JPH0777633A - Optical coupling device - Google Patents

Abstract

PURPOSE:To provide the optical coupling device which is used for an optical communication device, etc., is capable of collectively aligning the front ends of fibers by using jigs and does not increase packaging time even if the number of fiber arrays increases. CONSTITUTION:This optical coupler is constituted by previously separately producing an optical element array part 1 which is mounted with optical elements 6 and capillaries 4 on a V-groove substrate 3 and a fiber array part 2 which is formed by forming the V-grooves at a similar pitch on another V-groove substrate 31 having an equal thickness, fixing another capillaries 41 having the bore equal to the bore of the capillaries 4 described above into these grooves and inserting and fixing the optical fibers 5 therein at a prescribed length and finally, inserting the optical fiber array 5 of the optical fiber array part 2 into the capillaries 4 of the optical element array part 1, thereby making optical coupling.

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 in an optical communication device or the like.

[0002]

2. Description of the Related Art An array module in which an optical element array and an optical fiber array are combined requires a highly accurate alignment technique over multiple axes, and thus requires a great deal of time for adjustment and assembly processes. Simplification of the optical axis adjustment and fixing is required to reduce the cost of the module and mass-produce it. Therefore, studies are being made to eliminate adjustment in order to improve the component processing accuracy and the mounting accuracy.

FIG. 3 shows an example of this. This example is an integrated module in which a light emitting device (LD) is used as an optical device and is mounted on the same substrate as the fiber array. As shown in the figure, a plurality of V-grooves are formed on the Si substrate 01 by photolithography and anisotropic etching with an accuracy of the order of μm or less, and the inner diameter of these V-grooves is equal to the outer diameter of the optical fiber 05. Further, by fixing the thin tubes 04 formed with the outer diameter dimension accuracy of the order of μm or less and inserting the optical fibers 05 into these thin tubes 04, the thin tubes 04 are coupled with the light emitting element array 06 which is a plurality of light emitting elements. .

The height adjustment of the optical axes of the light emitting element array 06 and the optical fiber 05 is performed by adjusting the thin tube 0 so that the optical fiber 05 can be positioned at a height corresponding to the light emitting position of the light emitting element array 06.
It can be easily adjusted by selecting the outer diameter size of No. 4. This method uses a V groove whose dimensional accuracy of width and depth is in the order of μm or less, and a thin tube 04 whose dimensional accuracy of outer diameter and inner diameter is in the order of μm or less, so that the direction perpendicular to the surface of the substrate 01 ( Since the alignment in the Y-axis direction) and the parallel method (X-direction) are not necessary, the adjustment is performed only in the optical axis direction (Z-direction), and the assembly process can be simplified. Moreover, when the light emitting position of the light emitting element array 06 is changed, the outer diameter of the fiber insertion thin tube 04 may be changed, and it is not necessary to redesign the V groove substrate 01.

In this structure, in order to fix the light emitting element array 06 and the plurality of optical fibers 05 on the same substrate 01, first, the light emitting element array 06 is fixed by soldering, and then the thin tube 04 is bonded to the V groove with an adhesive. Then, the optical fiber 05 is finally inserted into the thin tube 04 and fixed with an adhesive.
This procedure is a result of considering the thermal history of solder fixing and adhesive fixing, and at the same time, when the optical fiber 05 is fixed first, the optical fiber pigtail having a length of about 1 m is fixed to the light emitting element array 06. By making the process difficult.

[0006]

However, when the array module is manufactured by the above procedure, the light emitting element array 06
Since the coupling distance between the optical fiber 05 and the optical fiber 05 is as short as several tens of μm or less, a jig for tip alignment is installed between the light emitting element array 06 and the optical fiber 05 to align the tips of the optical fibers 05 at once. I can't. Therefore, the plurality of optical fibers 05,
That is, it was difficult to insert the optical fiber arrays 05 into the thin tubes 04 all at once and align the ends of the fibers with an accuracy of μm or less. Further, the method of pressing the tip of the optical fiber 05 and aligning the tips of the fibers with the light emitting surface which is the end surface of the light emitting element array 06 as a reference, because the light emitting surface of the light emitting element array 06 is damaged by the tip of the fiber 05,
It is practically impossible.

Therefore, it is necessary to insert a plurality of optical fibers 05 into the thin tubes 04 one by one and fix them at the coupling position, and there is a problem that the mounting time becomes longer as the number of fiber arrays increases. The present invention has been made in view of the above-mentioned conventional technique, and it is possible to collectively align the fiber tips by using a jig, and the mounting time does not increase even if the number of fiber arrays increases. An object is to provide an optical coupling device.

