JPH0843674A - Connecting structure of optical waveguide device - Google Patents

Abstract

PURPOSE:To provide a connecting structure of an optical waveguide device which lessens insertion loss of light by connecting connecting sections in tight contact with each other at the time of connecting the optical waveguide device and the optical fiber composed of optical parts for connection by connecting the connecting sections in tight contact with each other. CONSTITUTION:This connecting structure of the optical waveguide device 8 is constituted to connect the optical waveguide device 8 fixing at least >=1 pieces of optical fibers to the optical parts 1, etc., for connection. Both connecting end faces are provided with proper curvature in such a manner that the core centers of the optical waveguide device 8 and the core centers of the optical fibers 2 fixed to the optical parts 1, etc., for connection project. In addition, these connecting end faces are connected at both end faces at which both front ends of the parts provided with the curvature exist on the same straight line or the centers of the respective curvatures exist in positions exclusive of the straight line connecting the centers of the respective cores.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connection between an optical waveguide device and an optical component for connection, etc., and more particularly to reduction of insertion loss of light generated at an end face of the optical waveguide device.

[0002]

2. Description of the Related Art A conventional optical waveguide module is composed of an optical waveguide and a connecting optical component as main components.
As the connecting optical component, for example, a component in which a V groove is formed on a quartz substrate and an optical fiber is fixed at a desired position with an adhesive or the like is used. The optical waveguide type device has a high refractive index in the optical waveguide substrate and has a function of branching and switching by forming a portion for confining and guiding light.

FIG. 5 is a schematic diagram showing an example of connection between a 1 × 4 branch type optical waveguide device 8 and a connecting optical component 1. The connecting end faces of the optical waveguide device 8 and the connecting optical component 1 are optical. The end faces are polished perpendicularly to the axis, and the core intervals of the 4-core optical fiber array of the connecting optical component 1 match the core intervals of the optical waveguide device 8. The optical waveguide device 8 and the connecting component 1 are provided with a guide hole 9 and a guide pin 7, respectively, and by inserting the guide pin 7 into the guide hole 9, the opposing optical axes can be coaxially aligned. It is like this.

However, in the above-mentioned conventional connection structure, when light is incident from the optical fiber 2 to the optical waveguide device 8 and from the optical waveguide device 8 to the optical fiber 2, Fresnel reflection at the connection end face of the optical waveguide device 8 and the optical fiber 2 is caused. Therefore, there was a problem that insertion loss occurred.

Therefore, as a method for solving this problem,
As shown in FIG. 6, an antireflection film 11 for preventing Fresnel reflection is provided on the connection end surface of the optical waveguide device 8, or a desired inclination is formed on the connection end surface of the optical waveguide device 8 and the connecting optical component 1 as shown in FIG. It is proposed to form the portion 12 to prevent Fresnel reflection.

[0006]

However, in the above-mentioned optical waveguide device having the connection end face provided with the antireflection film for preventing Fresnel reflection, the antireflection film is formed on the connection end face by vapor deposition at high temperature. However, there are problems such as destabilizing the optical characteristics of the optical waveguide device.

Further, a device in which Fresnel reflection is prevented by forming a desired inclination on the connection end faces of the optical waveguide device and the connecting optical component is a case where the cores of the optical fibers of the optical waveguide device and the connecting optical component have different refractive indices. However, for example, there is a problem that insertion loss occurs due to refraction when light enters an optical waveguide device from an optical fiber.

The present invention has been made in view of the above points, and an object thereof is to make the optical characteristics of an optical waveguide device unstable when connecting the optical waveguide device and a connecting optical component or the like. It is to provide a connection structure that prevents Fresnel reflection.

[0009]

SUMMARY OF THE INVENTION The present invention provides at least one
A connection structure of an optical waveguide device for connecting an optical waveguide device having a fixed number of optical fibers or more to an optical component for connection or the like, which is fixed to the core center of the optical waveguide device and the optical component for connection or the like. A connection structure for an optical waveguide device in which both connection end faces have appropriate curvatures so that the center of the core of the optical fiber protrudes, and both ends of the portion with the curvature are on the same straight line Is.

Further, the present invention provides a connection structure of an optical waveguide device for connecting an optical waveguide device having at least one optical fiber fixedly mounted thereto to a connecting optical component, the core structure of the optical waveguide device and the core structure of the optical waveguide device. Positions other than a straight line connecting the centers of the respective cores with appropriate curvatures on both connection end faces so that the center of the core of the optical fiber fixed to the connecting optical component and the like are in close contact with each other. 2 is a connection structure of an optical waveguide device for connecting both end faces in FIG.

Further, the present invention is a connection structure of an optical waveguide device in which each tip end portion having a curvature has the same height with respect to the bottom surface.

[0012]

According to the structure of the present invention, even if the cores of the optical waveguide device and the cores of the optical fibers forming the connecting optical parts have different refractive indexes, the cores of the respective connecting portions are brought into close contact with each other to be fixed. Therefore, a large loss does not occur when light is incident from the optical waveguide device to the connecting optical component and from the connecting optical component to the optical waveguide device.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 are schematic views of the configuration of an embodiment of the present invention, in which the same portions are denoted by the same reference numerals, in the drawings, 1 is a connecting optical component, 2 is an optical fiber, 3 is a core, and 4
Is a V groove substrate, 5 is a V groove, 6 is a cover, 7 is a guide pin,
Reference numeral 8 is an optical waveguide device, 9 is a guide hole, 10 is a connecting cross section having a curvature, 11 is an antireflection film, and 12 is an inclined portion.

FIG. 1 is a top view (a) and a side view (b) of a first embodiment showing a connection structure of an optical waveguide device according to the present invention. As shown in the figure, the centers of the core 3 of the optical waveguide device 8 and the core 3 of the optical fiber 2 fixed to the connecting optical component 1 are set to be the longest in the optical axis direction (so as to project). Give the connection end face a desired curvature,
Further, the connecting cross section 10 having a curvature is formed so that the tip of the portion having a curvature exists on the same straight line. The alignment is performed by the guide pin 7 and the guide hole 9, and by inserting the guide pin 7 into the guide hole 9, the optical waveguide device 8 and the opposing core 3 of the connecting optical component 1 are tightly connected. While maintaining the state, the connection and fixation are performed using a photocurable adhesive or the like. The connection and fixing may be performed after the photocurable adhesive is applied to the connecting cross section 10 having a curvature, or a clamp spring or the like may be used instead of the photocurable adhesive.

Here, as shown in FIG. 3, the connecting optical component 1 is used.
For example, four optical fibers 2 are arranged in four V-grooves 5 formed on a V-groove substrate 4 with high precision by cutting at desired intervals, and in this state, the optical fiber 2 is pressed from above by a cover 6. Adhesively fixed using a thermosetting adhesive, etc.,
After that, the end face 10 having a curvature is formed by polishing or another method.

FIG. 2 is a top view (a) and a side view (b) of a second embodiment showing a connection structure of an optical waveguide device according to the present invention. As shown in the figure, the connecting end face has a desired curvature so that the centers of the core 3 of the optical waveguide device 8 and the core 3 of the optical fiber 2 fixed to the connecting optical component 1 are in close contact, and the center of the curvature is A connection cross section 10 having a curvature that exists on a line other than the straight line connecting the centers of the cores parallel to the optical axis is formed.

FIG. 4 is a side view showing another embodiment of the connection cross section. The optical waveguide device 8 and the connecting optical component 1 are provided with slopes of a desired length near the bottom surface and the top surface of the optical waveguide device 8. The connecting cross section 10 has a curvature only in the vicinity of the core and the core of the optical fiber forming the connecting optical component.

[0018]

According to the configuration of the present invention, it becomes possible to closely connect the connection cross sections, and to reduce the insertion loss of light when connecting the optical waveguide device and the optical fiber forming the connecting optical component. You can

[Brief description of drawings]

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

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

FIG. 3 is a schematic view showing an example of an optical component for connection.

FIG. 4 is a side view showing another embodiment of the connection cross section.

FIG. 5 is a schematic view showing a connection structure of a conventional optical waveguide device.

FIG. 6 is a schematic side view showing a conventional structure in which reflected light is reduced.

FIG. 7 is a schematic side view showing another conventional structure in which reflected light is reduced.

[Explanation of symbols]

1: Optical component for connection, 2: Optical fiber, 3: Core, 4: V
Groove substrate, 5: V groove, 6: cover, 7: guide pin, 8:
Optical waveguide device, 9: guide hole, 10: connection cross section with curvature, 11: antireflection film, 12: inclined portion

Claims (2)

[Claims] 1. In a connection structure of an optical waveguide device for connecting an optical waveguide device having at least one optical fiber fixedly mounted thereto to an optical component for connection, etc., a core center of the optical waveguide device and the optical component for connection, etc. The connecting end surfaces should have appropriate curvatures so that the core center of the optical fiber that is fixed to the core protrudes, and both ends of the part with the curvatures should be connected at both end surfaces that are on the same straight line. A structure for connecting optical waveguide devices. 2. A connection structure of an optical waveguide device for connecting an optical waveguide device having at least one optical fiber fixed thereto to a connecting optical component or the like, wherein a core center of the optical waveguide device and the connecting optical component or the like are provided. Both connecting end faces have appropriate curvatures so that they are in close contact with the core center of the optical fiber fixed to the both end faces, and the centers of the respective curvatures are at positions other than on the straight line connecting the centers of the respective cores. A connection structure of an optical waveguide device, which is characterized in that: