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OFS FITEL, LLC

OFS FITEL, LLC Patent applications
Patent application numberTitlePublished
20120105831MEASURING MODAL CONTENT OF MULTI-MODED FIBERS - The output modal content of optical fibers that contain more than one spatial mode may be analyzed and quantified by measuring interference between co-propagating modes in the optical fiber. By spatially resolving the interference, an image of the spatial beat pattern between two modes may be constructed, thereby providing information about the modes supported by the optical fiber. Measurements of the phase front exiting the optical fiber under test are advantageously performed in the far field.05-03-2012
20120093461Production of Optical Pulses At A Desired Wavelength Utilizing Higher-Order-Mode (HOM) Fiber - An apparatus and method for producing optical pulses of a desired wavelength utilizes a section of higher-order-mode (HOM) fiber to receive input optical pulses at a first wavelength, and thereafter produce output optical pulses at the desired wavelength through soliton self-frequency shifting (SSFS) or Cherenkov radiation. The HOM fiber is configured to exhibit a large positive dispersion and effective area at wavelengths less than 1300 nm.04-19-2012
20120067997Optical Fiber Spool Inspection System - Methods and systems for inspecting a bare optical fiber spool are disclosed. The system inspects the bare optical fiber spool prior to optical fiber winding and determines whether the bare optical fiber spool is acceptable for the winding.03-22-2012
20120020635TOOL FOR ROUTING AN OPTICAL FIBER OR CABLE AT A LIVING UNIT OF CUSTOMER PREMISES - A tool for routing an optical fiber or a cable over a desired span on a visible supporting surface at a given premises. The tool includes a rod with a handle, and a reel or spool is mounted on the rod for storing a length of an optical fiber or a cable to be routed. An adhesive coating assembly is fixed on the rod for providing an adhesive on the fiber when the fiber is unwound from the spool during use of the tool. A fiber routing applicator is disposed at the distal end of the rod. The routing applicator is dimensioned and arranged to travel over the supporting surface at the premises to route the fiber with the adhesive thereon over the desired span, while urging the fiber against the surface so that the fiber adheres to the surface.01-26-2012
20120010842Self-Calibration Procedure For Optical Polarimeters - A procedure for self-calibration of an optical polarimeter has been developed that eliminates the need for “known” input signals to be used. The self-calibration data is then taken by moving a polarization controller between several random and unknown states of polarization (SOPs) and recording the detector output values (D01-12-2012
20110280517TECHNIQUES AND DEVICES FOR LOW-LOSS, MODEFIELD MATCHED COUPLING TO A MULTICORE FIBER - Devices and techniques are described for connecting each of plurality of terminals to respective individual cores of a multicore fiber. Each of the plurality of terminals is provided with a respective length of a single-core fiber. The single-core fibers are configured to maintain modal properties that arc substantially the same, within a tolerance range, at the front and rear ends, as the single-core fiber is tapered. The single-core fibers are assembled together. The front end of the assembly is tapered to form a front cross-section in which the single-core fiber cores are arranged in a configuration matching that of the cores of the multicore fiber.11-17-2011
20110279888MULTICORE TRANSMISSION AND AMPLIFIER FIBERS AND SCHEMES FOR LAUNCHING PUMP LIGHT TO AMPLIFIER CORES - An optical transmission and amplification system includes a multichannel transmission span with a length of a multicore transmission fiber having a plurality of individual transmission cores. A first tapered multicore coupler provides connectivity between the plurality of transmission cores of the multicore fiber and a respective plurality of individual transmission leads. A fiber amplifier is provided having a plurality of individual cores including at least one pump core and a plurality of amplifier core. A second tapered multicore coupler provides connectivity between the amplifier cores of the fiber amplifier and a respective plurality of amplifier leads, and between the at least one pump core and a respective pump lead.11-17-2011
