Abstract: Method for fabricating of all-optical-fiber based optical polarizer devoid of fusing of first and second optical fibers. The method includes a process of forming a substantially adiabatic optical fiber taper by pulling an optical fiber and interrupting this process when an optical power parameter measured at an output of the optical fiber is reduced below a pre-defined threshold as a result of said pulling. An optically-tapered single-mode polarization-maintaining optical fiber element fabricated according to the method and configured as such all-optical-fiber polarizer.

Abstract: An illuminated container for the growth of biological entities is provided. The container is illuminated by a flexible light diffusing fiber. The light diffusing fiber includes a core formed from a silica-based glass and a cladding in direct contact with the core. The light diffusing fiber also includes an outer polymer coating layer surrounding the cladding, the outer polymer coating layer being the cured product of a liquid polymer blend including a scattering material and a luminophore.

Abstract: An optical fiber inspecting device is disclosed. The optical fiber inspecting device includes a first light-emitting unit that irradiates an optical fiber with a first light beam, the optical fiber including a glass fiber and a coating resin and moving in an axial direction, and a first light-receiving unit that receives scattered light resulting from the first light beam scattered in the optical fiber, and converts the scattered light to an electrical signal. An optical axis of the first light-receiving unit passes through an irradiation position where the first light beam strikes the optical fiber, and the first light beam and the optical axis of the first light-receiving unit diagonally intersect each other, thereby preventing the first light beam from directly entering the first light-receiving unit.

Abstract: A fiber optic cable and connector assembly including a fiber optic connector mounted at the end of a fiber optic cable. The fiber optic connector includes a ferrule assembly including a stub fiber supported within a ferrule. The stub fiber is fusion spliced to an optical fiber of the fiber optic cable at a location within the fiber optic connector.

Abstract: Aspects of the disclosure are drawn to methods for producing a fused connector termination. An exemplary method may include setting a specification requirement to be met by the fused connector termination and applying an amount of heat to a proximal region of an unfused connector termination. The proximal region of the unfused connector termination may include an inner optical fiber coaxially positioned within an outer ferrule, and applying the amount of heat may at least partially fuse the optical fiber to the outer ferrule to form an at least partially fused connector termination. The method may also include imaging the proximal region of the at least partially fused connector termination and determining, based on the imaging, whether the proximal region of the at least partially fused connector termination meets the specification.

Abstract: A method of fabricating an optical fiber preform that can give stable and high deposition efficiency from the start to the end of the deposition when synthesizing a large size preform. When fabricating a preform by hydrolyzing a glass raw material gas in flame to generate glass particles and depositing the glass particles on a rotating starting material in the radial direction using a burner with a concentric multiple-tube structure having at least a plurality of small diameter combustion assisting gas-ejecting ports having the same focal length. L1 is made greater than L2 (L1>L2) during an early stage of deposition and L2 is increased in the course of the deposition so that L2 is greater than L1 (L1<L2), where the focal length is denoted by L1 and the distance from the tip of the burner to a deposition plane on the starting material is denoted by L2.

Abstract: An IR supercontinuum source for generating supercontinuum in the MIR or possibly LWIR spectral bands comprises a supercontinuum fiber formed from a heavy metal oxide host glass having low optical loss and high non-linearity over the spectral band that is stable, strong and chemically durable. The supercontinuum fiber is suitably a depressed inner clad fiber configured to support only single transverse spatial mode propagation of the pump signal and supercontinuum. The source suitably includes a tapered depressed inner clad fiber to couple the pump signal into the supercontinuum fiber. The source may be configured as an “all-fiber” source.

Abstract: A multicore fiber 1 includes a plurality of cores 3 disposed at predetermined intervals and surrounded by a cladding 5. The multicore fiber 1 also includes a marker 7 formed apart from the cores 3. The refractive index of the marker 7 is different from those of the cores 3 and the cladding 5. For example, the marker 7 may be made of a material having lower refractive index than that of the cladding 5. In this case, for example, the cores 3 may be made of germanium-doped quartz. The cladding 5 may be made of pure quartz. The marker 7 may be made of fluorine-doped quartz. Further, the marker 7 may be an empty hole.

Abstract: Methods for modifying multi-mode optical fiber manufacturing processes are disclosed. In one embodiment, a method for modifying a process for manufacturing multi-mode optical fiber includes measuring at least one characteristic of a multi-mode optical fiber. The at least one characteristic is a modal bandwidth or a differential mode delay at one or more wavelengths. The method further includes determining a measured peak wavelength of the multi-mode optical fiber based on the measured characteristic, determining a difference between the target peak wavelength and the measured peak wavelength, and modifying the process for manufacturing multi-mode optical fiber based on the difference between the target peak wavelength and the measured peak wavelength.

Abstract: Methods of making a stub lens element and assemblies for coherence tomography (OCT) applications are disclosed. The method of making the stub lens element includes drawing a rod of optical material and processing the drawn rod to form a lens integrally connected to a stub section. The methods also include operably supporting an optical fiber and a stub lens element in a cooperative optical relationship to form a stub lens sub-assembly. The methods also include operably supporting the stub lens sub-assembly and a light-deflecting member in a cooperative optical relationship to form a probe optical assembly that has a folded optical path.

Abstract: An IR supercontinuum source for generating supercontinuum in the MIR or possibly LWIR spectral bands comprises a supercontinuum fiber formed from a heavy metal oxide host glass having low optical loss and high non-linearity over the spectral band that is stable, strong and chemically durable. The supercontinuum fiber is suitably a depressed inner clad fiber configured to support only single transverse spatial mode propagation of the pump signal and supercontinuum. The source suitably includes a tapered depressed inner clad fiber to couple the pump signal into the supercontinuum fiber. The source may be configured as an “all-fiber” source.

Abstract: A tellurium oxide glass that is stable, strong and chemically durable exhibits low optical loss from the UV band well into the MIR band. Unwanted absorption mechanisms in the MIR band are removed or reduced so that the glass formulation exhibits optical performance as close as possible to the theoretical limit of a tellurium oxide glass. The glass formulation only includes glass constituents that provide the intermediate, modifiers and any halides (for OH— reduction) whose inherent absorption wavelength is longer than that of Tellurium (IV) oxide. The glass formulation is substantially free of Sodium Oxide and any other passive glass constituent including hydroxyl whose inherent absorption wavelength is shorter than that of Tellurium (IV) oxide. The glass formulation preferably includes only a small residual amount of halide.

Abstract: An apparatus and technique are used to fabricate optical microresonators. A fabrication chamber contains all fabrication materials and devices. The microresonators are fabricated from a glass preform mounted on a motorized spindle. A laser is focused onto the preform to partly or fully impinge on the preform. The laser's focus position is controlled by changing the positioning of a lens mounted on a translation stage. Piezoelectric control elements may be mounted to finished microresonators to control of nonlinear parametric oscillation and four-wave mixing effects of the microresonator, control of nonlinear optical stimulated Brillouin scattering and Raman effects of said microresonator and wideband tuning of the frequency spacing between the output modes of a nonlinear-Kerr-effect optical frequency comb generated with said microresonator.

Abstract: A method of inspecting a synthetic silica glass molded body includes: irradiating the synthetic silica glass molded body with a spectrum line of an Hg lamp having a wavelength of 248 nm; measuring light emitted by the synthetic silica glass molded body; and a procedure which may include screening a portion which satisfies a condition that a ratio of the bright line intensity and the fluorescent light intensity is of a certain value or less, or which may include determining whether a condition that a ratio of a minimum value and a maximum value of a measured fluorescent light intensity is in a certain range is satisfied or not.

Abstract: Optical waveguide coupling ratios can be modified for a package by providing a substrate with a photonic circuit disposed on a first section of the substrate and a plurality of optical waveguides formed in glass disposed on a second section of the substrate, the waveguides being connected to the photonic circuit, adjacent ones of the waveguides having a fixed coupling ratio. A three-dimensional region of the glass abutting an end of one or more of the waveguides is lased to change a refractive index of the glass in each three-dimensional region, and thereby extend a length of each waveguide abutting one of the three-dimensional regions so that the coupling ratio between that waveguide and an adjacent waveguide is changed as a function of the extended length. The lasing is controlled based on feedback so that each coupling ratio changed by the lasing varies by less than a target amount.

