JPH04178604A - Connector of optical waveguide and optical fiber - Google Patents

Abstract

PURPOSE:To enhance the coupling efficiency of light and to facilitate the connecting operation thereof by using an intermediate waveguide block, the side face of which is an ellipsoid of revolution. CONSTITUTION:Two end faces 33, 34 respectively including two focuses A, B are provided on the side face of the ellipsoid of revolution of the intermediate frequency block 3. The light introduced into the block 3 from the end face of the core 51 of an optical fiber 5 is radiated around the end face of the core 51 if the end face 11 of an optical waveguide 1 and the end face of the core 51 of the optical fiber 5 are so connected that these end faces exist respectively at the focuses A, B. The light advancing rectilinearly in the major axis direction in the block 3 is introduced as it is into the optical waveguide 1 at this time, but the light which does not advance rectilinearly is reflected by the side face 31 consisting of the ellipsoid of revolution and is completely condensed to another focus B. Since the end face 11 of the optical waveguide is disposed at this focus B, all the light is surely introduced into the optical waveguide. 1. The coupling efficiency of the light between the optical waveguide 1 and the optical fiber 5 is enhanced by constituting the connector in such a manner.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a connection device for an optical waveguide and an optical fiber.

[Conventional technology]

Conventionally, substrates with optical waveguides formed on or inside them have been used in the field of various optical devices.

In order to introduce light from the optical fiber 1 into this optical waveguide, the end face of the optical fiber is connected so as to face the end face of the optical waveguide.

Here, conventional connection devices between an optical waveguide and an optical core have the following structure.

■First, there is a structure in which the end faces of an optical fiber and an optical waveguide are directly connected to each other (BUTT-JOINI method). To fix the two, adhesive or laser welding may be used.

(2) There are also optical fibers in which the tip of the optical fiber is made spherical or the core shape of the optical fiber is made thin so that the core shape approximates the cross-sectional shape of the optical waveguide, thereby increasing the coupling efficiency.

(2) There is also a method in which a lens is inserted between the optical fiber female and the optical waveguide, or the vicinity of the connecting end surface of the optical waveguide is shaped to have a lens effect.

■In addition, the optical fiber is glued to the optical waveguide - the fixing adhesive has a light focusing effect.1. ,,-[,Using two types of adhesives with different refractive indexes, form a ``-7 lower part and a cladding part in the adhesive11, or create a cylindrical part, and then light 2 Light from the output end σ7) Some structures are wide or small.

[The invention is solved! The task I am trying to do is 1. Therefore, each of the above conventional examples has the following problems.
Since T2 is directly determined by the alignment accuracy of the optical fiber and the optical waveguide, the alignment error in positioning becomes severe, and even if the position is slightly blurred, the coupling efficiency will deteriorate considerably.

(2) , 1: In the conventional example described in ■, the previous I.
・The lower shape of ＼ is close to the cross-sectional shape of the optical waveguide.
1) Law is difficult and difficult. In addition, if the tip of the optical fiber is spherical, the connection and fixation of the optical waveguide to the optical eye/
The H-method is unstable compared to the connection fixing force method of the optical waveguide (8), which normally forces and loosens the end face in 7).

(Considering the conventional example ζ5' of March 2nd article ■, when inserting a lens between the optical waveguide and the optical waveguide, the number "Mitaren Q)
L.

〉/S production is expensive. Furthermore, when forming a reflection portion in the optical waveguide body, the production of the optical waveguide becomes complicated.

In the conventional example described in (4,)-,
, the bonding and fixing process becomes complicated.

The present invention has been made in view of the above points, and has seven aspects of (a) and (b).
Assuming its purpose: Niroha, optical waveguide and optical no? 1' It is possible to stabilize and increase the coupling efficiency of light between
7 has a restrained structure, and is capable of providing a connecting device between the leading waveguide and the optical fiber, which is easy to connect.