20110274435MULTICORE FIBER TRANSMISSION SYSTEMS AND METHODS - An optical data link includes first and second pluralities of transmission devices, at least one of which is configured as an array. A multichannel transmission link has a first end connected to the first plurality of transmission devices and a second end connected to the second plurality of transmission devices so as to form a plurality of parallel transmission channels therebetween. The multichannel transmission link includes a multicore fiber with a plurality of individual cores having a configuration matching the array configuration of the at least one plurality of transmission devices. The multicore fiber has an endface connected directly to the at least one plurality of transmission devices, with the individual cores of the multicore fiber aligned with respective devices in the at least one plurality of transmission devices. Further described are access networks and core networks incorporating a transmission link comprising at least one span of a multicore fiber.11-10-2011
20110274398MULTICORE FIBERS AND ASSOCIATED STRUCTURES AND TECHNIQUES - A multicore fiber comprises a plurality of cores extending along the length of a fiber body. Each of the cores is surrounded by a cladding. The plurality of cores and surrounding cladding provide respective index variations, so as to form a respective plurality of waveguides for conducting parallel data transmissions from a first end of the fiber to a second end. The plurality of cores has a cross-sectional geometry in which the plurality of cores is configured in a polygonal array, in which at least some of the cores are positioned at the vertices of the array. The polygonal array is configured such that neighboring cores in the array are separated from each other by a distance that is sufficient to prevent crosstalk therebetween.11-10-2011
20110274397TIGHT-BUFFERED OPTICAL FIBER HAVING IMPROVED FIBER ACCESS - Certain embodiments of the invention may include systems and methods for providing tight-buffered optical fiber having improved fiber access. According to an example embodiment of the invention, a method for making a tight buffer upcoated optical fiber having a predetermined buffer stripping force is provided. The method includes controlling residual acrylate unsaturation (RAU) and oxygen in at least an outer surface of un-buffered optical fiber to achieve a predetermined buffer stripping characteristic, applying a tight buffer composition comprising acrylate to the un-buffered optical fiber, and curing the tight buffer composition.11-10-2011
20110262148COMPACT PLENUM-RATED RIBBON CABLES - Embodiments of the present invention include an optical fiber cable for use in a plenum. The cable comprises a tube, at least one optical fiber ribbon positioned within the tube, the optical fiber ribbon having a width (W), a jacket around the tube, the jacket having an outer diameter (D) and a limited oxygen index (LOI) of approximately at least 65%, at least two longitudinal strength members positioned between the tube and an outer surface of the jacket; and a yarn positioned between the tube and the jacket, wherein the ratio of the width (W) of the optical fiber ribbon and the outer diameter (D) of the jacket is approximately at least 0.25.10-27-2011
20110229086MULTIFIBER CONNECTORS FOR MULTICORE OPTICAL FIBER CABLES - Structures and techniques are described relating to the alignment of multicore fibers within a multifiber connector. These structures and techniques include: multicore fibers having a number of different shapes, including, for example, circular, elliptical, D-shaped, double D-shaped, and polygonal; multifiber ferrules, having a plurality of fiber guide holes therein of various shapes; alignment fixtures for aligning multicore fibers within multifiber ferrules; and various multicore fiber alignment techniques.09-22-2011
20110229085SIMPLEX CONNECTORS FOR MULTICORE OPTICAL FIBER CABLES - An optical fiber cable connector includes a ferrule subassembly, in which a ferrule is mounted into a receptacle including a barrel section having a flange at its base. The ferrule subassembly is loaded into an enclosure having a plug housing at its lead end. The plug housing is configured to provide a connection between an endface of a multicore fiber mounted into the ferrule and a corresponding surface in a mating socket. A collar is rotatably mounted onto the barrel section of the ferrule subassembly such that it butts up against the flange. The collar has an opening that fits around the barrel section, and an outer perimeter that fits into a receiving cavity with the plug housing. The ferrule, receptacle, receptacle barrel section, mounted multicore fiber, enclosure, and plug housing have a common longitudinal axis. As a result, the ferrule, receptacle, receptacle barrel section, and mounted multicore fiber are continuously rotatable with respect to the enclosure and plug housing, thereby enabling a precise rotational alignment of the multicore fiber within the enclosure.09-22-2011
