Abstract: Various example embodiments of a multi-input coherent optical receiver are presented. The multi-input coherent optical receiver may be configured to support coherent detection of light from a set of multiple spatially separated optical input fibers. The multi-input coherent optical receiver may be configured to support coherent detection of light from a set of multiple spatially separated optical input fibers based on use of an optical hybrid array, dispersive optics, and an optical detector array, where the optical hybrid array is configured to produce optical hybrid output light by superposing local oscillator light with the light of the plurality of optical input channels, the dispersive optics are configured to disperse the optical hybrid output light into spectral channels that are spectrally and spatially separated, and the optical detector array is configured, for each respective spectral channel of the spectral channels, to detect optical hybrid output light of the respective spectral channel.

Abstract: Various example embodiments for supporting optical transport systems are presented. Various example embodiments for supporting optical transport systems may be configured to support optical transport systems that support multiple fibers based on use of spatial division multiplexing (SDM) techniques. Various example embodiments for supporting optical transport systems that support multiple fibers based on use of SDM techniques may be configured to support optical transport systems that support multiple fibers based on use of an anylane add/drop capability that is based on use of a Clos architecture (e.g., a spatially-switched distributed Clos architecture with a single stage of switching for network traffic that passes through the node, a spatially-switched distributed Clos architecture with two stages of switching for network traffic that passes through the node, a spatially-switched node-contained Clos architecture with three stages of switching for network traffic that passes through the node, or the like).

Abstract: A system and method are disclosed, in which data in an optical supervisory channel is transmitted from a first node of an optical fiber network to a second node of the optical fiber network and received in a coherent optical receiver at the second node of the optical fiber network. From a receiver output signal responsive to the received data, there is extracted at least one measure of phase variation and/or of signal attenuation on the optical fiber network between the first and second nodes.

Abstract: Various example embodiments for supporting optical transport systems are presented. Various example embodiments for supporting optical transport systems may be configured to support optical transport systems that support multiple fibers based on use of spatial division multiplexing (SDM) techniques. Various example embodiments for supporting optical transport systems that support multiple fibers based on use of SDM techniques may be configured to support optical transport systems that support multiple fibers based on use of an anylane add/drop capability that is based on use of a Clos architecture (e.g., a spatially-switched distributed Clos architecture with a single stage of switching for network traffic that passes through the node, a spatially-switched distributed Clos architecture with two stages of switching for network traffic that passes through the node, a spatially-switched node-contained Clos architecture with three stages of switching for network traffic that passes through the node, or the like).

Abstract: Various example embodiments for a wavelength selective switch including a direct grating interface are presented. In at least some example embodiments, a wavelength selective switch may include a light propagating element having a tilted fiber grating integrated therein, thereby providing a direct grating interface to the light propagating element. It is noted that use of such a direct grating interface may obviate the need for use of various components typically utilized within wavelength selective switches (e.g., front-end optics in the port direction, front-end optics and diffractive gratings in the wavelength direction, and so forth), thereby enabling the size of wavelength selective switches to be reduced or even for the wavelength selective switches to be made compact or even ultra-compact.

Abstract: An optical imaging system capable of performing holographic imaging through a multimode optical fiber. Images of an object acquired by the system using different object-illumination conditions can advantageously be used to obtain a holographic image with reduced speckle contrast therein. Additionally, a beat-frequency map of the object acquired by the system using optical-reflectometry measurements therein can be used to augment the depth information of the holographic image for more-detailed three-dimensional rendering of the object for the user. Digital back-propagation techniques may be applied to reduce blurring in the holographic image and in the depth information caused, e.g., by modal dispersion and mode mixing in the multimode optical fiber. Some embodiments may also provide the capability for polarization-sensitive holographic imaging in different spectral regions of light.

