. The optical fiber design may incorporate rare-earth dopants for efficient lasing. Additionally, the modal characteristics of the propagating modes in the optical core promote highly efficient nonlinear mixing, providing for a high beam quality (M2<1.5) output of the emitted light.

Abstract: Examples of optical splitter systems, methods and modules enable the stacking and interconnecting of one or more optical splitter modules. One example of a splitter module has a housing and one or more connection members for connecting to adjacent instances of like splitter modules. The housing includes a plurality of cable ports providing access to an optical splitter storage area. Each connection member includes a tab and a slot, the tab configured to slidingly engage with the slot of an adjacent connection member. Sliding engagement of adjacent instances of splitter modules can form a stack of splitter modules along a stacking axis. In some cases a splitter module includes a latching mechanism to removably engage an adjacent splitter module. The latching mechanism can restrict sliding engagement and thus decoupling of the adjacent splitter modules.

Abstract: A method includes multiplexing signal light of first polarization and excitation light, and multiplexing signal light of second polarization, which is perpendicular to the first polarization, and the excitation light, modulating the signal light of the first polarization before the wavelength conversion, and reducing a modulation component in signal light after wavelength conversion, modulating the signal light of the second polarization before the wavelength conversion, and reducing the modulation component in the signal light after the wavelength conversion, and multiplexing the signal light of the first polarization after the wavelength conversion and the signal light of the second polarization after the wavelength conversion.

Abstract: A sensor system includes an optical fiber. A set of wavelength shift sensors are inscribed on the optical fiber. The set includes at least one first wavelength shift sensor configured to reflect a first wavelength band of input light as a first optical output signal. The first wavelength shift sensor has a first value of an optical characteristic that modifies intensity of the first optical output signal. At least one second wavelength shift sensor is configured to reflect a second wavelength band of input light as a second optical output signal. The second wavelength shift sensor has a second value of the optical characteristic that modifies intensity of the second optical output signal, wherein the second value is different from the first value.

Abstract: Multimode optical fibers are disclosed herein. In some embodiment disclosed herein, a multimode optical fiber having a bandwidth of greater than 2 GHz·km includes: a glass matrix having a front endface, a back endface, a length (L), a refractive index n20 and a central axis (AC); and a plurality of cores arranged within the glass matrix, wherein the plurality of cores run generally parallel to the central axis between the front and back endfaces and having respective refractive indices n50, wherein n50>n20, wherein the glass matrix serves as a common cladding for the plurality of cores so that each core and the common cladding define a waveguide, wherein each core is a single mode at an operating wavelength; and wherein any two cores have an center-to-center spacing s of 3 ?m to 20 ?m and a coupling coefficient of greater than 10 m?1 but less than 200 m?1.

Abstract: A semiconductor detector (100) for electromagnetic radiation within a wavelength range is disclosed, comprising a first waveguide portion (110), a funnel element (130) configured to funnel incident electromagnetic radiation into a first end (112) of the first waveguide portion, and a second waveguide portion (120) extending in parallel with the first waveguide portion. The second waveguide portion is coupled to the first waveguide portion and configured to out-couple electromagnetic radiation from the first waveguide portion, within a sub-range of the wavelength range. Further, a photodetector (140) including a photoactive layer (144) is arranged at a second end (114) of the first waveguide portion and at an end (124) of the second waveguide portion, and configured to separately detect electromagnetic radiation transmitted through and exiting the first waveguide portion and the second waveguide portion.

Abstract: An optical transmission device includes: a substrate; a waveguide that is provided in the substrate and transmits an optical signal; a signal wiring that is provided in the substrate and transmits an electric signal; and a silicon wiring that is provided in the substrate and is silicon added with an impurity. The signal wiring is placed in an area of the substrate, the area being away from an end of the substrate by a predetermined distance or more. One end of the silicon substrate is connected to the signal wiring, and the other end of the silicon wiring extends to the end of the substrate.