20110210269Non-Linear Optical System and Techniques - Methods and systems are described using a non-linear optical system comprising a laser and a light delivery system comprising a single mode fiber, a mode converter, and a high order mode fiber, wherein the light delivery system that receives light from the source and provides a structured free-space beam having an embedded Gaussian beam. The light delivery system functions to illuminate a region of a sample and generate a non-linear response in a spatial region smaller than that associated with a Gaussian beam having a width comparable to the width of the embedded Gaussian beam. In another aspect, the light delivery system illuminates a region of a sample and generates a non-linear emission of radiation, is depicted. A further aspect of this embodiment includes an imaging assembly for detecting the non-linear emission and using a signal derived from the detected emission to generate a microscopic image of the sample.09-01-2011
20110194814BEND INSENSITIVITY IN SINGLE MODE OPTICAL FIBERS - An optical fiber that is relatively insensitive to bend loss comprises a core region and a cladding region configured to support and guide the propagation of light in a fundamental transverse mode, the cladding region including (i) an outer cladding region having a refractive index less than that of the core region, (ii) an annular cladding pedestal region having a refractive index higher than that of the outer cladding region and comparable to that of the core region, and (iii) an annular cladding inner trench region disposed between the core region and the pedestal region, the inner trench region having a refractive index less than that of the outer cladding region. In one embodiment, the fiber also includes a(iv) an annular cladding outer trench region disposed between the pedestal region and the outer cladding region, the outer trench region having a refractive index less than that of the outer cladding region. In addition, to suppress HOMs the pedestal region is configured to resonantly couple at least one other transverse mode of the core region to at least one transverse mode of the pedestal region. Such fiber is advantageously used as access fiber, but may have other applications, such as sensor fiber.08-11-2011
20110194813BEND INSENSITIVITY IN SINGLE MODE OPTICAL FIBERS - An optical fiber that is relatively insensitive to bend loss comprises a core region and a cladding region configured to support and guide the propagation of light in a fundamental transverse mode, the cladding region including (i) an outer cladding region having a refractive index less than that of the core region, (ii) an annular cladding pedestal region having a refractive index higher than that of the outer cladding region and comparable to that of the core region, and (iii) an annular cladding inner trench region disposed between the core region and the pedestal region, the inner trench region having a refractive index less than that of the outer cladding region. In one embodiment, the fiber also includes a (iv) an annular cladding outer trench region disposed between the pedestal region and the outer cladding region, the outer trench region having a refractive index less than that of the outer cladding region. In addition, to suppress HOMs the pedestal region is configured to resonantly couple at least one other transverse mode of the core region to at least one transverse mode of the pedestal region. Such fiber is advantageously used as access fiber, but may have other applications, such as sensor fiber.08-11-2011
20110188822OPTICAL FIBER COATINGS FOR REDUCING MICROBEND LOSSES - Certain embodiments of the invention may include systems and methods for providing optical fiber coatings to reduce microbend losses. According to an example embodiment of the invention, a method is provided for coating an optical fiber to reduce microbend losses and polarization mode dispersion (PMD). The method includes applying a primary layer to the optical fiber, wherein the optical fiber comprises a core region surrounded by a cladding region. The method includes applying a secondary layer to the primary layer, and curing the primary and secondary layers, wherein the cured primary layer adheres to the cladding region with a minimum pullout adhesion of 6 N/cm, and the cured secondary layer has an in situ modulus of about 700 MPa to about 1200 MPa at room temperature.08-04-2011
20110170829CONNECTOR COVER FOR OUTSIDE PLANT APPLICATIONS - Certain embodiments of the invention may include apparatuses, systems, and methods for providing a connector cover for outside plant application. According to an example embodiment of the invention, a connector cover assembly is provided. The assembly can include an elongated hollow cylindrical cover having a closed first end, and open second end. The assembly includes a plug comprising an elastomeric material and having a plug first end, a plug second end, a bore extending through the plug from the plug first end to the plug second end, and a cover mating surface adjacent to the plug first end. The cover mating surface is operable to slidingly engage the cover, and the plug is operable to surround and slidingly engage optical fiber cordage extending through the bore.07-14-2011
