Abstract: An optical fiber that complies with ITU-T G.657.A2 recommendations. The optical fiber comprises an inner cladding that is adjacent to the core, thereby extending from a core radius (rcore) to an inner cladding radius (rinner_clad). The inner cladding refractive index decreases approximately linearly as a function of radius (r), thereby decreasing approximately linearly from a first inner cladding relative refractive index (?inner_clad_1) to a second inner cladding relative refractive index (?inner_clad_2). The ratio of rinner_clad to rcore is between approximately 3.2 and approximately 4.2 (˜3.2?rinner_clad/rcore?˜4.2).

Abstract: An optical fiber is formed to include a specialized cladding layer that exhibits a change in refractive index as the fiber is tapered, related to the out-diffusion of a refractive index-decreasing dopant included in the cladding layer. The change in refractive index (propagation constant) is sufficient to maintain the local taper angle relation and prevent the institution of loss oscillations as the length of the taper extends to a desired value. In particular, the specialized cladding layer may be formed to include a sufficient concentration of an index-decreasing dopant such as F, which is known to diffuse faster that the conventional cladding layer index-increasing dopants (e.g., one or more of Ge, Cl, and P).

Abstract: A multicore fiber assembly in which multiple single-mode cores are coupled to form a single path. The assembly reduces the complexity of optical fiber sensor measurement and allows to keep back reflections low and measure various parameters such as fiber twist, temperature, axial strain, and fiber shape.

Abstract: A system comprising an enhanced back-scattering region, which is confined to a limited enhanced scattering bandwidth (e.g., approximately ten decibel (10 dB) scattering bandwidth over approximately fifteen nanometer (15 nm) wavelength range in the C-Band (Conventional Band)). A signal transmission wavelength (or telecom signal wavelength) carries an optical signal at a wavelength that is at least one nanometer (1 nm) outside of the enhanced scattering bandwidth.

Abstract: A system (e.g., an optical amplifier) comprising gain fibers (e.g., Bismuth-doped optical fiber) for amplifying optical signals. The optical signals have an operating center wavelength (?0) that is centered between approximately 1260 nanometers (˜1260 nm) and ˜1360 nm (which is in the O-Band). The gain fibers are optically coupled to pump sources, with the number of pump sources being less than or equal to the number of gain fibers. The pump sources are (optionally) shared among the gain fibers, thereby providing more efficient use of resources.

Abstract: Embodiments of the invention include an optical time domain reflectometer (OTDR) device having a transmitter for transmitting a series of optical pulses, a processor for controlling the duration and frequency of the transmitted optical pulses, an optical coupler for directing the transmitted optical pulses to a device under test coupled to the OTDR and receiving light reflected back from the device under test, a detector for converting light reflected back from the device under test to an electrical signal, a display for displaying a plot of the electrical signal, and a gating function device for removing at least one saturation event from the light reflected back from the device under test. The operation of the gating function device is controlled by a gating signal provided by the processor to the gating function device. The gating signal is based on at least one characteristic of the saturation event.

Abstract: In curing a matrix material of a rollable optical fiber ribbon, ultraviolet light may be concentrated in a selected range of wavelengths to avoid further curing the primary coating of each fiber. A ribbon may be made by aligning the fibers, each having at least a primary coating, into a ribbon shape, applying a matrix material in intermittently distributed portions along the ribbon-shaped group of fibers, and exposing the ribbon-shaped group of fibers and applied matrix material to ultraviolet light concentrated in a range of wavelengths absorbed more by the matrix material than by the primary coating.

Abstract: A hydrogen diffusion barrier is included as an intra-cladding layer (i.e., a “ring”) within an optical fiber structure. The hydrogen diffusion barrier ring may comprise alumina (or other glass oxides) and is positioned within the fiber cladding at an optimum location with respect to the central core region of the optical fiber. The thickness of the barrier ring may be controlled by fabrication processes to control properties such as hydrogen permeability. Other alkali and alkaline earth metal oxides may be included in the composition of the barrier ring and are useful in preventing crystal formation during the fiber fabrication process.

Abstract: The present disclosure provides systems and methods for optically coupling a solid-core fiber (SCF) with a hollow-core fiber (HCF). Briefly described, one embodiment of the system comprises a graded-index (GRIN) fiber and a hollow fiber (HF) that optically couple the SCF with the HCF. The combination of the GRIN with the HF permits mode matching between the SCF and the HCF, while concurrently increasing return loss from the HCF to the SCF.

Abstract: Embodiments of the invention include an optical fiber ribbon. The optical fiber ribbon includes a plurality of optical fibers arranged adjacent to one another in a linear array. The optical fiber ribbon also includes a bonding matrix material applied to at least a portion of the outer surface of at least two adjacent optical fibers. The optical fiber ribbon also includes at least one marking applied to the outer surface of at least one optical fiber. The at least one marking is applied to the outer surface of at least one optical fiber in a manner that reduces the optical transmission loss of the optical fibers.

Abstract: Embodiments of the present disclosure generally relate to systems, methods, and articles of manufacture for using a fiber laser with wavelength division multiplexers (WDMs) for a variety of purposes. For example, implementations described herein may be used with high-power Raman fiber laser (RFL) systems, or the like. A laser system is provided that may include a fiber laser; a laser path comprising optical fiber; and a plurality of wavelength division multiplexers (WDMs) positioned within the laser path coupling the optical fiber; wherein at least one of the plurality of WDMs has the widest wavelength spacing and is positioned first in the laser path, thereby providing increased power stability.

