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.
G01D 5/30 - Mechanical means for transferring the output of a sensing memberMeans for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for convertingTransducers not specially adapted for a specific variable using optical means, i.e. using infrared, visible or ultraviolet light with deflection of beams of light, e.g. for direct optical indication the beams of light being detected by photocells
G01M 11/00 - Testing of optical apparatusTesting structures by optical methods not otherwise provided for
G02B 6/44 - Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables
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.
G02B 6/27 - Optical coupling means with polarisation selective and adjusting means
H04B 10/2537 - Arrangements specific to fibre transmission for the reduction or elimination of distortion or dispersion due to scattering processes, e.g. Raman or Brillouin scattering
4.
REDUCTION OF THERMAL SENSITIVITY IN ACTIVE OPTICAL FIBERS
A rare earth-doped optical fiber (active fiber) is proposed that exhibits a reduction in the core region thermo-optic coefficient (dn / dT) with respect to the dn/dT of the surrounding cladding. The reduction of core region dn/dT has been found to reduce the effect of transverse mode instability (TMI) in the presence of high levels of pump power (or other conditions that may also increase the heat load present in the core region). Particularly, reducing core region dn/dT by as little as 10% with respect to cladding dn/dT has been found sufficient to extend the temperature range over which active fibers remain in single mode operation. The reduction in dn/dT may be provided by modifying the dopants introduced into the core region where, for example, the introduction of boron into Yb-doped fiber is known to reduce the dn/dT of the core region.
For a hollow-core preform (from which a hollow-core fiber is ultimately drawn), alignment of an inner resonator tube within a cladding tube is accomplished by providing a sleeve with an opening through which the hollow-core preform moves. The sleeve holds a magnet that extends a magnetic field into the opening and, consequently, into the cladding tube and further into the resonator tube. When a ferromagnetic ball is placed within the resonator tube, there arises an attractive force between the magnet and the ferromagnetic ball. The outer surface of the resonator tube maintains a precise contact line with the inner surface of the cladding tube because of the attractive force between the ferromagnetic ball and the magnet. Furthermore, because the ball rolls, the contact line is maintained even when the cladding tube and the resonator tube are moved axially (along a longitudinal axis of the hollow-core preform).
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 (λ0) 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.
H01S 3/091 - Processes or apparatus for excitation, e.g. pumping using optical pumping
H01S 3/094 - Processes or apparatus for excitation, e.g. pumping using optical pumping by coherent light
H01S 3/0941 - Processes or apparatus for excitation, e.g. pumping using optical pumping by coherent light of a semiconductor laser, e.g. of a laser diode
H01S 3/23 - Arrangement of two or more lasers not provided for in groups , e.g. tandem arrangement of separate active media
H04B 10/291 - Repeaters in which processing or amplification is carried out without conversion of the main signal from optical form
H04B 10/294 - Signal power control in a multiwavelength system, e.g. gain equalisation
9.
SYSTEM AND METHOD FOR TESTING OPTICAL DEVICES USING AN OPTICAL TIME DOMAIN REFLECTOMETER (OTDR) DEVICE
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.
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.
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.
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.
A device for enabling fiber optic network users to confirm their network connectivity. In one embodiment, the device has a housing with a front end for connecting to a network fiber inside a terminal at the premises. A device fiber inside the housing has a proximal end at the front of housing for receiving IR signals routed through the network fiber. The IR signals propagate to a distal end of the device fiber which projects into a viewable open region at the back of the housing, and corresponding IR signals are emitted from the distal end of the fiber. A card is supported in the open region near the fiber's distal end. The card is coated with a material that emits a visible light in response to the IR signals, thus enabling users to confirm network connectivity by viewing the card when the front of the housing is connected to the network fiber. Active embodiments of the inventive device are also disclosed.
H04B 10/077 - Arrangements for monitoring or testing transmission systemsArrangements for fault measurement of transmission systems using an in-service signal using a supervisory or additional signal
H04B 10/25 - Arrangements specific to fibre transmission
15.
SYSTEMS AND METHODS FOR WAVELENGTH DIVISION MULTIPLEXING
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.
H01S 3/094 - Processes or apparatus for excitation, e.g. pumping using optical pumping by coherent light
H01S 3/30 - Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range using scattering effects, e.g. stimulated Brillouin or Raman effects
H04J 14/02 - Wavelength-division multiplex systems
16.
OPTICAL FIBER ROLLABLE RIBBON HAVING LOW YOUNG'S MODULUS BONDING MATRIX MATERIAL
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.
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.
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.
In an optical fiber comprising a central axis (z) with a cladding that extend along z and a coating that is disposed about the cladding, a twist with a twist period (τ) is imparted on the optical fiber about z. The twist mitigates micro-bend-induced cross-talk. The cladding comprises a substantially circular axial cross section. The substantially circular axial cross-section comprises a cladding center and a cladding outer diameter (ODclad). Multiple cores (e.g., a first core, a second core, etc.) are disposed within the cladding. At least one core is disposed helically about z to form a helical core, with the helical core comprising a helical pitch (p) that is approximately equal to τ (meaning, p ≈ τ). The twist has a twist period (τ) that is less than 9.1 centimeters (meaning, τ < 9.1cm).
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 (δl) between the cores. In the present disclosure, the helical cores have a pitch (P) that reduces δl/L to a value that is less than 5·10−6 (i.e., δl/L<5·10−6).
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. A further embodiment relates to a method comprising receiving an optical fiber at an inlet of at least one heat source, the optical fiber including a coating having an original coating weight and an optical back-scatter along a fiber length and applying an annealing treatment to the optical fiber by the least one heat source at a predetermined temperature Ta during a predetermined time ta, wherein the original coating weight is reduced by at least 25% to a treated coating weight during the annealing treatment, wherein the optical back-scatter does not decrease along the fiber length by more than 3 dB after the annealing treatment.
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.
A Bismuth-doped fiber-optic amplifier (BDFA) system in which a Bismuth-doped optical fiber (BDF) is pumped by a fiber-laser pump (rather than by a semiconductor pump). Because higher-power fiber-laser pumps permit over-pumping of the BDF, there are benefits to the fiber-laser-pumped BDFA that cannot be realized with inherently lower-power semiconductor pumps.
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.
A strain-compensated optical cable comprises a strength member extending substantially along a length of the optical cable. The optical cable has a first buffer tube and a second buffer tube, both of which extend along the length of the optical cable. Positioned within the first buffer tube is a strain-measuring single-mode fiber (SMF). Positioned within the second buffer tube is a hollow-core fiber (HCF). The SMF is used as a means for measuring strain (s), thereby allowing for strain mitigation experienced by the HCF. A stranding material extends substantially along the length of the optical cable and strands together the first buffer tube and the second buffer tube. An outer jacket surrounds the stranding material and extends substantially along the length of the optical cable.
A storage device for an optical fiber ribbon. A spool includes a hub, a bottom flange, and a top flange. A spool opening extends axially through the hub and the flanges, and a circular array of recesses are formed along the edge of the opening in the bottom flange. A base has a number of circularly arrayed, pawls for engaging the recesses along the edge of the spool opening in the bottom flange so that when the bottom flange is engaged with the pawls on the base, the spool can rotate in only one winding direction. The hub has a hook member on its circumference which is formed to engage an optical fiber ribbon at a midpoint along its length while maintaining a specified minimum bend radius. When the ribbon is looped around the hook m ember and the spool is wound, two equal lengths of the ribbon are wound next to one another on the hub for storage. Designated fibers of the ribbon then are accessible from the stored lengths of the ribbon for splicing or other handling.
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.
An optical fiber cable comprises an inner tube with strength members that are located external to, and alongside of, the inner tube. Water-blocking material is also located external to the inner tube. A sheath surrounds the strength members and the water-blocking material. The cable further comprises an optical fiber with a core, a trench surrounding the core, a cladding surrounding the trench, and a coating applied over the cladding. The cable comprises a fiber arrangement with N optical fibers (with N being an integer (e.g., 16, 32, 48, 96, etc.), of which at least one optical fiber has: a maximum effective area (Aeff) of approximately seventy-five square micrometers (˜75 μm2) at a wavelength (λ) of approximately 1550 nanometers (˜1550 nm); a maximum mode field diameter (MFD) of ˜8.8 μm at λ of ˜1550 nm; a maximum cable cut-off λ of ˜1520 nm; and, a maximum attenuation of ˜0.180 decibels-per-kilometer (dB/km) at λ of ˜1550 nm.