[Failure to solve the problem]

In order to solve the above problems, the present invention (1-a) is made of a material that transmits a predetermined wavelength that can be optically used, and has an intermediate conductor on the side surface 31 of a spheroidal surface (or ellipsoidal surface ○). The wave block 3 is provided with 5, and the intermediate waveguide block 73 is provided with 1.
a focal point A of the spheroidal surface (or ellipsoidal surface 2-');
The end faces 33 and 34 of the optical waveguide 1 and the optical fiber 5 are installed, and the end face 11 of the optical waveguide 1 and the m=1 a51 end of the optical fiber 5 are installed. 2) The intermediate waveguide block I7 (3C) and the two end surfaces 33 are placed so that the focal point A, B or the vicinity thereof is at the position q'.
, 34 connected to 13. It was configured as follows.

[Effect]

] - As described above, the misalignment of the connection of the intermediate waveguide block 3 between the optical waveguide 1 and the optical fiber 5 is caused by the construction of the optical fiber 5.
The light introduced into the intermediate waveguide block 3 from one end is radiated around the end face of the core 51. At this time, the light that travels straight in the long axis direction in the intermediate waveguide 3 is directly introduced into the optical waveguide 1, but the light that does not travel straight in the long axis direction passes through the spheroid 1nj (or +i circular surface). ), and all of the light is focused on the other focal point B. Since the end face 11 of the optical waveguide 1 is not completely arranged at this focal point B), all of the end face 11 of the optical waveguide 1 is reliably introduced into the optical waveguide 1. By establishing the configuration in this way, the optical waveguide 1. The coupling efficiency of light between the optical fiber 5 and the optical fiber 5 can be increased.

〔Example〕

Hereinafter, one embodiment of moxibustion according to the present invention will be described in detail based on the drawings.

FIG. 1 shows one embodiment of the present invention, and FIG.
is a plan view, and the same figure (b) is a hypervisual area.

As shown in the figure, the optical waveguide and optical fiber connection device according to the present invention is constructed by disposing an intermediate waveguide block 3 between the optical waveguide 1 and the optical fiber 5. ing.

Below, each component will be explained in detail.

The optical waveguide 1 is provided on a substrate 21, and the end surface 11 of A
and end surface 2 of the substrate 2 are cut perpendicularly to the optical axis of the optical waveguide 1.

The optical fiber 5 is constituted by a normal optical fiber (for example, a single mode optical fiber/N) with an end face 53 cut perpendicularly to the optical axis.

- The intermediate waveguide block 3 is made of a material that is optically transparent to the wavelength of the light to be used. It has a shape in which end faces 33 and 34 are provided by cutting in a vertical plane.In other words, this intermediate waveguide pro- ri 3 has a side surface 31 as a spheroidal surface and both end faces 33 and 34 as flat surfaces. It is configured as

Here, FIG. 2 is a side sectional view of this intermediate waveguide block 3 taken along a plane including the long axis.

As shown in the figure, both end surfaces 3 of this intermediate waveguide block 1]
3.34 have the foci A and B of the spheroid in them, respectively.
It is cut perpendicular to the long axis to include the Note that both end surfaces 33 and 34 are optically polished. Furthermore, it would be a good idea to coat both end faces 33 and 34 with an anti-reflection film.

On the other hand, it is desirable to provide an optical reflective film on the side surface 31 of the intermediate waveguide block 3 so that the light emitted from the optical fiber 5 can be completely reflected.

The optical components 1- are assembled by connecting the end surface 53 of the optical fiber 5 and the end surface 11 of the optical waveguide 1 to both end surfaces 33 and 34 of the intermediate waveguide block 3, respectively. At this time, the center of the end face of the core 51 of the optical fiber 5 is located at the focal point A in the end face 33 of the intermediate waveguide block 3, and the center of the end face of the optical waveguide 1 is located at the position of the focal point A in the end face 34 of the intermediate waveguide block 3. The connection can be made so that it is at the focal point B.

Next, the operation of this optical waveguide and optical fiber connecting device will be explained.

FIG. 3 is a diagram showing the state of light completely introduced into the intermediate waveguide block 3 from the optical fiber 5.

As shown in the figure, the light that has been completely introduced into the intermediate waveguide block 3 from the end face of the core 51 of the optical fiber 5 is completely radiated around the end face of the core 51.

The light traveling straight in the long axis direction within the intermediate waveguide block 3 is introduced into the optical waveguide 1 as it is.

On the other hand, all of the light that does not travel straight in the long axis direction within the intermediate waveguide block 3 and is reflected by the side surface 31 formed of a spheroidal surface is focused on the other focal point B due to the nature of the ellipse. Since the end face of the optical waveguide 1 is completely arranged at this focal point B, all of the light can also be introduced into the optical waveguide 1.

With this configuration, the optical waveguide 1 and the light 774
The coupling efficiency of light between 65 can be increased.

On the other hand, even when the light is completely introduced from the optical waveguide 1 into the intermediate waveguide block 3, it is similarly focused on the focal point A, and the light is effectively introduced into the core 51 of the optical fiber 50.

In the above embodiment, the entire surface of the side surface 31 of the intermediate waveguide block 30 is formed of a spheroidal surface, but the present invention is not limited to this, and a part of the side surface 31 may be formed of a spheroidal surface. good.

FIG. 4 is a perspective view showing another embodiment of the intermediate waveguide block.

This intermediate waveguide block 3' has a shape in which both ends of a thin elliptical cylinder in the long axis direction are cut perpendicularly to the long axis including focal points A and B of the ellipse. That is, the first
Unlike the intermediate waveguide block 3 shown in the figure, the intermediate waveguide block 3' has an ellipsoidal surface 36 on its side surface, and has planar end surfaces 33' and 34' at both ends. It is composed of With this configuration, the light emitted from the end face (focal point A) of the optical fiber into the intermediate waveguide block 3' and completely reflected by the ellipsoidal surface 36 gathers approximately in the vicinity of the focal point B and is introduced into the optical waveguide 1. , the coupling efficiency of light between the optical waveguide 1 and the optical fiber 5 can be increased.

Note that in each of the above embodiments, a case is shown in which both end faces of the intermediate waveguide block are completely cut on a plane perpendicular to the long axis of the ellipse, but the present invention is not limited to this. That is, the end faces can be cut into any shape as long as they include the focal points A and B of the ellipse.

〔Effect of the invention〕

As described above in detail, the optical waveguide and optical fiber connection device according to the present invention has the following excellent effects.

(1) Since the end face of the optical waveguide and the core end face of the optical fiber are respectively placed at the two focal points of the intermediate waveguide block, the light emitted from the core end face of the optical fiber into the intermediate waveguide block will be reliably transmitted through the optical waveguide block. is introduced into the end face of the optical waveguide, thereby increasing the coupling efficiency between the optical waveguide and the optical fiber. Note that the same applies when light is incident from the opposite direction.

(Also, it is possible to connect the optical fiber or the intermediate waveguide block to the end face of the optical fiber or optical waveguide without having to make a special shape for the end face structure of the terminal part. Therefore, the manufacturing of these parts and the connection between these parts are easy. The answer is easy and certain.

(3) The end face including the focal point connecting the optical waveguide end face of the intermediate waveguide block and the core end face of the optical fiber can be configured in a planar shape. When configured in a planar shape, a large contact area can be obtained, and the connection can be made stably, reliably, and easily.

(4) The optical waveguide and optical fiber can be connected to the intermediate waveguide block by bringing the end surfaces of the optical waveguide and optical fiber into direct contact with both end surfaces provided on the intermediate waveguide block. This makes the connection easier than when the focal point is located outside the lens.

[Brief explanation of drawings]

1(a) and 1(b) are diagrams showing one embodiment of the present invention, FIG. 2 is a side sectional view of the intermediate waveguide block 3 cut along a plane including the long axis, and FIG. 3 is a diagram showing the optical fiber 5. to intermediate waveguide block 3
FIG. 4 is a perspective view showing another embodiment of the intermediate waveguide block. In the figure, 1... optical waveguide, 11... end face, 3, 3'...
...Intermediate waveguide block, 33.34...End face, A, B
. . . focal point, 5 . . . optical fiber, 51 . . . core.

Claims (1)

[Claims] A connecting device for an optical waveguide and an optical fiber, comprising an intermediate waveguide block made of a material that transmits a predetermined optically usable wavelength and having an elliptical or spheroidal surface on its side surface. , the intermediate waveguide block is provided with two end faces each including two foci of the ellipsoid or spheroidal surface, and the optical waveguide and the optical fiber are arranged such that the end face of the optical waveguide and the core end face of the optical fiber are located at the two ends of the optical fiber. A connection device for an optical waveguide and an optical fiber, characterized in that the connection device is connected to two end faces of the intermediate waveguide block so as to be located at or near the focal point.