[0008]

The structure of the present invention which achieves such an object is similar to that of an optical element array part in which an optical element and a narrow tube are mounted on a V-groove substrate and another V-groove substrate having the same thickness. V-grooves are manufactured at a pitch, another thin tube with the same inner diameter as the above thin tube is fixed, and an optical fiber is inserted and fixed in a predetermined length to this, and the fiber array part is manufactured separately. The optical fiber array of the optical fiber array section is inserted into the thin tube of the element array section to perform optical coupling.

[0009]

By separately manufacturing the optical element array section and the optical fiber array section in this manner, the optical fiber array section is not restricted by mounting the optical element array, and as described above, the optical element array end surface is Even if the fiber tips are not aligned with each other, it is possible to align the fiber tips collectively using a jig. Moreover, since the inner diameters of the thin tubes of the optical element array and the optical fiber array are both equal to the outer diameter of the fiber, by inserting and fixing the fiber array into the thin tubes of the optical element array, complicated alignment work is not required, and many The core fibers can be optically coupled at the same time. Further, by setting the length of the thin tube of the optical element array portion shorter than the V groove and the length of the thin tube of the optical fiber array portion longer than the V groove, the mechanical strength of the optical coupling portion is maintained.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the embodiments shown in the drawings. FIG. 1 shows a first embodiment of the present invention. In this embodiment, a light emitting element is applied as an optical element. In FIG. 1, 1 is an optical element array section, 2 is a fiber array section, 3 and 31 are V-groove substrates, 4 and 41 are optical fiber insertion thin tubes, 5 is an optical fiber, and 6 is a light emitting element array (optical element array). , 8 are markers indicating the position of the fiber tip where the maximum coupling efficiency is obtained.

The optical element array section 1 comprises a V-groove substrate 3, a narrow tube 4, a light emitting element 6 and a marker 7. The fiber array unit 2 includes a V-groove substrate 31, a narrow tube 41, and an optical fiber array 5. The V-groove substrate 3 has an optical element mounting portion and a marker 8 formed on the Si substrate having a width of 5 mm × a length of 10 mm and a thickness of 450 μm by the thin film technology, and further, the accuracy is less than μm by the photolithography technology and anisotropic etching. Four V-grooves having a width of 178 μm, a depth of 123 μm and a pitch of 500 μm are formed.

As the thin tube 4 fixed in the V groove, for example,
Made of glass, outer diameter 250 ± 1μm, inner diameter 126μ
m ± 1μm (inner diameter at one end spreads in a cone shape, maximum 1
80 ± 5 μm) and the length is 7 mm. The V-groove substrate 31 is
The thickness was the same as that of the V-groove substrate 3, the width was 5 mm and the length was 5 mm, and the V-groove substrate 3 was manufactured in the same process as above. Thin tube 4 fixed in V groove
2 is, for example, an outer diameter of 250 μm ± 1 μm (the outer diameter of one end is gradually tapered, a minimum of 200 ± 5 μm), and an inner diameter of 126 ± 1.
μm and length 7 mm. As the optical fiber 5, a spherical fiber having an outer diameter of 125 μm was used.

The optical coupling device of this embodiment is manufactured as follows. First, the light emitting element 6 is aligned and fixed to the optical element mounting portion on the V-groove substrate 3 with a precision bonding device (not shown) with an accuracy of μm or less. In order to fix the light emitting element 6, a predetermined amount of AuSn, for example, was vapor-deposited on the optical element mounting portion in advance. Next, the thin tubes 4 are aligned in the V-grooves by using a fixing jig (not shown).
The optical element array section 1 is manufactured by adhering and fixing with the following accuracy. At this time, the thin tube 4 was fixed 2 mm inside from the end of the V-groove substrate 3 on the optical fiber insertion side.

Similarly, the optical fiber array section 2 is manufactured. First, the thin tube 41 is bonded and fixed to the V-groove substrate 31. At this time, the thin tube 41 is 2 mm from the end of the V-groove substrate 31.
I made it stick out. A large number of optical fibers 5 are collectively inserted into the thin tube 41 by using a jig (not shown), the tips are aligned with an accuracy of μm or less, and then fixed. The length of the optical fiber 5 was adjusted in advance so that the tip of the optical fiber 5 was aligned with the marker 8 of the V-groove substrate 3 at the time of coupling. In addition, this matching method is, for example,
Using another optical element array section 1 without an optical element mounted,
The insertion length in the thin tube 41 may be adjusted using a jig so that the tip of the fiber 5 is aligned with the marker 8 provided on the V-groove substrate 3. Finally, the thin tube 4 of the optical element array section 1
Then, the optical fiber array 5 of the optical fiber array section 2 is inserted and fixed, and the optical coupling element of this embodiment is completed.

