Abstract: The present invention provides a connector-integrated type polymer optical waveguide, comprising: an optical waveguide including a film substrate for clad, an optical waveguide core provided on the film substrate, and a clad layer formed on side faces and a top face of the core; a pair of connector sleeves formed at positions at which the connector sleeves sandwich the optical waveguide core at least in one end portion of the polymer optical waveguide; and a rigid member for connector formation, wherein the film substrate for clad and the connector sleeves are fixed to the rigid member for connector formation in such a state that the center of the optical waveguide core and the center for connector sleeves are substantially on the same plane. The present invention also provides a method for producing the above-mentioned connector-integrated type polymer optical waveguide and a mold to be used for the method.

Abstract: A perturbed, multimode optical fiber exhibits order-of-magnitude improved capacity attributed to mode mixing—high per-channel bit rate, and large channel number due to large available bandwidth—without the added loss which, in the past, was associated with the perturbation stream.

Abstract: Disclosed is an amplifying optical fiber for amplifying optical signal transmitted therethrough by stimulated emission, the amplifying optical fiber comprising: an inner core disposed at a center of said optical fiber and containing MX, GaS3/2 and RE; an outer core surrounding said inner core and containing SiO2; and a cladding surrounding said outer core and containing SiO2, wherein said M contained in MX is one component selected from the group consisting of Na, K, Rb and Cs; said X contained in MX is one component selected from the group consisting of F, Cl, Br, and I; and said RE is one component selected from the group consisting of Ce, Pr, Pm, Nd, Sm, Eu, Gd, Tb, Ho, Dy, Er, Tm and Yb.

Abstract: An optical switching device including a substrate and at least an organic film as a light control part formed on the substrate. Optical switching is performed by applying signal light and control light to the organic film, the wavelengths of the signal light and the control light being set in a region in the vicinity of resonance on the longer wavelength side in the absorption spectrum of the organic film; and by changing a real part or real and imaginary parts of the refractive index of the light control part by using the control light, to thereby cause a phase difference in the signal light.

Abstract: The present invention provides an optical semiconductor device comprising: a wiring circuit board; at least one optical semiconductor element mounted on the wiring circuit board; resin layer A that encapsulates the at least one optical semiconductor element therewith; and resin layer B interposed between the resin layer A and the wiring circuit board, and having a tensile modulus as measured at 30° C. of 0.001 to 0.4 GPa.

Abstract: An electro-optic system in accordance with an embodiment of the present invention comprises a high glass transition temperature (Tg?about 210° C.) polymer matrix featuring aromatic groups on the backbone repeating unit, which hosts a guest, high hyperpolarizability organic NLO chromophore. Electro-optic systems according to embodiments of the present invention exhibit relatively high electro optical activity and low optical loss, and may exhibit optical stability at temperatures exceeding 70° C. Guest-host polymer systems in accordance with embodiments of the present invention may be formed into unique and appropriate shapes such as waveguides.

Abstract: The invention relates to an optical waveguide (optical fiber) based on quartz glass having reduced internal mechanical stresses. In prior art optical waveguides, the internal mechanical stresses are primarily due to the production process, namely due to the difference of the linear thermal coefficients of expansion of the core and sheathing material during the cooling of the fiber and due to the drawing itself. In an inventive optical waveguide, the difference of the linear thermal coefficients of expansion of the core and/or sheathing material is selected by means of an appropriate doping of the core and sheathing material. This selection is made so that the internal mechanical stresses, which are caused by the cooling during the production process, are significantly reduced or eliminated and/or they counteract the stresses caused by the drawing.

Abstract: A dispersion compensating optical fiber includes an uncovered dispersion compensating optical fiber containing a core and a cladding, and a resin coating which is disposed around the uncovered dispersion compensating optical fiber, wherein the resin coating has an adhesive property of 10 g/mm or less, and which includes an outer coating layer which is formed to have a thickness of 3 ?m or more, and the outer diameter of the uncovered dispersion compensating optical fiber is in a range from 90 to 125 ?m, and the outer diameter of the dispersion compensating optical fiber is in a range from 180 to 250 ?m.