Abstract: An optical interconnect circuit for transmitting data between two or more electronic chips. In an example embodiment, the optical interconnect circuit comprises two or more photonic chips, each of which is vertically stacked with the corresponding electronic chip such that compact optical modulators and/or photodetectors of the photonic chip are in close proximity to the data sources/sinks of the corresponding electronic chip. Multi-core optical fibers and vertical coupling structures are used to provide multiple optical connections between different photonic chips. Advantageously, the provided capability to place optical modulators close to the data sources and to place photodetectors close to the data sinks can be used to reduce the amount of required electrical wiring. Optical-waveguide connections to the multi-core fibers can be used to allow for high density of optical conduits without spatially constraining the placement of data sources and/or data sinks on the electronic chips.

Abstract: An optical frequency-domain reflectometer (OFDR) capable of estimating the transfer matrix of a multimode optical fiber using mode-selective measurements performed from a single end of the fiber. In an example embodiment, the multimode optical fiber includes distributed reflectors designed to generate relatively strong light reflections along the length of the fiber at a desired spatial resolution. The embodiments may employ a signal-processing algorithm to estimate the fiber's transfer matrix by estimating segment transfer matrices corresponding to the fiber segments located between different ones of the distributed reflectors. Different embodiments of the disclosed OFDR can beneficially be adapted for use in different applications, such as fiber-optic component and module characterization, distributed optical sensing, biomedical imaging, OCT, etc.

Abstract: An optical frequency-domain reflectometer (OFDR) capable of estimating the transfer matrix of a multimode optical fiber using mode-selective measurements performed from a single end of the fiber. In an example embodiment, the multimode optical fiber includes distributed reflectors designed to generate relatively strong light reflections along the length of the fiber at a desired spatial resolution. The embodiments may employ a signal-processing algorithm to estimate the fiber's transfer matrix by estimating segment transfer matrices corresponding to the fiber segments located between different ones of the distributed reflectors. Different embodiments of the disclosed OFDR can beneficially be adapted for use in different applications, such as fiber-optic component and module characterization, distributed optical sensing, biomedical imaging, OCT, etc.

Abstract: An optical interconnect circuit for transmitting data between two or more electronic chips. In an example embodiment, the optical interconnect circuit comprises two or more photonic chips, each of which is vertically stacked with the corresponding electronic chip such that compact optical modulators and/or photodetectors of the photonic chip are in close proximity to the data sources/sinks of the corresponding electronic chip. Multi-core optical fibers and vertical coupling structures are used to provide multiple optical connections between different photonic chips. Advantageously, the provided capability to place optical modulators close to the data sources and to place photodetectors close to the data sinks can be used to reduce the amount of required electrical wiring. Optical-waveguide connections to the multi-core fibers can be used to allow for high density of optical conduits without spatially constraining the placement of data sources and/or data sinks on the electronic chips.

Abstract: An apparatus including an optical fiber connector module and an integrated optical device. The optical fiber connection module including an array of holes there-through for holding end segments of optical fibers therein such that the end of each of the optical fibers has a fixed distance relationship with an external surface of the module, the module having one or more electrical conductor lines therein with electrical contacts thereto along the external surface and having one or more first mechanical alignment structures along the external surface. The integrated optical device having one or more second mechanical alignment structures along an outer surface thereof, the first and second mechanical alignment structures capable of being fitted together such that the outer surface and external surface have a fixed relative positional relationship and such that the electrical contacts of the optical fiber connector module are adjacent to electrical contacts of the integrated optical device.

Abstract: Various embodiments relate to a method including: coupling one or more optical spatial pilot signals into a first end of optical fiber, wherein the optical fiber is a multimode optical fiber; Reflecting and modifying each mode of the optical pilot signals at a second end of the optical fiber; receiving a reflected portion of the one or more optical spatial pilot signals at the first end of the of the optical fiber in response to the reflected portion having propagated through the optical fiber in both directions; processing the reflected spatial pilot to determine components of one of a round-trip transfer matrix of the optical fiber and a single-direction transfer matrix of the optical fiber.

