JPH0357447B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in optical communication components and manufacturing methods.

Optical fiber communication has many advantages over conventional telecommunications using metal cables, such as the ability to make cables smaller in diameter, lower loss, larger capacity, and lighter in weight. Development is underway. On the other hand, miniaturization of optical communication components or component storage cases is also being developed as an important technical item. However, conventional optical communication parts, parts, and storage cases have to be made somewhat large due to restrictions on the allowable curvature of optical fibers, and miniaturization has been prevented. In other words, applying bending or other deformation to an optical fiber generates stress, and even if the stress is less than the strength of the optical fiber, it may break due to fatigue. This is because the wire must be deformed at a small deformation rate that prevents wire breakage over time. Further, even if the optical fiber is deformed at a small deformation rate, if there are scratches or the like on the surface of the fiber material, the scratches will develop under stress and there is a risk that the optical fiber will break.

The present invention was made in consideration of the above circumstances, and
Its purpose is to reduce or virtually eliminate stress and strain caused by bending or other deforming forces applied to optical fibers, and to improve reliability and reduce size for optical communications. Our goal is to provide parts.

Another object of the present invention is to provide a method for manufacturing optical communication components that can improve the reliability and reduce the size of the optical communication components described above.

First, an overview of the present invention will be explained. In the present invention, an optical fiber is subjected to bending or other deformation, and after heat treatment is applied to the same fiber while maintaining this state,
Furthermore, by cooling the optical fiber while maintaining the above-mentioned state, the stress generated by the above-mentioned deformation is alleviated and a "bending habit" corresponding to the deformation is imparted, thereby reducing the stress strain of the optical fiber. The obtained optical fiber has a desired curvature and is deformed in the axial direction, for example, into a semicircular shape, a coil shape, or the like. The degree of bending thus created varies depending on processing temperature, processing time, applied stress, fiber composition, etc. By using bent optical fibers to conduct branching of optical transmission lines, connections, and other wiring within the housing, it becomes possible to realize small, highly reliable optical communication components that do not cause fatigue. Further, in the present invention, since the heat treatment temperature is set to a temperature lower than the transition temperature of the fiber material, the following effects are achieved. In other words, glass generally becomes brittle when its surface is scratched, so the surface of the fiber is coated with some kind of resin, but since it can be carried out at a temperature range where this resin does not melt, there is no need to damage the optical fiber during manufacturing. It's over. The thus obtained deformed optical fiber with reduced stress strain can be applied not only to miniaturization of optical communication components but also to other fields. For example, if you make a coiled optical fiber, it can be expanded and contracted.
This is also advantageous for connecting vehicles, etc.

Hereinafter, the details of the present invention will be explained with reference to Examples.

Example 1 A multicomponent glass fiber having a core of barium silicate glass with a transition temperature of 600 [°C] and a cladding of porosilicate glass with a transition temperature of 480 [°C] was wound around a quartz tube with a diameter of 9 [mm]. ,
The fiber was attached to the quartz tube using fixing tape. Then, heat treatment was performed at 260 [°C] for 30 [minutes] in an electric furnace. The fiber has a core diameter of 100 [μ
It has an outer diameter of 140 [μm] and is coated with polyvinylidene fluoride resin about 15 [μm] thick to prevent the fiber from being damaged during winding.

After performing the above heat treatment, the fiber was left as it was and allowed to cool. However, when the fixing tape was removed, the fiber was bent to a diameter of 35 mm. When the stress distribution of this bent fiber was measured, there was no difference between the stress distribution of the straight fiber and the straight fiber before heat treatment, and the stress caused by the bending disappeared.

Example 2 A multicomponent system consisting of a core made of alkali borosilicate glass with a transposition temperature of 440 [°C] and a cladding made of borosilicate glass with a transposition temperature of 480 [°C] was used to form a glass fiber into a quartz tube with a diameter of 9 [mm]. Heat treatment was performed at 260 [°C] for 30 [minutes] in the same manner as in Example 1. The fiber has a core diameter of 80 [μ
m], outer diameter 125 [μm], and a silicone primary coat approximately 65 [μm] thick. The bend in this case was 37 mm in diameter. Furthermore, there was no change in stress distribution measurements compared to the straight fiber.

Example 3 Using the same multicomponent glass fiber and quartz tube as in Example 1, 260 [°C], 2 [H], and 260 [°C],
When heat treated at 10 [H], the resulting bends had diameters of 32 [mm] and 30 [mm], respectively. In addition, using the same multi-component glass fiber and quartz tube as in Example 1, temperatures of 200 [°C], 2 [H] and 300 [°C] were measured.
When heat treatment was performed for 2 [H], the resulting bends had diameters of 48 [mm] and 26 [mm], respectively.

As described above, the degree of bending changes depending on the heat treatment time, temperature, etc., and the effect of temperature is greater than the effect of time.

Example 4 The same multi-component glass fiber as in Example 1 was used with a diameter of 16 mm.
When wrapped around a [mm] quartz tube and heat-treated at 300 [℃] for 25 [minutes], the resulting bend became a diameter of 55 mm.
It was [mm]. Of course, in this case as well, there was no change in stress distribution compared to the straight fiber.

In this way, by heat-treating the optical fiber while applying stress at a temperature below the dislocation temperature of the material of the fiber, the stress caused by deformation can be alleviated or practically reduced to zero. Therefore, it is possible to improve the reliability and reduce the size of optical communication components. Note that the lower limit of the heat treatment temperature is not clear, but for example, even at 50 [℃], 100
By holding it at [H] level, I was able to create a bending habit. However, in practice, the
It is preferably 200°C or higher and lower than the transition temperature of the fiber material.

Furthermore, although barium silicate glass and borosilicate were used in the above embodiments, other multicomponent glasses such as soda lime glass and lead glass may also be used. In addition, the present invention can be implemented with various modifications without departing from the gist thereof.

Claims (1)

[Claims] 1. Stress caused by stress strain in a deformed portion of an optical fiber that is at least partially deformed with a curvature causing a direct optical fiber to be deformed with the curvature. An optical communication component characterized by reduced distortion. 2 applying a deforming force to the optical fiber so that it has at least a partial curvature, and heat-treating the optical fiber to an optical fiber material at a temperature below the transition temperature;
Thereafter, by cooling the optical fiber while maintaining the deformation force, the optical fiber is deformed, and the stress strain in the deformed portion of the optical fiber causes the optical fiber to have the curvature as described above. 1. A method for manufacturing optical communication components, characterized by obtaining an optical fiber with reduced stress strain compared to that caused by causing deformation. 3 The optical fiber material has a transition temperature of 400
3. The method for manufacturing an optical communication component according to claim 2, characterized in that a multi-component glass having a temperature of 600°C to 600°C is used. 4. The method of manufacturing optical communication components according to claim 2, wherein the cooling is natural cooling. 5. The method of manufacturing an optical communication component according to claim 2, wherein the heating is performed at a temperature of 200° C. or higher.