Abstract: An optical fiber-type optical filter includes: two fiber regions, namely, the first and second PBGF regions, each of which includes: a core section extending in a waveguide direction of incident light; and a clad section extending in the waveguide direction and surrounding the core section, wherein the clad section includes a plurality of high rods which have a refractive index higher than that of a base material of the clad section, extend in the waveguide direction, and are arranged periodically in a cross section perpendicular to the waveguide direction, and a light loss region between mutually-facing end surfaces of the first and second fiber regions, for coupling a radiation mode with a waveguide mode in which light intensity is observed in the high refractive-index sections in the clad section.

Abstract: The present disclosure provides an approach to more efficiently amplify signals by matching either the gain materials or the pump profile with the signal profile for a higher-order mode (HOM) signal. By doing so, more efficient energy extraction is achieved.

Abstract: A large diameter fiber is composed of a multimode optical fiber and provided with a fiber body having a constant diameter in an optical axis direction XA and a tapered section tapered in diameter toward a light exit surface. An adhesive member attaches the large diameter fiber inside a retaining hole of a tubular housing such that an outer circumferential surface of a tapered clad of the tapered section is entirely exposed to air to a predetermined depth from the light exit surface. A light passing space is a ring-like space formed between the exposed outer circumferential surface of the tapered clad and an inner circumferential surface of the tubular housing. Light in the tapered section is output from the light exit surface and partially leaked to the tapered clad. A part of the leaked light is released from the light passing space.

Abstract: An optical fiber includes: a core (1) having an outer diameter (D1) of greater than or equal to 8.2 ?m and less than or equal to 10.2 ?m; a first cladding (2) surrounding the core (1) and having an outer diameter (D2) of greater than or equal to 30 ?m and less than or equal to 45 ?m; a second cladding (3) surrounding the first cladding (2) and having a thickness (T) of greater than or equal to 7.4 ?m; and a support layer (4) surrounding the second cladding (3). The relative refractive index difference which is the ratio of the difference between the refractive index of the support layer (4) and that of the second cladding (3) to the refractive index of the support layer (4) is greater than or equal to 0.5%.

Abstract: Multimode optical fibers with a large core diameter and high numerical aperture are disclosed herein. Multimode optical fibers disclosed herein comprise a core region having a radius greater than 30 microns and a cladding region surrounding and directly adjacent to the core region, the cladding region comprising a depressed-index annular portion comprising a depressed relative refractive index. The depressed cladding region is surrounded by a titania doped cladding region. The fiber has a total outer diameter of less than 120 microns, and exhibits an overfilled bandwidth at 850 nm greater than 200 MHz-km.

Abstract: The present invention embraces an optical fiber that includes a central core having a graded-index profile with respect to an outer cladding. The optical fiber also includes an inner cladding, a depressed trench, and an outer cladding. The optical fiber achieves reduced bending losses and a high bandwidth with a reduced cladding effect for high-data-rate applications.

Abstract: An optical fiber includes a cladding, a first core, and a second core. At least one of the first core and the second core is hollow and is substantially surrounded by the cladding. At least a portion of the first core is generally parallel to and spaced from at least a portion of the second core. The optical fiber includes a defect substantially surrounded by the cladding, the defect increasing a coupling coefficient between the first core and the second core.

Abstract: Disclosed is an improved, single-mode optical fiber possessing a novel coating system. When combined with a bend-insensitive glass fiber, the novel coating system according to the present invention yields an optical fiber having exceptionally low losses. The coating system features (i) a softer primary coating with excellent low-temperature characteristics to protect against microbending in any environment and in the toughest physical situations and, optionally, (ii) a colored secondary coating possessing enhanced color strength and vividness. The secondary coating provides improved ribbon characteristics for structures that are robust, yet easily entered (i.e., separated and stripped). The optional dual coating is specifically balanced for superior heat stripping in fiber ribbons, with virtually no residue left behind on the glass. This facilitates fast splicing and terminations.

Abstract: A structure for optical fiber with single layer coating suitable for field termination process is provided, including a glass core, a cladding layer, and a permanent coating protective layer. The thickness of the permanent coating ranges preferably from about 4 um to 8 um, and remains on the optical fiber during the field termination process to provide protection to the optical fiber after the buffer layer is striped off. In addition, the optical fiber structure of the present invention still conforms to the specification of the standard optical fiber. The optical fiber of the structure according to the present invention can simplify the field termination process so that the quality efficiency of the deployment is improved.