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.
A packaging scheme for a fiber-based optical device includes a substrate for supporting the fiber-based optical device, with a set of individual adhesive bonds used to affix the device to the substrate. Individual bonds are placed along the length of the device in a manner that reduces the possibility of fiber movement subsequent to packaging, even in the presence of changes in ambient temperature over the lifetime of the packaged optical device.
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).
A system comprising an enhanced back- scattering region, which is confined to a limited enhanced scattering bandwidth (e.g., approximately ten decibel (lOdB) scattering bandwidth over approximately fifteen nanometer (15nm) 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 (Inm) outside of the enhanced scattering bandwidth.
A system for sensing microbends and micro-deformations in three-dimensional space is based upon a distributed length optical fiber formed to include a group of offset cores disposed in a spiral configuration along the length of the fiber, each core including a fiber Bragg grating that exhibits the same Bragg wavelength. A micro-scale local deformation of the multicore fiber produces a local shift in the Bragg wavelength, where the use of multiple cores allows for a complete micro-scale modeling of the local deformation. Sequential probing of each core allows for optical frequency domain reflectometry (OFDR) allows for reconstruction of a given three-dimensional shape, delineating location and size of various microbends and micro-deformations.
G01B 11/16 - Measuring arrangements characterised by the use of optical techniques for measuring the deformation in a solid, e.g. optical strain gauge
G01D 5/353 - Mechanical means for transferring the output of a sensing memberMeans for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for convertingTransducers not specially adapted for a specific variable using optical means, i.e. using infrared, visible or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
An optical connector for terminating a cable containing one or more multicore fibers. The connector has a plug housing, a ferrule disposed inside the housing, a rotatable frame, and a multicore fiber (MCF) stub having a length of a first MCF a portion of which is fixed inside the ferrule so that a first endface of the fiber is exposed at the front end of the ferrule. An opposite endface of the first MCF is cleaved for fusion splicing to a second MCF in the cable to be terminated. The ferrule also has a flange, and the frame is formed to engage the flange for rotation so that cores in the first MCF can be aligned and positioned in a prescribed orientation relative to the plug housing, and cores in the second MCF can be aligned with corresponding cores in the first MCF when the first and the second MCFs are fusion spliced to one another.
A hydrogen diffusion barrier is included as an infra-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.
An amplified hollow-core fiber (HCF) optical transmission system for low latency communications. The optical transmission system comprises a low-latency amplified HCF cable. The low-latency amplified HCF cable comprises multiple HCF segments (or HCF spans). Between consecutive HCF segments, the system comprises low-latency remote optically pumped amplifiers (ROPAs). Each ROPA comprises a gain fiber, a wavelength division multiplexing (WDM) coupler, and an optical isolator. Preferably, the ROPAs are integrated into the HCF cable. Each ROPA is pumped by a remote optical pump source, which provides pump light to the gain fiber. The gain fiber receives an optical transmission signal from the HCF. The WDM coupler combines the pump light with the optical transmission signal, thereby allowing the gain fiber to amplify the optical transmission signal to an amplified transmission signal. The amplified signal is transmitted to another HCF segment through the optical isolator.
G02B 6/028 - Optical fibres with cladding with core or cladding having graded refractive index
G02B 6/036 - Optical fibres with cladding core or cladding comprising multiple layers
H04B 10/00 - Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
41.
HIGH-TEMPERATURE HYDROGEN-RESISTANT SCATTERING ENHANCEMENT IN OPTICAL FIBER
Described herein are systems, methods, and articles of manufacture for a spatially nonuniform scattering profile along its length, whose backscattering signal can be used for sensing even after fiber attenuation increases due to the conditions in the sensing environment. In one embodiment, the fiber has been pre-exposed to the conditions that produce attenuation, and the spatially nonuniform profile compensates for this. Subsequent exposure then results in very little or at least acceptable levels of additional attenuation. An exemplary fiber comprises a fiber length 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 a hydrogen-rich first environment having a given pressure and temperature. An exemplary method comprises drawing a fiber, applying a UV coating, post-processing the fiber using an interferogram, measuring optical back scatter enhancement dependence based on a UV dosage, incrementally increasing the reflectivity, exposing the fiber to a hydrogen-rich first environment.
