JPH04204510A - Waveguide passage type optical part - Google Patents

Abstract

PURPOSE:To connect the input/output part of an optical circuit and an optical fiber with high precision by forming at least one groove in the orthogonal direction which extends at a right angle to a guide groove on a light waveguide film. CONSTITUTION:Since at least one groove 5, 6 in the orthogonal direction formed on a light waveguide film 1 works the connection surface of a core part 2, namely, the light input/output part of an optical circuit into a vertical plane, the top edge surface of an optical fiber 4 accommodated into a guide groove 3 and the vertical plane of the core part 2 are closely attached with no gap, and the connection loss is reduced, and the connection loss characteristic is improved. Further, if an adhesive is applied, in order to fix the optical fiber, the groove 5, 6 in the orthogonal direction is charged with the adhesive, which is locally concentrated. Accordingly, the flow-out of the adhesive to a broad surface is prevented, and the uniform hardening contraction is realized.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a waveguide type optical component that allows input/output optical fibers to be easily connected accurately and economically.

<Prior Art> With the progress of the optical industry including optical fiber communications, various optical components are required. The implementation forms of these optical components include (1) bulk type, (2) fiber type, and (3)
) Waveguide type is known.

Among these, waveguide type optical components require connection of optical fibers for light input to the optical circuit and for light output from the optical circuit.

In recent years, in order to take advantage of the small size of waveguide-type optical components, it has been implemented to form devices with a large number of optical inputs and outputs or to form a plurality of optical circuits into one waveguide-type component.

As described above, when a single waveguide-type optical component requires a large number of inputs and outputs, or when a plurality of optical circuits are formed, multiple input/output optical fibers are required.

Conventionally, when connecting multiple optical fibers, 01 pieces 1
A method of individually connecting optical fibers, and a method of arranging a plurality of optical fibers in advance to form an optical fiber array and connecting them collectively have been devised.

FIG. 2 shows an example of the conventional connection method (2) above.

As shown in the figure, an optical waveguide film 1 having a core portion 2 is formed on the substrate, and an optical circuit (not shown) is constructed on this optical waveguide film 1. A guide groove 3 is formed in the optical waveguide film 1 by etching or the like. The guide groove 3 is arranged at the position of the core part 2 which becomes the optical input/output part of the optical circuit, and by inserting and fixing the optical fiber 4 into this guide groove 3, the axis of the optical fiber 4 and the core part 2 are aligned. or positioning. Therefore, according to such a structure, the optical fiber 4 and the core part 2 can be easily connected without aligning the optical fibers one by one.

<Problems to be Solved by the Invention> However, in the above-mentioned conventional technology, since the guide groove 3 is processed by etching or cutting, it is difficult to process the connecting surface of the core portion 2 to the optical fiber 4 perpendicularly.

For this reason, the connecting surface of the core section 2, which is the optical input/output section of the optical circuit, and the tip end surface of the optical fiber 4 do not come into close contact with each other and are tilted, resulting in a gap or gap between them, which deteriorates the connection characteristics. There was. Furthermore, if adhesive is used to connect the optical fibers 4, the applied adhesive will flow out into the guide groove 3 and spread over a wide area, so the adhesive will not shrink uniformly and the connection characteristics and reliability will deteriorate. There was a problem with it declining.

The present invention has been made in view of the above-mentioned prior art, and
It is an object of the present invention to provide a waveguide-type optical component that improves the conventional technology using guide grooves and further utilizes its advantages to accurately connect the input/output section of an optical circuit and an optical fiber.

In other words, the connecting surface on the optical circuit side, for which processing of guide grooves is not sufficient, is processed with high precision using a separate process, and at the same time, the application of the adhesive used is localized to ensure uniform curing and shrinkage. This is the purpose.

<Means for Solving the Problems> The configuration of the present invention to achieve the above object includes configuring an optical circuit in an optical waveguide film formed on a substrate, and also forming a guide groove in the optical waveguide film for accommodating an end of an optical fiber. In a waveguide-type optical component formed by connecting a core portion that is formed and becomes an optical input/output portion of the optical circuit and the tip end face of the optical fiber, the optical waveguide film has an orthogonal groove extending in a direction perpendicular to the guide groove. At least one directional groove is formed, and one of the orthogonal grooves is formed by processing a connecting surface of the core portion into a vertical surface.

Effect> At least one orthogonal groove formed in the optical waveguide film is
Since the connection surface of the core section, which serves as the optical input/output section of the optical circuit, is processed to be a vertical surface, the tip surface of the optical fiber stored in the guide groove and the vertical surface of the core section are in close contact with each other without any gaps. These connection losses are reduced and the connection loss characteristics are improved.

