A multi-core fiber (23) connects an optical transmitter device (10) and an optical receiver device (30) to each other. The multi-core fiber (23) includes cores each having a wavelength dispersion characteristic different from a wavelength dispersion characteristic of another adjacent core of the cores. In an optical transport system (100), the optical transmitter device (10) and the optical receiver device (30) are connected in series by the plurality of multi-core fibers (23).

A multicore optical fiber comprises a common cladding and a plurality of core portions disposed in the common cladding. Each of the core portions includes a central axis, a core region extending from the central axis to a radius r.sub.1, the core region comprising a relative refractive index Δ.sub.1, an inner cladding region extending from the radius r.sub.1 to a radius r.sub.2, the inner cladding region comprising a relative refractive index Δ.sub.2, and a depressed cladding extending from the radius r.sub.2 to a radius r.sub.3, the depressed cladding region comprising a relative refractive index Δ.sub.3 and a minimum relative refractive index Δ.sub.3 min. The relative refractive indexes may satisfy Δ.sub.1>Δ.sub.2>Δ.sub.3 min. The mode field diameter of each core portion may greater than or equal to 8.2 μm and less than or equal to 9.5 μm.

An optical fiber includes: a central core portion; an intermediate layer; a trench layer; and a cladding portion. Further, Δ1>Δ2>Δ3 and 0>Δ3 are satisfied, where Δ1 is a relative refractive-index difference of the central core portion, Δ2 is a relative refractive-index difference of the intermediate layer, and Δ3 is a relative refractive-index difference of the trench layer with respect to the cladding portion, respectively, and (c−b) is smaller than 4.5 μm when Δ1 is equal to or larger than 0.36% and equal to or smaller than 0.40%, Δ2 is equal to or larger than −0.05% and equal to or smaller than 0.05%, |Δ3| is equal to or smaller than 0.25%, Δ1×|Δ3| is equal to or smaller than 0.08%.sup.2, an inner diameter of the trench layer is 2b, and an outer diameter of the trench layer is 2c.

A single mode optical fiber is provided that includes a core region having an outer radius r.sub.1 and a maximum relative refractive index Δ1.sub.max. The single mode optical fiber has a bend loss at 1550 nm for a 15 mm diameter mandrel of less than about 0.75 dB/turn, has a bend loss at 1550 nm for a 20 mm diameter mandrel of less than about 0.2 dB/turn, and a bend loss at 1550 nm for a 30 mm diameter mandrel of less than 0.002 dB/turn. Additionally, the single mode optical fiber has a mode field diameter of 9.0 microns or greater at 1310 nm wavelength and a cable cutoff of less than or equal to about 1260 nm.

The invention relates to a supercontinuum light source comprising a microstructured optical fiber and a pump light source. The microstructured optical fiber comprises a core and a cladding region surrounding the core, as well as a first fiber length section, a second fiber length section and an intermediate fiber length section between said first and second fiber length sections. The first fiber length section comprises a core with a first characteristic core diameter. The second fiber length section comprises a core with a second characteristic core diameter, smaller than said first characteristic core diameter, where said second characteristic core diameter is substantially constant along said second fiber length section. The intermediate length section of the optical fiber comprises a core which is tapered from said first characteristic core diameter to said second characteristic core diameter over a tapered length.

The present disclosure provides an optical fibre (100). The optical fibre (100) includes a glass core (102), a trench region (106) and a cladding (108). The trench region (106) has a trench curve parameter α.sub.trench in range of 5 to 8. The optical fibre (100) has a mode field diameter in range of 8.7 micrometers to 9.7 micrometers at wavelength of 1310 nanometer.

An optical fiber includes: a core portion made of glass; and a cladding portion made of glass, having a refractive index lower than the refractive index of the core portion, and positioned on an outer periphery of the core portion. Further, the cladding portion has an outer diameter smaller than 100 μm, and the core portion has a relative refractive-index difference of 0.32% to 0.40% with respect to the cladding portion.

A method for determining if a graded-index glass optical multimode fiber has a refractive index profile that will compensate modal dispersion with chromatic dispersion when used in an optical channel having a multimode vertical cavity surface emitting laser has at least two weighting functions. The functions are used to compute the relative mode group delays over two radial offset regions within the core of the optical fiber. The peak group delay of the of the higher-order fiber mode distribution is less than the peak group delay of the lower-order mode distribution.

A low-dispersion single-mode fiber includes a core and claddings covering the core. The core layer has a radius in a range of 3-5 μm and a relative refractive index difference in a range of 0.15% to 0.45%. The claddings comprise a first depressed cladding, a raised cladding, a second depressed cladding, and an outer cladding arranged sequentially from inside to outside. The first depressed cladding has a unilateral width in a range of 2-7 μm and a relative refractive index difference in a range of −0.4% to 0.03%. The raised cladding has a unilateral width in a range of 2-7 μm and a relative refractive index difference in a range of 0.05% to 0.20%. The second depressed cladding has a unilateral width in a range of 0-8 μm and a relative refractive index difference in a range of 0% to −0.2%. The outer cladding is formed of pure silicon dioxide glass.

An optical fiber includes a glass portion, a primary coating layer, and a secondary coating layer. In the optical fiber, a value of microbend loss characteristic factor F.sub.μBL_GΔβ is 6.1 ([GPa.sup.−1.Math.μm.sup.−2.5/rad.sup.8].Math.10.sup.−12) or less when represented by
F.sub.μBL_GΔβ=F.sub.μBL_G×F.sub.μBL_Δβ,
where F.sub.μBL_G is geometry microbend loss characteristic and F.sub.μBL_Δβ is optical microbend loss characteristic.