20110159178SYSTEMS AND METHODS FOR PURGING UV CURING TUBES - Certain embodiments of the invention may include systems and methods curing a coated optical fiber. The method includes drawing the coated optical fiber through a gas chamber filled with a predetermined gas, drawing the fiber through a cure tube coupled to the gas chamber, and purging at least a portion of an inner surface of the cure tube with a purge gas as the coated optical fiber is drawn through the cure tube.06-30-2011
20110150404OPTICAL FIBER COATING WITH A COLOR CONCENTRATE HAVING SLICKNESS ADDITIVE - Certain embodiments of the invention may include systems and methods for coating an optical fiber. The method includes coating an optical fiber with a primary coating, preparing a secondary coating by selectively mixing a concentrate with an ultraviolet (UV) curable diluent coating, wherein the concentrate comprises predetermined amounts of a color agent and a release agent, and applying the secondary coating to the optical fiber and primary coating.06-23-2011
20110129190Techniques for Manipulating Crosstalk in Multicore Fibers - A multicore optical fiber includes a plurality of core regions disposed within a common cladding region. Each of the plurality of core regions is configured, in combination with the common cladding region, to propagate light along a longitudinal axis of the fiber. At least two core regions are configured to inhibit resonant coupling of propagated light therebetween within a selected region of operation. At least one segment of the fiber includes a twist that is configured such that when the twisted segment is subjected to a bend having a selected radius, the twist creates a controlled change in the amount of crosstalk between the at least two core regions, compared with the amount of crosstalk between the at least two core regions when a bend having the selected radius is introduced into a non-twisted segment of the fiber.06-02-2011
20110110619TUNABLE DISPERSION COMPENSATOR WITH MINIMUM DIFFERENTIAL GROUP DELAY - In a method and system for providing dispersion compensation in an optical system, there is coupled into the optical system at least one pathway into which there is connected a tunable chirped fiber Bragg grating, each such grating providing a respective tunable amount of dispersion. At least one respective DGD element is connected into the respective pathway for each such grating. The set of all such respective DGD elements in a given pathway introduces a bias differential group delay DGD05-12-2011
20110097048Techniques for Manufacturing Birefringent Optical Fiber - In a technique for fabricating a birefringent optical fiber, a preform rod is fabricated having a longitudinal axis, an outer peripheral surface, and a selected refractive index variation. At least one longitudinal groove is cut into the preform rod through its outer peripheral surface, wherein the at least one longitudinal groove has a cross sectional area equal to that of a respective birefringence-inducing stress element to be loaded into the groove, such that when the stress element is loaded into the groove, a portion of the stress element protrudes outside of the circumference of the preform. A respective birefringence-inducing stress element is loaded into the at least one longitudinal groove. A preform assembly is created by positioning the loaded preform rod within an overcladding tube. The preform assembly is drawn into optical fiber.04-28-2011
20110067451Method of Fabricating Optical Fiber Using An Isothermal, Low Pressure Plasma Deposition Technique - An isothermal, low pressure-based process of depositing material within a substrate has been developed and results in creating an extremely narrow reaction zone within which a more uniform and efficient deposition will occur. Sets of isothermal plasma operating conditions have been found that create a narrow deposition zone, assuring that the deposited material is clear glass rather than soot particles. The chemical delivery system, in one arrangement, utilizes rods of solid phase source material (which may otherwise be difficult to obtain in gaseous form). The operating conditions are selected such that the hot plasma does not transfer a substantial amount of heat to the substrate tube, where the presence of such heat has been found to result in vaporizing the reactant material (creating soot) and developing hot spots.03-24-2011