Abstract: The present disclosure is directed to an apparatus comprising two components mounted on opposite sides of a window but proximate to each other where the two components are communicatively coupled through an optical link and where each component can be communicatively coupled with a wireless data source. In another embodiment, the components can include one or more of light indicators, audio indicators, and magnetic assistance to guide an optical alignment between the two components. In another embodiment, the components can include one or more of an array of lasers, larger photo diodes, adjustable lenses, and can utilize gain parameters to increase the tolerance level for a misaligned optical link. In another embodiment, methods are disclosed to perform communication coupling via an optical transmission link. In another embodiment, methods are disclosed to assist a user in optically aligning the two components.

Abstract: An optical apparatus includes a front optics section and a spectrometer section. The front optics section includes a spot de-multiplexer configured to receive a plurality of multi-mode optical signals each having a plurality of modal components, and to output in a linear array of a corresponding plurality of optical beams for each multimode optical signal. The spectrometer section includes a wavelength steering element configured to separate each of the optical beams into a plurality of wavelength channels. A fiber steering element is configured to steer the wavelength channels between the optical beams.

Abstract: Various embodiments relate to a method including: coupling one or more optical spatial pilot signals into a first end of optical fiber, wherein the optical fiber is a multimode optical fiber; Reflecting and modifying each mode of the optical pilot signals at a second end of the optical fiber; receiving a reflected portion of the one or more optical spatial pilot signals at the first end of the of the optical fiber in response to the reflected portion having propagated through the optical fiber in both directions; processing the reflected spatial pilot to determine components of one of a round-trip transfer matrix of the optical fiber and a single-direction transfer matrix of the optical fiber.

Abstract: An optical apparatus includes a front optics section and a spectrometer section. The front optics section includes a spot de-multiplexer configured to receive a plurality of multi-mode optical signals each having a plurality of modal components, and to output in a linear array of a corresponding plurality of optical beams for each multimode optical signal. The spectrometer section includes a wavelength steering element configured to separate each of the optical beams into a plurality of wavelength channels. A fiber steering element is configured to steer the wavelength channels between the optical beams.

Abstract: An optical amplifier includes a multi-mode pump laser module, a multi-mode waveguide, a multi-mode to multiple single-mode fiber converter module and a plurality of single-mode cores. The multi-mode pump laser module emits pump light having a plurality of modes to the multi-mode fiber or waveguide. The multi-mode waveguide propagates the emitted pump light to the converter module. The converter module receives the pump light and distributes the pump light approximately uniformly to a plurality of single-mode cores.

Abstract: Various exemplary embodiments relate to an optical amplifier, including: a multicore rare-earth doped optical fiber with a first plurality of cores associated with a first stage of the optical amplifier and a second plurality of cores associated with a second stage of the optical amplifier; a three dimensional (3D) waveguide configured to couple input space division multiplexed (SDM) channels into the first plurality of cores at a first end of the multicore rare-earth doped optical fiber and to couple channels from the second plurality of cores to output SDM channels; a reflector configured to optically interconnect the first plurality of cores to the second plurality of cores; and pump laser coupled to the multicore rare-earth doped optical fiber configured to produce laser pump light to pump the multicore rare-earth doped optical fiber.

Abstract: An optical apparatus, comprising a wavelength selective switch, the wavelength selective switch including: one or more planar lightwave circuits and a plurality of optical beam steering assemblies. Each one of the planar lightwave circuits have at least one arrayed waveguide grating located thereon.

Abstract: In a method for dynamic buffer adjustment at a line card of router, a current buffer occupancy at the line card is compared with at least a first buffer occupancy threshold, the first buffer occupancy threshold being calculated based on a buffer occupancy threshold parameter and a capacity of at least a first buffer memory at the line card; and an active buffer capacity is adjusted by at least one of activating and deactivating buffer memory blocks at the line card based on the comparing step, the activating including switching on the buffer memory blocks, and the deactivating including causing the buffer memory blocks to enter a sleep state.