Abstract: The invention relates to a reflexive optical screen that can show bright images with efficiency, and a viewing system that incorporates the same, and provides a reflexive optical screen 10 comprising a plurality of zonal V-grooved reflecting surfaces substantially concentrically located within a given surface and having a retrorelection action. Each of the zonal V-grooved reflecting surfaces comprises mutually orthogonal two conical facets 2 and 3 in a section orthogonal to a ridgeline of a V groove, and the conical facets 2 and 3 of each of the zonal V-grooved reflecting surfaces are located such that a bisector 5 for angles that the two conical facets 2 and 3 make in a section of each of the zonal V-grooved reflecting surfaces is oriented in the direction of a light ray incident on a position thereof.

Abstract: The present invention relates to an illumination device comprising light source and a light guide coupled thereto, preferably a liquid light guide, the light exit end of which is provided in the form of a light diffuser, said light diffuser comprising a polymer, preferably a fluorocarbon polymer. The scattering effect of the diffuser is obtained because of its crystalline structure or by fluorescent additives in the polymer. The crystallinity may be inherent to the internal structure of the polymer itself and/or be created or varied by compounding the polymer with other materials. The diffuser is welded to the sheathing tube of the liquid light guide simultaneously providing the seal for the liquid at the distal end of the liquid light guide. A preferred use of the illumination device is photodynamic diagnostics and therapy in the field of medicine.

Abstract: A coated optical fiber can have a primary coating and a secondary coating, where the primary coating can have good microbending resistance and is obtained by curing a composition having a high cure speed. In one example, a coated optical fiber can include as optical fiber, a primary coating and a secondary coating. The optical fiber can have an attenuation increase of less than 0.650 dB/km at 1550 nm, with the primary coating having a modulus retention ratio of at least 0.5, a glass transition temperature of ?35° C., and where the primary coating is obtained by curing a primary coating composition having a cure dose to attain 95% of the maximum attainable modulus of less than 0.65 J/cm2.

Abstract: A method of coating an optical fiber constituted by a doped silica core (1) and by silica cladding (2) consists in surrounding the doped silica core (1) and the silica cladding (2) in coating constituted by a first coating portion (3) of photocurable resin and a second coating portion (4) made by extruding a thermoplastic polymer.

Abstract: In a single mode optical fiber formed of a silica-based glass and including a glass part having a central core and a cladding region, the density of non bridging oxygen hole center in the glass part is not higher than 1.0×1014 spins/g in terms of the spin density measured by an electron spin resonance method.

Abstract: A wide band dispersion-controlled fiber which comprises a core forming an optical signal transmission path and having a peak refractive index, and a cladding surrounding the core and having a peak refractive index lower than the peak refractive index of the core. The wide band dispersion-controlled fiber further comprises at least one dispersion control layer arranged between the core and the cladding and having a refractive index profile such that its refractive index increases from an inner periphery to an outer periphery. The minimum refractive index of the dispersion control layer is less than the peak refractive indices of the core and cladding.

Abstract: Disclosed are a functional material and a functional device, each of which is capable of changing a wavelength of a transmission electromagnetic wave such as transmission light or a transmission sound wave such as a transmission ultrasonic wave through the device on the basis of a signal supplied from external. Each of the functional material and the functional device includes a periodic structure having a periodicity with a unit cycle on the order of a wavelength of an electromagnetic wave or a sound wave, and means for disturbing the periodicity which is inserted in at least one portion of the periodic structure, wherein a wavelength of the electromagnetic wave or sound wave passing through the periodic structure by controlling the means on a signal supplied from external.

Abstract: A photonic crystal comprising a waveguide made of material. The waveguide has a periodic set of holes. The material proximate to at least one of the holes in the periodic set of holes exhibits an index of refraction that has been modified by the application of laser energy relative to the material proximate to other holes in the periodic set of holes.

Abstract: The present invention adds a gel-swellable layer in fiber optic cables to aid in protecting the fibers within the cable. The gel-swellable layer can be placed on the fibers, individual ribbons, stacks of ribbons and on the inner surface of tubes by various methods, such as co-extrusion, and can be cured by either heat curing or UV curing. The gel-swellable layers of this invention can be either smooth or textured. When the fibers are placed into the tubes and the tubes are filled with the water resistant gel, the gel-swellable layer absorbs some of the gel causing it to “swell”. As a result of the “swelling” a certain volume of gel is absorbed by the layer, thus reducing the capability of the gel to flow at elevated temperatures.

