JPH01169417A - Mounting structure of optical fiber and optical elements - Google Patents

Abstract

PURPOSE:To prevent the deterioration of the coupling efficiency and to improve the reliability by constituting the title structure so that the eccentric quantity in a columnar holder becomes larger than a distance between loci drawn by the center of an optical fiber and a projection point of the center of the optical element on a plane being orthogonal to an optical axis, when a fixing means has been moved by a moving means. CONSTITUTION:When first and second fixing means 10, 11 have been moved by first and second moving means 12, the eccentric quantity of an optical element 8 in a columnar holder 9 becomes larger than a distance between loci drawn by the center of an optical fiber and a projection point of the center of the optical element 8 on a plane being orthogonal to an optical axis. In such a way, by interactions of a ferrule 7, the first fixing means 10 for fixing the ferrule 7, the columnar holder 9, the second fixing means 11 for fixing the columnar holder 9, and also, the first and the second moving means 12 for moving the fixing means 10, 11, the optical fiber and the optical element can be aligned simply with the maximum efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a mounting structure for optical fibers and optical elements.

[Conventional technology]

Optical fibers are coupled with optical elements (light emitting elements, light receiving elements, etc.) on boats, and are known as a means of transmitting optical information.

With the recent development of communication networks and the increase in communication capacity, there has been a demand for high precision on the micron level as a coupling technology between optical fibers and optical elements.

FIG. 4 shows a conventional mounting structure for optical fibers and optical elements. The ferrule 1 holds the optical fiber strand 2 in the optical axis direction, and the ferrule 1 is fixed to the sleeve 3. On the other hand, the optical element 4 is fixed to one end of the optical element holder 5, and is mounted so that the end face (input or output end face) of the optical fiber 2 held by the ferrule 1 faces the optical element 4. .

The method of fixing each component will be explained below.

First, the optical element 4 is fixed to the lower opening of the optical element holder 5, and the ferrule 1 and sleeve 3 are fixed while aligning the optical axis direction. Next, the sleeve 3 and the optical element holder 5 are fixed while aligning on a plane perpendicular to the optical axis so that the coupling efficiency between the optical fiber 2 and the optical element 4 is maximized. The sleeve 3 and the optical element holder 5 are assembled by applying solder to the part A in FIG. 4 and heating with high frequency.
Alternatively, it may be fixed by applying a resin adhesive.

[Problem that the invention seeks to solve]

However, when fixing with solder, there is a drawback that the solder becomes fluidized during high-frequency heating, resulting in optical axis misalignment.

Further, when fixing with a resin adhesive, the sleeve 3 and the optical element holder 5 are less likely to shift during bonding, but there is a drawback that long-term reliability is lacking.

Furthermore, when fixing with the above-mentioned solder or adhesive, it is difficult to fix the sleeve 3 and the optical element holder 5 with high precision without tilting the sleeve 3 and the optical element holder 5. If the sleeve 3 and the optical element holder 5 are fixed at an angle, thermal expansion of the material due to temperature fluctuations occurs. Therefore, there was a drawback that the binding effect fluctuated.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a mounting structure for an optical fiber and an optical element that does not deteriorate coupling efficiency during mounting and has excellent long-term reliability.

[Means for solving problems]

In order to solve the above problems, the present invention includes a ferrule for holding an optical fiber, a cylindrical holder for eccentrically holding an optical element, a first fixing means for fixing the ferrule, and a cylindrical holder for fixing the cylindrical holder on a cylindrical axis. a second fixing means for fixing the first or second fixing means so as to be rotatable in the circumference; a first moving means for moving the first or second fixing means substantially in the optical axis direction;
A second method for moving the fixing means in a direction substantially perpendicular to the optical axis.
When the first and second fixing means are moved by the first and second moving means, the center of the optical fiber and the center of the optical element are located on a plane perpendicular to the optical axis. It is characterized in that the amount of eccentricity of the optical element in the cylindrical holder is larger than the distance between the trajectories drawn by the projection points.

[Effect]

Since this invention is constructed as described above, the ferrule,
Due to the interaction of the first fixing means for fixing this ferrule, the cylindrical holder, the second fixing means for fixing this cylindrical holder, and the first and second moving means for moving the above-mentioned fixing means, the maximum Optical fibers and optical elements can be easily aligned with efficiency.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the optical fiber and optical element mounting structure according to the present invention will be described below with reference to the accompanying drawings.

In the description, the same reference numerals will be used for the same elements, and duplicate description will be omitted.

FIG. 1 shows an embodiment of a mounting structure for an optical fiber and an optical element according to the present invention. This embodiment basically consists of a ferrule 7 that holds an optical fiber 6, an optical element holder 9 (cylindrical holder) that holds an optical element 8, and a ferrule stand 10 that fixes the ferrule 7 with a V-shaped groove 10a.
(first fixing means), an optical element stand (second fixing means) 11 that fixes the optical element holder 9 with a U-shaped groove 11a, and a moving table 12 (first and second moving means). A V-shaped groove 10a is formed in the ferrule stand 10, and the ferrule 7 that holds the optical fiber strand 6 is placed in this V-shaped groove 10a. Therefore, the direction of the V-shaped groove 10a is parallel to the optical axis of the optical fiber strand 6. This ferrule stand 1
A trapezoidal rail-shaped groove 10b is formed in the V-shaped groove 10a in a direction substantially perpendicular to the V-shaped groove 10a, and a moving table 12, which will be described next, is connected to the rail. Therefore, the moving table 12 is movable relative to the ferrule table 10 in a direction substantially perpendicular to the optical axis. This moving table 12 is composed of a concave block body, and members 12g forming the concave block body,
12b has an inner side (the side where members 12a and 12b face each other)
Trapezoidal rail-shaped grooves 12c, 12c are formed in a direction substantially perpendicular to the rail-shaped groove 10b. The optical element stand 11 is rail-coupled to the rail-shaped grooves 12c, 12c. Therefore, the optical element stand 11 is movable relative to the movable table 12 in a direction substantially parallel to the optical axis. This optical element stand 11 is constituted by a rectangular parallelepiped that can be fitted between the members 12a and 12b, and has a U-shaped groove 11a formed therein.

After all, the optical element stand 11 is movable with respect to the ferrule stand 10 in a direction substantially perpendicular to the optical axis and in a direction parallel to the optical axis by interposing the moving stand 12. Note that since the optical element holder 9 is fixed to the optical element stand 11 and the ferrule 7 is fixed to the ferrule stand 10, this mounting structure allows the optical element holder 9 and the ferrule 7 to be aligned in a direction substantially orthogonal to the optical axis and parallel to each other. You can move it in the direction you want.

In this embodiment, a V-shaped groove 10a and a U-shaped groove 11a are used as the first fixing means and the second fixing means, but the shape of the grooves is not limited to V-shape or U-shape. , for example, may be trapezoidal. By making it trapezoidal, the cylindrical member (ferrule, optical element holder) can be held at three points, and the fixing force is strengthened.

Note that what is more important in this invention is the fixing position of the ferrule 7 and the optical element holder. As described above, the optical element holder 9 and the ferrule 7 are relatively movable in a direction substantially perpendicular to the optical axis (horizontal direction in this embodiment); Considering the stationary coordinates on the plane, the trajectory drawn by the optical fiber 6 on the plane (hereinafter referred to as "fiber trajectory") is shown in FIG. This fiber trajectory G and optical element holder 9
The vertical distance from the cylinder axis 0 to the cylinder axis 0 is the perpendicular distance between the plane where the U-shaped groove 11a of the optical element stand 11 is formed and the fiber trajectory G on g1, and the perpendicular distance from the plane to the cylinder axis 0 to L. Then, it is expressed as L0g. Further, if the distance (decentering amount) between the optical element 8 and the cylinder axis 0 in the optical element holder 9 is e, the ferrule 7 and the optical element holder 9 are fixed so that e≧(L+jl) is always satisfied. In other words, an optical element holder 9 is used in which the optical element 8 is eccentric from the cylindrical axis 0 by a distance greater than the distance between the centers of the optical fiber 6 and the optical element 8.

With such a mounting structure, when the optical element holder 9 is rotated around the cylindrical axis 0, the fiber trajectory G
The number of intersections between the optical element 8 and the optical element 8 is one or two (H, I), which facilitates positioning.

Note that the optical fiber wire 6 used in the above-mentioned mounting structure
uses a tapered spherical fiber with a spherical surface near the core and a tapered shape around the core. In this embodiment, an optical element holder 9 that holds the optical element 8 eccentrically and a ferrule 7 that holds the optical fiber 6 without eccentrically are used.
It may be a ferrule that holds the optical element eccentrically, and in this case, the optical element 8 does not need to be eccentrically held. What is important is that the optical fiber 6 (optical fiber) and the optical element 8 are mounted so that the relationship e≧(Ll) is always maintained.