Abstract: 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.

Abstract: An optical fiber cable has a transparent core for transmitting optical data and a biodegradable protective covering. When placed in water, the protective covering dissolves in water after a few days. The raw remaining optical fiber cover is very thin, approximately 0.003 inches in diameter and very fragile. The optical core is easily broken into fine particles which becomes sand on the sea floor.

Abstract: An optic device includes a multilayer zone forming a redirection section for redirecting and transmitting photons through total internal reflection, each multilayer zone including a high index material having a first real refractive index n1 and a first absorption coefficient ?1, a low index material having a second real refractive index n2 and a second absorption coefficient ?2, and a grading zone disposed between the high index material and the low index material and including a grading layer having a third real refractive index n3 and a third absorption coefficient ?3, wherein n1>n3>n2.

Abstract: An ytterbium-doped optical fiber of the present invention includes: a core which contains ytterbium, aluminum, and phosphorus and does not contain germanium; and a cladding which surrounds this core. The ytterbium concentration in the core in terms of ytterbium oxide is 0.09 to 0.68 mole percent. The molar ratio between the phosphorus concentration in the core in terms of diphosphorus pentoxide and the above ytterbium concentration in terms of ytterbium oxide is 3 to 30. The molar ratio between the aluminum concentration in the core in terms of aluminum oxide and the above ytterbium concentration in terms of ytterbium oxide is 3 to 32. The molar ratio between the above aluminum concentration in terms of aluminum oxide and the above phosphorus concentration in terms of diphosphorus pentoxide is 1 to 2.5.

Abstract: 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.

Abstract: The present invention relates to an optical communications system that allows improving OSNR while suppressing the power increase of pumping light for distributed Raman amplification. In the optical communications system, an optical fiber is laid in a transmission section between a transmitter station (or repeater station) and a receiver station (or repeater station), and optical signals are transmitted from the transmitter station to the receiver station via the optical fiber. In the optical communications system, pumping light for Raman amplification, outputted by a pumping light source provided in the receiver station, is fed into the optical fiber via an optical coupler, and the optical signals are distributed-Raman-amplified in the optical fiber. The transmission loss and the effective area of the optical fiber satisfy, at the wavelength of 1550 nm, a predetermined relationship.

Abstract: 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.

Abstract: Described are multi-tube fabrication techniques for making 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.

Abstract: An optical fiber includes a center core portion; an inner core layer formed around an outer circumference of the center core portion, a refractive index of which is less than that of the center core portion; an outer core layer formed around an outer circumference of the inner core layer, a refractive index of which is less than that of the inner core layer; and a cladding portion formed around an outer circumference of the outer core layer. A refractive index of the cladding portion is substantially equal to that of the inner core layer. At a wavelength of 1550 nm, an effective core area is equal to or larger than 130 ?m2 and a bending loss is equal to or less than 100 dB/m when the optical fiber is bent with a diameter of 20 mm. A cable cut-off wavelength is equal to or less than 1530 nm.

Abstract: The specification describes an improved optical fiber produced by a hybrid VAD/MCVD process. The core of the fiber is produced using VAD and the inner cladding layer has a depressed index and is produced using MCVD. In preferred embodiments, the optical power envelope is essentially entirely contained in VAD produced core material and the MCVD produced depressed index cladding material. Optical loss is minimized by confining most of the optical power to the VAD core where OH presence is low, as well as by maximizing the optical power in the un-doped silica region. The MCVD substrate tube material is essentially devoid of optical power.

Abstract: According to some embodiments an optical waveguide fiber comprises: (i) a Ge free core having an effective area of 90 ?m2 to 160 ?m2, at a 1550 nm wavelength, and ? value 12???25, said core comprising: (a) a central core region extending radially outwardly from a centerline to a radius 0 ?m?r0?2 ?m, and having a relative refractive index percent profile ?0(r) in % measured relative to pure silica, wherein ?0.1%??0(r)?0.1%, wherein the central core region has a maximum relative refractive index percent, ?0MAX; (b) a first annular core region surrounding and directly adjacent to the central core region and extending to an outer radius r1, wherein 4.8 ?m?r1?10 ?m, and having a relative refractive index percent profile, ?1(r) in % measured relative to pure silica, and a minimum relative refractive index, ?2MIN, and the relative refractive index measured at a radius r=2.5 ?m being: ?0.15??1(r=2.5 ?m)?0, and ?0MAX??1(r=2.

Abstract: Each of a first clad region (12) and a second clad region (13) has holes (12a, 13a) which have identical diameters and are periodically formed so that the first clad region (12) and the second clad region (13) each have an effective refractive index lower than a refractive index of a core region (11), the effective refractive index of the first clad region (12) being lower than that of the second clad region (13).

Abstract: A fiber laser device includes a pumping light source configured to output pumping light having a wavelength ?, and a rare earth-doped fiber, wherein when the intensity change rate of the pumping light with respect to the temperature is denoted by ?P dB/° C., the wavelength change rate of the pumping light with respect to the temperature is denoted by ??p nm/° C., the pumping light absorption change rate of the rare earth-doped fiber per unit wavelength change at the wavelength of ? nm when the wavelength of the pumping light changes is denoted by A?(?) dB/nm, and the pumping light absorption change amount of the rare earth-doped fiber per unit temperature change at the wavelength of ? nm when the temperature of the rare earth-doped fiber changes is denoted by ?A(?) dB/° C., the wavelength ? of the pumping light is such a wavelength ? that ?P, ??p×A?(?) and ?A(?) compensate with each other.

Abstract: A single-mode optical fiber possesses, at a wavelength of 1550 nanometers, an effective area greater than about 90 pm2 without degradation of the optical fiber's other optical parameters. The single-mode optical fiber includes a central core, a first intermediate cladding, a second intermediate cladding, and an outer cladding. The optical fiber also has a cable cut-off wavelength of less than 1260 nanometers. Additionally, at a wavelength of 1310 nanometers, the optical fiber possesses a mode field diameter of between about 8.6 microns and 9.5 microns. Furthermore, the optical fiber possesses a zero chromatic dispersion wavelength of between about 1300 nanometers and 1324 nanometers and, at the zero chromatic dispersion wavelength, a dispersion slope of less than 0.092 ps/(nm2?km).

Abstract: An optical fiber that has a small bending loss can be securely prevented from being fractured due to accidental bending during installation or other operations. The optical fiber includes a core, a first cladding, a second cladding, and a third cladding. The relative refractive index difference ?1 of the core is in the range of 0.3% to 0.38%, the relative refractive index difference ?2 of the first cladding is equal to or smaller than 0%, and the relative refractive index difference ?3 of the second cladding is in the range of ?1.8% to ?0.5%. The inner radius r2 and the outer radius r3 of the second cladding satisfy the expression “0.4r2+10.5<r3<0.2r2+16”, and the inner radius r2 of the second cladding is equal to or greater than 8 ?m.

Abstract: The specification describes an improved optical fiber produced by a hybrid VAD/MCVD process. The core of the fiber is produced using VAD and the inner cladding layer has a depressed index and is produced using MCVD. In preferred embodiments, the optical power envelope is essentially entirely contained in VAD produced core material and the MCVD produced depressed index cladding material. Optical loss is minimized by confining most of the optical power to the VAD core where OH presence is low, as well as by maximizing the optical power in the un-doped silica region. The MCVD substrate tube material is essentially devoid of optical power.

Abstract: A microstructured fiber or photonic crystal fiber is described having a doped solid core region and a cladding region, holes being provided in the cladding region, the fiber having a low hybrid splice loss to conventional fiber as well as being able to be tightly bent due to the microstructured cladding. The cladding region can contain a plurality of holes surrounding and distanced from the core. These holes are preferably located symmetrically around the core and extend longitudinally along the length of fiber. The holes may be two or more D-shaped holes or truncated D-shaped holes arranged symmetrically around the care. In other embodiments, the holes comprise hole structures arranged symmetrically around the core in a ring. The holes may be arranged having the inner side facing the core formed from arcs of a circle, e.g. equal arcs of a circle. Between the arcs circular holes may be provided called capillaries, i.e. smaller holes.