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.
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.
H01S 3/094 - Processes or apparatus for excitation, e.g. pumping using optical pumping by coherent light
H01S 3/0941 - Processes or apparatus for excitation, e.g. pumping using optical pumping by coherent light of a semiconductor laser, e.g. of a laser diode
An optical fiber cable having reduced surface friction may include a low-friction, fire retardant cable jacket structure. The cable jacket structure may include a thicker, highly fire-retardant cable jacket, and a thinner, low-friction skin layer formed over the cable jacket.
In accordance with a plurality of embodiments of the present invention, exemplary systems and articles of manufactures are described herein that are configured to propagate a MM signal from a light source, such as an optical fiber assembly for propagating a multimode (MM) signal from a light source, the optical fiber assembly comprising a multicore fiber (MCF) having a fiber numerical aperture (NA) value, a first core diameter and a first outer diameter (OD), and a combiner including a taper fiber bundle (TFB) portion in communication with the MCF, and at least one pigtail portion in communication with the light source, wherein the combiner propagates the MM signal from the light source, the MM signal having a signal NA value that is less than the fiber NA value such that the MM signal underfills the at least one pigtail portion.
Described herein are systems, methods, and articles of manufacture for reducing coupling loss between optical fibers, more particularly, to reducing coupling loss between a hollow-core optical fiber (HCF) and another fiber, such as solid core fibers (SCF), through the use of mismatched mode field diameter (MFD). According to one embodiment, an article is configured to reduce a coupling loss between multiple optical fibers, wherein the article includes an HCF supporting the propagation of a first mode and an SCF coupled to the HCF. According to a further embodiment, a method is described for reducing the coupling loss or splicing loss between optical fibers, such as an exemplary HCF and a solid core SMF. These exemplary methods may include coupling/splicing an exemplary HCF to an exemplary SMF with significantly smaller MFD.
An optical fiber amplifier is formed to include a grating structure inscribed within the rare earth-doped gain fiber itself, providing distributed wavelength-dependent filtering (attenuation) and minimizing the need for any type of gain-flattening filter to be used at the output of the amplifier. The grating structure may be of any suitable arrangement that provides the desired loss spectrum, for example, similar to the profile of a prior art discrete GFF. Various types of grating structures that may be used to provide distributed wavelength-dependent filtering along the gain include, but are not limited to, tilted gratings, weak Bragg gratings, long-period grating (LPG), and any suitable combination of these grating structures.
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.
G02B 6/04 - Light guidesStructural details of arrangements comprising light guides and other optical elements, e.g. couplings formed by bundles of fibres
G02B 6/44 - Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables
G02B 6/38 - Mechanical coupling means having fibre to fibre mating means
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 (λ0) 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.
H01S 3/094 - Processes or apparatus for excitation, e.g. pumping using optical pumping by coherent light
H01S 3/0941 - Processes or apparatus for excitation, e.g. pumping using optical pumping by coherent light of a semiconductor laser, e.g. of a laser diode
H01S 3/23 - Arrangement of two or more lasers not provided for in groups , e.g. tandem arrangement of separate active media
H04B 10/291 - Repeaters in which processing or amplification is carried out without conversion of the main signal from optical form
H04B 10/294 - Signal power control in a multiwavelength system, e.g. gain equalisation
H01S 3/091 - Processes or apparatus for excitation, e.g. pumping using optical pumping
50.
METHODS OF INCREASING HIGHER-ORDER MODE SUPPRESSION IN LARGE-MODE AREA RING FIBERS AND SYSTEMS THEREOF
Embodiments of the present disclosure generally relate to methods of increasing higher-order mode suppression in large-mode area ring fibers. This approach may raise the transverse mode instabilities (TMI) threshold and allow further mode-field diameter (MFD) scaling for higher power. Disclosed herein is a core having a set of core properties, a cladding ring around the core, wherein the optical fiber has fundamental mode effective MFD between 14 microns and 40 microns; and wherein the optical fiber exhibits a higher-order mode loss of LHOM.
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.
