Single mode optical fiber with ultralow loss and large effective area and manufacturing method thereof

Abstract

The invention discloses a single mode optical fiber with ultralow loss and a large effective area and a manufacturing method thereof. A bare optical fiber of the single mode optical fiber comprises acore layer and a cladding layer from inside to outside in sequence, the core layer comprises an inner core layer and an outer core layer which are arranged from inside to outside in sequence, the radius R1 of the inner core layer is 1.5-3 microns, the relative refractive index difference delta 1 of the inner core layer is greater than or equal to 0.01% and less than or equal to 0, the radius R2 ofthe outer core layer is 5-6 microns, and the relative refractive index difference delta 2 of the outer core layer is greater than or equal to 0 and less than or equal to 0.05%. The core layer is hardly doped with germanium and is a silicon glass layer doped with fluorine and an alkali metal oxide; the cladding layer includes a depressed cladding layer and an outer cladding layer which are arranged from inside to outside in sequence, the radius R3 of the depressed cladding layer is 40-50 microns, the relative refractive index difference delta 3 of the depressed cladding layer is greater than or equal to -0.25% and less than or equal to -0.15%, the ratio R3 / R2 of the radius R3 of the depressed cladding layer to the radius R2 of the outer core layer is greater than or equal to 8, the radiusR4 of the outer cladding layer is 62.5 microns, and the outer cladding layer is a pure silica glass layer. According to the single mode optical fiber with ultralow loss and the large effective area and the manufacturing method thereof, attenuation coefficients can be reduced, and the effective area is increased.

Description

technical field [0001] The invention relates to the field of optical fibers, in particular to an ultra-low loss large effective area single-mode optical fiber and a manufacturing method thereof. Background technique [0002] With the emergence of coherent transmission technology, in the field of optical fiber transmission, some important indicators that originally limited long-distance, large-capacity and high-speed transmission are no longer the main limiting factors. In the future transmission system, the indicators of dispersion and polarization mode dispersion will be further relaxed. However, the growth of transmission capacity and distance requires higher fiber input power and lower fiber loss to meet the requirement of resolvable signal-to-noise ratio. With the increase of fiber power, nonlinear effects such as phase modulation, cross-phase modulation, and four-wave mixing will inevitably occur in the fiber core layer, especially the stimulated Brillouin scattering e...

AI Technical Summary

Problems solved by technology

Therefore, in the actual drawing process, the high-temperature viscosity matching of the optical fiber material components leads to incomplete optical fiber structure, which seriously affects the reduction of optical fiber transmission loss, and it is difficult to realize the manufacture of low-loss optical fibers; on the other hand, the high-temperature viscosity mismatch is due to The core material has different characteristic temperatures such as glass softening temperature. During the wire drawing process, different specific temperatures of the core will cause a large residual stress in the optical fiber

This not only destroys the designed waveguide structure, but also affects the strength and service life of the fiber

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