Disclosed is an optical transmission fiber having reduced bending and microbending losses that is commercially usable in FTTH or FTTC transmission systems.

Single mode optical fiber

The present invention embraces a single-mode optical fiber that, at a wavelength of 1550 nanometers, has bending losses of 0.15 dB/turn or less for a radius of curvature of 5 millimeters.

Bend-insensitive single-mode optical fiber

The present invention relates to a multi-core optical fiber having a structure to effectively reduce crosstalk between adjacent core regions among a plurality of core regions. The multi-core optical fiber (1) has a leakage reduction portion (50), at least a portion of which is arranged at a position on a straight line connecting adjacent core regions together among a plurality of core regions (10). The leakage reduction portion (50) reduces leakage light in the multi-core optical fiber (1) from each of the core regions (10), thereby effectively reducing crosstalk between adjacent core regions.

Multi-core optical fiber

The present invention embraces a multimode optical fiber that includes a central core having an alpha-index profile, an inner cladding, a depressed trench, and an outer cladding (e.g., an outer optical cladding). Typically, the central core's alpha-index profile has a minimum refractive index at the central core's radius that corresponds to a refractive index difference with respect to the outer cladding. The optical fiber achieves reduced bending losses and a high bandwidth with a reduced cladding effect for high-data-rate applications.

High-Bandwidth Multimode Optical Fiber Having Reduced Bending Losses

An optical fiber according to an embodiment of the present invention comprises: a glass core extending from a centerline to a radius R1 wherein R1 is greater than about 5 µm; a glass cladding surrounding and in contact with the core, the cladding comprising: (i) a first annular region extending from the radius R1 to a radius R2 the first annular region comprising a radial width, W2 = R2 - R1, (ii) a second annular region extending from the radius R2 to a radius R3, and comprising a radial width, W3 = R3 - R2, and (iii) a third annular region surrounding the second annular region and extending from the radius R3 to an outermost glass radius R4; wherein the core comprises a maximum relative refractive index, Δ1max, relative to the third annular region, and wherein Δ1MAX is greater than about 0.1 % and less than about 0.3 %; the first annular region has a refractive index delta Δ2(r) is less than about 0.025%; wherein the second annular region comprises a minimum relative refractive index, Δ3MIN, relative to the third annular region; wherein Δ1MAX > Δ2MAX > Δ3MIN, and Δ2MIN > Δ3MIN<0; and wherein the core and the cladding provide a fiber with cable cutoff less than 1500 nm, and an effective area at 1550 nm greater than 95 µm2 and bend loss of =≤0.5 dB/turn on a 20 mm diameter mandrel.

Large effective area fiber

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. The improved coating system provides optical fibers that offer significant advantages for deployment in most, if not all, fiber-to-the-premises (FTTx) systems.

Microbend-Resistant Optical Fiber

A multimode optical fiber has an equivalent modal dispersion value (DMD inner&outer ) of less than 0.11 ps/m for (Δλ max ×D)>0.07 ps/m as measured on a modified DMD graph. The modified DMD graph accounts for chromatic dispersion to ensure that the multimode optical fiber has a calculated effective bandwidth EBc greater than 6000 MHz-km when used with multimode transverse sources.

Multimode optical fibers

A dispersion-shifted optical fiber (NZDSF) includes a central core (r 1 , Dn 1 ), an inner cladding having at least three zones with a first intermediate cladding zone (r 2 , Dn 2 ), a second ring zone (r 3 , Dn 3 ) and a third buried trench zone (W tr , Dn t ) The buried trench zone has an index difference (Dn t ) with the optical cladding between −5·10 −3 and −15·10 −3 and has a width (W tr ) between 25 μm and 55 μm The present optical fiber, at a wavelength of 1550 nm, has reduced Rayleigh scattering losses of less than 0164 dB/km, with limited bending losses

Dispersion shifted optical fiber

A multimode optical fiber includes a central core having a graded-index profile with a delta value of about 1.9 percent or greater. The graded-index core profile has at least two different alpha parameter values along the core radius, namely a first value in an inner zone of the central core and a second value in an outer zone of the central core. The second alpha parameter value is typically less than the first alpha parameter value. The graded-index core profile and its first derivative are typically substantially continuous over the width of the graded-index core.

Multimode Optical Fiber

The present invention relates to a transmission optical fiber. The optical fiber includes, from its center to its periphery a central core, an intermediate cladding, and a depressed cladding. The optical fiber has an effective area (S eff ) of at least about 120 μm 2 at a wavelength of 1550 nm and an effective cutoff wavelength (λ Ceff ) of less than 1600 nm. The optical fiber has an effective area of more than 120 μm 2 with a cutoff wavelength limited to less than about 1600 nm without degradation of other optical parameters (e.g., attenuation losses and dispersion).

Pierre Sillard

Papers

Microbend-Resistant Optical Fiber

Multimode optical fibers

Dispersion shifted optical fiber

Multimode Optical Fiber

Transmission optical fiber having large effective area