Disclosed herein is an all-fiber, easy to use, wavelength tunable, ultrafast laser based on soliton self-frequency-shifting in an Er-doped polarization-maintaining very large mode area (PM VLMA) fiber. The ultrafast laser system may include an all polarization-maintaining (PM) fiber mode-locked seed laser with a pre-amplifier; a Raman laser including a cascaded Raman resonator and an ytterbium (Yb) fiber laser cavity; an amplifier core-pumped by the Raman laser, the amplifier including an erbium (Er) doped polarization maintaining very large mode area (PM Er VLMA) optical fiber and a passive PM VLMA fiber following the PM Er VLMA, the passive PM VLMA for supporting a spectral shift to a longer wavelength.
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, wherein 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.
C03C 25/62 - Surface treatment of fibres or filaments made from glass, minerals or slags by application of electric or wave energySurface treatment of fibres or filaments made from glass, minerals or slags by particle radiation or ion implantation
G02B 6/036 - Optical fibres with cladding core or cladding comprising multiple layers
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 (51) between the cores. In the present disclosure, the helical cores have a pitch (P) that reduces δ1/L to a value that is less than 5· 10-6(i.e., δ1/L < 5· 10-6).
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.
An alignment apparatus and method is proposed that is configured to perform alignment before bringing the fiber end faces into proximity of the arc discharge system used to perform fusion splicing. Preferably, the alignment itself is performed by using an "additive component" methodology that identifies the portions of the transverse geometry requiring substantially perfect azimuthal alignment (e.g., critical features such as core regions) and then selects the best azimuthal alignment option from the identified options based on best-fit of azimuthal asymmetries (such as markers, different cladding structures, etc.) to the set of optional alignments.
effeff) of approximately seventy-five square micrometers (~75μm2 ) at a wavelength (λ) of approximately 1550 nanometers (~1550nm); a maximum mode field diameter (MFD) of ~8.8μm at λ of ~1550nm; a maximum cable cut-off λ of ~1520nm; and, a maximum attenuation of ~0.180 decibels-per-kilometer (dB/km) at λ of ~1550nm.
A system for installing an optical fiber cable in a building hallway or living unit includes an elongated cylinder for containing an adhesive, and a continuous length of an optical fiber cable embedded in the adhesive in a configuration that avoids kinks or knots in the cable. An elongated nozzle is fixed at a first end of the cylinder for depositing the adhesive and the cable from an open tip of the nozzle, along a desired routing path in the hallway or living unit. An applicator assembly is constructed and arranged for receiving the cylinder, and for applying a dispensing force at a second end of the cylinder opposite the first end so as to urge the adhesive and the cable out of the open tip of the nozzle.
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.
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.
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.
Bismuth (Bi) doped optical fibers (BiDF) and Bi-doped fiber amplifiers (BiDFA) are shown and described. The BiDF comprises a gain band and an auxiliary band. The gain band has a first center wavelength (λ1) and a first six decibel (6 dB) gain bandwidth. The auxiliary band has a second center wavelength (λ2), with λ2>λ1. The system further comprises a signal source and a pump source that are optically coupled to the BiDF. The signal source provides an optical signal at λ1, while the pump source provides pump light at a pump wavelength (λ3).
An optical fiber comprising a core, a cladding disposed about the core, and a primary coating disposed about the cladding. The primary coating is cured during draw to at least eighty-five percent (85%) of the primary coating's fully cured primary-coating in situ modulus (P-ISM) value.
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.
G01K 11/3206 - Measuring temperature based on physical or chemical changes not covered by group , , , or using changes in transmittance, scattering or luminescence in optical fibres at discrete locations in the fibre, e.g. using Bragg scattering
C08G 77/20 - Polysiloxanes containing silicon bound to unsaturated aliphatic groups
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.
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.
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.
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.
H01S 3/30 - Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range using scattering effects, e.g. stimulated Brillouin or Raman effects
72.
SYSTEM FOR MEASURING MICROBENDS AND ARBITRARY MICRO-DEFORMATIONS ALONG A THREE-DIMENSIONAL SPACE
A system for sensing microbends and micro-deformations in three- dimensional space is based upon a distributed length optical fiber formed to include a group of offset cores disposed in a spiral configuration along the length of the fiber, each core including a fiber Bragg grating that exhibits the same Bragg wavelength. A micro-scale local deformation of the multicore fiber produces a local shift in the Bragg wavelength, where the use of multiple cores allows for a complete micro-scale modeling of the local deformation. Sequential probing of each core allows for optical frequency domain reflectometry (OFDR) allows for reconstruction of a given three-dimensional shape, delineating location and size of various microbends and micro-deformations.