Abstract: Methods for making a preform for a graded-index multimode fiber by using an inside deposition process are disclosed. The methods are characterized by an iterative refractive index profile correction with the following steps: determining a target refractive index profile for the preform to be produced, carrying out an inside deposition process with fixed volume flows for the reacting gases inside a tube and a given burner speed for all deposited layers, collapsing the tube and measuring the actual refractive index profile, comparing the target profile with the actual profile and calculating a correction value of index differences, converting this correction value in corrected burner speeds as varying process parameter, carrying out a inside deposition process with fixed gas flows and corrected burner speeds for all layers to be deposited.

Abstract: A fusion splicing apparatus fusion-splices end faces 1a and 3a of a pair of optical fibers 1 and 3 to each other. The apparatus includes a mirror shaft 21 provided with a mirror 23 that is arranged between the end faces 1a and 3a of the pair of optical fibers 1 and 3 that are faced toward and spaced away from each other and is movable between a first position to reflect an image of the end face 1a and a second position to reflect an image of the end face 3a, a first camera 25 that takes the image of the end face 1a reflected in the first position, and a second camera 27 that takes the image of the end face 3a reflected in the second position.

Abstract: An optical fiber (1) includes (i) an inner core (111) whose refractive index distribution has an a profile, (ii) an outer core (112) which surrounds the inner core (111), and (iii) a clad (12) which surrounds the outer core (112). In the optical fiber (1), Rd is set to not less than 0.15, where Rd is a ratio of a refractive index difference between the outer core (112) and the clad (12) to a refractive index difference between a center part of the inner core (111) and the clad (12).

Abstract: Methods of making a stub lens element and assemblies for coherence tomography (OCT) applications are disclosed. The method of making the stub lens element includes drawing a rod of optical material and processing the drawn rod to form a lens integrally connected to a stub section. The methods also include operably supporting an optical fiber and a stub lens element in a cooperative optical relationship to form a stub lens sub-assembly. The methods also include operably supporting the stub lens sub-assembly and a light-deflecting member in a cooperative optical relationship to form a probe optical assembly that has a folded optical path.

Abstract: Apparatus and methods are described herein for cleaving an optical element at a defined distance from a splice (or other reference point/feature) of the optical element within a desired precision and/or accuracy. In some embodiments, a method includes receiving an indication of a location of a feature in an intermediate optical assembly visible within an image of the intermediate optical assembly. The feature can be for example, a splice. A position of the intermediate optical assembly is translated relative to a cleave unit based on the indication. After translating, the intermediate optical assembly, the intermediate optical assembly is cleaved to form an optical assembly that has an end face at a location disposed at a non-zero distance from the location of the feature. In some embodiments, the location of the feature can be determined with an image recognition system.

Abstract: An optical device including an active core layer of silica glass doped with ions which serve as optical emitters, the active core layer being on a silica glass substrate and having a layer thickness of at least 5 ?m, and wherein the layer is sintered at a temperature range of 1500-1600 C and subsequently heat treated by a laser.

Abstract: A remote sensor element for spectrographic measurements employs a monolithic assembly of one or two fiber optics to two optical elements separated by a supporting structure to allow the flow of gases or particulates therebetween. In a preferred embodiment, the sensor element components are fused ceramic to resist high temperatures and failure from large temperature changes.

Abstract: An optical waveguide circuit includes: an optical interferometer including an optical waveguide; and a heating unit that is disposed along at least a part of the optical waveguide included in the optical interferometer and performs heating of imparting, to the optical waveguide, reversible refractive index changes different from each other along two principal axes of refractive index of the optical waveguide and heating of imparting, to the optical waveguide, permanent refractive index changes different from each other along the two principal axes of refractive index of the optical waveguide. The optical interferometer has a polarization dependent frequency shift that is reduced by the heating of imparting the permanent refractive index changes.

Abstract: A method of manufacturing an optical fiber includes providing a preform in a furnace, and drawing a plurality of optical fibers from the preform at a plurality of different draw tensions. A bandwidth characteristic of each of the optical fiber is drawn at the different draw tensions is measured. A draw tension setpoint is selected based on the measured bandwidth characteristic of each optical fiber and the draw tension is adjusted to the selected draw tension setpoint. The method further includes drawing from the preform a tuned optical fiber at the selected draw tension setpoint which provides peak bandwidth.

Abstract: An object of the present invention is to provide an artificial quartz member inhibited from suffering the decrease in transmittance in a laser light wavelength region which is caused by long-term irradiation with a laser light having a wavelength of 200 nm or shorter; and a process for producing the artificial quartz member. The invention provides an artificial quartz member for use as an optical element to be irradiated with a laser light having a wavelength of 200 nm or shorter, having an aluminum content of 200 ppb or lower.

Abstract: A method of manufacturing an optical fiber includes providing a preform in a furnace, and drawing a plurality of optical fibers from the preform at a plurality of different draw tensions. A bandwidth characteristic of each of the optical fiber is drawn at the different draw tensions is measured. A draw tension setpoint is selected based on the measured bandwidth characteristic of each optical fiber and the draw tension is adjusted to the selected draw tension setpoint. The method further includes drawing from the preform a tuned optical fiber at the selected draw tension setpoint which provides peak bandwidth.

Abstract: A porous layer is formed by depositing a silica glass particle around a core rod. The porous layer is dehydrated. The dehydrated porous layer is sintered under a decreased pressure until the dehydrated porous layer becomes a translucent glass layer containing a closed pore. The translucent glass layer is vitrified under an ambient atmosphere including an inert gas other than a helium gas.

Abstract: Techniques and systems suitable for performing low-loss fusion splicing of optical waveguide sections are provided. According to some embodiments, multiple laser beams (from one or more laser) may be utilized to uniformly heat a splice region including portions of the optical waveguide sections to be spliced, which may have different cross-sectional dimensions. According to some embodiments, the relative distance of the optical waveguide sections and/or the power of the multiple laser beams may be varied during splicing operations.

Abstract: A measuring method of a longitudinal distribution of bending loss of an optical fiber includes calculating an arithmetical mean value I(x) from two backscattering light intensities of two backscattering light at a position x obtained by bidirectional OTDR measurement of the optical fiber; and obtaining a bending loss value at the position x from a mode field diameter 2W(x) and a relative refractive index difference ?(x) at the position x calculated from the arithmetical mean value.

Abstract: A manufacturing process of a microstructured optical fiber including a void-containing region, includes the steps of: drawing a microstructured optical fiber along a longitudinal direction from a heated preform, wherein the optical fiber is continuously advanced along the longitudinal direction; directing a radiation beam at a longitudinal position in the longitudinal direction of the optical fiber so as to produce an interference pattern; detecting the interference pattern and producing at least one electrical detection signal corresponding to the interference pattern and including a plurality of signal fringe cycles; feeding the first detection signal into a first counter circuit; determining a first number of interference fringe increments in the plurality of signal wave fringe cycles of the at least one detection signal by using the first counter circuit; determining the outer diameter of the optical fiber, and controlling the microstructure of the optical fiber during advancement of the optical fiber.

Abstract: A method for determining a rotational characteristic of an optical fiber is disclosed. The method includes forming an orientation registration feature in an optical fiber preform and drawing an optical fiber from the preform such that the orientation registration feature formed in the optical fiber preform is imparted to the optical fiber. The optical fiber is then rotated about a longitudinal axis and the direction of rotation is periodically reversed. An orientation signal of the optical fiber is determined based on a position of the orientation registration feature as the optical fiber is rotated. A rotational characteristic of the optical fiber is then determined based on the orientation signal.

Abstract: A manufacturing process of a microstructured optical fibre including a void-containing region, includes the steps of: drawing a microstructured optical fibre along a longitudinal direction from a heated preform, wherein the optical fibre is continuously advanced along the longitudinal direction; directing a radiation beam at a longitudinal position in the longitudinal direction of the optical fibre so as to produce an interference pattern; detecting the interference pattern and producing at least one electrical detection signal corresponding to the interference pattern and including a plurality of signal fringe cycles; feeding the first detection signal into a first counter circuit; determining a first number of interference fringe increments in the plurality of signal wave fringe cycles of the at least one detection signal by using the first counter circuit; determining the outer diameter of the optical fibre, and controlling the microstructure of the optical fibre during advancement of the optical fibre.

Abstract: A hole diameter measuring method for a holey optical fiber of the present invention is a hole diameter measuring method for a holey optical fiber having: continuously irradiating a side of a holey optical fiber bare wire with parallel light rays, the holey optical fiber bare wire obtained by drawing an optical fiber base material; continuously detecting, with a detecting portion, forward scattering light that is generated by the irradiation of the holey optical fiber bare wire with the parallel light rays; and calculating a diameter of at least one hole in the holey optical fiber bare wire using a correlation relationship between a scattering intensity pattern of the detected forward scattering light and the diameter of the at least one hole.

Abstract: A method for producing a single-mode fiber for submarine cables including washing and flame polishing of a preform, fiber drawing, coating with a first coating layer and curing therein using an UV-curing device, coating with a second coating layer and curing therein using the UV-curing device, fiber selection with a 2% screening strain, and testing the properties of the fiber. The fiber has a high strength and long coiling length exceeding 100 km and the method is easy to practice with low production cost and parameters involved therein are highly controllable.

Abstract: According to one embodiment, a method for characterizing a multimode, bend resistant optical fiber may include determining a core refractive index profile for a core portion of a preform and determining a moat refractive index profile for a moat portion of the preform. Thereafter, a property of a multimode optical fiber is determined prior to drawing the multimode optical fiber from the preform. The property of the multimode fiber is determined based on the core refractive index profile of the preform, the moat refractive index profile of the preform, the inner radius rin and the outer radius rout of a depressed-index annular portion of the multimode optical fiber and fiber property coefficients.

Abstract: There is provided a method of manufacturing an optical waveguide, the method including: allowing a beam to be incident in an optical waveguide direction of an optical waveguide material; generating an optical soliton in the optical waveguide material by adjusting intensity of the incident beam according to the optical waveguide material; allowing the incident beam to be re-incident at an intensity higher than an intensity of the incident beam after checking generation of the optical soliton in the optical waveguide material; and increasing a refractive index of an optical soliton-generating area of the optical waveguide material by the re-incident beam to thereby form an optical waveguide.

Abstract: A method of determining a heating amount adequate for fusion splicing is provided. In the method, the melting state of the end portions of optical fibers can be monitored on a real time basis so that fewer tests need to be performed. A method of fusion splicing and a fusion splicer are also provided. In the method of determining the heating amount, end portions of optical fibers that are placed opposite one another with a predetermined gap therebetween are heat-melted; an image of portions to be heat-melted is observed with an image-capturing device; and a luminance, a light emitting width, or a change in the luminance or the light emitting width is measured. In the method of fusion splicing, optical fibers are heat-melted with the heating amount that is determined using test fibers in advance, or determined using the optical fibers to be fusion spliced.

Abstract: According to a known vertical drawing method for producing a cylindrical glass body, the cylinder longitudinal axis of the glass cylinder is adjusted by hand in relation to the longitudinal axis of a heating tube. The aim of the invention is to optimize the stability of said glass body.

Abstract: A method and apparatus for impulsively spinning optical fiber while the optical fiber is being drawn is disclosed herein.

Abstract: In splicing two optical fibers to each other using an electric arc formed between electrodes images of the regions being heated and thereby fusioned to each other are taken. The images cover a rectangular field (43) having the fibers located centrally, along a center line of the field and parallel to the long sides of the field. The images are evaluated to determine a value of the position of the center of the electric arc in relation to the position of the end surfaces of the fibers. This value can then be used for placing the end surfaces just at the arc center. In the image the image of the optical fibers can be excluded so that only light intensity from the air discharge of the electric arc is recorded in the captured images. The field (41) excluded can be a narrow strip of uniform width located symmetrically around the image of the fibers.

Abstract: An optical fiber adapted to carry optical power for powering an electrical device and also optionally adapted to carry optical data for signal processing. The optical fiber capable of carrying both optical data and optical power includes a central data waveguide region that carries data light and an annular power waveguide region concentrically surrounding the data waveguide region and adapted to carry relatively large amounts of optical power. A first annular isolation region between the data and power waveguide regions and that includes microstructures serves to optically isolate the waveguide regions. An outer annular isolation region serves to confine power light to the power waveguide region and contributes to the bend-resistance of the optical fiber. An optical power and optical data distribution system that utilizes the optical fiber is also described.

Abstract: The hydroxyl content in an optical fiber is stabilized by a manufacturing process involving exposure of the optical fiber to a mixture of deuterium and a predetermined amount of hydrogen.

Abstract: This invention provides a method for measuring and monitoring the state of polarization (SOP) of a polarization maintaining (PM) fiber and the like using a narrowband fiber Bragg grating (FBG) written on the same. The PM fiber therefore comprises a first narrowband reference FBG which is used as a reference to measure and monitor the SOP of the PM fiber. Due to the birefringence properties of the PM fiber, the reference FBG will generally reflect two narrowband spectra, each having a central wavelength; one in the slow axis and one in the fast axis. By measuring the intensity of the reflected spectra in each axis and by tuning the fiber with a polarization controller, it is possible to adjust the fiber to a predetermined SOP. After having adjusted the PM fiber to a predetermined SOP, it is possible to accurately measure the optical properties of a second grating, or of another optical device, according to the predetermined SOP.

Abstract: In a known method for the production of a blank mold for optical fibers, a fluorine-doped SiO2 enveloping glass is produced on a core glass cylinder that rotates about its longitudinal axis, wherein a silicon-containing starting substance is fed to a plasma burner, said substance is then oxidized in a plasma flame assigned to the plasma burner to obtain SiO2 particles, the SiO2 particles are deposited by layers on the enveloping surface of the cylinder of the core glass cylinder in the presence of fluorine and sintered into the enveloping glass. The invention aims at providing an economical method, which builds upon the above-mentioned method, in order to produce a blank mold from which optical multi-mode fibers (52) can be obtained.

Abstract: A glass base material, which is a base material of an optical fiber, comprising: a core; and a clad surrounding the core; wherein: a rate of change in a relative-refractive-index-difference between the core and the clad in a longitudinal direction of the glass base material is substantially 6% or less.

Abstract: An electro-optical high-voltage sensor includes a waveguiding sensing fiber of an electro-optical material. The electrical field of the voltage to be measured is substantially parallel to the longitudinal axis of the sensing fiber. The sensing fiber carries two orthogonally polarized light waves, with the applied field affecting the birefringence between the waves. Using an electro-optical waveguiding fiber in this configuration allows the voltage between two widely spaced points to be accurately measured.

Abstract: For a substrate having fine convexoconcave patterns on its surface, the dimensions of the convexoconcave patterns in a vertical direction of a quartz glass substrate are controlled to be uniform with extreme accuracy and over the entire substrate surface. The quartz glass substrate is made to have a fictive temperature distribution of at most 40° C. and a halogen concentration of less than 400 ppm, and the etching rate of the surface of the quartz glass substrate is made uniform, whereby the dimensions of the convexoconcave patterns in a vertical direction of the quartz glass substrate are controlled to be uniform with good accuracy and over the entire substrate surface.

Abstract: Embodiments of the invention include a method for making optical fiber having reduced aging or hydrogen aging loss over the life of the fiber and optical fiber systems including such optical fibers. Improved silicon-oxygen stoichiometry during one or more preform manufacturing steps reduces the amount of Si defects generated in the optical fiber preform. Also, deuterium exposure of optical fiber drawn from the preform reduces the likelihood of having atomic defects such as Si defects in the optical fiber that, over time, attract and bond with hydrogen atoms to form molecules that contribute to increased water absorption loss. The inventive method produces optical fibers with improved transmission characteristics, e.g., optical fibers made by methods according to embodiments of the invention have transmission loss at 1385 nanometers that is less than 0.33 dB/km and the aging loss increase thereafter is less than 0.04 dB/km.

Abstract: An optical sensor includes at least one optical coupler and an optical waveguide in optical communication with the at least one optical coupler. The optical waveguide is configured to receive a first optical signal from the at least one optical coupler. The first optical signal has a group velocity and a phase velocity while propagating through at least a portion of the optical waveguide, the group velocity less than the phase velocity. An interference between the first optical signal and a second optical signal is affected by perturbations to at least a portion of the optical sensor.

Abstract: In a LMA optical fiber the index of the core region is graded (i.e., as viewed in a radial cross-section) and has a grading depth of ?ng, as measured from a central maximum at or near the axis to a lower level that is not greater than the central maximum and not less than the index of the cladding region. When the fiber is to be bent at a bend radius, the grading depth, the radius of the core region, and the difference between the central maximum index and the cladding region index are configured to reduce bend distortion. They may also advantageously be configured to maximize the effective mode-field area of the fundamental mode, suppress higher order modes, and reduce bend loss. In a preferred embodiment, the core region includes a centralized gain region, which in turn includes a dark region that is no more than 30% of the area of the gain region. Also described is a method of making such LMA fibers.