Abstract: A photoinduced refractive index-changing material is coupled directly to both a first port and a second port. An optical interconnect structure (for optically coupling the first port to the second port) is formable in the photoinduced refractive index-changing material by selectively exposing a portion of the photoinduced refractive index-changing material. The selective exposure induces a refractive index change in the photoinduced refractive index-changing material. The change in refractive index provides the waveguiding properties of the optical interconnect structure.

Abstract: Embodiments of the invention include an optical fiber ribbon having a low Young's modulus bonding matrix material. The optical fiber ribbon includes a plurality of optical fibers arranged adjacent to one another in a linear array. The optical fiber ribbon also includes a plurality of bonding matrix material portions applied to at least a portion of the outer surface of at least two adjacent optical fibers. The bonding matrix material portions have a low Young's modulus. Also, the plurality of bonding matrix material portions are applied to at least a portion of the outer surface of at least two adjacent optical fibers in such a way that the linear array of optical fibers forms a partially bonded optical fiber ribbon.

Abstract: A system of aligning concatenated sections of multicore optical fiber incorporates the capability of intentionally changing core assignments as part of the azimuthal alignment process. The intentional changing of core assignments, referred to as offset clocking, compensates for differences in properties of the individual core regions in a way that reduces variations between the spatial channels supported in the transmission system. The offset clocking technique can be used, e.g., to improve the attenuation (or other selected properties of the propagating signals). The offset clocking technique may be used to step through sequential changes core assignments at one or more splice locations (passive clocking) or identify a particular pairing of cores from one fiber section to the next (e.g., “good quality” core assigned to a “poor quality” signal exiting the first section) and rotate the fiber sections with respect to each other to achieve this particular core assignment.

Abstract: Described herein are systems, methods, and articles of manufacture for high back-scattering waveguides (e.g., optical fibers) and sensors employing high back-scattering optical fibers. Briefly described, one embodiment comprises a high back-scattering fiber, or enhanced scattering fiber or “ESF,” that features resistance specifications that remain intact over lengths of fiber in excess of 1 m, or preferably >100 m, or preferably >1 km, wherein the reflectivity of the ESFs may be precisely tuned within a range from ?100 dB/mm to ?70 dB/mm, and wherein the enhanced scattering may be spatially continuous or, alternatively, may be at discrete locations spaced apart by 100 microns to >10 m.

Abstract: A multi-core optical fiber comprises at least two (2) helical cores. When the multi-core optical fiber is bent, such that it has a bend length (L) and a bend radius (R), each core experiences a different strain, thereby resulting in an effective optical length difference (?l) between the cores. In the present disclosure, the helical cores have a pitch (P) that reduces ?l/L to a value that is less than 5·10?6 (i.e., ?l/L<5·10?6).

Abstract: Described herein are systems, methods, and articles of manufacture for a coated fiber modified by actinic radiation to increase back-scattering, which experiences very little back-scattering decay at a temperature and time of exposure that is sufficient to noticeably degrade the coating and/or noticeably degrade the optical fiber due to outgassing of hydrogen from the coating. In one embodiment, an optical fiber comprises a fiber length, a coating having a treated coating weight, wherein the treated coating weight is at least 25% less of an original coating weight prior to an annealing treatment, and an optical back-scatter along the fiber length greater than a Rayleigh back-scattering over the fiber length, wherein the optical back-scatter does not decrease along the fiber length by more than 3 dB after exposure to annealing treatment.

Abstract: An extended length of optical fiber having an offset core with an inscribed Bragg grating is used a distributed sensor in combination with an optical frequency domain reflectometer (OFDR) to enable measurement small-scale (e.g., sub-millimeter) contortions and forces as applied to the fiber. The offset core may be disposed in a spiral configuration around the central axis of the optical fiber to improve the spatial resolution of the measurement. A reference surface exhibit a predetermined texture (in the form of a series of corrugations, for example, that may be periodic or aperiodic, as long as known a priori) is disposed adjacent to a longitudinal portion of the sensor fiber. The application of a force to the combination of the plate and the fiber creates a local strain in the grating formed along the offset core of the fiber that results in a shift in the Bragg wavelength of the grating.

Abstract: Embodiments of the invention include an optical fiber cable. The optical fiber cable includes a multi-fiber unit tube that is substantially circular and dimensioned to receive a plurality of optical fibers. The optical fiber cable also includes a plurality of partially bonded optical fiber ribbon units positioned within the multi-fiber tube. The partially bonded optical fiber ribbon units are partially bonded in such a way that each partially bonded optical fiber ribbon is formed in a substantially circular shape or a random shape. The optical fiber cable also includes at least one elastomeric strength layer formed around the partially bonded optical fiber ribbon units. The optical fiber cable also includes an outer jacket surrounding the multi-fiber tube.

Abstract: Drop lines are supported and routed from a an ADSS trunk cable to designated users. Each of a number of non-metallic elongated support members has a main passage, and a first slit for enabling the cable to be urged into the passage from outside. Each member also has a number of aligned outer passages, and associated second slits for enabling a drop line to be urged into a given outer passage from outside. A band may be applied about each support member to prevent the cable and the drop lines from escaping the member through the slits. One end of each drop line is connected to the cable fibers inside a closure fixed at one end of a cable span. A drop line exiting an outer passage in a given support member is routed either through an outer passage in a successive member, or away from the cable to a designated user.