JPH0610690B2 - Optical device package - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention has an optical component holding function and an optical axis adjusting function in order to couple an optical integrated device and an optical fiber with their optical axes aligned. In particular, the use of a small and fine processing technology by anisotropic etching of silicon single crystal makes it possible to align the optical axis with extremely high accuracy and in a short time. The present invention relates to an optical device package that can be applied with sufficient accuracy to align the optical axes when integrated by a hybrid method.

[Conventional technology]

Conventionally, when an optical fiber is mounted on an optical integrated device, for example, “Materials and Manufacturing Method of Optical Waveguide; In the method of forming the groove for fiber coupling, as announced in "Body material", there is a technique of forming a groove into which an optical fiber is inserted on the substrate, adjusting the optical axis, and then fixing using an adhesive or the like. Was used.

FIG. 2 shows this concrete method. A groove 4 for receiving an optical fiber 3 is formed in a substrate 2 on an extension of a three-dimensional waveguide 1 (hereinafter referred to as a channel waveguide), and the optical fiber 3 is embedded in the groove 4. Then, the optical axis is adjusted using a fine movement table or the like, and after the adjustment is completed, it is fixed with an adhesive or the like.

[Problems to be solved by the invention]

The conventional technique shown in FIG. 2 requires precision in cutting the substrate. In particular, there is a drawback in that the degree of difficulty of cutting is extremely high, such as when mounting on parallel waveguides that are close to each other. Further, in order to increase the coupling efficiency of the light of the optical waveguide and the fiber, it is necessary to perform an optical polishing treatment on the cut surface, but it is impossible to polish because of the stepped difference in the normal polishing method, The cost is high because a device is required. On top of that, it is difficult to obtain parallelism between the input side fiber and the output side fiber and the optical integrated device, and to align the optical axes at the same time.

In summary, these conventional techniques have the following problems.

First, it is necessary to have a substrate cutting accuracy of the same size as an optical fiber (about 125 μm).

Secondly, in order to increase the coupling efficiency of the optical fiber and the light of the waveguide, the optical polishing of the cut surface is required, but this is not possible with the ordinary optical polishing method and a special machine is required. To do. Therefore, the cost becomes high.

Third, it is difficult to simultaneously adjust the parallelism of the input side fiber, the optical integrated device, and the output side fiber to adjust the optical axis.

[Means for solving problems]

The present invention has been made to overcome such a situation, and since the fiber is held by a square ferrule (which is a pedestal for holding the optical fiber), a normal optical polishing process is performed. The end face treatment of the optical device will be completed with just this, and since the fine patterning technology by anisotropic etching that skillfully utilizes the directionality of the crystal is used for processing, it is possible to obtain highly accurate parallel flatness. I got it. Therefore, it is possible to adjust the parallelism of the input side fiber, the optical device and the output side fiber at the same time, and to provide an optical device package using the silicon anisotropic etching process that enables the optical axis alignment in a short time.

[Embodiment] FIG. 1 is a structural diagram of an optical device package according to an embodiment of the present invention.

In the figure, a silicon base 5 is provided with a through hole 8 for adjusting the height of an optical device 20 in a small piece cut out from a silicon wafer having an excellent parallel flatness, and an input side ferrule 6 and an optical fiber introducing portion which are optical fiber introducing portions. A slide groove 9 is provided for sliding the output side ferrule 7 as a part.
The input side ferrule 6 and the output side ferrule 7 can be combined with the optical device 20 housed in the package. Further, adhesive receiving grooves 10 for preventing leakage of the adhesive from the package and for putting a large amount of the adhesive for the purpose of increasing the package strength are provided on both sides of the silicon base 5.

Each process is performed by anisotropic etching, and the silicon used is 250 μm thick and 70 μm / 2.
The etching was repeated at a rate of time. The left-right symmetry and parallel flatness of the silicon table 5 realized by the etching process were maintained at the initial high precision.

The input-side ferrule 6 and the output-side ferrule 7 were made from two highly precise parallel-plane-polished square silicon substrates and polished by a conventional optical polishing treatment method.
Of the two, the lower silicon ferrule 11 was provided with a trapezoidal protrusion 13 which coincided with the recess of the slide groove 9 for the optical axis alignment.

Further, a V groove 14 for holding an optical fiber is provided on the surface opposite to the surface on which the trapezoidal protrusion 13 is provided. The V groove 14 spacing is 20
Three pieces are provided at intervals of 0 μm, and the upper silicon ferrule 1 is also formed.
In No. 2 as well, the V grooves 15 were provided at intervals of 200 μm. The lower silicon ferrule 11 is assembled such that the surface having the V groove 14 faces the surface having the V groove 15 of the upper silicon ferrule 12, and is formed by a combined V groove of the upper silicon ferrule 12 and the lower silicon ferrule 11. An optical fiber was placed in the hollow part. Furthermore, the slide groove 9 of the silicon base 5 and the trapezoidal protrusion 13 of the lower silicon ferrule 11 of the input side ferrule 6 and the output side ferrule 7 are overlapped, and the input side ferrule 6 and the output side ferrule 7 are formed. The heights of the optical axes of were matched. After that, the processed surface of the silicon base 5 and the optical axis of the optical device 20 are arranged in parallel, and the input side ferrule 6 and the output side ferrule 7 are slid to the end face of the optical device, and only the height of the optical device is adjusted. The optical axes were aligned and fixed.

[Action]

The operation of the present invention will be described below with reference to FIG.

