JPS63316009A - Optical coupling structure - Google Patents

Abstract

PURPOSE:To easily position an optical axis by forming specific grooves, and fixing 1st and 2nd members so that waveguides are sandwiched. CONSTITUTION:This structure consists of the 1st member 7 formed in a rectangular prism shape by forming a groove 9 of certain wide width nearly in the center of one plane part and plural grooves 8 a little bit wider than the external diameter of optical fibers 6 opposite at the wide groove 9 at right angles and fixing the optical fibers in those grooves so that their end surfaces are aligned with the flank of the wide groove 9, and the 2nd member 10 formed in a rectangular prism shape by embedding a waveguide 11 in its one plane part while projecting from the plane part so that the waveguide 11 can be fitted in the wide groove 9 of the 1st member 7. Those 1st member 7 and 2nd member 10 are fixed while the waveguide 11 is sandwiched. Consequently, the optical axis of the waveguide in the depth direction can be aligned without any adjustment and when the optical axis is adjusted laterally, the optical axis can be aligned only by moving the waveguide finely along the reference surface of the 1st member 7.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a single optical coupling structure for coupling a waveguide type optical element substrate and an optical fiber of an external transmission system.

[Conventional technology]

This type of optical coupling structure that has already been proposed is
As shown in FIG. 4, a structure in which a groove 2 is formed directly on the optical element substrate 1 and an optical fiber core wire 3 is fixed within this groove 2,
Alternatively, as shown in FIG. 5, the device 4 constituting the optical fiber array and the optical device substrate 5 were directly butted against each other.

[Problem that the invention seeks to solve]

However, in the conventional optical coupling structure shown in FIG. 4, the groove 2 is formed directly on the optical element substrate 1, so the size of the optical element substrate 1 itself becomes large, and moreover, the optical coupling structure shown in FIG. When fixing the optical fiber core wires 3 to the element substrate l, there is a drawback that it is necessary to check each fiber one by one using a microscope or the like. Furthermore, during the work of fixing the optical fiber core wire 3, the functional parts of the optical element substrate 1 are exposed to the working environment, and there is also a drawback that there is a high possibility that the functions will deteriorate.

Furthermore, in the structure shown in Fig. 5, the element 4 and the optical element substrate 5 that constitute the optical fiber array are basically fixed while aligning the optical axes, so fine adjustment is required to align the optical axes. Moreover, even after fixation, the optical axis tends to shift due to temperature changes and external shocks, resulting in a lack of reliability. Furthermore, when fixing using an adhesive or the like, there was a risk that the optical axis would shift during curing due to shrinkage of the adhesive.

[Means for solving problems]

The optical coupling structure according to the present invention is formed in the shape of a rectangular parallelepiped, and has a groove with a certain width at approximately the center of one plane part thereof, and a groove that is perpendicular to the wide groove and slightly wider than the outer diameter of the optical fiber. a first member having a plurality of optical fibers facing each other and fixing the optical fibers in the second groove with their end faces aligned with the side surfaces of the wide groove; , the waveguide is formed by a second member protruding from the flat part so as to fit into the wide groove of the first member, and the first member and the second member sandwich the waveguide. It has a fixed structure.

[Effect]

In the optical coupling structure according to the present invention, if the lower surface of the waveguide is aligned with the reference plane of the wide groove of the first member, the optical axes of the waveguide in the depth direction will coincide, and later So this waveguide is the reference plane! By slightly moving the waveguide in the horizontal direction, it is possible to align the optical axes of the optical fiber and the waveguide. Therefore, it is possible to match the optical axes in the depth direction of the waveguide without any adjustment, and the optical axis adjustment in the Chinese direction can be done by simply moving the waveguide slightly in the direction along the reference plane of the first member. The optical axes can be aligned with each other.

Therefore, alignment of the optical axis can be easily performed. Furthermore, since the optical fiber and waveguide are fixed on one part, the optical axis will not shift due to impact or temperature changes, making it extremely stable.

〔Example〕

Hereinafter, the present invention will be explained in detail using embodiments shown in the drawings.

FIG. 1 and FIG. 2 are diagrams showing an embodiment of the optical coupling structure according to the present invention.