G01L 1/24 - Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis
G01N 21/00 - Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
73.
Active optical cable assembly with multicore fiber
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.
Described herein are systems, methods, and articles of manufacture for a spatially nonuniform scattering profile along its length, whose backscattering signal can be used for sensing even after fiber attenuation increases due to the conditions in the sensing environment. In one embodiment, the fiber has been pre-exposed to the conditions that produce attenuation, and the spatially nonuniform profile compensates for this. Subsequent exposure then results in very little or at least acceptable levels of additional attenuation. An exemplary fiber comprises a fiber length 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 a hydrogen-rich first environment having a given pressure and temperature.
Described herein are systems, methods, and articles of manufacture for reducing coupling loss between optical fibers, more particularly, to reducing coupling loss between a hollow-core optical fiber (HCF) and another fiber, such as solid core fibers (SCF), through the use of mismatched mode field diameter (MFD) and optical connector assemblies for low latency patchcords. According to one embodiment, an article is configured to include an HCF supporting the propagation of a first mode and an SCF coupled to the HCF. A method is described for reducing the coupling loss or splicing loss. These exemplary articles and methods may include coupling/splicing an exemplary HCF to an exemplary SMF with significantly smaller MFD as well as a splice-on-connector (SOC) assembly including a bridge fiber spliced between the HCF and the SCF, wherein the bridge fiber has a third MFD that is greater than the second MFD and smaller than the first MFD.
An amplified hollow-core fiber (HCF) optical transmission system for low latency communications. The optical transmission system comprises a low-latency amplified HCF cable. The low-latency amplified HCF cable comprises multiple HCF segments (or HCF spans). Between consecutive HCF segments, the system comprises low-latency remote optically pumped amplifiers (ROPAs). Each ROPA comprises a gain fiber, a wavelength division multiplexing (WDM) coupler, and an optical isolator. Preferably, the ROPAs are integrated into the HCF cable. Each ROPA is pumped by a remote optical pump source, which provides pump light to the gain fiber. The gain fiber receives an optical transmission signal from the HCF. The WDM coupler combines the pump light with the optical transmission signal, thereby allowing the gain fiber to amplify the optical transmission signal to an amplified transmission signal. The amplified signal is transmitted to another HCF segment through the optical isolator.
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.
In curing a matrix material of a Tollable 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.
G02B 6/44 - Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables
G02B 1/10 - Optical coatings produced by application to, or surface treatment of, optical elements
G02B 1/12 - Optical coatings produced by application to, or surface treatment of, optical elements by surface treatment, e.g. by irradiation
G02B 6/04 - Light guidesStructural details of arrangements comprising light guides and other optical elements, e.g. couplings formed by bundles of fibres
80.
OUTDOOR/INDOOR OPTICAL CABLES WITH LOW-FRICTION SKIN LAYER
An optical fiber cable having reduced surface friction may include a low-friction, fire retardant cable jacket structure. The cable jacket structure may include a thicker, highly fire-retardant cable jacket, and a thinner, low-friction skin layer formed over the cable jacket.
In accordance with a plurality of embodiments of the present invention, exemplary systems and articles of manufactures are described herein that are configured to propagate a MM signal from a light source, such as an optical fiber assembly for propagating a multimode (MM) signal from a light source, the optical fiber assembly comprising a multicore fiber (MCF) having a fiber numerical aperture (NA) value, a first core diameter and a first outer diameter (OD), and a combiner including a taper fiber bundle (TFB) portion in communication with the MCF, and at least one pigtail portion in communication with the light source, wherein the combiner propagates the MM signal from the light source, the MM signal having a signal NA value that is less than the fiber NA value such that the MM signal underfills the at least one pigtail portion.
A method of splicing multicore optical fibers to one another for use in a data network. First and second multicore optical fibers each have a number of cores arranged in a certain pattern about the fiber axis, thus defining a number of pairs of cores wherein the cores of each pair are arrayed symmetrically with respect to a key plane that includes the fiber axis. Ends of the first and the second fibers are arranged in axial alignment to one another such that the key plane at the end of the first fiber is aligned with the key plane at the end of the second fiber, thereby placing a defined pair of cores in the first fiber in position for splicing to a corresponding defined pair of cores in the second fiber. The defined pairs of cores in the two fibers are then spliced to one another.