Abstract: It is an object of the present invention to provide an optical fiber for transmitting ultraviolet ray which has an improve transmittance and is prevented from deterioration by ultraviolet ray with which it is irradiated. It is another object of the present invention to provide an optical fiber probe which can propagate vacuum ultraviolet ray and deep ultraviolet ray at a high transmittance, is deteriorated only to a limited extent when irradiated with ultraviolet ray and can be etched to have a desired shape of the sharpened section at the fiber end. The present invention provides the optical fiber for transmitting ultraviolet ray which has a core 5 of silica glass containing a given content of fluorine and a clad 6a of silica glass containing a given content of fluorine or boron, a clad 6b of a resin which transmits ultraviolet ray or a clad 6c having air holes H. The clad may be coated with a protective layer and further with a covered layer for protection.

Abstract: A light guiding plate, characterized by comprising a transparent thermoplastic resin composition containing 1-200 ppm of fine particles having a refractive index of 1.7-3.0 and an average particle diameter of 0.01-1.0 ?m. This light guiding plate is suitable for display devices used in office automation apparatuses such as personal computers, word processors, etc. and various monitors displaying image signals such as panel monitors, television monitors, etc., display devices used in illuminators for indoor or outdoor space, and signs.

Abstract: Disclosed is a substantially transparent glass-ceramic ceramic, and a method for making a glass-ceramic, exhibiting an aluminogallate spinel crystal phase and having a glass-ceramic composition that lies within the SiO2—Al2O3—ZnO—K2O—Ga2O3—Na2O system and particularly consisting essentially, in weight percent on an oxide basis, of 25-50% SiO2, 15-45% ZnO, 0-26% Al2O3, 0-25% K2O, 0-10% Na2O, 0-32% Ga2O3, a K2O+Na2O amount of greater than 10%, a Al2O3+Ga2O3 of greater than 10%, the glass ceramic microstructure containing a crystal phase comprising at least 15%, by weight, of hexagonal ZnO crystals. Another aspect disclosed is optical element selected from the group consisting of an optical fiber, a gain or laser medium, and an amplifier component, a saturable absorber, with the element comprising a transparent glass-ceramic of the same composition and containing a crystallinity of at least about 15% by weight of hexagonal ZnO crystals.

Abstract: The invention provides a method for producing a polymer optical waveguide equipped with a plurality of alignment marks (AM), which comprises bringing a film substrate into contact with a mold having concave portions corresponding to convex portions for the optical waveguide and convex portions for a plurality of AMs, introducing a curable resin from an end of the mold into concave portions, curing the resin, peeling the mold, and forming a cladding layer on a core/AM-forming surface, or bringing a film substrate into contact with the mold having concave portions corresponding to convex portions for the optical waveguide and notches, introducing the curable resin from an end of the mold into the concave portion, curing the resin, applying a material for AM to the film substrate through the notches and, thereafter, forming the cladding layer on the core/AM-forming surface.

Abstract: The present invention discloses an optical switching element that uses reversible electroplating mirrors includes a trench with transparent sidewalls located at the intersection of two waveguides A and B. The trench has two electrodes; one, which is transparent, is placed on the trench sidewall and the other is placed on the trench floor. The trench is filled with an index-matching electrolytic solution containing ions of a metal that can electro-deposit on these two electrodes. To actuate the switching element, a negative electrical potential is applied to the sidewall electrode. Actuation causes metal deposits to form on the sidewall electrode, creating a mirror that reflects light from waveguide A to waveguide B. To deactivate the switching element, a positive electrical potential is applied to the sidewall electrode. Deactivation causes metal deposits move off the sidewall and form on the trench floor.

Abstract: This invention pertains to an optical device and method for using a chalcogenide glass waveguide to amplify a pump light beam by means of stimulated Raman scattering and obtaining a depleted pump light beam and an amplified beam at a wavelength higher than the wavelength of the depleted pump light beam.

Abstract: Disclosed is a method of making a photonic crystal optical fiber preform by stacking and bonding individual glass disks. In one embodiment, each glass disk has a pattern of voids formed therethrough, and the pattern for each disk is the same. In another embodiment, glass blanks are formed without voids and stacked with disks having voids wherein an optical fiber preform is formed having channels closed at both ends by glass having no channels. Also disclosed is an optical fiber having channels closed at both ends by glass without channels.

Abstract: A waveguide structure includes a glass body and a waveguide pattern formed in the glass body by irradiating a predetermined track on the glass body with sufficient energy to grow a crystalline phase along the predetermined track.

Abstract: An optical waveguide structure is formed by embedding a core material within a medium of lower refractive index, i.e. the cladding. The optical index of refraction of amorphous silicon (a-Si) and polycrystalline silicon (p-Si), in the wavelength range between about 1.2 and about 1.6 micrometers, differ by up to about 20%, with the amorphous phase having the larger index. Spatially selective laser crystallization of amorphous silicon provides a mechanism for controlling the spatial variation of the refractive index and for surrounding the amorphous regions with crystalline material. In cases where an amorphous silicon film is interposed between layers of low refractive index, for example, a structure comprised of a SiO2 substrate, a Si film and an SiO2 film, the formation of guided wave structures is particularly simple.

Abstract: A polyimide excelling in heat resistance, chemical resistance, water repellency, dielectric characteristics, electrical characteristics, and optical characteristics and a polyamide acid useful as the raw material therefor are provided. Specifically, a polyamide acid containing a chlorine atom and a fluorine atom and comprising a repeating unit represented by the following formula (1): (wherein X and X? independently denote a divalent organic group; Y and Y? independently denote a chlorine, bromine, or iodine atom; p and p? denote independently denote the number of fluorine atom {F in the formula (1)} bonded to the relevant benzene ring, representing an integer of 0-3; q and q? independently denote an integer of 0-3; and p+q total 3, and p?+q? total 3).

Abstract: The invention pertains to optical fiber transmission networks, and is particularly relevant to transmission of high volume of data and voice traffic among different locations. In particular, the improvement teaches improvements to an optical transport system to allow for efficient and flexible network evolution.

Abstract: An optical waveguide is provided. The optical waveguide includes a polymer substrate and a lower cladding disposed on the substrate. The lower cladding is a first perhalogenated polymer. The optical waveguide also includes a core disposed on at least a portion of the lower cladding. A method of manufacturing the optical waveguide is also provided.

Abstract: A light diffusive protective film for a surface light source device for protecting other base material and improving the luminance of information display is disclosed which comprises a transparent plastic film and a concave/convex layer stacked on the surface of the transparent plastic film and satisfies requirements that: (1) the ten-point mean roughness of the uneven surface in the concave/convex layer is 0.5 ?m to 2.0 ?m; and (2) the count number of profile peaks is 16 to 60 as determined by measuring a roughness curve for the uneven surface of the concave/convex layer and determining the count number of profile peaks by a peak count method.

Abstract: The invention concerns a method for re-cladding an optical fiber (10) at least partly stripped over part of its length (16). The invention is characterised in that it comprises steps which consist in: placing a flexible tube (20) on the zone (16) of stripped fiber, injecting a polymer material (40) into the tube (20), through an axial end thereof, and polymerising the injected material (40) so that it adheres to the outer surface of the zone (16) of stripped fiber and to the inner surface of the tube (20), over the entire length of the tube (20). The invention also concerns the resulting optical fibers.

Abstract: An arrangement is disclosed for holding optical components, particularly light guides, and is characterized in that the parts of the holder contacting the optical component are made of a material with an index of refraction associated with the index of refraction of the material of optical component.

Abstract: A fiber optic cable for use in a hostile environment includes a fiber in metal core. The fiber in metal core includes one or more optical fibers that are disposed inwardly from an inner axial tube. The fiber optic cable also includes a hydrogen barrier shell that is disposed outwardly from the inner axial tube. The hydrogen barrier shell includes a material that is capable of reducing hydrogen permeation through the fiber optic cable. In this particular embodiment, the hydrogen barrier layer also includes a thickness of at least one-thousandth of an inch.

Abstract: A waveguide structure and method of fabricating the same, the method comprising forming a first graded layer on a substrate, wherein the first graded layer comprises a first and a second optical material, and a lattice constant adjusting material, wherein the concentration of the second optical material increases with the height of the first graded layer and the concentration of the lattice constant adjusting material varies in proportion to the second optical material; and forming a second graded layer, the second graded layer comprising the first and second optical materials, and a lattice constant adjusting material, wherein the concentration of the second optical material decreases with the height of the second graded layer and the concentration of the lattice constant adjusting material varies in proportion to the second optical material.

Abstract: An optical module of the present invention includes a first substrate 1, a second substrate 2, a PD 3, a LD 4, and an optical fiber 5. The first substrate 1 has a first optical waveguide core 1c formed therein. The second substrate 2 has a second optical waveguide core 2c formed therein. The first optical waveguide core 1c and the second optical waveguide core 2c form an optical connecting portion where the first substrate 1 and the second substrate 2 are bonded to each other. The LD 4 is capable of transmitting an optical signal via the second optical waveguide core 2c and the optical fiber 5. The PD 3 is capable of receiving an optical signal which enters the second optical waveguide core 2c from the optical fiber 5, and propagates through the first optical waveguide core 1c via the optical connecting portion formed between the first optical waveguide core 1c and the second optical waveguide core 2c.

Abstract: An optical fiber is colored to provide a striped pattern while maintaining a substantially uniform diameter of the fiber. In one embodiment, a coating of a first curable material having a base color is applied to an optical fiber core section using a coloring die. One or more stripes of a second curable material are applied using the die to the coating before the coating is fully cured. The stripe has a stripe color different from the base color and is formed in the coating such that the diameter of the fiber remains substantially uniform. In another embodiment, a tandem coloring system is used in which the coating is partially cured and one or more striping nozzles apply stripe(s) to the partially cured coating. In a further embodiment, the base color coating is applied and cured leaving one or more gaps. One or more stripes are applied in the gap(s) and cured to fully cover the fiber with a substantially uniform diameter.

Abstract: The invention provides a step index optical fiber which presents cladding having an index lower than the index of silica and a core with an index higher than the index of silica. The fiber is obtained by drawing a preform made by chemical vapor deposition using a deposition tube of index lower than the index of silica. Inner cladding of index substantially equal to the index of the deposition tube, and then a core of index higher than the index of the inner cladding are deposited in succession therein. The invention makes it possible to obtain a fiber having a large effective area, reduced attenuation, and suitable for being fabricated at low cost by chemical vapor deposition.

Abstract: An optical waveguide sensor for glucose measurement comprises a substrate, a first optical waveguide layer formed on a surface of the substrate, an entrance grating and an exit grating which are formed contacting with the first optical waveguide layer and being spaced from each other, a second optical waveguide layer located between the entrance grating and the exit grating while being in contact with the first optical waveguide layer, the second optical waveguide layer having a higher refractive index that that of the first optical waveguide layer, and a functioning layer containing an enzyme and a coloring reagent which is formed on the second optical waveguide layer.

Abstract: An optical device includes a waveguide bounded by a region containing a photonic band gap the properties of which determined the transfer characteristic of the waveguide. Such a device may serve as a component of, for example a wavelength division multiplexer, a monochromatic laser or a chemical sensor. It may serve as an optical bus for an electronic component such as a microprocessor. These devices are particularly suitable for incorporation in optical and opto-electronic intergrated circuits as they permit the fabrication of waveguides having right-angle bends with a radius of the order of 2 ?m.

Abstract: A method for manufacturing an article capable of constraining a propagating wave is disclosed. The method includes contacting a crystalline substrate with a source of deuterium ions to create a region in the crystalline substrate having a crystal structure that includes deuterium ions. The region is capable of constraining a propagating wave to the region.

Abstract: An electro-optic waveguide device, comprising (a) a first polymer buffer clad having a refractive index of about 1.445 to about 1.505 and a thickness of about 2.2 ?m to about 3.2 ?m; (b) a first polymer clad having a refractive index of about 1.53 to about 1.61 and a thickness of about 1.0 ?m to about 3.0 ?m; (c) an electro-optic polymer core having a refractive index of about 1.54 to about 1.62 and a thickness of about 1.0 ?m to about 3.0 ?m; and (d) a second polymer buffer clad having a refractive index of about 1.445 to about 1.505 and a thickness of about 2.2 ?m to about 3.2 ?m.

Abstract: An optical fiber bundle unit is provided for transmitting ultraviolet light in which the increase of the transmission loss caused by radicals generated in the optical fiber by irradiation or transmission of ultraviolet light is suppressed and a stable energy state is maintained even after the irradiation or transmission of ultraviolet light. The optical fiber bundle unit for transmitting ultraviolet light includes an optical fiber bundle and a sealed container in which the optical fiber bundle is held, wherein the sealed container contains a hydrogen gas.