20110058769All-Fiber Module for Femtosecond Pulse Compression And Supercontinuum Generation - An all-fiber optical pulse compression arrangement comprises a concatenated arrangement of a section of input fiber (e.g., a single mode fiber), a graded-index (GRIN) fiber lens and a section of pulse-compressing fiber (e.g., LMA fiber). The GRIN fiber lens is used to provide mode matching between the input fiber (supporting the propagation of chirped optical pulses) and the pulse-compressing fiber, with efficient pulse compression occurring along the length of the LMA fiber. The dispersion and length of the LMA fiber section are selected to provide the desired degree of pulse compression; for example, capable of reconstituting a femtosecond pulse as is used in supercontinuum generation systems.03-10-2011
20110052128Optical Fiber Preform With Improved Air/Glass Interface Structure - An optical fiber preform comprising a plurality of longitudinal air holes is subjected to a thermal treatment (i.e., heating), coupled with the application of a compressive force on either end of the heated preform to compress the entire preform structure a predetermined amount. The thermal compression treatment has been found to smooth any roughened glass surfaces and heal microcracks that may have formed during the preform fabrication process, essentially “knitting” the glass material back together and forming a preform of improved quality over the prior art microstructured preforms.03-03-2011
20100303402Phase-Engineered Fibers for Use in Generating Cylindrical Vector Beams - A phase-engineered fiber is described for generating a cylindrically polarized beam. The fiber includes a core region, a ring region surrounding the core region, and an outer cladding region surrounding the ring region. The fiber regions are configured to cause the fiber to have a refractive index step proximate to the peak amplitude value of the mode intensity profile of an LP12-02-2010
20100278486Fiber Based Laser Combiners - An all-fiber combiner device is described for combining multiple high power inputs, such as high power laser inputs. The device includes a first tapered fiber section made from fibers that allow for efficient size reduction of the optical signals. The output of the first tapered fiber section may then be coupled to a multimode output fiber for delivery of the combined power beam. Alternately, the first tapered section can be coupled to a second, multimode, tapered section, which provides further size reduction of the core for splicing into a final output fiber, while adding cladding to the main fiber.11-04-2010
20100266284Method and Apparatus Using Distributed Raman Amplification and Remote Pumping In Bidirectional Optical Communication Networks - A bidirectional optical communications network comprises an optical transmission fiber for carrying a downstream signal at a first wavelength and a multiplicity of upstream signals at a second, different wavelength. The fiber is characterized by distributed Raman gain over at least an extended portion of its length. A first terminal, optically coupled to one end of the fiber, includes a first transmitter for generating the downstream signal, a first receiver for detecting the upstream signals, and at least one pump source for generating pump light that provides Raman amplification to either the downstream signal or the upstream signal or both. A multiplicity of second terminals, optically coupled to another end of the fiber, each includes a second transmitter for generating one of the upstream signals, and a second receiver for detecting a downstream sub-signal. A passive optical node is configured to (i) split the downstream signal into a multiplicity of downstream sub-signals each propagating at the first wavelength to a separate one of the second terminals and (ii) to combine each of the upstream signals from each of the second terminals onto the fiber for transmission to the first terminal. In another embodiment, the network is a GPON compatible with current ITU standards.10-21-2010
20100220969Fiber Optic Cable Pulling Strain Relief - A strain relief for distributing strain along an outer surface of an optical fiber cable is disclosed. The strain relief is shaped to surround and tangentially grip the cable via friction between the outer surface of the cable and an inner surface of the strain relief. The strain relief also includes a pulling eye to protect the cable (and a connector) from pulling force (i.e. strain), water and dust. The strain relief is relatively small, low cost and easy to use.09-02-2010