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 (λ0) that is centered between approximately 1260 nanometers (~1260nm) and ~1360nm (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.
An optical fiber amplifier is formed to include a grating structure inscribed within the rare earth-doped gain fiber itself, providing distributed wavelength- dependent filtering (attenuation) and minimizing the need for any type of gain- flattening filter to be used at the output of the amplifier. The grating structure may be of any suitable arrangement that provides the desired loss spectrum, for example, similar to the profile of a prior art discrete GFF. Various types of grating structures that may be used to provide distributed wavelength-dependent filtering along the gain include, but are not limited to, tilted gratings, weak Bragg gratings, long-period grating (LPG), and any suitable combination of these grating structures.
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. The signal processor generates the control signal to instruct the optical control device to impart the 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.
G05D 25/02 - Control of light, e.g. intensity, colour or phase characterised by the use of electric means
A61B 1/06 - Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopesIlluminating arrangements therefor with illuminating arrangements
G02B 6/04 - Light guidesStructural details of arrangements comprising light guides and other optical elements, e.g. couplings formed by bundles of fibres
A61B 1/07 - Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopesIlluminating arrangements therefor with illuminating arrangements using light-conductive means, e.g. optical fibres
Described herein are systems, methods, and articles of manufacture for reducing coupling loss between optical fibers, more particularly, to reducing coupling loss between a hollow-core optical fiber (HCF) and another fiber, such as solid core fibers (SCF), through the use of mismatched mode field diameter (MFD). According to one embodiment, an article is configured to reduce a coupling loss between multiple optical fibers, wherein the article includes an HCF supporting the propagation of a first mode and an SCF coupled to the HCF. According to a further embodiment, a method is described for reducing the coupling loss or splicing loss between optical fibers, such as an exemplary HCF and a solid core SMF. These exemplary methods may include coupling/splicing an exemplary HCF to an exemplary SMF with significantly smaller MFD.
A fiber-optic cable having optical fibers that are arranged as a rollable ribbon. Water-swellable material (e.g., superabsorbent liquid, superabsorbent powder, superabsorbent adhesive, etc.) is applied directly to the rollable ribbon, thereby eliminating the need to incorporate conventional water-absorbing yarns, tapes, or other such similar materials. The rollable ribbon is surrounded by a tube, with a dielectric strength member positioned external to the tube and substantially parallel to the tube. A jacket, with a ripcord along a substantial length of the jacket, surrounds the tube. Also taught is a process for manufacturing a rollable-ribbon fiber-optic cable, in which a water-swellable material is applied directly to the rollable ribbon, thereby eliminating the need to incorporate conventional water-absorbing yarns, tapes, or other such similar materials.
Disclosed herein is an all-fiber, easy to use, wavelength tunable, ultrafast laser based on soliton self-frequency-shifting in an Er-doped polarization-maintaining very large mode area (PM VLMA) fiber. The ultrafast laser system may include an all polarization-maintaining (PM) fiber mode-locked seed laser with a pre-amplifier; a Raman laser including a cascaded Raman resonator and an ytterbium (Yb) fiber laser cavity; an amplifier core-pumped by the Raman laser, the amplifier including an erbium (Er) doped polarization maintaining very large mode area (PM Er VLMA) optical fiber and a passive PM VLMA fiber following the PM Er VLMA, the passive PM VLMA for supporting a spectral shift to a longer wavelength.
A method of connecting lengths of multicore optical fibers (MCFs) to one another. First and second lengths of a MCF whose cores are arranged in a certain pattern about the fiber axis to define pairs of cores are provided, and the cores of each pair of cores are disposed symmetrically with respect to a key plane that includes the axis of the fiber. Ends of the first and the second lengths of the MCF are arranged in axial alignment with one another, and the key plane at the end of the first length of the MCF is aligned with the key plane at the end of the second length of the MCF. Each defined pair of cores in the first length of the MCF is thereby positioned to mate with the same defined pair of cores in the second length of the MCF.
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.
