It is an object of the present invention to provide a multicore optical fiber, a design method for the multicore optical fiber and an optical transmission method using the multicore optical fiber including four cores having a standard cladding diameter of 125±1 μm for an existing single mode optical fiber covering several thousands of kilometers of transmission. The multicore optical fiber according to the present invention disposes two-stage claddings with different refractive indices around each core, and designates as a predetermined range, a core radius a1, a radius a2 of a first cladding region surrounding each core, specific refractive index Δ1 relative to the core of the first cladding region and a specific refractive index Δ2 relative to the core of a second cladding region including four cores and the first cladding region.

An optical fiber is provided that includes a core region, a cladding region having a radius less than about 62.5 microns; a polymer coating comprising a high-modulus layer and a low-modulus layer, wherein a thickness of the low-modulus inner coating layer is in a range of 4 microns to 20 microns, the modulus of the low-modulus inner coating layer is less than or equal to about 0.35 MPa, a thickness of the high-modulus coating layer is in a range of 4 microns to 20 microns, the modulus of the high-modulus inner coating layer is greater than or equal to about 1.6 GPa, and wherein a puncture resistance of the optical fiber is greater than 20 g, and wherein a microbend attenuation penalty of the optical fiber is less than 0.03 dB/km, and wherein an outer diameter of the coated optical fiber is less than or equal to 175 microns.

The disclosure provides optical fibers that exhibit low macrobend loss at 1550 nm at bend diameters between 10 mm and 40 mm. The relative refractive index profile of the fibers includes a trench cladding region with small depth, large width and a trench volume configured to minimize macrobend loss at large and small bend diameters. The optical fiber includes an outer cladding region that surrounds and is directly adjacent to the trench cladding region and an optional offset cladding region between the trench cladding region and the core region. In some embodiments, the trench cladding region has a relative refractive index that decreases monotonically from the inner radius to the outer radius. The monotonic decrease in relative refractive index may have a constant slope. The low macrobend loss at large and small diameters makes the optical fibers well suited for space-constrained deployment environments, such as data centers.

A single mode optical fiber including a core region doped with an alkali metal. The optical fiber has a total attenuation at 1550 nm of about 0.155 dB/km or less such that extrinsic absorption in the optical fiber contributes to 0.004 dB/km or less of the total attenuation

An optical fiber is provided that includes a core region, a cladding region having a radius less than about 62.5 microns; a polymer coating comprising a high-modulus layer and a low-modulus layer, wherein a thickness of the low-modulus inner coating layer is in a range of 4 microns to 20 microns, the modulus of the low-modulus inner coating layer is less than or equal to about 0.35 MPa, a thickness of the high-modulus coating layer is in a range of 4 microns to 20 microns, the modulus of the high-modulus inner coating layer is greater than or equal to about 1.6 GPa, and wherein a puncture resistance of the optical fiber is greater than 20 g, and wherein a microbend attenuation penalty of the optical fiber is less than 0.03 dB/km, and wherein an outer diameter of the coated optical fiber is less than or equal to 175 microns

The present disclosure provides an optical fiber (100). The optical fiber (100) includes a core region (102). The core region (102) is defined by a region around central longitudinal axis (112) of the optical fiber (100). In addition, the core region (100) has a first annular region (106). The first annular region (106) is defined from the central longitudinal axis (112) to a first radius from the central longitudinal axis. Moreover, the core region (102) has a second annular region (108). The second annular region (108) is defined from the first radius to a second radius. Further, the core region (102) has a third annular region (110). The third annular region (110) is defined from the second radius to a third radius. Also, the optical fiber (100) includes a cladding (104). The cladding region (104) has a fourth radius.

An optical fiber includes a core and a cladding. The core contains silica glass and includes a central portion (part having a diameter of 0.5 μm or more and 4 μm or less). The central portion has the central axis of the optical fiber. The cladding contains silica glass and surrounds the core. The core contains chlorine. A chlorine concentration averaged in the entire core is 10,000 ppm or more and 50,000 ppm or less. The chlorine concentration averaged in the entire core minus a chlorine concentration averaged in the central portion is 4,500 ppm or more and 13,500 ppm or less.

An object is to obtain an optical fiber having a small diameter and suppressing the increase of a microbending loss of the optical fiber. The optical fiber includes: a core portion made of silica glass; a cladding portion made of silica glass, the cladding portion covering the outer periphery of the core portion and having a refractive index smaller than a maximum refractive index of the core portion; and a coating portion covering the outer periphery of the cladding portion. The outer diameter of the cladding portion is 100 μm or smaller, the relative refractive-index difference Δ1 of the core portion is 0.5% or smaller, and the thickness of the coating portion is 10 μm or larger.

In some embodiments, a data center optical communications system includes: a transmitter comprising a light source, wherein the light source is configured to provide light; an optical fiber operably connected to said transmitter and configured to receive light from the light source, wherein the optical fiber has a length L of 50 km or greater; a receiver configured to receive light from the optical fiber, wherein the receiver includes a detector for detecting the light, wherein the system has a power consumption of 15 W or less

An optical fiber is provided that includes a core region and a cladding region. The core region is formed of silica glass doped with chlorine and/or an alkali metal. The cladding region surrounds the core region and includes an inner cladding directly adjacent to the core region, an outer cladding surrounding the inner cladding, and a trench region disposed between the inner cladding and the outer cladding in a radial direction. The trench region has a volume of about 30% Δ-micron.sup.2 or greater. Additionally, the optical fiber has an effective area at 1550 nm of about 100 micron.sup.2 or less.