JPH0669602A - Manufacturing method of hybrid integrated optical module - Google Patents

Abstract

(57) [Summary] [Object] To provide a method for manufacturing a hybrid integrated optical module of an optical semiconductor element and an optical waveguide, which is easy to manufacture and can reduce the module size. [Structure] A part of the optical waveguide 7 is formed from the upper surface of the optical waveguide to the substrate 8.
A submodule 4 in which an optical semiconductor element 1 and a fiber 3 are coupled to the square hole 20 is formed by forming a square hole 20 inwardly.
And the submodule 4 is directly fixed to the cross section of the optical waveguide substrate 8 by aligning the optical axes of the fiber 3 and the optical waveguide 7 in the square hole 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a hybrid integrated optical module in which an optical semiconductor element such as a laser diode is mounted on an optical waveguide, and particularly to a small size suitable for use in optical communication and optical sensors. The present invention relates to a method for manufacturing an optical module.

[0002]

2. Description of the Related Art An attempt to realize a compact and highly functional hybrid integrated optical module by mounting an optical semiconductor element such as a laser diode (LD) on a glass optical waveguide (hereinafter simply referred to as a glass waveguide). Has been done so far. Basically these configurations are
It can be classified into one in which an optical semiconductor element is directly mounted on a glass waveguide substrate, and one in which an optical semiconductor element is assembled in another submodule and optically coupled with a glass waveguide by a fiber. A typical example of the above is shown in FIG. 3A is an overall structural view of the hybrid module, and FIG. 3B is an enlarged perspective view of an optical semiconductor element (LD gate array in this case) mounting portion. (Reference: ECOC 87 pp.243-246
"SINGLE-MODE GUIDED-WAVE O
PTICAL GATE MATRIX SWITC
H ") To assemble this, first create a glass waveguide by a normal process, then form an optical semiconductor element insertion part by dry etching or precision machining, and place the optical semiconductor element on the glass waveguide. Fix them with solder while aligning the optical axes (however, only in the horizontal direction, and in the height direction, preliminarily match the dimensional accuracy of the element and the optical waveguide). Next, a representative example of is shown in FIG. (References:
1990 IEICE Spring National Convention C-274
"Optical waveguide WDM transceiver module") In this example, L
D, the glass waveguide circuit, the photodiode (PD), and the fiber portion are individually made into submodules, and then each submodule is welded with a YAG laser to be assembled. However, the conventional techniques represented by the above two types have the following problems.

[0003]

That is, in the case where the optical semiconductor element of (1) is directly mounted on the glass substrate,
Since the optical semiconductor element is directly handled, there is a high risk of damage to the element, and it is difficult to adjust the element spatially about all three-dimensional axes because of the structure. Therefore, high dimensional accuracy is required for the optical semiconductor element and the glass waveguide. There was a problem that became. In particular, when the optical semiconductor element is an LD, the allowable amount of misalignment with the glass waveguide is usually 1 μm or less, which is very strict, and the manufacturing yield cannot be increased. In the case where the optical semiconductor element is assembled into another sub-module and is optically coupled to the glass waveguide with a fiber, the characteristics are good because the module is individually modularized, but the module size is large, and the glass waveguide There is a problem that the circuit design of the glass waveguide is restricted because the input / output section must be exposed on the end face. An object of the present invention is to provide a method for manufacturing a hybrid integrated optical module of an optical semiconductor element and an optical waveguide, which solves such a problem, is easy to manufacture, and can reduce the module size.

[0004]

In order to achieve the above object, in the method for manufacturing a hybrid integrated optical module of the present invention, as shown in FIG. 1, for example, as shown in FIG. To the inside of the substrate 8 in a concave shape
Then, the sub-module 4 in which the optical semiconductor element 1 and the fiber 3 are combined is inserted into the square hole 20, and the sub-module 4 is inserted into the square hole 20 to form the fiber 3 and the optical waveguide 7.
The optical axes of and are aligned and fixed directly to the cross section of the optical waveguide substrate 8.

[0005]

According to the present invention, the sub-modularized optical semiconductor element is incorporated in a required part of the optical waveguide module. Therefore, the optical waveguide can be connected in the shortest distance without connecting the optical semiconductor element and the optical waveguide module, and the module size can be reduced. Further, there is no problem that three-dimensionally high accuracy is required for connection, which is a problem in the conventional technique. Therefore, manufacturing becomes easy.