A hollow core optical fiber and cable combination is configured to exhibit minimal SNR and loss degradation. This is achieved by either: (1) reducing the coupling between the fundamental and other (unwanted) modes propagating within the hollow core fiber; or (2) increasing the propagation loss along the alternative. The first approach may be achieved by designing the cable to minimize perturbations and/or designing the hollow core fiber to fully separate the fundamental mode from the unwanted modes so as to reduce coupling into the unwanted modes. Whether through fiber design or cable design, the amount of light coupled into unwanted modes is reduced to acceptable levels. The second approach may be realized through either fiber design and/or cable design to suppress the light in unwanted modes so that an acceptably low level of light is coupled back into the fundamental mode.
A guide tool device for an optical fiber includes a body having an adhesive passage between a proximal end and a flat distal end of the body. The passage communicates an adhesive supplied at the proximal end to an exit opening in the distal end. Each of a pair of fiber guide channels extends from the body to guide an optical fiber when aligned inside the channel, for relative movement over the exit opening in the distal end of the body during use of the device. A connector fixed on the proximal end of the body in communication with the passage, mates with a connector at the distal end of a syringe containing the adhesive. When urged by the syringe, the adhesive flows through the passage and out the exit opening in the distal end of the body, thereby coating the fiber when guided over the distal end during use.
G02B 6/46 - Processes or apparatus adapted for installing optical fibres or optical cables
B05C 17/005 - Hand tools or apparatus using hand-held tools, for applying liquids or other fluent materials to, for spreading applied liquids or other fluent materials on, or for partially removing applied liquids or other fluent materials from, surfaces for discharging material through an outlet orifice by pressure
97.
Optical cable methods of manufacture thereof and articles comprising the same
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 1.5% longer than its respective flexible protective tube; wherein an allowable strain on the optical cable with substantially zero stress on the optical fibers is determined by equations (1) and (2) below:
)
where d is the amount of optical fiber clearance for free movement within the flexible protective tube, D is an average helical diameter of the helically wound flexible protective tubes, and p is an average helical pitch of the helically wound flexible protective tubes.
G01L 1/24 - Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis
G01K 11/32 - Measuring temperature based on physical or chemical changes not covered by group , , , or using changes in transmittance, scattering or luminescence in optical fibres
G01D 5/353 - Mechanical means for transferring the output of a sensing memberMeans for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for convertingTransducers not specially adapted for a specific variable using optical means, i.e. using infrared, visible or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
G01D 5/26 - Mechanical means for transferring the output of a sensing memberMeans for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for convertingTransducers not specially adapted for a specific variable using optical means, i.e. using infrared, visible or ultraviolet light
G02B 6/44 - Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables
A system for installing an optical fiber cable in a building hallway or living unit includes an elongated cylinder for containing an adhesive, and a continuous length of an optical fiber cable embedded in the adhesive in a configuration that avoids kinks or knots in the cable. An elongated nozzle is fixed at a first end of the cylinder for depositing the adhesive and the cable from an open tip of the nozzle, along a desired routing path in the hallway or living unit. An applicator assembly is constructed and arranged for receiving the cylinder, and for applying a dispensing force at a second end of the cylinder opposite the first end so as to urge the adhesive and the cable out of the open tip of the nozzle.
G02B 6/46 - Processes or apparatus adapted for installing optical fibres or optical cables
B32B 37/14 - Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding characterised by the properties of the layers
B65H 49/00 - Unwinding or paying-out filamentary materialSupporting, storing, or transporting packages from which filamentary material is to be withdrawn or paid-out
A system for installing an optical fiber cable in a building hallway or living unit includes an elongated cylinder for containing an adhesive, and a continuous length of an optical fiber cable embedded in the adhesive in a configuration that avoids kinks or knots in the cable. An elongated nozzle is fixed at a first end of the cylinder for depositing the adhesive and the cable from an open tip of the nozzle, along a desired routing path in the hallway or living unit. An applicator assembly is constructed and arranged for receiving the cylinder, and for applying a dispensing force at a second end of the cylinder opposite the first end so as to urge the adhesive and the cable out of the open tip of the nozzle.
G02B 6/46 - Processes or apparatus adapted for installing optical fibres or optical cables
B32B 37/14 - Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding characterised by the properties of the layers
B65H 49/00 - Unwinding or paying-out filamentary materialSupporting, storing, or transporting packages from which filamentary material is to be withdrawn or paid-out
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.