Also, if you apply adhesive to fix the optical fiber,
The adhesive fills these orthogonal grooves and is locally concentrated. Therefore, there is an advantage that the adhesive does not flow out widely and the curing shrinkage is uniform.

<Examples> The present invention will be described in detail below with reference to examples shown in the drawings.

FIG. 1 shows an embodiment of the present invention. In this example, the present invention is applied to a straight waveguide in a silica-based glass waveguide film.

That is, an optical waveguide film 1 is formed on a silicon substrate, and an optical circuit (not shown) is constructed in this optical waveguide l. The optical waveguide film 1 is made by laminating a cladding part, a core part, and an upper cladding part, which are made transparent by depositing porous silica-based glass particles on a silicon substrate and heating them. It is made into a membrane. In addition, the core part 2
is formed by etching using photolithography.

Furthermore, a guide groove 3 is formed in this optical waveguide film 1 by photolithography. The guide groove 3 is arranged at the position of the core part 2, which serves as a light input/output part, and the optical fiber 4 is inserted into the guide groove 3.

If the connecting surface of the core portion 2 remains a curved surface processed by etching, the connection with the optical fiber 4 will be less accurate.

For this reason, in the present invention, orthogonal grooves 5 and 6 are formed in a direction perpendicular to the guide groove 3.

That is, in this example, the guide groove 4 is cut in parallel three times using a groove cutting machine with a blade width of 1 mm.
The orthogonal groove 5 has a width of 2.8 mm and a depth of 0.
A groove of 2 mm was formed. In addition, in this embodiment, at a position further 0.5 mm away from the groove on the connecting surface,
Using the same blade, a groove 1 mm wide and 0.2 mm deep was formed as the orthogonal groove 6 to the guide groove 3. The optical fiber 4 was fixed by filling these orthogonal grooves 5 and 6 with an ultraviolet curing adhesive. In addition, optical fiber 4
A resin for refractive index matching was applied to the tip. The resin for refractive index matching may be omitted or may be replaced by an ultraviolet curing adhesive, depending on the case.

In this embodiment having the above configuration, since the groove 5 in the direction perpendicular to the guide groove 3 is machined, the connection surface of the core part 2, which is the optical input/output part of the optical circuit, is machined perpendicularly, so the tip surface of the optical fiber and the connecting surface of the core portion 2 are in close contact with each other without any gaps, thus reducing connection loss.

For example, in the case of a straight waveguide in the quartz-based waveguide film of this example, the connection loss is 0.3 dB, which is 0.5 dB compared to the connection loss in the case of a conventional guide groove without orthogonal grooves.
Better results were obtained compared to the previous case.

Further, since the ultraviolet curing adhesive used to connect the optical fibers 4 is filled in the orthogonal grooves 5 and 6 and concentrated locally, it is not guided by the guide groove 3 and flows over a wide range. Therefore, the curing shrinkage of the adhesive becomes uniform, and a decrease in reliability due to non-uniform shrinkage can be avoided.

In the above embodiment, the present invention is applied to a straight waveguide in a silica-based glass waveguide film, but the present invention can also be applied to various other actual optical waveguide circuits.

<Effects of the Invention> As specifically explained above based on the embodiments, in the present invention, a groove is formed in a direction perpendicular to the guide groove, so that the connection loss to the optical fiber is reduced and the connection loss characteristics are improved. We were able to.

This makes non-adjustable connection technology using guide grooves practical and contributes to economical production of optical circuit modules. Further, when an optical fiber is fixed using an adhesive, since the adhesive is filled into the groove in the orthogonal direction, the curing shrinkage becomes uniform, which has the advantage of improving reliability.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is an explanatory diagram of a conventional technique. In the drawings, 1 is an optical waveguide film, 2 is a core portion, 3 is a guide groove, 4 is an optical fiber, and 5.6 is an orthogonal groove.

Claims (1)

[Claims] An optical circuit is formed on an optical waveguide film formed on a substrate, and a guide groove for accommodating an optical fiber end is formed in the optical waveguide film to form a core portion that becomes an optical input/output part of the optical circuit and a tip of the optical fiber. In the waveguide type optical component, the optical waveguide film has at least one orthogonal groove extending perpendicularly to the guide groove, and any of the orthogonal grooves is connected to the core portion. A waveguide type optical component characterized in that it is formed by processing a connection surface into a vertical surface.