Abstract: A system and method for improving the efficiency and effectiveness of installing and pulling microducts through subterranean pathways is provided. The system includes a device that is placed over at least one microduct and secured through tapered screws that enter through the end cap of the body of the device and into at least one microduct. The tapered screw both expands the microduct, pressing it against the inner wall of the body and guide rod, as well as securing the microduct to the cap end of the body. Securing the microducts against seal provides further protection from water, debris, and other contaminants, and the expansion of the microducts provides friction and adherence to the body, aiding in keeping microducts in place. The device further includes a pulling apparatus connected to the device body, allowing it to be connected to a pulling mechanism for installation of the microducts.

Abstract: A waveguide is provided for conveying image light. The waveguide includes an input port for receiving a first beam of image light carrying an image in a wavelength band. A first diffraction grating of the waveguide includes a plurality of volume Bragg gratings (VBGs) configured to expand the first beam along a first axis and to redirect the first beam towards a second diffraction grating of the waveguide. The second diffraction grating includes a plurality of VBGs configured to receive the first beam from the first diffraction grating and to out-couple different portions of the first wavelength band of the first beam along a second axis, thereby expanding the first beam along the second axis for observation of the image by a user.

Abstract: An optical coupling device can couple incident light from a fiber into waveguides, but can reduce the coupling of return light from the waveguides into the fiber. A Faraday rotator layer can rotate by forty-five degrees, with a first handedness, respective planes of polarization of incident beams, and can rotate by forty-five degrees, with a second handedness opposite the first handedness, respective planes of polarization of return beams. A redirection layer can include at least one grating coupler that can redirect an incident beam of one polarization so that the redirected path extends within the redirection layer toward a first waveguide, and can redirect an incident beam of an opposite polarization so that the redirected path extends within the redirection layer toward a second waveguide. An optional birefringent layer can spatially separate incident beam having different polarizations, so that two single-polarization grating couplers can be used.

Abstract: An optical fiber includes a core and a cladding. The core contains silica glass and includes a central portion (part having a diameter of 0.5 ?m or more and 4 ?m or less). The central portion has the central axis of the optical fiber. The cladding contains silica glass and surrounds the core. The core contains chlorine. A chlorine concentration averaged in the entire core is 10,000 ppm or more and 50,000 ppm or less. The chlorine concentration averaged in the entire core minus a chlorine concentration averaged in the central portion is 4,500 ppm or more and 13,500 ppm or less.

Abstract: A grating coupler reflector (retro reflector) is formed within a photonics chip and includes a vertical scattering region, an optical waveguide, and a reflector. The optical waveguide is optically coupled to the vertical scattering region. The reflector is positioned at an end of the optical waveguide. The reflector is configured to reflect light that propagates through the optical waveguide from the vertical scattering region back toward the vertical scattering region. The location of the grating coupler reflector on the photonics chip is determinable by scanning a light emitting active optical fiber over the chip and detecting when light is reflected back into the active optical fiber from the grating coupler reflector. The determined location of the grating coupler reflector on the photonics chip is usable as a reference location for aligning optical fiber(s) to corresponding optical grating couplers on the photonics chip.

Abstract: Connector assemblies are described herein. For example, a connector assembly including: a housing configured to accept a first ferrule and a second ferrule. The connector assembly may also have a latch component that is removably connected to the housing. The connector may furthermore include a push-pull tab removably connected to the housing and configured to move horizontally along the outer surface of housing when a biasing force is applied in at least one of a forward direction and a rearward direction. Accordingly, the push-pull tab can compress the latch component when moving horizontally along the housing, and an inverted ramp at a proximal end of the push/pull, the ramp aides in depressing the latch downward to release the connector from a receptacle.

Abstract: A return loss in an optical connector connection structure according to a lens scheme is reduced. An optical connector (10) according to this disclosure, includes: a plurality of optical fibers (18) arranged in an array; and a lens array plate (14) that includes a first principal surface (40) with a plurality of lenses (44) corresponding to the respective optical fibers being formed on this surface, and a second principal surface (41) joined to end faces (180) of the optical fibers so as to be opposed to the first principal surface and optically coupled to the optical fibers to which the respective lenses correspond, wherein at least one of the end faces of the optical fibers and the second principal surface is inclined from a plane (182) perpendicular to optical axes (181) of the optical fibers.