JP3329951B2 - Connection structure between optical element and optical component for connection - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connection structure between an optical element used in an optical communication system or the like and an optical component for connection.

[0002]

2. Description of the Related Art In general, a waveguide type optical component mainly comprises an optical waveguide type device and a connection optical component as main components. As the connection optical component, for example, a V-groove is formed on a quartz substrate. In this case, an optical fiber is disposed and fixed at a position with an adhesive or the like. The optical waveguide type device has a high refractive index, a portion for confining and guiding light, formed in an optical waveguide substrate, and has functions such as branching and switching.

The biggest problem in putting a waveguide type optical component composed of such components into practical use is how to efficiently and stably connect the optical waveguide and the optical fiber. . Until now, as a method of connecting an optical waveguide and an optical fiber, a method using fusion or an adhesive has been proposed, and in particular, curing is performed by ultraviolet light for reasons such as low cost, low loss, and shortening of curing time. UV adhesives are receiving attention.

FIG. 2 is a view showing an example of connection between the optical waveguide device 3 and the optical component 1 for connection.
The connection end face of the connection optical component 1 is polished at a desired angle with respect to the optical axis, and the interval between the cores of the optical fibers 2 constituting the connection optical component is the same as the interval between the optical waveguides of the optical waveguide device 3. It is made to match. Also, 1
Reference numeral 3 denotes an adhesive layer made of a UV adhesive interposed between connection sections of the optical waveguide device 3 and the connection optical component 1.

FIG. 3 is an explanatory view of a component assembling process for manufacturing such a conventional waveguide type optical component. The optical waveguide device 3 and the connecting optical component 1 are held by a fixed base 9 and a fine adjustment moving base 8, respectively.
The other end of the connection section of the optical fiber 2 constituting the
The optical fiber 2 constituting the other connecting optical component 1
The other end of the connection cross section is connected to the light receiver 11.

In order to assemble a waveguide type optical component with such an apparatus, first, the connection cross section of the connection optical component 1 on the fine movement base 8 is brought close to the connection cross section of the optical waveguide device 3 on the fixed base 9. . At this time, light is incident from a light source 10, and the intensity of the light emitted through the optical waveguide device 3 and subsequently through the optical fiber 2 constituting the connection optical component 1 is measured by the light receiver 1.
1 to detect. The detected light intensity is processed by a feedback processing device, and the optical axis is adjusted so that the optical axes coincide. Further, the optical waveguide device 3 and the connection optical component 1
An adhesive, for example, a UV adhesive also serving as a refractive index matching agent is applied to the connection cross section of, and when the optical axis adjustment is completed, the connection portion is irradiated with ultraviolet light to solidify the UV adhesive and adhere. The assembly is completed by forming the layers.

[0007]

However, in the above-described connection structure for a waveguide type optical component, the adhesive is applied before or after the connection cross section of the connection optical component approaches the connection cross section of the optical waveguide device. Need to do. As a result, the adhesive adheres to the side surfaces orthogonal to the connection cross sections other than between the connection cross sections, and the alignment of the optical axis performed in the assembly process may be deviated due to the influence of the curing shrinkage of the adhesive adhered to the side surfaces. Further, the adhesive adhered to the side surface is easily affected by the temperature change, and the fluctuation of the loss due to the temperature change becomes large.
The present invention provides a connection structure between an optical element and an optical component for connection, which can prevent the influence of curing shrinkage and temperature change of an adhesive.

[0008]

According to the present invention, there is provided an optical element having an optical waveguide formed on a substrate, and at least one optical element formed on a V-groove substrate.
In the connection structure of the connection optical component in which the optical fibers are arranged and held down with a cover, the adhesive is injected and applied to one or both of the connection portions on the substrate-side bottom surface of the optical element and the connection optical component. Is formed.

[0009]

[0010]

According to the connection structure of the present invention, when the adhesive is applied after the connection cross section of the connection optical component is brought close to the connection cross section of the optical waveguide device, the recess becomes an adhesive pool and the adhesive adheres to the side surface. Adhesive connection without any

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view of an embodiment showing a connection structure according to the present invention. The optical waveguide device 3 is a 1 × 8 branch type optical waveguide device 3, and a quartz optical waveguide is formed on a silicon substrate. The connection optical component 1 connected to the eight optical waveguides has eight optical fibers arranged in eight V-grooves of a V-groove substrate 4 formed at the same precision as the distance between the optical waveguides by cutting. Further, in the connection optical component 1 connected to one optical waveguide, one optical fiber is arranged in one V-groove of a V-groove substrate 4 manufactured by the same processing method. In this state, the optical fibers 2 placed in both V-grooves
Is pressed down from above by a cover 6 and bonded and fixed using a thermosetting adhesive or the like, and then a connection cross section perpendicular to the optical axis is formed by polishing. C-planes 12 are formed on the sides formed by the connection surface and the bottom surface (the silicon substrate side and the V-groove substrate 4 side) of the optical waveguide device 3 and the connection optical component 1, respectively. After the axis is adjusted, this C
A UV adhesive is injected and applied from the concave portion formed by the surface 12 and irradiated with ultraviolet rays to form an adhesive layer 13 between the connection cross sections.

[0012]

[0013]

Although the embodiment of the present invention has been described in detail, the present invention is not limited to this. For example, in the above-described embodiment, the concave portion is formed by the C surface 12, but the concave portion can be formed in the connection cross section. Any shape may be used as long as a concave portion for injecting and applying an adhesive is formed in one or both of the connection portions of the optical element and the connection optical component.

[0015]

As described above, according to the structure of the present invention, when the adhesive is injected and applied to the connection section between the optical element and the optical component for connection, the concave portion becomes an adhesive pool and the adhesive adheres to the side surface. Never do.

[Brief description of the drawings]

FIG. 1 is a side view showing an embodiment of the present invention.

FIG. 2 is a side view showing a conventional example.

FIG. 3 is an explanatory view of a conventional assembly process.

[Explanation of symbols]

 1: Connection optical component 2: Optical fiber 3: Optical waveguide device 4: V-groove substrate 6: Cover 8: Fine adjustment moving base 9: Fixed base 10: Light source 11: Light receiving surface 12: C surface 13: Adhesive layer

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-34543 (JP, A) JP-A-5-257033 (JP, A) JP-A-61-278806 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) G02B 6/30

Claims (1)

(57) [Claims] An optical element having an optical waveguide formed on a substrate;
In a connection structure of an optical component for connection, in which at least one optical fiber is disposed on a V-groove substrate and held down and fixed by a cover, both the optical element and the connection portion on the bottom surface of the optical component for connection on the substrate side have C-planes. And a concave portion for injecting and applying a UV adhesive is formed by the C surface . A connection structure between an optical element and an optical component for connection.