[0006]

EXAMPLE 1 FIG. 1 is a diagram for explaining the first example, and shows a structure when an LD is coupled to a glass waveguide in a top view and a sectional view. Here, 1 is an LD element, 2 is a heat sink, 3 is a spherical fiber, 4 is a sub-module package, 5 is a fiber fixing plate, 6 is a reinforcing glass plate, 7 is a glass waveguide, 8 is a silicon substrate, and 20 is a corner. The holes and the stippled areas are the areas where the adhesive is applied. To assemble this, first, the sub-module 4 in which the LD element 1 is coupled to the front spherical fiber 3 is assembled. This is a conventional technique (Japanese Patent Application No. 1-152211).
No.) is possible. The fiber 3 is cleaved or polished at the end of the submodule package 4 to expose the end face. On the other hand, in the glass waveguide 7, in order to accommodate and connect the submodule by ultrasonic processing from the upper surface of the glass waveguide to the inside of the silicon substrate at the portion to be connected, a square hole 20 is made slightly larger than the submodule. At this time, the glass plate 6 is pasted on the upper surface of the glass waveguide for the purpose of preventing chipping of the end face and reinforcing the bonded portion. After that, an adhesive is applied to the end surface of the sub-module 4, which is inserted into the square hole 20, and fixed while aligning the optical axis with the glass waveguide 7. If an adhesive having a refractive index matching with the fiber or the glass waveguide is used, the adhesive can be bonded without a large loss even if the end face has some irregularities.

Embodiment 2 FIG. 2 is a diagram for explaining the second embodiment, and also shows the structure when the LD amplifier is coupled to the glass waveguide in a top view and a sectional view. Here, 2 to 8 and the stippled area are the same as in FIG. 3, 9 is a glass capillary (glass tube) having an inner diameter slightly larger than the outer diameter of the fiber, 10 is an LD amplifier element, and 20 is a square hole. In order to assemble this, the LD amplifier element 10 is made to have the same shape as that of the first embodiment, with the spherical fibers 3, 3 '.
Make a sub-module that is combined with. In the case of an LD amplifier, the fibers come out on both sides, but one fiber 3 is cleaved or polished at the end of the submodule package 4 to expose the end face, and the other fiber 3'is a long rectangular hole in the glass waveguide. Cleave according to the situation. On the other hand, the glass waveguide 7 is ultrasonically processed to form a square hole 20 that is considerably longer than the submodule. Then fiber 3 of submodule 4
An adhesive is applied to the end face of the glass waveguide 7 and the glass waveguide 7 is fixed while the optical axis is aligned. When this adhesive is sufficiently solidified, the other fiber 3'is then passed through the glass capillary 9 and the optical axis of the fiber is aligned with the glass waveguide 7'and bonded and fixed. By using the capillary 9 in this step, the workability at the time of adjusting the optical axis is improved and the adhesive strength is enhanced, and by extending the fiber on one side, it is possible to absorb the inclination and displacement of the fiber due to the dimensional error of the submodule or the like. There are advantages. Although the case where the glass waveguide is used is described in the present embodiment, the present invention is not limited to the glass waveguide and can be generally applied to the case where the optical waveguide is used. In addition, in this embodiment, the case where a square hole is formed in a concave shape from the upper surface of the optical waveguide for mounting a sub-module having an optical semiconductor element has been described. It is needless to say that the present invention is also advantageous.

[0008]

As described above, according to the present invention, the optical element can be mounted inside the waveguide circuit, so that the flexibility of designing the waveguide circuit is high and the size of the entire module can be reduced. Tolerance at the time of assembly is relatively loose, and the manufacturing yield can be increased by screening at the sub-module stage.

[Brief description of drawings]

FIG. 1 is a diagram of a first embodiment of the present invention.

FIG. 2 is a diagram of a second embodiment of the present invention.

FIG. 3 is a diagram showing a configuration example of a conventional hybrid integrated optical circuit,
FIG. 1 (a) is an overall structural diagram of the hybrid module,
FIG. 1B is an enlarged perspective view of the optical semiconductor element mounting portion.

FIG. 4 is a structural example diagram of a conventional hybrid optical module in which a sub-module is mounted on the end face of a glass waveguide.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... LD element 2 ... Heat sink (radiator) 3 ... Front fiber 4 ... Sub-module package 5 ... Fiber fixing plate 6 ... Reinforcing glass plate 7 ... Glass waveguide 8 ... Silicon substrate 9 ... Glass capillary 10 ... LD amplifier element 20 ... Square hole

Claims (1)

[Claims] 1. A method of manufacturing a hybrid integrated optical module comprising an optical semiconductor element such as a laser diode mounted in an optical waveguide on a substrate, wherein a part of the optical waveguide is provided from the upper surface of the optical waveguide to the substrate. A square hole is formed in a concave shape with respect to the inside, and a sub-module in which the semiconductor element and the fiber are coupled is inserted into the square hole, and the sub-module is provided with the optical axis of the fiber and the optical waveguide in the square hole. A method of manufacturing a hybrid integrated optical module, which is characterized in that it is directly fixed to the cross section of the optical waveguide substrate.