JPS6356611A - Optical fiber bundle and its manufacture - Google Patents

Abstract

PURPOSE:To easily manufacture an optical fiber bundle which is improved in condensation efficiency with a light emission source by gathering optical axes of respective optical fibers at almost the same position and making the end surface of the optical fiber bundle concave. CONSTITUTION:End surfaces 10 of plural optical fibers 4 are gathered and adhered with shrinkable resin 5 and further ground into a plane. Then a convex spherical die 6 is pressed against them to curve the end surface, an end face is bent along the die 6 due to the shrinkability of the resin 5 and the flexibility of the fiber, thereby spreading the respective fibers 4 of the bundle in a fan shape. Then magnetic resin 7 is injected into the gap of the fibers 4 to fix the fibers 4, and then the pattern 6 is removed and the fibers 4 are fixed. Thus, the optical fiber bundle which has the concave spherical end surface and the end surfaces of the optical fibers radially is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical fiber bundle that has an end face shape that improves the coupling efficiency with one light emitting source and is easy to manufacture, and a method for manufacturing the same.

[Prior Art] Conventionally, as a method of coupling an optical fiber bundle and a light source, as shown in FIG. 8, the end face of the optical fiber bundle 2 is brought directly close to the light source 1 and coupled, and as shown in FIG. via the lens 3, or the first O
As shown in the figure, there is a method of machining the end face of the bundle into a concave shape.

[Problems to be Solved by the Invention] However, in the case of a normal light source with a wide radiation angle, only a portion of the light from the light source is incident on the end face of the bundle, and only a portion of the light incident obliquely is received by the fiber. Since light having an incident angle larger than the angle of incidence cannot be combined, there is a problem in that the coupling efficiency is poor.

[Means for Solving the Problems] A first object of the present invention is to solve the problems of the prior art described above.
To provide an optical fiber bundle which eliminates the drawbacks of the conventional example and improves coupling efficiency with a light source by forming the end face of the optical fiber bundle into a concave shape and by aligning the direction of light incidence with the optical axis of the optical fiber. There is a particular thing.

Further, a second object of the present invention is to provide a method for manufacturing an optical fiber bundle that allows the above-mentioned optical fiber bundle to be manufactured by a simple method.

The first object is to provide an optical fiber bundle in which a plurality of optical fibers are glued together, the optical axes of each optical fiber being gathered at approximately the same position, and the end surface of the optical fiber bundle being concave. This is achieved by optical fiber bundles.

The second purpose is to bond the tips of multiple optical fibers with stretchable resin to form a bundle, shape the end surfaces into a flat shape (if necessary), and then press them into a convex mold. This is achieved by a method of manufacturing an optical fiber bundle characterized in that the end face is formed into a concave shape and each optical fiber is fixed in that state.

[Function] According to the optical fiber bundle as described above, the entrance surface of each optical fiber is flattened as necessary, and by arranging each optical fiber so that its concave end face wraps around the light source, the radiation from the light source is reduced. It becomes possible to allow light to be incident over a wide angular range. In particular, when a light source is placed near the center of the concave surface, the optical axis of each optical fiber and the emission direction of the light from the light source are adjusted so that the light from the light source enters the incident surface of each optical fiber perpendicularly. The effect can be enhanced by matching.

Further, according to the method for manufacturing an optical fiber bundle of the present invention, a plurality of optical fibers are formed into a bundle shape with a certain degree of elasticity in advance, the end faces of which are made flat, and then the fibers are pressed against a convex mold. Since the end face is formed into a concave shape, an optical fiber bundle with high coupling efficiency with the light source can be obtained extremely easily.

In other words, since each fiber can be deformed while maintaining its connection, even a convex spherical mold can be molded without gaps.

[Examples] Hereinafter, the optical fiber bundle of the present invention and its manufacturing method will be described in detail based on Examples.

FIGS. 1 to 3 are diagrams showing an example of the method for manufacturing an optical fiber bundle of the present invention, and the present invention will be explained with reference to these diagrams.

In Figures 1 to 3, 4 is an optical fiber, 5 is a stretchable resin for bonding the optical fiber 4, 10 is the end face of the optical fiber, 6 is a convex spherical mold, and 7 is injected between the optical fibers 4. 1 is a point light source.

FIG. 1 shows the state after the end faces 10 of a plurality of optical fibers 4 have been assembled and bonded with a stretchable resin 5 such as rubber, and have been flattened by polishing or the like. From this state, when pressed against the convex spherical mold 6 in Fig. 2,
Since the adhesive resin 5 is stretchable and the fibers are also flexible, the end face 10 is curved along the mold 6 as shown in FIG. 2, and each fiber 4 making up the bundle is shaped like a fan. After fixing the fiber 4 by injecting hardening resin 7 into the gap between the fibers 4 and removing the mold 6, the end face shape becomes a convex spherical shape as shown in Fig. 3. An optical fiber bundle according to the present invention is formed which has an end face 10 in which the fibers constituting the bundle are arranged radially.

If a point light source 1 as shown in FIG. 4 is placed near the center of the concave spherical end surface io formed in this way, the light source 1 will be covered by the concave spherical surface, and the emitted light from the light source l will be directed at a wide angle. It becomes possible to enter within a range. More importantly, the bundle configuration is arranged radially, and the optical axis of each optical fiber is aligned with the emission direction of the light from the light source so that the light from the light source is incident perpendicularly to the entrance plane of each optical fiber. Since all of the light emitted from the light source is incident on the fiber cross section, the coupling efficiency is greatly improved.

A feature of the optical fiber bundle of the present invention is that light from a radiation light source such as a light bulb can be incident on an optical fiber at a wide angle and at a substantially constant light intensity without passing through a special optical system. Therefore, it is natural that the shape of the end face of the bundle can be changed in accordance with the shape of the light source through which light is incident.

FIG. 5 is a schematic perspective view of an embodiment of the present invention in which the light source is a radiation light source such as a light bulb 20.

In this case, the dome-shaped end face 21 receives the light emitted in the approximately 180' area. In the case of a semiconductor laser or the like, since the aperture angle is narrow, the dome-shaped end face 21 may have a narrower angle.

FIG. 6 is a schematic perspective view showing an embodiment of the present invention in which the light source is a linear light source such as a fluorescent lamp 23. FIG. In this case, the end face 24 of the bundle may be cylindrical.

The present invention is not limited to the above-mentioned embodiments, and various modifications and applications are possible.

For example, the above embodiment deals with a case where a light source is located on a concave spherical end face, but the present invention can also be applied to a case where light collected by a lens 8 or the like as shown in FIG. 7 is coupled to a fiber bundle. can. In the embodiment shown in FIG. 7, the incident direction of light coincides with the fiber axis direction at any position on the end face, making it possible to increase the coupling efficiency. In addition, unlike the case where light is simply incident on the focal point of a lens, each fiber that makes up the bundle has spatial selectivity, so by selecting a fiber, it is possible to extract light from any direction. .

[Effects of the Invention] As described above, the optical fiber bundle of the present invention can significantly improve the coupling efficiency with the light source, and the method of manufacturing the optical fiber bundle of the present invention can There is an effect that an optical fiber bundle having a concave end face such as a spherical shape can be manufactured by a simple method.

[Brief explanation of the drawing]

FIGS. 1 to 3 are schematic diagrams showing the method of manufacturing an optical fiber bundle of the present invention, and FIG. 4 is a schematic diagram showing how light from a point light source enters the optical fiber bundle. FIGS. 5 and 6 are schematic perspective views showing an example of an end face according to the present invention, and FIG. 7 is a schematic view showing another embodiment of the present invention. FIGS. 8 to 10 are schematic diagrams each showing a method of connecting a conventional optical fiber bundle to a light source. 4: Optical fiber 5: Stretchable resin 6: Convex spherical mold 7: Fixing resin 1: Point light source 8: Lens 20: Light bulb 23: Linear light source 10. 21, 24: Light entrance end surface agent Patent attorney Figure 5, Figure 7

Claims (6)

[Claims] (1) An optical fiber bundle in which a plurality of optical fibers are glued together, wherein the optical axes of each optical fiber are gathered at approximately the same position, and the end surface of the optical fiber bundle is concave. bundle. (2) When a light source is placed near the center of the concave end surface, the optical axis of each optical fiber and the light source are aligned so that the light from the light source enters the incident surface of each optical fiber perpendicularly. 2. The optical fiber bundle according to claim 1, wherein the light emission directions are made to coincide with each other. (3) The optical fiber bundle according to claim 1, wherein the concave end surface is a concave spherical surface. (4) The tips of a plurality of optical fibers are bonded with stretchable resin to form a bundle, the end surfaces are formed into a concave shape by pressing them against a convex mold, and each optical fiber is fixed in this state. A method for manufacturing an optical fiber bundle characterized by: (5) The method for manufacturing an optical fiber bundle according to claim 4, wherein the convex mold is a convex spherical surface. (6) The optical fiber according to claim 4, characterized in that when pressed against the convex mold, the optical fibers are fixed by injecting a curable resin between the optical fibers. Method of manufacturing fiber bundles.