JP3284697B2 - Optical coupling device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical coupling device used for an optical communication device or the like.

[0002]

2. Description of the Related Art As a conventional example of optically coupling an optical element array and an optical fiber array, for example, when a typical end face type light emitting element array is optically coupled to an optical fiber array equal in number to the number of light emitting elements, a connection is required. It is important to couple with low loss and high efficiency. For this reason, a coupling system of a light emitting element array and a spherical lens array in which the tip of an optical fiber is processed into a lens shape is often used. In this coupled system,
The number of adjustment axes increases to 6 for both the orthogonal axis and the rotation axis, and high-precision optical coupling technology is required.

FIG. 3 shows a basic configuration according to the prior art. As shown in FIG.
2. A fiber support 33 is disposed, a light emitting element 34 is mounted on the light emitting element support 32 via a heat sink 35, and a spherical fiber array (hereinafter referred to as an optical fiber array) 36 is mounted on the fiber support 33. Is installed.

As a method of adjusting the optical axis, a light emitting element support 3 is used.
2 is fixed to the substrate 31 and the fiber support 33 is moved on the substrate 31 to align the light emitting element 34 and the fiber array 36.
The method of fixing on 1 is common. As a method of aligning the optical fiber array, there are a method of performing precise alignment using a centering device, a method of performing coarse adjustment by fitting into a processed block or the like, and then performing a fine adjustment using a minute spring or screw.

[0005]

However, when the optical axis adjustment of the light emitting element array and the optical fiber array is performed by the above method, the number of axes to be adjusted is as large as 6 in both the orthogonal axis and the rotation axis, and the Axis adjustment took a lot of time. When a spring or a screw is used, there is a problem that the mounting area is increased by an amount occupied by the spring or the screw.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned prior art, and has as its object to provide an optical coupling device which makes the optical coupling between a light emitting element array and an optical fiber array compact and facilitates alignment. And

[0007]

According to the present invention, there is provided an optical coupling device in which an optical element array and an optical fiber array fixed to a first substrate are coupled on a second substrate. In the optical element array, two or more first members are fixed in parallel with the optical axis of the optical element array, and a plurality of the first members on the opposite side to the optical element array. A tangent plane connecting the members is parallel to a plane including the center of the active surface of the optical element array and the optical axis of the optical element array, and the optical fiber array is arranged on the first substrate with respect to the number of the optical fibers and the number of the optical fibers. The pitch is equal to the number and pitch of the optical element array,
The optical axis of each fiber of the optical fiber is fixed so as to be parallel to the optical axis of the optical element array, and the line connecting the center of each fiber core of the optical fiber array is The second substrate is fixed to the first substrate at least two in parallel to the optical axis of the optical fiber array, the second member being perpendicular to the optical axis of the fiber array and being on a straight line .
The tip of the member protrudes beyond the tip of the optical fiber array
And a plane connecting a straight line connecting the centers of the respective fiber cores of the optical fiber array and an optical axis of the optical fiber, the plurality of second members being opposite to the first substrate. Are parallel to a tangent plane connecting the plurality of first members fixed to the optical element array and the plurality of second members fixed to the first substrate. A groove equal in width and pitch is formed.

Here, the optical fiber array may be inserted into a thin tube for each fiber.

[0009]

According to the above arrangement, by inserting the first member fixed to the optical element array and the second member fixed to the optical fiber array into the first groove on the second substrate, the The optical axis directions of the element array and the optical fiber array can be matched.

In addition, the cross-sectional dimensions of the first member and the second member, for example, the diameter of a cylindrical member is selected to a predetermined value,
The distance from the tangent plane connecting the first member on the side not in contact with the optical element array to the plane including the center of each active surface of the optical element array and its optical axis is the second on the side not in contact with the first substrate. By making the distances from the tangent plane connecting the above members to the center of each fiber core of the optical fiber array and the plane including the optical axis thereof equal, the optical axis heights can also be matched.

Therefore, a high-precision alignment device or a positioning screw is not required unlike the prior art, so that optical coupling can be easily performed and the structure can be reduced in size. Further, by using an optical fiber array that is inserted into a thin tube for each fiber, handling can be further facilitated.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings. FIG. 1 shows a first embodiment of the present invention. In the figure, 1 is a second substrate, 2 is a light emitting element array, 3 is an optical fiber array, 4 is a first member, 41
Is a second member, 5 is a first substrate, 6 is an opening, 7 is a first groove formed in the second substrate 1, and 11 is a marker.

The second substrate 1 is provided with two parallel first grooves 7 for inserting the first member 4 and the second member 41, for example, with a precision of submicron by cutting. It is provided. The first member 4 and the second member 41 are, for example, columnar, and both have a diameter of, for example, 250 μm.
m.