Abstract: The present invention provides an optical polyimide precursor for use in making a polyimide. The precursor is defined by the following formula: wherein X is Cl, Br, oxo-halide, or fully halogenated alkyl, and A is a divalent aromatic or halogenated aromatic moiety. The present invention provides a method of preparing a diamine compound for use as an optical polyimide precursor. The method includes the steps of dissolving 2-chloro-5-nitrobenzotrifluoride and a diol in N,N-dimethylacetamide to form a solution, adding potassium carbonate, tert-butylammonium chloride and copper powder to said solution and heating the resulting mixture, removing the copper, precipitating and recrystallizing a dinitro-compound resulting from heating the mixture, and dissolving the dinitro-compound and reducing the dinitro-compound to yield a diamine compound.

Abstract: A passive optical waveguide device deposited on a wafer that includes an insulator layer and an upper semiconductor layer formed at least in part from silicon. The upper silicon layer forms at least part of an optical waveguide, such as a slab waveguide. The passive optical waveguide device includes an optical waveguide, a gate oxide, and a polysilicon layer. The polysilicon layer projects a region of static effective mode index within the optical waveguide having a different effective mode index than the optical waveguide outside of the region of the static effective mode index. The region of static effective mode index has a depth extending within the optical waveguide. The value and position of the effective mode index within the region of static effective mode index remains substantially unchanged over time.

Abstract: The invention relates to an optical component comprising a dispersion of layered minute particulate materials in a binder, the layered materials having a layer thickness, a concentration of particulate in the binder, and a basal plane spacing sufficient to provide a component having a light transmissivity of at least 50%.

Abstract: Waveplates formed of mesogen-containing polymers and planar lightwave circuits containing such waveplates. Polymers have sidechains containing mesogens such as biphenyl-containing groups. Polymers may have a glass transition temperature between 100 C and 300 C, and polymers may be stretched in excess of 150% to increase birefringence of polymer and provide thin films. Waveplates formed of stretched polymer films may have high biaxial birefringence.

Abstract: Applicants have discovered the existence of loss peaks in optical fiber transmission systems using wavelengths in the E-band and the L-band. Specifically, they have discovered the existence of narrow loss peaks at 1440 nm, 1583 nm and 1614 nm. Because the peaks are relatively narrow, they cannot be easily removed by conventional gain equalizers in long haul transmission systems, and although the peaks are relatively small, they can nonetheless cause transmission channels to drop out in amplified DWDM transmission systems. Applicants have further discovered that these loss peaks are due to carbon contamination of the transmission fiber. Thus optical fibers should be fabricated essentially free of carbon contamination. This means eliminating carbon-containing reagents in preform and tube-making processes.

Abstract: An apparatus and method are provided for converting light into a surface plasmon polariton on a plasmon supporting nanostructure and then controlling the emission of the re-emitting light. A circuit component is also described that is constructed of a nanostructure, which is comprised of at least one plasmon supporting metal. The metal can propagate the light, as a surface plasmon polariton, through the one-dimensional nanostructure and re-emit the light. The metal is a plasmon supporting metal, for example but not limited to, gold, silver, copper, and aluminum.

Abstract: A method of increasing the monomolecular recombination and the immunity to noise of a continuously tunable laser is disclosed. A concentration of recombination centers in the range of about 1×1016 cm?3 to about 1×1018 cm?3 in the tuning region of the laser device is achieved by doping the waveguide layer with impurity atoms, by irradiating the waveguide layer with high energy particles or by varying the growth conditions of the waveguide layer to introduce native point defects due to lattice mismatch. This way, the monomolecular recombination is increased and the radiative recombination over low current ranges is reduced. By increasing the monomolecular recombination, the immunity to noise is improved but the tuning efficiency is reduced. Nevertheless, only a minimal effect on the tuning efficiency is noted over high current ranges and, therefore, the overall tuning range is only insignificantly changed.

Abstract: The present invention provides materials suitable for use as secondary coatings of optical fibers. According to one embodiment of the invention, a curable composition includes an oligomer and at least one monomer, which when cured forms a cured polymeric material having a Young's modulus of at least about 1200 MPa, and a fracture toughness of at least about 0.7 MPa·m1/2. According to another embodiment of the invention, a coated optical fiber includes an optical fiber; a primary coating encapsulating the optical fiber; and a secondary coating encapsulating the primary coating, the secondary coating having a Young's modulus of at least about 1200 MPa, and a fracture toughness of at least about 0.7 MPa·m1/2.