Abstract: The selection of starting materials used in the process of forming an MCR is controlled to specifically define the physical properties of the core tube and/or the capillary tubes in the local vicinity of the core tube. The physical properties are considered to include, but are not limited to, the diameter of a given tube/capillary, its wall thickness, and its geometry (e.g., circular, non-circular). A goal is to select starting materials with physical properties that yield a final hollow core optical fiber with a “uniform” core region (for the purposes of the present invention, a “uniform” core region is one where the struts of cladding periodic array surrounding the central core are uniform in length and thickness (with the nodes between the struts thus being uniformly spaced apart), which yields a core wall of essentially uniform thickness and circularity.

Abstract: An optically transparent protective coating is described that remains stable at elevated temperatures associated with optical fiber-based sensor applications and is sufficiently transparent to allow for conventional fiber Bragg gratings (FBGs) to be formed by directly writing through the coating. In particular, vinyl group-containing silicone polymers have been found to provide the UV transparency required for a write-through coating (WTC) and promising mechanical properties for protecting the optical fibers, while also being able to withstand elevated temperatures for extended periods of time.

Abstract: A technique for fabricating a hollow core optical fiber with a controllable core region (in terms of diameter) is based upon regulating conditions (gas flow, volume, and/or temperature) within the hollow core region during the fiber draw process. The introduction of a gas, or any change in volume or temperature of the hollow core region, allows for the diameter of the hollow core region to self-regulate as a multistructured core rod (MCR) is drawn down into the final hollow core optical fiber structure. This self-regulation provides a core region having a diameter that selected and then stabilized for the duration of the draw process. The inventive process is also useful in controlling the diameter of any selected hollow region of an MCR including, but not limited to, shunts and corner capillaries disposed around the core region.

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: An all-fiber supercontinuum (SC) optical source utilizes a combination of a seed pulse supply of short-duration optical pulses with a highly non-linear optical medium in the form of two or more concatenated sections of highly non-linear optical fiber (HNLF) of different dispersion values and lengths. The two or more sections of HNLF are configured to include at least one section that exhibits a positive dispersion value and one section that exhibits a negative dispersion value. Non-linear effects such as self-phase modulation (SPM), cross-phase modulation (XPM), Raman amplification, and the like, cause the seed pulses to broaden as they propagate through each section of HNLF, where the differences between the dispersion values, as well as the lengths of each fiber section, are particularly configured to create an SC output that is wide and smooth, exhibiting a stable intensity and high coherence level.

Abstract: A wavelength-swept optical source is based upon a combination of a coherent source of ultra-short optical pulses, doped fiber amplifier, and specialized dispersive optical medium to create time-stretched pulses. The pulses are broadened to have a spectral bandwidth that covers a wavelength range of interest for a particular wavelength sweeping application and are thereafter subjected to time-stretching within the dispersive optical medium so as to sufficiently separate in time a number of wavelength components within each pulse.

Abstract: An optical preform manufacturing process is disclosed in which an alkali dopant is deposited between an optical fiber core rod and an optical fiber cladding jacket. Depositing the alkali dopant between the core rod and the cladding jacket permits diffusion of the alkali dopants into the core during fiber draw when the core and the cladding are at their respective transition (or vitrification) temperatures. Introduction of the alkali dopants between the core rod and the cladding jacket also permits decoupling of the alkali doping process from one or more of other optical preform manufacturing processes. The optical preform manufacturing process can also include placing alkali dopants between an optical fiber inner cladding jacket and an optical fiber outer cladding jacket to reduce the glass viscosity during fiber draw.

Abstract: An optical probe includes an optical source that generates an optical beam that propagates from a proximal end to a distal end of an optical fiber that imparts a transformation of a spatial profile of the optical beam. An optical control device imparts a compensating spatial profile on the optical beam that at least partially compensates for the transformation of the spatial profile of the optical beam imparted by the optical fiber in response to a control signal from a signal processor. A distal optical source generates a calibration light that propagates through the one or more optical waveguides from the distal end to the proximal end of the optical fiber. An optical detector detects the calibration light and generates electrical signals in response to the detected calibration light.

Abstract: A higher-order mode (HOM) fiber is configured as a polarization-maintaining fiber by including a pair of stress rods at a location within the cladding layer that provides for a sufficient degree of birefringence without unduly comprising the spatial mode profile of the propagating higher-order modes. An optical imaging system utilizing polarization-maintaining HOM fiber allows for different wavelength probe signals to be directed into different modes, useful in applications such as STED microscopy, 2D sensing, and the like.

Abstract: An optical fiber cable may include a cable jacket, a rigid tensile reinforcement member centered within the cable jacket, and a plurality of partially bonded optical fiber ribbons around the rigid tensile reinforcement member. The optical fiber cable does not include any buffer tubes but may include a cushioning layer adjacent the ribbons.

Abstract: A fiber amplifier that is particularly configured to provide gain across a large extent of the C-band spectral range (i.e., a gain bandwidth of at least 42 nm, preferably within the range of 46-48 nm) utilizes a specially-designed discrete Raman amplifier in combination with a high inversion level EDFA to extend the gain bandwidth of a conventional EDFA C-band optical amplifier, while maintaining the gain ripple below an acceptable value. The EDFA provides operation at a highly-inverted level and the specialized discrete Raman amplifier (sDRA) element has particular parameters (dispersion, length, effective area) selected to maintain operation within a “small gain” regime while also extending the long wavelength edge of the gain bandwidth and reducing the gain ripple attributed to the EDFA component.

