JPH0668568B2 - How to connect the optical waveguide to the optical fiber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Outline] At a side edge of a substrate, an elongated substrate protrusion having an optical waveguide terminal is provided to reduce the heat capacity on the optical waveguide side, and the optical fiber end face is brought into contact with the optical waveguide end face. By fusing an optical waveguide and an optical fiber, it is possible to provide a connection method that facilitates connection work and has high connection reliability.

[Industrial application field]

The present invention relates to an improvement in a method for connecting an optical fiber to an optical waveguide formed on a substrate.

In recent years, an optical device has been formed by forming an optical waveguide on a surface of a substrate such as a glass plate or a silicon wafer plate, inserting an optical film in the optical waveguide, or mounting an optical element such as a light receiving element or a light emitting element. We are promoting miniaturization and cost reduction of optical couplers, optical multiplexers / demultiplexers, optical attenuators, optical integrated circuits, etc.

At this time, there is a demand for a highly reliable connection method for connecting an optical waveguide of an optical device and an optical fiber that is an external transmission line.

[Conventional technology]

FIG. 2 is a perspective view showing a conventional method, in which an optical waveguide 2 is formed on a surface of a substrate 1 made of glass, silicon or the like, and a side edge portion of the substrate 1 on an extension line of an optical waveguide terminal 2A is provided. A guide block 4 having a groove into which the end portion of the optical fiber 3 is inserted is provided. This substrate 1 has a rectangular shape, and its width (which means a direction orthogonal to the optical waveguide terminal 2A) is, for example, about 10 mm.

The guide block 4 is formed by depositing quartz glass on the upper surface of the substrate 1, covering it with a partial mask corresponding to the guide block 4, and performing dry etching or the like.

The optical waveguide 2 is formed as follows.

First, a clad layer is formed on the surface of the substrate 1 and a core layer is formed on the upper surface of the clad layer by a method such as a vacuum vapor deposition method, a sputtering method, a CVD method, and a flame deposition method. Next, the core layer and the clad layer are etched to form an optical waveguide having a desired pattern, and then the clad layer is formed on the entire surface of the optical waveguide except the optical waveguide end face 2a to complete the optical waveguide 2. Let

That is, the optical waveguide 2 has a prismatic core layer formed in the center and clad layers formed on four side surfaces of the core layer.
The cross-sectional shape of this core layer is a predetermined dimension determined by the core diameter of the optical fiber 3 to be connected, and is, for example, a prism of 10 μm to 60 μm.

The end portion of the optical fiber 3 is inserted into the groove of the guide block 4 as described above, and the axis of the optical fiber 3 is set to the optical waveguide end.
After aligning with the axis of 2A, the optical fiber end face 3a is brought into contact with the optical waveguide end face 2a, and in this state, the contact end face portion is irradiated with CO ₂ laser light to fuse the optical waveguide 2 and the optical fiber 3 to each other. is doing.

[Problems to be solved by the invention]

However, in the above conventional method, the substrate portion on which the optical waveguide terminal 2A is formed is as large as the width of the substrate 1. Therefore, when the contact end face portion between the optical waveguide and the optical fiber is irradiated with laser light, A large amount of heat diffuses.

Therefore, the optical waveguide and the optical fiber are completely fused,
Moreover, it is difficult to set the heating specifications, that is, the power of the laser beam and the irradiation time for heating the core to such an extent that the core is not deformed or damaged, and as a result, the reliability of the connection is low. It was

[Means for solving problems]

In order to solve the above-mentioned conventional problems, the method of the present invention provides, as shown in FIG. 1, an elongated substrate protrusion 10 having an optical waveguide terminal 2A formed on the side edge of the substrate 1. Then, the optical fiber end face 3a is brought into contact with the end face 2a of such an optical waveguide terminal 2A, and the contact end face portion is irradiated with laser light or the like so that the optical waveguide 2 and the optical fiber 3 are fused. Is.

[Action]

According to the above method of the present invention, the substrate 1 of the optical waveguide terminal 2A portion
Is small, the heat capacity on the optical fiber 3 side and the heat capacity on the optical waveguide terminal 2A side are substantially equal and small. Therefore, the heating specifications by the laser light are stable, the setting is easy, and the reliability of connection is improved.

〔Example〕

The method of the present invention will be specifically described below with reference to the drawings. The same reference numerals denote the same objects throughout the drawings.

FIG. 1 is a perspective view showing an embodiment of the method of the present invention,
An elongated substrate protrusion 10 is provided on the side edge of the substrate 1, and an optical waveguide terminal 2A is formed on the upper surface of the substrate protrusion 10.

The width of the substrate protrusion 10 is, for example, 150 μm, which is slightly larger than the outer diameter of the optical fiber 3, and the length thereof is about 5 mm.

The axis of the optical fiber 3 is aligned with the axis of the optical waveguide terminal 2A, the optical fiber end face 3a is brought into contact with the optical waveguide end face 2a, and the abutting end face portion is irradiated with, for example, CO ₂ laser light to obtain the optical waveguide. And the optical fiber 3 are fused.

As described above, by providing the substrate protrusions 10 and fusing them, the power of the laser light and the irradiation time can be easily set, and the reliability of connection is improved.

In the illustrated example, the optical waveguide terminal 2A is formed so that the optical waveguide end face 2a and the projecting end face 10a of the substrate projecting portion 10 are aligned with each other, but the invention is not limited to this, and the substrate projecting portion is not limited thereto. The protrusion length of 10 is made slightly larger than the end face 2a of the optical waveguide, and the end of the optical fiber 3 is supported on the upper surface of the substrate protrusion 10.
The contact end surface may be fused.

〔The invention's effect〕

As described above, the method of the present invention is a method of providing an elongated substrate protrusion having an optical waveguide terminal formed on the side edge of the substrate and fusing the optical waveguide and the optical fiber together. The original setting is easy, the connection work is easy, and the connection reliability is high, which is an excellent effect in practical use.

[Brief description of drawings]

 FIG. 1 is a perspective view showing an embodiment of the method of the present invention, and FIG. 2 is a perspective view showing a conventional method. In the figure, 1 is a substrate, 2 is an optical waveguide, 2A is an optical waveguide terminal, 2a is an optical waveguide end face, 3 is an optical fiber, 3a is an optical fiber end face, 10 is a substrate protrusion, and 10a is a protrusion end face.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Kazuhiko Soeda, 1015 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa, Fujitsu Limited (72) Inventor, Kazuya Sasaki, 1015, Kamikodanaka, Nakahara-ku, Kawasaki, Kanagawa, Fujitsu Limited ( 56) References JP-A-60-17406 (JP, A)

Claims (1)

[Claims] 1. An elongated substrate projection (10) having an optical waveguide terminal (2A) formed on a side edge of a substrate (1), and an optical fiber end face (3a) is brought into contact with an optical waveguide end face (2a), A method for connecting an optical waveguide and an optical fiber, characterized in that the optical waveguide (2) and the optical fiber (3) are fused together.