The invention relates to a method for producing glass fibers that laterally emit light and to glass fibers produced according to said method. The problem of providing a method that relies on standard available glass components, thus making possible an economical production method that allows a glass fiber to be produced which emits laterally and, in an optically active manner, spectrally shifts, scatters and/or filters light coupled into the fiber when said light exits through the fiber cladding, is solved in that, first, glass tubes (7) and glass rods (5) of identical chemical composition and identical optical refractive index are selected, then first the glass rod (5) is coated completely or over parts of its outer periphery with a vitrifiable material mixture containing optically active substances, in the liquid phase, and the glass rod (5) coated in such a way with this coating (6) after said coating has been dried or consolidated is brought into the glass tube (7) and both are jointly drawn, under the application of heat, to form a glass fiber in a known way.

A method for drawing an optical fibre from an optical fibre preform with a core section, a cladding section, a first gap and a second gap. The optical fibre preform is attached to an optical fibre draw tower through a handle. In addition, the optical fibre preform is connected to a vacuum system to supply and remove gas from the first gap and the second gap. Moreover, the gas is supplied to create a thermal barrier between the core section and the cladding section during heating of the optical fibre preform. Further, the optical fibre preform is heated inside a heating furnace to draw the optical fibre from the optical fibre preform.

In a method of manufacturing an optical fiber preform, from a powder body containing an alkali metal component or an alkaline earth metal component and silica powder, the alkali metal or the alkaline earth metal is diffused into a silica glass tube through a heat treatment, the powder body that is not fixed to the silica glass tube is removed from the silica glass tube, and a cladding portion is formed so as to surround an outer periphery of the silica glass tube.

A method for producing an optical fiber includes heating and melting an optical fiber preform and drawing the optical fiber preform. In this method for producing an optical fiber, the optical fiber is formed to include a core, a surrounding cladding surrounding a periphery of the core, and an outer cladding surrounding the surrounding cladding. In the drawn optical fiber, a maximum compressive stress of at least 100 MPa or more is applied to an optical waveguide region including at least the core.

The invention relates to a method for producing glass fibers that laterally emit light and to glass fibers produced according to said method. The problem of providing a method that relies on standard available glass components, thus making possible an economical production method that allows a glass fiber to be produced which emits laterally and, in an optically active manner, spectrally shifts, scatters and/or filters light coupled into the fiber when said light exits through the fiber cladding, is solved in that, first, glass tubes (7) and glass rods (5) of identical chemical composition and identical optical refractive index are selected, then first the glass rod (5) is coated completely or over parts of its outer periphery with a vitrifiable material mixture containing optically active substances, in the liquid phase, and the glass rod (5) coated in such a way with this coating (6) after said coating has been dried or consolidated is brought into the glass tube (7) and both are jointly drawn, under the application of heat, to form a glass fiber in a known way.