The first groove 7 has, for example, a U-shaped cross section, a width of, for example, 250 μm, which is equivalent to the width of the first member 4 and the second member 41, and a constant depth. is there. A marker 11 is provided beside the first groove 7 as a reference for positioning the light emitting element array 2.

An opening 6 is formed in the second substrate 1 so that the electrodes of the light emitting element array 2 fixed to the second substrate 1 can be electrically connected to a circuit board (not shown) by wire bonding or the like. Is provided. In the light emitting element array 2, two third grooves, for example, by etching, are formed on the light emitting element substrate surface on the light emitting surface side in parallel with the optical axis.

A first member 4 is aligned and fixed in a third groove of the light emitting element array 2 using a jig (not shown). The end surface of the first member 4 is flush with the light-emitting side end surface of the light-emitting element array 2. A V-groove is formed in the first substrate 5 equal to the number and pitch of the light emitting element arrays 2 and parallel to the optical axis of the light emitting element arrays 2. Two fourth grooves are formed at the same pitch as the grooves.

The optical fiber array 3 is aligned and fixed in the V-groove of the first substrate 5 by using an unillustrated device, and an unillustrated device is installed in the fourth groove of the first substrate 5. Using this, the second member 41 is aligned and fixed. The tip of the second member 41 is made to protrude beyond the tip of the optical fiber array 3.

The optical coupling device of the present embodiment having the above configuration is assembled as follows. First, after the first member 4 fixed to the light emitting element array 2 is inserted into the first groove 7 of the second substrate 1, the end face of the light emitting element array 2 on the light emitting surface side using a jig (not shown). Is matched with the marker 11 and fixed. Next, the second member 41 fixed to the first substrate 5 is inserted into the first groove 7 of the second substrate 1, and the end face of the first member 4 facing the optical fiber array 3 is placed on the end face of the first member 4. The end face of the second member 41 protruding from the tip of the fiber array 3 is fixed while being pressed.

As described above, when the end surface of the first member 4 is in contact with the end surface of the second member 41, the light emitting element array 2
Since the light emitting surface of the light emitting element array 2 is not in contact with the tip of the optical fiber array 3 , the light emitting surface of the light emitting element array 2 is
No damage at the tip of 3 .

Further, if the amount of protrusion of the tip of the second member 41 from the tip of the optical fiber array 3 is set to a distance at which the optical coupling efficiency between the light emitting element and the optical fiber is maximized, the most efficient coupling state is obtained. be able to.

The first member 4 is fixed to a third groove formed in the light-emitting element array 2, and is formed at opposite end faces of the optical element array 2 perpendicular to a tangent plane of the first member 4. It may be fixed to both ends of the light emitting element 2 which does not include the light emitting surface. In this case, if necessary, the light emitting element array 2 and the first member 4 may be fixed to a substrate (not shown).

The first member 4 and the second member 41 may have a prismatic shape other than a columnar shape, and the first groove 7 may have a V-shape. Further, the first member 4 and the second member 41
May have different diameters, and if they are different,
The width and depth of the first groove 7 are not constant, and may be changed at the position of the marker 11 according to the diameter of the first member 4 and the second member 41.

FIG. 2 shows a second embodiment of the present invention. In this embodiment, the optical fiber array 3 is provided with a thin tube 42 for each fiber.
To be inserted and fixed respectively. Other configurations are the same as those of the above-described embodiment. In the drawing, 21 is a second substrate, 2 is a light emitting element array, 3 is an optical fiber array, 4 is a first member, 41 is a second member,
2 capillary, the first substrate 5, 6 openings, a first groove formed on the second substrate 2 1 7, 22 second groove formed on the second substrate 21, 11 is a marker It is.

As shown in FIG.
Are inserted into the thin tubes 42 for each fiber, and are aligned and fixed in the V-grooves formed in the first substrate 5. The end face of the thin tube 42 on the side facing the light emitting surface of the light emitting element array 2 is
The second member 41 is fixed so as not to protrude from the end surface. In this embodiment, the first member 4 and the second member 4
1 and the thin tube 42 are the same member, for example, 250 μm in outer diameter.
m, a cylinder having an inner diameter of 126 μm is used.

Further, the first groove formed in the light emitting element array 2, the V-groove formed in the first substrate 5, and the fourth groove have the same shape and size. However, when the V-groove is formed by anisotropic etching, after the first member 4 is fixed to the optical element array 2, the first member 4 is fixed to the optical element array 2 from the contact plane connecting the first members 4 on the side not in contact with the optical element array 2. The distance between the optical element active center and the plane including the optical axis and the tangent plane connecting the second member 41 on the side not in contact with the first substrate 5 to the optical fiber array 3
Under the condition that the distance from the center of the core to the plane including the optical axis of the optical fiber array 3 is equal,
And the first substrate 5 may have different V-groove shapes (for example, angles formed by the V-grooves).