Abstract: A safety device for modules that store windings of communication lines, includes a metallic rod whose ends are configured to receive metallic screws to secure the rod on a base of a given module. End sections of the rod extend to a height at least equal to the height of the stored windings. Intermediate sections of the rod extend in opposite directions from the end sections, substantially parallel to the module base. Outer ends of the intermediate sections at least coincide with the outer periphery of the stored windings. A central section of the rod has opposite ends adjoining the outer ends of the intermediate sections. The central section rises over a path that at least coincides with the outer periphery of the stored windings. The end sections of the rod capture the windings, and the central section prevents them from dropping below the module during a building fire.

Abstract: Embodiments of the invention include a connectorized optical fiber cable. The connectorized optical fiber cable includes at least one multi-fiber unit tube and at least one rollable optical fiber ribbon comprising a plurality of optical fibers positioned within the multi-fiber unit tube. The plurality of optical fibers are rollable in such a way that a first portion of the at least one rollable optical fiber ribbon inside of the at least one multi-fiber unit tube is formed in a substantially circular shape and a second portion of the at least one rollable optical fiber ribbon extending from an end of the at least one multi-fiber unit tube is formed in a substantially flat shape. The connectorized optical fiber cable also includes a jacket surrounding the multi-fiber unit tube and a multi-fiber ferrule connected to an end of the second portion of the at least one rollable optical fiber ribbon.

Abstract: An active optical cable may include a multicore optical fiber, a connector housing, a mateable electrical connector, an array of optoelectronic converter devices in the connector housing, and an optical waveguide structure. The optical waveguide structure is configured to couple optical signals between the fiber cores and the optoelectronic converter devices in the connector housing.

Abstract: A high backscattering optical fiber comprising a perturbed segment in which the perturbed segment reflects a relative power such that the optical fiber has an effective index of neff, a numerical aperture of NA, a scatter of Rp?r(fiber) that varies axially along the optical fiber, a total transmission loss of ?fiber, an in-band range greater than one nanometer (1 nm), and a figure of merit (FOM) in the in-band range. The FOM being defined as: FOM = R p ? r ( fiber ) ? fiber ? ( NA 2 ? n eff ) 2 .

Abstract: A hollow core fiber (HCF) has a cross section with a substantially-circular hollow core in a cladding lattice, an axial center and a reference direction that extends radially in one direction from the axial center. The HCF comprises modified holes that are located along linear paths that extend radially outward from the axial center. The modified holes, which are located at various radial distances from the axial center and at various azimuthal angles from the reference direction, have non-uniform modified properties. These non-uniform modified properties include radially-varying properties, azimuthally-varying properties, or a combination of radially-varying and azimuthally-varying properties.

Abstract: A high backscattering optical fiber comprising a perturbed segment in which the perturbed segment reflects a relative power such that the optical fiber has an effective index of neff, a numerical aperture of NA, a scatter of Rp?r(fiber), a total transmission loss of ?fiber, an in-band range greater than one nanometer (1 nm), a center wavelength (?0) of the in-band range (wherein 950 nm<?0<1700 nm), and a figure of merit (FOM) in the in-band range. The FOM>1, with the FOM being defined as: FOM = R p ? r ( fiber ) ? fiber ? ( NA 2 ? n eff ) 2 .

Abstract: Before pulling a leading end of a fiber optic cable through a duct in order to splice the cable fibers to other fibers located at a far end of the duct, the outer jacket of the cable and elements surrounding the cable fibers are removed to expose the fibers. The exposed fibers are prepared by (a) removing coatings on the fibers, (b) cleaving the ends of the fibers, and (c) placing the cleaved fibers into one or more protective covers. A cable grip or sock is dimensioned and formed to envelop the leading end of the cable including the protective covers, up to and including the outer jacket. The grip together with the cable are pulled through the duct, and the grip and the protective covers are removed at the far end of the duct to expose the cleaved fibers for splicing to the other fibers at the far end.

Abstract: Embodiments of the invention include a method for making a partially bonded optical fiber ribbon. The method includes providing a linear array of optical fibers, and applying a bonding matrix material randomly to at least a portion of at least two adjacent optical fibers. The bonding matrix material is applied randomly to the adjacent optical fibers in such a way that the linear array of optical fibers forms a partially bonded optical fiber ribbon. The bonding matrix material applied randomly to the adjacent optical fibers is dense enough to allow the resulting partially bonded optical fiber ribbon to lay substantially flat. Also, the bonding matrix material applied randomly to the adjacent optical fibers is sparse enough to allow the resulting partially bonded optical fiber ribbon to be rolled into a substantially circular shape.

Abstract: Disclosed herein is an optical cable comprising a support; flexible protective tubes helically wound around the support, each flexible protective tube comprising an optical fiber comprising an optical core; a cladding disposed on the core; and a primary coating external to the cladding; and a deformable material surrounding the optical fiber; an outer jacket surrounding the flexible protective tubes; wherein each optical fiber is about 0.5% to about 1.