As described above, in this embodiment, the multi-core fibers can be optically coupled at the same time without requiring complicated alignment, and the time required for coupling can be shortened. Further, since the length of the thin tube 4 of the optical element array section 1 is shorter than the V groove and the length of the thin tube 41 of the optical fiber array section 2 is longer than the V groove, the thin tube 41 of the optical fiber array section 2 is It is positioned in the V groove 1 and the mechanical strength of the optical coupling portion can be maintained.

Incidentally, in this embodiment, it may be fixed to a flat substrate (not shown), for example, a Si substrate, if necessary. Further, the light emitting element 6 and the V groove substrate 3 may be integrated. Further, the V groove is not limited to the V groove in the strict sense, and may be processed into a U groove or the like by high precision cutting. Further, the width and depth of the V-grooves of the V-groove substrate 3 and the V-groove substrate 31 and the thin tubes 4 and 4 are provided.
The outer diameters of 1 may be different.

Next, a second embodiment of the present invention will be described with reference to FIG. The present embodiment is an example in which a surface emitting element array or a light receiving element array is applied as the optical element array. In this embodiment, as the optical fiber, it is necessary to use the obliquely polished fiber array 7, but Japanese Patent Application No. 4-159.
In the fiber array manufactured according to the invention of No. 420, since the fiber tip can be projected from the V-groove substrate 31 by several mm, it is possible to easily manufacture the coupling structure in a short time in the same manner as the above-mentioned spherical fiber. You can

The oblique polishing fiber 7 is the optical element array 6
The outer diameters of the thin tubes 4 and 41 may be selected so that the thin tubes 4 and 41 are located above. The abutting surface of the optical element array portion and the fiber array portion may be not only the Si substrate but also the glass surface whose end surface is a polished surface.

[0019]

As described above in detail with reference to the embodiments, in the optical coupling device of the present invention, since the optical element array section and the optical fiber array section are separately manufactured, the optical fiber array section is It is not affected by mounting the optical element array, and the tips of the fibers can be aligned at once by using a jig. Therefore, even if the number of fiber cores increases, the time required for aligning the ends does not become long. Moreover, since the inner diameter of the thin tube of the optical element array section and the inner diameter of the thin tube of the optical fiber array section are both equal to the outer diameter of the fiber, complicated alignment is required by inserting and fixing the fiber array into the thin tube of the optical element array section. The multi-core fibers can be optically coupled at the same time without shortening the time required for coupling.
At this time, at least the alignment accuracy of the thin tubes in the optical element array is ±
If it is within 1 μm, the alignment accuracy of the fiber array in the fiber array portion is within ± 1 μm. Moreover, since the optical element array section and the fiber array section can be manufactured separately, the yield of the optical coupling device is improved. Further, by setting the thin tube length of the optical element array portion shorter than the V groove and making the thin tube length of the optical fiber array portion longer than the V groove, the mechanical strength of the optical coupling portion can be maintained.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an optical coupling device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of an optical coupling device according to a second embodiment of the present invention.

FIG. 3 is a schematic view of a conventional optical coupling device.

[Explanation of symbols]

 1 Optical Element Array Section 2 Fiber Array Section 3, 31 V-Groove Substrate 4, 41 Capillary Tube 5 Optical Fiber Array 6 Light Emitting Element Array (Light Emitting Element Array) 7 Oblique Polished Fiber Array

Front page continued (72) Inventor Yukio Irita 1-3-1 Gotenyama, Musashino City, Tokyo NTT Advanced Technology Co., Ltd.

Claims (2)

[Claims] 1. An optical element mounting portion and a first V groove are formed on a first substrate, and a first thin tube having an inner diameter equal to the outer diameter of an optical fiber is fixed to the first V groove. A second V groove having the same pitch as the first V groove is formed on the optical element array portion and a second substrate having the same thickness as the first substrate, and the second V groove is formed. A second thin tube having the same inner diameter as the first thin tube is fixed, and further comprises an optical fiber array section in which an optical fiber is inserted into the second thin tube, and the first of the optical element array section is formed. An optical coupling device that optically couples by inserting the optical fiber of the optical fiber array section into the thin tube, wherein the first thin tube end is fixed deeper than the first substrate end, and The optical coupling device, wherein the end of the second thin tube projects more than the end of the second substrate. . 2. The first thin tube according to claim 1,
An optical coupling characterized in that the inner diameter in the vicinity of the optical fiber insertion opening is larger than the outer diameter of the optical fiber, and the second thin tube has an outer diameter in the vicinity of an end smaller than the outer diameter of the central portion of the second thin tube. apparatus.