The second substrate 21 is provided with a second groove 22 having the same depth as that of the first groove 7 and having a width capable of accommodating a plurality of thin tubes 42, and is used for assembling the optical coupling device. Capillary 4
2 does not hit the second substrate 21. Also in the optical coupling device of the present embodiment having the above configuration, it can be assembled by the same procedure as in the above-described embodiment,
When the end face of the first member 4 and the end face of the second member 41 are in contact with each other, the light emitting surface of the light emitting element array 2 and the tip of the optical fiber array 3 are not in contact with each other.
Is not damaged by the tip of the optical fiber array 3 .

[0027] Moreover, in this embodiment, since the optical fiber array 3 is inserted into capillary 4 2, compared to the case where not inserted into capillary 4 2, there is an advantage to be easier further handling.

[0028]

As described above in detail with reference to the embodiments, the optical coupling device of the present invention has the first member fixed to the optical element array in the first groove on the second substrate. By inserting the second member fixed to the optical fiber array, the optical axis directions of the optical element array and the optical fiber array can be matched. Moreover, the cross-sectional dimensions of the first member and the second member, for example, if the cylindrical member, the diameter is selected to a predetermined value,
The distance from the tangent plane connecting the first member on the side not in contact with the optical element array to the plane including the center of each active surface of the optical element array and its optical axis is the second on the side not in contact with the first substrate. By making the distances from the tangent plane connecting the above members to the center of each fiber core of the optical fiber array and the plane including the optical axis thereof equal, the optical axis heights can also be matched. Therefore, unlike the related art, a high-precision alignment device or a positioning screw is not required, so that optical coupling can be easily performed and the structure can be reduced in size. Here, handling can be further facilitated by inserting each fiber into a thin tube as an optical fiber array. Furthermore, by adopting a structure in which the tip of the second member fixed to the optical fiber array protrudes from the tip of the fiber, the tip of the fiber does not damage the active surface of the optical element during optical coupling, and the amount of protrusion is maximized. An optical coupling device having a high optical coupling efficiency can be obtained by pressing the second member end surface on the optical fiber array side against the first member end surface on the optical element array side if the distance is equal to the optical element-optical fiber distance at which the efficiency is obtained. It has the advantage that it can be manufactured and therefore can be used in mass production processes.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a first embodiment of the present invention.

FIG. 2 is an explanatory view showing a second embodiment of the present invention.

FIG. 3 is an explanatory diagram of a conventional technique.

[Explanation of symbols]

 1, 21 Second substrate 2 Light emitting element array 3 Optical fiber array 4 First member 5 First substrate 6 Opening 7 First groove 11 Marker 22 Second groove 41 Second member 42 Thin tube

Continuation of the front page (72) Inventor Yukio Irita 1-3-1 Gotenyama, Musashino-shi, Tokyo NTT Advanced Technology Co., Ltd. (56) References JP-A-4-216509 (JP, A) JP-A-4-340507 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02B 6/42-6/43

Claims (2)

(57) [Claims] 1. An optical coupling device in which an optical element array and an optical fiber array fixed to a first substrate are coupled on a second substrate, wherein the optical element array includes the optical element array. Two or more first members are fixed in parallel to the optical axis of the optical element array, and the tangent plane connecting the plurality of first members on the opposite side to the optical element array is the center of the active surface of the optical element array. The optical fiber array is parallel to a plane including the optical axis of the optical element array, and the optical fiber array has an array number and a pitch of the optical fibers equal to the array number and the pitch of the optical element array with respect to the first substrate; The optical axis of each fiber of the optical fiber is fixed so as to be parallel to the optical axis of the optical element array, and the line connecting the center of each fiber core of the optical fiber array is the optical fiber Perpendicular to and aligned with the optical axis of the array; Two or more second members are fixed to one substrate in parallel with the optical axis of the optical fiber array, and the tip of the second member is
Protrudes from the end of the optical fiber array and is fixed.
And a plane connecting the optical axis of the optical fiber and a straight line connecting the center of each fiber core of the optical fiber array is connected to connect the plurality of second members on the opposite side of the first substrate. Parallel to a plane, and the second substrate has a plurality of first members fixed to the optical element array and a width and a pitch of the plurality of second members fixed to the first substrate. An optical coupling device, wherein a groove equal to the following is formed. 2. The optical coupling device according to claim 1, wherein the optical fiber array is inserted into a thin tube for each fiber.