Abstract: Various embodiments include large cores fibers that can propagate few modes or a single mode while introducing loss to higher order modes. Some of these fibers are holey fibers that comprising cladding features such as air-holes. Additional embodiments described herein include holey rods. The rods and fibers may be used in many optical systems including optical amplification systems, lasers, short pulse generators, Q-switched lasers, etc. and may be used for example for micromachining.

Abstract: A high confinement nonlinear optical fiber is provided along with methods of parametric amplification for use thereof. The nonlinear optical fiber may include a plurality of concentric layers which are configured to provide different guiding regimes to low-frequency and high-frequency components through transverse geometry and refractive index profiling, thus reducing waveguide dispersion. The resulting optical fiber provides a parametric device with phase-matching in any spectral region of interest, such that a fiber optic parametric amplifier (FOPA) implementing the optical fiber can amplify in any spectral window of interest. A narrow-band FOPA configured to minimize phase mismatching is also provided for use with the optical fiber, and may be implemented as a light source or a monochromator.

Abstract: Optical fiber apparatus having a wavelength of operation, that comprises an optical fiber including a core comprising an active material for providing light having the operating wavelength responsive to the optical apparatus receiving pump optical energy having a pump wavelength; a cladding disposed about the core; at least one region spaced from the core; and wherein the optical fiber is configured and arranged such that at the wavelength of operation the optical fiber can propagate a plurality of modes and wherein the optical fiber comprises a fundamental mode that is primarily a mode of the core and at least one higher order mode (HOM) that is a mixed mode of a selected mode of the core and of a selected mode of the at least one region.

Abstract: Various embodiments include photonic bandgap fibers (PBGF). Some PBGF embodiments have a hollow core (HC) and may have a square lattice (SQL). In various embodiments, SQL PBGF can have a cladding region including 2-10 layers of air-holes. In various embodiments, an HC SQL PBGF can be configured to provide a relative wavelength transmission window ??/?c larger than about 0.35 and a minimum transmission loss in a range from about 70 dB/km to about 0.1 dB/km. In some embodiments, the HC SQL PBGF can be a polarization maintaining fiber. Methods of fabricating PBGF are also disclosed along with some examples of fabricated fibers. Various applications of PBGF are also described.

Abstract: The multicore fiber comprises 7 or more cores, wherein diameters of the adjacent cores differ from one another, wherein each of the cores performs single-mode propagation, wherein a relative refractive index difference of each of the cores is less than 1.4%, wherein a distance between the adjacent cores is less than 50 ?m, wherein, in a case where a transmission wavelength of each of the cores is ?, the distance between the adjacent cores is , a mode field diameter of each of the cores is MFD, and a theoretical cutoff wavelength of each of the cores is ?c, (/MFD)·(2?c/(?c+?))?3.95 is satisfied, and wherein a distance between the outer circumference of the coreand an outer circumference of the clad is 2.5 or higher times as long as the mode field diameter of each of the cores.

Abstract: Various types of holey fiber provide optical propagation. In various embodiments, for example, a large core holey fiber comprises a cladding region formed by large holes arranged in few layers. The number of layers or rows of holes about the large core can be used to coarse tune the leakage losses of the fundamental and higher modes of a signal, thereby allowing the non-fundamental modes to be substantially eliminated by leakage over a given length of fiber. Fine tuning of leakage losses can be performed by adjusting the hole dimension and/or the hole spacing to yield a desired operation with a desired leakage loss of the fundamental mode. Resulting holely fibers have a large hole dimension and spacing, and thus a large core, when compared to traditional fibers and conventional fibers that propagate a single mode. Other loss mechanisms, such as bend loss and modal spacing can be utilized for selected modes of operation of holey fibers. Other embodiments are also provided.

Abstract: An embodiment of an apparatus includes an optical fiber for which a complete orthogonal basis of propagating modes at an optical telecommunication frequency includes ones of the propagating modes with different angular momenta. The optical fiber has a tubular optical core and an outer optical cladding in contact with and surrounding the tubular optical core. The tubular optical core has a larger refractive index than the optical cladding. The tubular optical core is configured such that those of the propagating modes whose angular momenta have the lowest magnitude for the propagating modes have substantially the same radial intensity profile.

Abstract: The present invention embraces an optical fiber that includes a central core having an alpha refractive index profile with respect to an outer cladding. The optical fiber also includes an inner cladding, a depressed trench, and an outer cladding. The optical fiber achieves reduced bending losses and a high bandwidth with a reduced cladding effect for high-data-rate applications.