The optical fiber 6 includes a first member 7 formed in a rectangular parallelepiped shape.
It has a structure in which it is placed and fixed in a groove 8 provided in the. This groove 8 is formed to be slightly wider than the outer diameter of the optical fiber 6, and a plurality of grooves 8 are provided facing each other.

Further, a wide groove 9 is formed at approximately the center of one plane portion 7a of the first member 7, and is perpendicular to the groove 8. They are fixed in the groove 8 with their edges aligned.

The second member IO is formed in the shape of a rectangular parallelepiped, and has a structure in which a waveguide 11 is embedded in one plane portion 10a. This waveguide 11 is protruded from one plane part 10a so that it can fit into the wide groove 9 of the first member 7. Both side surfaces 11a of the waveguide 11 are connected to both side surfaces 1 of the second member 10.
0b, and the waveguide 1
The lower surface 11b of the first member 7 comes into contact with the reference surface 9b of the wide groove 9 provided in the first member 7 when the first member 7 and the second member 10 are bonded together. ing.

Now, if we consider a diffused waveguide as the waveguide 11, the thickness of the waveguide 11 will vary by several microns from chip to chip, but the depth of the diffused waveguide will be very large, less than 1 micron. High accuracy has been achieved. Here, the depth of the groove 8 in which the optical fiber halo of the first member 10 is fixed is processed to a depth that is above the reference plane 9b by the protruding depth of the waveguide 11. An optical fiber 6 is fixed.

The groove 8 can be machined with a processing accuracy of 1 micron or less, and it is sufficient to use an optical fiber 6 whose core eccentricity is 1 micron or less. Furthermore, if the lower surface 1 ],b of the waveguide 11 is aligned with the reference surface 9b that has been scraped off from the first member 7, the optical axes of the waveguide 11 in the curvature direction will coincide with each other. By slightly moving the waveguide 11 in the lateral direction along the reference plane 9b, the optical axes of the optical fiber 6 and the waveguide 11 can be aligned.

In addition, when processing the first member 7, as shown in FIG.
After the optical fiber 6 is fixed in the groove 8, the reference surface 9b is cut off. In this way, the optical fiber 6a on the input side and the optical fiber 6b on the output side are left uncut.
c, and it becomes possible to suppress the gap deviation due to the influence of the adhesive provided between the optical fiber 6 and the waveguide 11 in the normal optical fiber abutting portion.

〔Effect of the invention〕

As explained above, according to the optical coupling structure according to the present invention,
The optical axes in the depth direction of the waveguide can be aligned without adjustment, and the optical axis in the lateral direction can be adjusted by slightly moving the waveguide in the direction along the reference plane of the first member. The axes can be aligned. In addition, since the optical fiber and waveguide are fixed on one member (the first member), the optical axis will not shift due to shock or temperature changes, making it extremely stable. become. Furthermore, even during manufacturing, if the precision of the processing machine that cuts the waveguide and the processing hole that creates the grooves are maintained, it becomes possible to process the member with good reproducibility.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view showing an embodiment of the optical coupling structure according to the present invention, Fig. 2 is a sectional view taken along the line ■-■ of Fig. 1, and Fig. 3 is a perspective view showing an example of the first member. 1 and 5 are perspective views each showing an example of a conventional optical coupling structure. 6...Optical fiber, 7...First member, 7a...One plane part, 8.9...Groove, 9a... Side surface, 9b...Reference surface, 10
...Second member, loa...One plane part, 11...Waveguide.

Claims (1)

[Claims] Formed in the shape of a rectangular parallelepiped, a groove with a certain width is provided approximately in the center of one plane part of the groove, and a plurality of grooves, which are perpendicular to the wide groove and slightly wider than the outer diameter of the optical fiber, are provided facing each other, A first member having an optical fiber fixed to the groove with its end surfaces aligned with the side surfaces of the wide groove, and a waveguide embedded in one plane part of the first member, which is formed into a rectangular parallelepiped shape, and this waveguide is connected to the first member. a second member protruding from the flat part so as to be able to fit into a wide groove of the waveguide, and the first member and the second member are fixed to sandwich the waveguide. Optical coupling structure.