An example of the manufacturing method will be described below with reference to FIGS. 1 and 2. First, the ferrule 7 is fixed in the V-shaped groove 10a of the ferrule stand 10.

Next, the moving table 12 is moved relative to the ferrule table 10 so as to substantially face the optical fiber 6 attached to the ferrule 7, and the optical element holder 9 is fixed in the U-shaped groove 11a. When the optical element holder 9 is rotated here, it draws a trajectory J as shown in FIG. On the other hand, when the moving table 12 is moved, the optical fiber 6 draws a fiber trajectory G. Intersections H and I between the trajectory J and the fiber trajectory G are positions where the coupling efficiency between the optical fiber 6 and the optical element 8 is maximized.

The movable base 12 is fixed to the ferrule base 10 at one of the above positions (H or H).

Finally, in order to position in the optical axis direction, the optical element stand 11 is moved in the optical axis direction while being monitored, and at the position where the coupling efficiency is maximized, the optical element stand 11 is fixed to the moving stand 12. The mounting structure for optical fibers and optical elements is completed.

Note that the ferrule 7 and the optical element holder 9 are fixed with solder or resin, but since the horizontal direction perpendicular to the optical axis is already fixed by the groove, there is no possibility of misalignment (and long-term reliability is ensured). good.

FIG. 3 shows a ferrule 13 as a modified example applicable to the present invention. The difference from the ferrule 7 described above is that a hole 13a for inserting a focusing rod lens 14 is provided at one end of the ferrule 13. The optical fiber wire 6 is attached to the other end. The focusing rod lens 14 is inserted into the hole 13a and efficiently guides the light from the light emitting element into the optical fiber. Therefore, by attaching such a focusing rod lens 14 to the fiber end face, the coupling efficiency can be improved.

〔Effect of the invention〕

Since this invention is configured as explained above,
It is easy to manufacture, and the coupling efficiency between the optical fiber and the optical element can be easily improved.

Furthermore, since there is little deterioration in coupling efficiency due to manufacturing, it has excellent long-term reliability.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the optical fiber and optical element mounting structure according to the present invention, and FIG. 2 is a diagram in which the fiber locus and the optical element locus are projected onto a plane orthogonal to the optical axis. , FIG. 3 is a perspective view showing a modification of the ferrule that can be used in the embodiment shown in FIG. 1, and FIG. 4 is a partial cross-sectional view showing a conventional mounting structure of an optical fiber and an optical element. 1.7.13... Ferrule, 2,6... Optical fiber wire, 3... Sleeve, 4.8... Optical element, 5
゜9...Optical element holder, 10...Ferrule stand,
11... Optical element stand, 12... Moving stand, 14...
Focusing rod lens. Patent applicant: Sumitomo Electric Industries, Ltd. Representative patent attorney Yoshiki Hase
Mountain 1) Row - Figure 4

Claims (1)

[Claims] 1. A ferrule that holds an optical fiber; a cylindrical holder that holds an optical element eccentrically; a first fixing means that fixes the ferrule; a second fixing means for fixing the first or second fixing means so as to be rotatable in the direction of the optical axis; a first moving means for moving the first or second fixing means substantially in the optical axis direction; and a second moving means for moving the first and second fixing means in a direction substantially perpendicular to the optical axis, when the first and second fixing means are moved by the first and second moving means, the optical axis is perpendicular to the optical axis. A mounting structure for an optical fiber and an optical element, characterized in that the amount of eccentricity of the optical element in the cylindrical holder is greater than the distance between the trajectories drawn by the projection points of the center of the optical fiber and the center of the optical element on a plane. . 2. The optical fiber and optical element mounting structure according to claim 1, wherein the first and second fixing means are a V-shaped groove and a U-shaped groove. 3. The optical fiber and optical element mounting structure according to claim 1, wherein the first and second fixing means are trapezoidal grooves. 4. A claim in which the first and second moving means move the second fixing means with respect to the first fixing means in an optical axis direction and in a direction substantially orthogonal to the optical axis. A mounting structure for the optical fiber and optical element according to item 1. 5. The optical fiber and optical element mounting structure according to claim 1, wherein the ferrule includes a focusing rod lens at one end. 6. The optical fiber and optical element mounting structure according to claim 1, wherein the optical element is a light emitting element. 7. The optical fiber and optical element mounting structure according to claim 1, wherein the optical element is a light receiving element.