An optical fiber production method includes: drawing an optical fiber from an optical fiber preform; and cooling the optical fiber. When in the cooling process, the optical fiber is passed through a plurality of annealing furnaces and Equation (1) is held. A time constant of relaxation of a structure of glass forming a core in the optical fiber is (T.sub.n). A temperature of the optical fiber at a point in time when the optical fiber is delivered into an nth annealing furnace from an upstream side is T.sub.n. A fictive temperature of glass forming the core at the point in time when the optical fiber is delivered is T.sub.fn. A fictive temperature of glass forming the core after a lapse of time t from the point in time when the optical fiber is delivered is T.sub.f.
20 C.<T.sub.fT.sub.n=(T.sub.fnT.sub.n)exp(t/(T.sub.n))<100 C.(1)

An optical fiber production method includes: drawing an optical fiber from an optical fiber preform; and cooling the optical fiber. When in the cooling process, the optical fiber is passed through a plurality of annealing furnaces and Equation (1) is held. A time constant of relaxation of a structure of glass forming a core in the optical fiber is (T.sub.n). A temperature of the optical fiber at a point in time when the optical fiber is delivered into an nth annealing furnace from an upstream side is T.sub.n. A fictive temperature of glass forming the core at the point in time when the optical fiber is delivered is T.sub.fn. A fictive temperature of glass forming the core after a lapse of time t from the point in time when the optical fiber is delivered is T.sub.f.
20 C.<T.sub.fT.sub.n=(T.sub.fnT.sub.n)exp(t/(T.sub.n))<100 C.(1)

A diselenide protective film, a method of using the diselenide protective film, and a method of making the diselenide protective film are provided. The diselenide protective film includes at least one of three novel diselenide organic polymer structures, and the film provides protection against corrosion of metals such as steel. The method of making the diselenide protective film comprising at least one of three novel diselenide organic polymer structures includes reacting a diselenide-based diamine with one of a diisocyanate, a diisocyanate and phosgene, or a diisocyanate, epichlorohydrin and potassium hydroxide.

A diselenide protective film, a method of using the diselenide protective film, and a method of making the diselenide protective film are provided. The diselenide protective film includes at least one of three novel diselenide organic polymer structures, and the film provides protection against corrosion of metals such as steel. The method of making the diselenide protective film comprising at least one of three novel diselenide organic polymer structures includes reacting a diselenide-based diamine with one of a diisocyanate, a diisocyanate and phosgene, or a diisocyanate, epichlorohydrin and potassium hydroxide.

The glass-fiber-yarn joined body 1 is provided with glass fiber yarns 2, 3, and a connection 5 in which a resin yarn 4 is wound around ends of both of the glass fiber yarns 2, 3, the ends being superimposed with each other. The connection 5 has a width W.sub.1 of 20 to 40 mm. When a connection diameter R as a total of diameters of the respective glass fiber yarns 2, 3 and the thickness of the resin yarn 4 wound around the connection 5 is 500 to 5000 m and a mass of each of the glass fiber yarns 2, 3 is 200 to 6000 tex, a value of a ratio of mass of each of the glass fiber yarns 2, 3 relative to the connection diameter R is in the range of 0.32 to 2.00.

The glass-fiber-yarn joined body 1 is provided with glass fiber yarns 2, 3, and a connection 5 in which a resin yarn 4 is wound around ends of both of the glass fiber yarns 2, 3, the ends being superimposed with each other. The connection 5 has a width W.sub.1 of 20 to 40 mm. When a connection diameter R as a total of diameters of the respective glass fiber yarns 2, 3 and the thickness of the resin yarn 4 wound around the connection 5 is 500 to 5000 m and a mass of each of the glass fiber yarns 2, 3 is 200 to 6000 tex, a value of a ratio of mass of each of the glass fiber yarns 2, 3 relative to the connection diameter R is in the range of 0.32 to 2.00.

Methods, apparatuses and systems of manufacturing an optical fiber are disclosed herein. The methods may include heating an optical preform in a draw furnace, drawing an optical fiber from the optical preform, cooling the optical fiber with a slow cooling device, and annealing the optical fiber by passing the optical fiber through an RF plasma heating apparatus.

Methods, apparatuses and systems of manufacturing an optical fiber are disclosed herein. The methods may include heating an optical preform in a draw furnace, drawing an optical fiber from the optical preform, cooling the optical fiber with a slow cooling device, and annealing the optical fiber by passing the optical fiber through an RF plasma heating apparatus.

The present invention discloses a method for preparing all-solid-state photonic crystal fiber preform by extrusion. Firstly, aligning the center of the first jacking end of the first jacking rod with the center of the core outlet mold. The adverse effect on this part of extruded core glass by oxygen or other impurities in air during the extrusion out of the core outlets can be avoided. The defects on the core glass surface and the cladding glass surface can be effectively removed, and the purity and quality of the core component in the obtained fiber preform can be improved.

The present invention discloses a method for preparing all-solid-state photonic crystal fiber preform by extrusion. Firstly, aligning the center of the first jacking end of the first jacking rod with the center of the core outlet mold. The adverse effect on this part of extruded core glass by oxygen or other impurities in air during the extrusion out of the core outlets can be avoided. The defects on the core glass surface and the cladding glass surface can be effectively removed, and the purity and quality of the core component in the obtained fiber preform can be improved.