Since anisotropic etching of silicon is performed by photolithography technology using a high-precision photomask like the photomask used in LSI and the like, very fine processing is possible. Moreover, since the etching rate differs depending on the crystal direction, it is possible to control the etching depth at the crystal level. That is, if the (001) plane of a silicon wafer is used by utilizing the anisotropic silicon etching technique, the <110> directions are orthogonal to each other in the plane, and therefore a trapezoidal etching surrounded by the (111) plane is used. Is selectively performed. The angle formed by the (001) plane and the (111) plane is
Since it is determined to be 54 ° 77 ″, it is possible to process a certain shape with high precision. Since the certain shape can be processed with high precision, the depth of the V-grooves 14 and 15 is the radius of the optical fiber, and the width is By making the optical fiber in contact with the slopes of the V-grooves 14 and 15, the fiber can be stably held.

The package is composed of a silicon base 5, an optical fiber introducing part which becomes an input side ferrule 6, and an optical fiber introducing part which becomes an output side ferrule 7, and an optical device 20 which is housed in the package between the optical fiber introducing parts. Are formed.

The silicon table 5 is a slide groove for forming a height adjusting hole 8 of the optical device 20 on a silicon wafer which is ground with high accuracy in parallel and sliding the input side ferrule 6 and the output side ferrule 7. 9 is provided.
Further, in order to prevent the adhesive agent from leaking from the package and to increase the adhesive strength, adhesive agent receiving grooves 10 capable of containing a large amount of the adhesive agent are provided on both sides of the silicon base 5. Since all of these processes can be realized by etching, it is possible to process the left-right symmetry and parallel flatness of the silicon table 5 with high precision. The input-side ferrule 6 and the output-side ferrule 7 are each made of two highly-accurate parallel-plane-polished silicon substrates, and are composed of a lower silicon ferrule 11 and an upper silicon ferrule 12. The lower silicon ferrule 11 is provided with a trapezoidal protrusion 13 having a protrusion corresponding to the recess of the slide groove 9 for aligning the optical axis.

The lower silicon ferrule 11 has a V groove 14 for holding an optical fiber on the surface opposite to the surface on which the trapezoidal protrusion 13 is provided.
Is provided. On the other hand, the upper silicon ferrule 12 was provided with V grooves 15 at the same intervals as the V grooves 14 of the lower silicon ferrule 11. The upper silicon ferrule 12 and the lower silicon ferrule 11 are combined so that the surfaces having the V grooves 14 and 15 face each other, and the combined V grooves 14 and 15 of the upper silicon ferrule 12 and the lower silicon ferrule 11 are combined. The optical fiber is arranged and fixed in the hollow portion formed in (3). Furthermore, the slide groove 9 of the silicon base 5, the input side ferrule 6, and the trapezoidal protrusion B of the output side ferrule 7 are overlapped with each other, and the input side ferrule 6 and the output side ferrule 7 are arranged.
Is configured to move only in the direction perpendicular to the end surface of the optical device.

With such a configuration, the heights of the optical axes of the input side ferrule 6 and the output side ferrule 7 are made to coincide with each other. Then, the etched surface of the silicon base 5 and the waveguide of the optical device 20 are arranged in parallel, and the input side ferrule 6, the optical device and the output side ferrule 7 are arranged.
The optical axis is aligned by adjusting the height closer to the optical device 20 side.

According to the method of the present invention, it is possible to align the optical axes of the fibers on the input side and the output side at the same time with the optical axis of the optical device 20 by a simple optical axis adjustment by using a silicon wafer having good accuracy of parallel plane polishing. It will be possible.

〔The invention's effect〕

As described above, by using the silicon anisotropic etching technique, the trapezoidal protrusion and the trapezoidal groove with a high precision of 54 ° 77 ″ whose tilt angle is crystallographically determined at the molecular level are formed. When it is possible to align the optical axis by molding a hybrid integrated functional optical component, it is possible to align the optical axis with extremely high precision and in a short time because extremely fine processing is possible. In addition, it is possible to apply the conventional method to the optical polishing treatment, and it is possible to apply a large amount of the same quality by using the photolithography technology, which is economical and industrial. You can expect to improve productivity.

[Brief description of drawings]

FIG. 1 shows an embodiment of an optical device package. Second
The figure shows a conventional method for forming a groove for fiber coupling. In the figure, 1 is a channel waveguide, 2 is a substrate, 3 is an optical fiber, 4 is an optical fiber coupling groove, 5
Is a silicon base, 6 is an input side ferrule (optical fiber introduction part), 7 is an output side ferrule (optical fiber introduction part), 8
Is an optical device height adjusting hole (through hole), 9 is a slide groove, 10 is an adhesive receiving groove, 11 is a lower silicon ferrule,
12 is an upper silicon ferrule, 13 is a trapezoidal protrusion, 14 and 15 are V grooves, and 20 is an optical device.

Claims (1)

[Claims] 1. A through hole (8) capable of receiving at least a part of an optical device, and a concave slide provided on both sides sandwiching the through hole (8) and having an inclination angle of about 54 °. A silicon base (5) having a groove (9) and an adhesive receiving groove (10) having an inclination angle of approximately 54 °, which is provided on each of the other sides of the through hole (8), and An optical fiber introducing part (6 and 7) consisting of an upper silicon ferrule (12) and a lower silicon ferrule (11) provided at both ends of the optical device so that they can be coupled to each other, and the lower silicon ferrule (11) is A trapezoidal protrusion (13) slidably fitted in the slide groove (9) having an inclination angle of about 54 ° is provided on the lower side thereof, and an inclination angle capable of receiving an optical fiber is provided on the upper side thereof. Is almost 54 ° The V-groove (15) has a groove (14) and the upper silicon ferrule (12) is aligned with the V-groove (14) on the lower side of the V-groove (15) and has an inclination angle of about 54 ° for receiving the optical fiber. ). An optical device package comprising: