JP2001249245A - Connection method between optical waveguide and optical fiber and optical module - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a method for connecting an optical waveguide and an optical fiber and an optical module, which require only a short time for alignment when a waveguide element and an optical fiber block are abutted. SOLUTION: A waveguide element 20 and an optical fiber block 2 are provided.
6 before connecting them to the alignment marks 24, 3
1 and connecting the waveguide element 20 and the optical fiber block 26 while fitting the alignment marks 24 and 31 together, it is not necessary to perform fine alignment such as optical axis alignment, and the connection can be made in a short time. can do.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for connecting an optical waveguide to an optical fiber and an optical module.

[0002]

2. Description of the Related Art A waveguide device for an optical module forms a core (waveguide) having a desired shape by etching a core film having a high refractive index on a substrate such as quartz glass or silicon. It has a structure covered with a cladding layer having a lower refractive index than the core. This waveguide element for an optical module has a good matching with a silica-based optical fiber, and is a practical optical component in optical communication.

Conventionally, the connection between a waveguide element and an optical fiber block has been performed by the following method.

FIG. 7 is a partial side sectional view of an optical module to which a conventional connection method between an optical waveguide and an optical fiber is applied. FIG. 8 is a sectional view of a waveguide element used in the optical module shown in FIG. FIG. 9 is a plan view of an optical fiber block used in the optical module shown in FIG.

As shown in FIG. 7, a waveguide element 1 and an optical fiber block 2 are connected such that cores 3 and 4 are joined to each other.

[0006] As shown in FIG.
And a plurality of (only one is shown in the figure for simplicity of description) cores (optical waveguides) 3 formed on the substrate 5.
And a cladding layer 6 formed so as to cover the core 3 and the substrate 5. Adhesive dummy plates 7 and 8 are attached to both surfaces with an adhesive 9.

[0007] As shown in FIG.
Is a plurality of optical fibers 1 (only one is shown in the figure) composed of a core 4 and a cladding layer 10 covering the core 4.
1 and an upper V-groove block 12 and a lower V-groove block 13 in which a pair of upper and lower V-grooves sandwiching the optical fiber 11 are arranged so as to be arranged at the same pitch as the pitch of the core 3 of the waveguide element 1 It is composed of

The end face of the core 3 of the optical waveguide of the waveguide element 1 shown in FIG. 8 and the end face of the core 4 of the optical fiber 11 of the optical fiber block 2 shown in FIG.

Next, light enters from the optical fiber 11 side and receives light on the exit side of the waveguide element 1.

The optical fiber block 2 is finely moved, such as up and down, left and right, or rotated, and when the optical output is maximized, the optical waveguide element 1 and the optical fiber block 2 are fixed by using a thermosetting resin 14 as shown in FIG. An optical module as shown in FIG.

[0011]

However, in the above-mentioned conventional technique, it takes a long time from the alignment of the waveguide element 1 to the optical fiber block 2 to the fixing thereof. In particular, there is a problem that it takes a lot of time for alignment when the waveguide element 1 and the optical fiber block 2 are butted.

Accordingly, an object of the present invention is to solve the above-mentioned problems and to provide a method of connecting an optical waveguide and an optical fiber and an optical module in which alignment when a waveguide element and an optical fiber block are abutted in a short time. Is to do.

[0013]

In order to achieve the above object, a method of connecting an optical waveguide to an optical fiber according to the present invention comprises an optical waveguide in which a core through which light propagates is covered by a cladding layer having a lower refractive index than the core. The formed waveguide element and the optical fiber are V
In the connection method for connecting an optical fiber block disposed on a groove, after the surface of a cladding layer of an optical waveguide element is flattened, an alignment comprising a projection or a groove is formed on the cladding layer for alignment with the optical fiber block. Form a mark, form another alignment mark consisting of a groove or a projection that fits with the alignment mark in the optical fiber block, and fit the two alignment marks to adjust the waveguide element and the optical fiber block without alignment. Connect.

An optical module according to the present invention comprises: a waveguide element having an optical waveguide formed by covering a core through which light propagates with a cladding layer having a lower refractive index than the core; and an optical fiber having an optical fiber disposed on a V-groove. In an optical module connected to a block, an alignment mark formed of a protrusion or a groove formed on a flattened surface of a clad layer of an optical waveguide element and another alignment mark formed of a groove or a protrusion formed on an optical fiber block And the waveguide element and the optical fiber block are connected without any adjustment.

In addition to the above configuration, the optical module of the present invention comprises:
Preferably, the projections are made of a high molecular organic material such as a polymer.

According to the present invention, before connecting the waveguide element and the optical fiber block, an alignment mark is formed on both, and the waveguide element and the optical fiber block are connected while fitting the two alignment marks. Accordingly, it is not necessary to perform fine alignment such as optical axis alignment, and connection can be made in a short time.

[0017]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a partial sectional view showing an embodiment of an optical module to which the method for connecting an optical waveguide and an optical fiber according to the present invention is applied. 2 (a) to 2 (d) are manufacturing process diagrams of the waveguide element used in the optical module shown in FIG. FIG. 3 is a side view of an optical fiber block used in the optical module shown in FIG.

First, the manufacturing process of the waveguide element 20 will be described.

As shown in FIG. 2A, a core 22 is formed on a substrate 21, and a cladding layer 23 is formed so as to cover the core 22 and the substrate 21. Although the core 22 is formed below the substrate 21 for convenience of description, the core 22 is formed on the substrate 21 in an actual process.

As shown in FIG. 2B, the surface of the cladding layer 23 is flattened by polishing. This is for removing irregularities on the waveguide surface after manufacturing the waveguide element, and for setting the height of the surface of the cladding layer 23 from the core 22 to a predetermined value.

As shown in FIG. 2C, a mask 25 made of a photoresist for forming an alignment mark 24 on the cladding layer 23 is formed using photolithography and etching.

As shown in FIG. 2D, an alignment mark 24 consisting of a projection is formed by etching. After the etching, the mask 25 is removed.

Next, the optical fiber block 26 will be described.

As shown in FIG. 3, the core 27 and the clad 2
The other V-groove-side surface of the lower V-groove block 30 for fixing the optical fiber 29 made of 8 forms another alignment mark 31 made of a groove at a position where it fits with the alignment mark 24 of the waveguide element 20. I do.

The optical fiber block 26 is formed by bonding the optical fiber 29 between the lower V-groove block 30 and the upper V-groove block 32 and bonding them.

Waveguide element 20 and optical fiber block 26
The optical waveguide and the optical fiber are connected by fitting the two alignment marks 24 and 31 together with a microscope and fixing them with a thermosetting resin using a microscope.
Is formed.

FIG. 4 is a partial sectional view showing another embodiment of an optical module to which the method for connecting an optical waveguide and an optical fiber according to the present invention is applied. 5A to 5E are manufacturing process diagrams of the waveguide element used in the optical module shown in FIG. FIG. 6 is a side view of an optical fiber block used in the optical module shown in FIG.

First, the manufacturing process of the optical waveguide device 40 will be described.

As shown in FIG. 5A, a core 42 is formed on a substrate 41, and a cladding layer 43 is formed so as to cover the core 42 and the substrate 41. Although the core 42 is formed below the substrate 41 for convenience of description, the core 42 is formed on the substrate 41 in an actual process.

As shown in FIG. 5B, the surface of the cladding layer 43 is flattened by polishing.

As shown in FIG. 5C, a high-molecular polyamide is applied on the cladding layer 43 and heat-treated to form a polyimide film 44.

As shown in FIG. 5D, the polyimide film 44
Mask 4 for forming alignment mark 46 thereon
5 is formed using photolithography and etching.

As shown in FIG. 5E, the optical waveguide element 40 is formed by etching the alignment mark 46 consisting of a projection.

Next, the optical fiber block 47 will be described.

As shown in FIG. 6, a lower V-groove block 51 for fixing an optical fiber 50 composed of a core 48 and a cladding layer 49 is fitted with the alignment mark 46 of the optical waveguide element 40 by using photolithography and etching. Another alignment mark 52 composed of a groove is formed at the position where the alignment mark 52 is to be formed.

The optical fiber block 47 is formed by bonding the optical fiber 50 between the lower V-groove block 51 and the upper V-groove block 53.

Optical waveguide element 40 and optical fiber block 4
Then, the optical waveguide and the optical fiber are connected by fitting both alignment marks 46 and 52 together using a microscope and fixing with a thermosetting resin, thereby forming the optical module shown in FIG.

In the above embodiment, the case where the alignment marks 24 and 46 are formed by protrusions and the other alignment marks 31 and 52 are formed by grooves is described. However, the present invention is not limited to this. Other alignment marks may consist of protrusions.

In the above, according to the present invention, adjustment is performed by forming an alignment mark for connecting an optical fiber block on a waveguide element, and also forming an alignment mark on an optical fiber block and connecting and fixing the two. This eliminates the need, and the waveguide and the optical fiber are connected in a short time.

[0041]

In summary, according to the present invention, the following excellent effects are exhibited.

It is possible to realize a method for connecting an optical waveguide to an optical fiber and an optical module, which require only a short time alignment when the waveguide element and the optical fiber block are abutted.

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing an embodiment of an optical module to which a method for connecting an optical waveguide and an optical fiber according to the present invention is applied.

FIGS. 2A to 2D are manufacturing process diagrams of the waveguide element used in the optical module shown in FIG.

FIG. 3 is a side view of an optical fiber block used in the optical module shown in FIG.

FIG. 4 is a partial sectional view showing another embodiment of the optical module to which the method for connecting an optical waveguide and an optical fiber according to the present invention is applied.

5 (a) to 5 (e) are manufacturing process diagrams of the waveguide element used in the optical module shown in FIG.

FIG. 6 is a side view of an optical fiber block used in the optical module shown in FIG.

FIG. 7 is a partial side sectional view of an optical module to which a conventional method for connecting an optical waveguide and an optical fiber is applied.

8 is a sectional view of a waveguide element used in the optical module shown in FIG.

9 is a plan view of an optical fiber block used in the optical module shown in FIG.

[Explanation of symbols]

 Reference Signs List 20 waveguide element 26 optical fiber block 24, 31 alignment mark

Claims (3)

[Claims] 1. A waveguide element having an optical waveguide formed by covering a core through which light propagates with a cladding layer having a lower refractive index than the core, and an optical fiber block having an optical fiber disposed on a V-groove. In the connection method, after the surface of the cladding layer of the optical waveguide element is flattened, an alignment mark formed of a protrusion or a groove is formed on the cladding layer for alignment with the optical fiber block. Forming another alignment mark consisting of a groove or a projection to be fitted with the alignment mark, and connecting the waveguide element and the optical fiber block without alignment by fitting both alignment marks. The connection method between the optical waveguide and the optical fiber. 2. A waveguide element having an optical waveguide formed by covering a core through which light propagates with a cladding layer having a lower refractive index than the core, and an optical fiber block having an optical fiber disposed on a V-groove. In the optical module, an alignment mark formed of a projection or a groove formed on the flattened surface of the clad layer of the optical waveguide element and another alignment mark formed of a groove or a projection formed on the optical fiber block are fitted. An optical module, wherein the waveguide element and the optical fiber block are connected to each other without adjustment. 3. The optical module according to claim 2, wherein the projections are made of a polymer organic material such as a polymer.