20100080521OPTICAL FIBER WITH WATER-BLOCKING - Polymer-coated transmission media having water-blocking material embedded in the outer surface of the transmission media prevents water penetration into the transmission media and reduces the overall diameter of a cable made from the transmission media by eliminating a water-blocking tape layer in the cable. The outer surface of the transmission media is a polymer whose outer surface is embedded with a water-blocking material. The water-blocking material is applied before the polymer is cured. The transmission media may be any known type of optical media, which guides a light within the optical media. In various embodiments, optical fibers, buffered optical fibers and fiber ribbons are used as the transmission media.04-01-2010
20090290841Reduced Bend Sensitivity and Catastrophic Bend Loss In Single Mode Optical Fibers and Method of Making Same - An optical fiber that is relatively insensitive to bend loss and alleviates the problem of catastrophic bend loss comprises a core region and a cladding region configured to support and guide the propagation of light in a fundamental transverse mode. The cladding region includes (i) an outer cladding region, (ii) an annular pedestal (or ring) region, (iii) an annular inner trench region, and (iv) an annular outer trench region. The pedestal region and the outer cladding region each have a refractive index relatively close to that of the outer cladding region. In order to suppress HOMs the pedestal region is configured to resonantly couple at least one (unwanted) transverse mode of the core region (other than the fundamental mode) to at least one transverse mode of the pedestal region. In a preferred embodiment, the fiber is configured so that, at a signal wavelength of approximately 1550 nm, its bend loss is no more than about 0.1 dB/turn at bend radius of 5 mm and is no more than about 0.02 dB/turn at a bend radius of 10 mm. In addition, in one embodiment, the core region also includes an inner core region and an annular outer core (or shelf) region surrounding the inner core region. The outer core region extends radially a distance of less than 9 μm from the fiber axis. In another embodiment, the inner trench region includes an annular inner portion and an annular outer (or step) portion surrounding said inner portion. The refractive index of the step portion is greater than that of the inner portion. In a preferred embodiment, both of the foregoing features of the core region and the inner trench region are incorporated in the fiber. Also described are multi-tube fabrication techniques for making such fibers.11-26-2009
20090262779Multi-Core Fiber Grating Sensor - A twin core fiber for sensor applications is developed. It is particularly useful in de-coupling the strain and temperature and thus obtaining both measurement parameters at the same time and location. It is also particularly useful for measuring the temperature in a high humidity environment. The twin core fiber has two cores and each of the cores having a different dopant regime. Also, each of the cores includes a grating having substantially the same grating period.10-22-2009
20090257711Systems and Techniques for Generating Bessel Beams - A technique is described for generating a Bessel beam. An input optical fiber is provided that supports propagation in the fundamental mode. The input fiber is connected to a fiber mode converting device that provides phase matching, at a predetermined excitation wavelength, between the fundamental mode and a selected azimuthally symmetric higher-order mode. As an input to the fiber mode converting device, a coherent light beam is fed through the input optical fiber to provide a fundamental mode input at the excitation wavelength. The fiber mode converting device resonantly excites the selected azimuthally symmetric mode. The azimuthally symmetric mode is provided as a beam output from an endface of the fiber mode converting device to approximate a Bessel beam.10-15-2009
20090230580Systems and Techniques for Reducing Group Delay Ripple in a Dispersion Compensating Grating - A technique is described for reducing group delay ripple in a fiber dispersion compensation grating. The grating is mounted into a trimming setup that includes a trimming device and a scanning assembly for causing a region of the grating to be scanned along its length by the trimming device output. The grating is sensitive to the trimming device output, such that exposure to the trimming device output causes a change in the effective refractive index of the scanned region, the amount of change varying as a function of scanning velocity. A region of the grating to be trimmed is selected, and a scanning velocity profile is programmed into the scanning assembly that is calculated to modify the effective refractive index of the selected grating region along its length so as to smooth out group delay ripple in the selected grating region.09-17-2009

Patent applications by OFS FITEL, LLC