JP3268541B2 - Optical coupling method - 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 method used for an optical communication device or the like.

[0002]

2. Description of the Related Art In coupling an optical fiber array and an optical element, for example, an end face type light emitting element array, it is important to couple the optical fiber array with a small connection loss and high efficiency. Therefore, an optical coupling system between a light emitting element array and an array of front-end fibers in which the fiber ends are processed into a lens shape is often used. In this coupling system, the number of adjustment axes is six in both the orthogonal axis and the rotation axis, and high-precision optical coupling technology is required.

FIG. 3 shows a basic configuration of an optical module. As shown in FIG.
2. A fiber mounting board 33 is arranged, a light emitting element 34 is mounted on the light emitting element mounting board 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 mounting board 33. Is installed.

In this optical axis adjusting method, a light emitting element mounting substrate 32 is fixed to a substrate 31, a fiber mounting substrate 33 is moved on the substrate 31, and a light emitting element 34 and a fiber array 36 are aligned. , Fiber mounting board 3
The method of fixing 3 on the substrate 31 is general. 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. Further, when the light emitting position of the light emitting element is changed, there is a problem that it is difficult to easily change the position of the optical fiber to be coupled thereto.

[0006] The present invention has been made in view of the above prior art, the optical coupling method between the light emitting element array and the optical fiber array, and an object thereof is aligned to provide a simple optical coupling method .

[0007]

According to a first aspect of the present invention, there is provided an optical coupling method comprising: an optical element array;
In an optical coupling method for coupling with a fiber array,
In the element array mounting part and the array pitch of the optical element array
Optical fiber array having a plurality of V-grooves of equal pitch
And the optical element array mounting part are formed on the same substrate.
The optical element array is fixed to the
Have an inner diameter equal to the outer diameter of the constituent optical fiber and the outer diameter
Prepare multiple thin tubes with different dimensions, and after inserting the optical fiber
The optical element has an optical axis height of the optical fiber fixed to the substrate.
Combine with the light emitting part or light receiving part of the optical element that constitutes the ray
A thin tube having an outer diameter dimension to be the height is formed from the plurality of thin tubes.
Select, align and fix the selected capillary in the V-groove,
Inserting the optical fiber array into a thin tube fixed in a V-groove
It is characterized by being fixed. Also achieved the above objective
The optical coupling method according to claim 2 of the present invention is
In the optical coupling method described above, the capillary is an optical fiber array.
The inner diameter near the insertion port is larger than the outer diameter of the optical fiber, and
In the vicinity of the capillary end opposite to the optical fiber array insertion port
The characteristic is that the diameter is smaller than the outer diameter of the optical fiber.

[0008]

According to the present invention, an optical device mounting substrate and the optical fiber array mounting substrate, i.e., the fixed substrate for an optical fiber aligned with the same substrate, and prepare different optical fiber insertion fine tube of several outer diameter The outer diameter dimension is selected such that the optical axis height of the optical fiber after insertion of the optical fiber becomes a predetermined height for coupling with the light emitting portion or the light receiving portion of the optical element.
Further, the thin tube is fixed to the V groove corresponding to an array pitch of the light element formed on the substrate described above, to insert the optical fiber.

[0009] The thin tube is equal major inner diameter as the optical axis height does not vary during the insertion optical fiber and optical fiber outer diameter, the outer diameter is possible to manufacture the high precision any dimension ± 1 [mu] m, It can easily cope with a change in the height of the light emitting portion or the light receiving portion of the optical element. Further, with the optical fiber insertion hole and the other side of the inner diameter near the thin tube end is made smaller than the optical fiber outer diameter cone, when the optical fiber insertion, in particular the light emitting portion or light receiving portion of the end face type optical element Can be prevented from being damaged.

[0010]

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 Si-V groove substrate for aligning optical fibers, 2 is a capillary, 3 is an optical fiber, and 4 is an optical element.

The optical fiber alignment V- groove substrate 1 has a width of 178 μm on a Si substrate by photolithography and anisotropic etching.
In this example, four V-grooves having a length of m, a depth of 123 μm, and a pitch of 500 μm are formed. The dimension of the formed V-groove was a processing accuracy on the order of μm. The capillary 2 is made of, for example, glass or ceramic and has a length of 10 mm, an inner diameter of 126 μm, and an outer diameter of 242 μm, 244 μm, 246 μm, 248 μm, 2 μm.
Five types of 50 μm were prepared.

As the optical fiber 3, an optical fiber having an outer diameter of 125 μm was used. The optical element 4 is directly mounted on the optical fiber alignment V-groove substrate 1 at a predetermined position with high precision of 1 μm or less by a high-precision bonding device (not shown). It is 85 μm from the surface.
As the optical element 4, for example, an end face type light emitting element array is used. As for the solder, for example, a predetermined amount of AuSn is deposited on the V-groove substrate 1 side or the optical element (light emitting element) 4 side.

[0013] outer diameter of the light emitting portion adapted to the height fine tube 2 of the light-emitting element used as an optical element 4 in this case was 246Myuemu. Therefore, by using a fixing jig (not shown), align the fine tube outer diameter 246μm in V grooves, by fixing, it was possible to align the optical fiber center to the light emitting element emitting point. The alignment and fixing of the fine tube, the tip aligned fine tube end is not required. In the case where the thickness of the optical device 4 for bonding to the substrate varies, or solder thickness in order to increase the bonding strength is changed emitting unit height increases, fine tube 2
The height can be easily adjusted by simply changing the outer diameter of the.

[0014] According to the present embodiment as described above, to secure the Hososuga 2 normal fiber alignment V-groove substrate 1 fabricated with a precision of μm order by anisotropic etching having a predetermined outer diameter, the fine By inserting the optical fiber 3 into the tube 2, the alignment of the light emitting portion or the light receiving portion of the optical element 4 in the height direction (Y direction) and the optical element array pitch direction (X direction) can be easily performed.

Therefore, the alignment is performed only in the optical axis direction (Z direction) as compared with the prior art which requires six axial directions, so that the time required for optical axis adjustment is greatly reduced. The spring and screws fine adjustment device is not required, and the optical coupling system can be downsized, and further, as a fine tube 2, by the internal shape and a cone shape, when the optical fiber insertion, in particular of the end face type There is an advantage that there is no possibility of damaging the light emitting portion or the light receiving portion of the optical element.

In the above embodiment, the light emitting element and the optical fiber are fixed on the same substrate. However, the light emitting element and the optical fiber are separately fixed on substrates having the same thickness. Each may be fitted into a groove machined with precision. Further, the optical fiber alignment V-groove substrate and the light emitting element may be integrated. FIG. 2 shows a second embodiment of the present invention. Thin tube shown in FIG. (Glass tube) 21, the fine tube tip inner diameter has a fiber outside diameter larger than the cone-shaped, the optical fiber insertion hole and an inside diameter of the optical fiber out of the vicinity of the fine tube end opposite is obtained by a small reverse conical than the diameter, except for the inner diameter shape has the same outer diameter as fine tube 1 shown in FIG. 1, a length.

[0017] For thin tube 21 of this embodiment is the tip thin tube has a cone-shaped, when inserting the optical fiber into small tube 21 can be inserted smoothly, moreover, the insertion opening and the opposite side since the inner diameter is in the reverse conical, fine tube 21
The length protruding from the light emitting element is limited, does not reach the light emitting element emission surface, and the light emitting element is not damaged by the fiber tip.

In the above embodiment, the connection between the end face light emitting element array and the fiber array has been described. However, the present invention is not limited to this. Can be similarly applied. Furthermore, the above embodiment is performed alignment in the height direction by changing the outer diameter of fine tube, the outer diameter of fine tube may be changed V groove height is constant. Further, the groove shape is not limited to the V-groove in a strict sense, and also includes a U-groove or the like that is cut with high precision, and the substrate material may be not only Si but also crystallized glass. .

[0019]

As described above in detail with reference to the embodiments, according to the present invention, the optical axes of the optical element array and the optical fiber array can be easily adjusted only by inserting the optical fiber array into the thin tube. Is possible. Therefore, not only a high-precision alignment device is not required, but also a positioning adjustment mechanism such as a spring or a screw is not required, so that the coupling system can be downsized. Further, by setting the inner diameter of the thin tube to be a cone shape, it is possible to prevent the light emitting element from being damaged by mistake when the optical fiber is inserted into the thin tube and to prevent the light emitting element from being damaged.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first embodiment of the present invention.

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

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

[Explanation of symbols]

1 optical fiber aligning Si-V groove substrate 2, 21 optical fiber insertion fine tube 3,36 optical fiber 4 and 34 optical element 31 substrate 32 light-emitting element mounting substrate 33 fiber mounting substrate 35 sink

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Yukio Irita 1-3-1 Gotenyama, Musashino-shi, Tokyo NTT Advanced Technology Co., Ltd. (56) References JP-A-53-84744 (JP) JP-A-4-161907 (JP, A) JP-A-2-93505 (JP, A) JP-A-5-60950 (JP, A) JP-A-1-224711 (JP, A) (58) Field surveyed (Int.Cl. ⁷ , DB name) G02B 6/24-6/26 G02B 6/30-6/43

Claims (2)

(57) [Claims] An optical element array is connected to an optical fiber array.
In the optical coupling method, the optical element array
A plurality of pitches equal to the array pitch of the light storage element array
Optical fiber array fixing part with V groove on the same substrate
Forming the optical element array on the optical element array mounting portion.
Fixation of the optical fibers constituting the optical fiber array
A plurality of thinners with inner diameter equal to outer diameter and different outer diameter
Prepare the tube and set the optical axis height of the optical fiber after inserting the optical fiber.
Optical element forming an optical element array fixed to the substrate
The outer diameter dimension, which is the height to be combined with the light emitting unit or light receiving unit
The capillary having the selected capillary is selected from the plurality of capillaries.
A tube is aligned and fixed in the V-groove, and the thin tube fixed in the V-groove
Inserting and fixing the optical fiber array inside
Optical coupling method to be characterized. 2. The optical coupling method according to claim 1, wherein
The inside diameter of the capillary near the optical fiber array insertion port is
Larger than the outer diameter of the bar, and
The inside diameter near the opposite end of the capillary is smaller than the outside diameter of the optical fiber.
An optical coupling method that is characterized by the fact.