Abstract: An in-line optical device adapted to be bonded in between ends of an optical fiber line is disclosed. The in-line optical device has an inner optical field interaction region, an outer support structure, and at least one radial opening. In some embodiments, a void region substantially surrounds the inner optical field interaction region. Systems including the in-line optical device and methods of making and using the in-line optical device are provided. Numerous other aspects are provided.

Abstract: A method for manufacturing an optical fiber preform includes the steps of depositing an inner cladding and a central core inside a fluorine doped silica tube and thereafter collapsing the silica tube to form a primary preform. The fluorine doped silica tube has a cross section area that is no more than about 15 percent smaller than the cross section area of the resulting primary preform. The present method facilitates reduced-cost manufacturing of a high-capacity optical fiber preform, which may be drawn to produce an optical fiber having reduced transmission losses.

Abstract: Disclosed is an amplifying optical fiber having a central core and an optical cladding surrounding the central core. The central core is based on a silica matrix that includes nanoparticles, which are composed of a matrix material that includes doping ions of at least one rare earth element. The amplifying optical fiber can be employed, for example, in an optical amplifier and an optical laser.

Abstract: An optical fiber that has a small bending loss can be securely prevented from being fractured due to accidental bending during installation or other operations, and is compliant with the G. 652 standard. The optical fiber includes a core, a first cladding, a second cladding and a third cladding. The relative refractive index difference ?1 of the core is in the range of 0.3% to 0.38%, the relative refractive index difference ?2 of the first cladding is equal to or smaller than 0%, and the relative refractive index difference ?3 of the second cladding is in the range of ?1.8% to ?0.5%. The inner radius r2 and the outer radius r3 of the second cladding satisfy the expression “0.4r2+10.5<r3<0.2r2+16”, and the inner radius r2 of the second cladding is equal to or greater than 8 ?m.

Abstract: The present invention relates to an optical fiber comprising at least a first end with an first end facet, the optical fiber comprising a core region capable of guiding light at a first wavelength ?; and a microstructured cladding region surrounding said core region. The cladding region comprises an inner cladding region and an outer cladding region. The inner cladding region comprises inner cladding features arranged in an inner cladding background material having a refractive index n1, said inner cladding features comprising thermally collapsible holes or voids. The outer cladding region comprising outer cladding features arranged in an outer cladding background material, said outer cladding features comprising solid material with refractive index n2, wherein n2 is lower than n1. The invention further relates to methods for splicing such an optical fiber to an optical component and to methods for using such an optical fiber.

Abstract: Optical fiber lasers and components for optical fiber laser. An optical fiber laser can comprise a fiber laser cavity having a wavelength of operation at which the cavity provides output light, the cavity including optical fiber that guides light having the wavelength of operation, the fiber having first and second lengths, the first length having a core having a V-number at the wavelength of operation and a numerical aperture, the second length having a core that is multimode at the wavelength of operation and that has a V-number that is greater than the V-number of the core of the first length optical fiber at the wavelength of operation and a numerical aperture that is less than the numerical aperture of the core of the first length of optical fiber. At least one of the lengths comprises an active material that can provide light having the wavelength of operation via stimulated emission responsive to the optical fiber receiving pump light.

Abstract: Optical waveguide fiber that has large effective area and low loss characteristics, such as low attenuation and low bend loss. The optical waveguide fiber includes a dual trench design wherein an annular region closer to the core is preferably doped with at least one downdopant such as fluorine, which annular region is surrounded by another annular region that preferably includes closed, randomly dispersed voids.

Abstract: Various embodiments described herein include rare earth doped glass compositions that may be used in optical fiber and rods having large core sizes. Such optical fibers and rods may be employed in fiber lasers and amplifiers. The index of refraction of the glass may be substantially uniform and may be close to that of silica in some embodiments. Possible advantages to such features include reduction of formation of additional waveguides within the core, which becomes increasingly a problem with larger core sizes.

Abstract: Multi-clad optical fibers and fiber amplifiers are disclosed. Various embodiments include multi-clad, large core fiber amplifiers. In various implementations mixing of pump modes is enhanced relative to that obtainable with conventional double-clad fibers. In some embodiments end terminations are provided with increased length of end-cap fiber. In at least one embodiment a multi-clad fiber is provided, with a pump cladding formed by stacking a layer of low index rods in the preform. Various embodiments include a multi-clad fiber amplifier system. The system includes a pump source to pump said fiber amplifier. The system also includes an optical fiber having a core and a cladding, wherein the cladding includes a pump cladding having a corrugated boundary. In various embodiments the pump cladding is formed by rods in a preform, which are disposed to mix the pump modes and/or scatter or reflect pump energy into the core.

Abstract: A silica-based multi core optical fiber and a fabrication method for the same are provided, and include two or more cores of GeO2—SiO2 glass including an fluorine concentration not less than about 15 w % and a germanium concentration about 0.05 wt % to 2 wt %, in a core. A relative refractive index difference of a cladding and a core is not less than about 3%; and a ratio of a cladding diameter to a core diameter is about 1.02 to 3.0. A silica-based single core optical fiber is also provided, and includes a core having a germanium concentration not less than about 15 wt % and an fluorine concentration about 0.05 wt % to 2 wt %.

Abstract: A silica-based multi core optical fiber and a fabrication method for the same are provided, and include two or more cores of GeO2—SiO2 glass including an fluorine concentration not less than about 15 w % and a germanium concentration about 0.05 wt % to 2 wt %, in a core. A relative refractive index difference of a cladding and a core is not less than about 3%; and a ratio of a cladding diameter to a core diameter is about 1.02 to 3.0. A silica-based single core optical fiber is also provided, and includes a core having a germanium concentration not less than about 15 wt % and an fluorine concentration about 0.05 wt % to 2 wt %.

Abstract: Optical apparatus, comprising an optical fiber having a wavelength of operation, the optical fiber comprising an inner core, the inner core supporting a fundamental mode and at least first and second higher order modes (HOMs) at the wavelength of operation; a first ring-shaped core region spaced from and disposed about the inner core; a second ring-shaped core region spaced from and disposed about the ring-shaped core region; and wherein the optical fiber is configured and arranged such that the first HOM optically interacts with the first ring-shaped core region and the second HOM optically interacts with the second ring-shaped core region.

Abstract: A single mode fiber having a core, an inner cladding, a depressed cladding, and an outer cladding composed of pure silica glass. The core is surrounded in sequence with the inner cladding and the depressed cladding. The core has silica glass doped with germanium and fluorine, with a diameter (a) of 8.0-8.8 ?m, a relative refractive index difference (?1) of 0.35-0.38%, and the contribution of fluoride (?F) is ?0.09±0.02%. The inner cladding has silica glass doped with germanium and fluorine, with a diameter (b) of 18-21 ?m and a relative refractive index difference (?2) of 0±0.02%. The depressed cladding has silica glass doped with fluorine, with a diameter (c) of 26-36 ?m and a relative refractive index difference (?32) at the external interface thereof is between ?0.22 and ?0.35%, and a relative refractive index difference (?31) at the internal interface thereof is between ?0.20 and ?0.35%, and ?32??31.

Abstract: A plastic glass optical fiber includes a glass core (diameter a1, relative refractive index difference ?1, and refractive index n1), a polymer core (diameter a2, relative refractive index difference ?2, and refractive index n2), and a polymer cladding (refractive index n3), in which the diameter a1 of the glass core is within a range of 110 ?m to 200 ?m, a parameter X (X is a22/a12) is within a range of 1.15?X?2.9, a parameter Y (Y is ?2/?1) is within a range of 0.25?Y?0.84X?0.68 (when 1.15?X?2) or 0.48X?0.71?Y??(2/9)X+13/9 (when 2?X?2.9), a parameter ZR (ZR is Z2core/Z1core; Z2core=a22?/4×?(n12?n32) and Z1core=a12?/4×?(n12?n22)) is within a range of 1.25?ZR?4.

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.

Abstract: Apparatus and method are provided for transmitting at least one electro-magnetic radiation is provided. In particular, at least one optical fiber having at least one end extending along a first axis may be provided. Further, a light transmissive optical arrangement may be provided in optical cooperation with the optical fiber. The optical arrangement may have a first surface having a portion that is perpendicular to a second axis, and a second surface which includes a curved portion. The first axis can be provided at a particular angle that is more than 0° and less than 90° with respect to the second axis.