JPH11174279A - Optical coupling method and structure thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical coupling method and the structure capable of highly efficient optical coupling in a small size and high mass productivity at a low working cost. SOLUTION: On the upper surfaces of both substrates 1A and 1B for making a tip surface 1a abutt on a tip substrate 1b, by photolithography and anisotropic etching, V grooves 3 for an optical fiber to be linear to each other at the time of making a substrate 1A abutt on a substrate 1B and the V grooves 5, 5 for guide pins in parallel to the V grooves 3 for the optical fiber to be linear to each other at the time of making the substrate 1A abutt on the 1B are formed. In this case, an optical fiber 7 is held and fixed to the V grooves 3 for the optical fiber of both substrates 1A and 1B while making an end face be flat with the tip surfaces 1a and 1b, guide pins 9, 9 are held and fixed to the V grooves 5, 5 for the guide pins of one of the substrate 1A while being projected for a prescribed length, the tip surface 1a is made to abutt on the tip substrate and the projected parts of the guide pins 9, 9 of one of the substrate 1A are inserted into the V grooves 5, 5 for the guide pin of the other substrate 1B. Thus, the optical axes of both optical fibers 7 are aligned and optically coupled and the highly efficient optical coupling is made possible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical coupling method and an optical coupling structure that enable optical coupling between optical fibers or between an optical fiber and an optical waveguide with high efficiency.

[0002]

2. Description of the Related Art Conventionally, various structures have been known as optical coupling structures for transmitting light between optical fibers or between an optical fiber and an optical waveguide. For example, in a conventional optical coupling structure in which optical fibers are optically coupled to each other, a cylindrical metal fitting processed in micron units to the same diameter as the outer diameter of each optical fiber is provided at the tip of the optical fibers to be optically coupled. Cylindrical glass (ferrule) is mounted on the outer circumference of each optical fiber, and each cylindrical metal fitting or cylindrical glass (ferrule) mounted on the outer circumference of each optical fiber is replaced with a cylindrical split sleeve having spring properties. By regulating and aligning the outer shape of the optical fiber, the optical fibers are optically coupled by aligning the axes of the two optical fibers coupled to each other.

[0003]

However, the conventional optical coupling structure as described above has the following problems. A cylindrical fitting or glass is attached to the ends of the optical fibers to be optically coupled, so that the optical coupling structure becomes large, and a cylindrical split is formed around the outer circumference of the cylindrical fitting or glass. Since the structure is arranged by the sleeve, there is a problem that the structure for performing a plurality of optical couplings is further enlarged, and there is a problem that it is difficult to reduce the size in order to integrate the optical device substrate. In addition, cylindrical split sleeves for aligning optical fibers are generally manufactured by machining, but it takes time to perform machining that satisfies the required accuracy. It is necessary to frequently change the blades of the machine, so that the mass productivity of the split sleeve is poor and the machining cost is high.

The present invention has been made in view of such a point, and an object thereof is to realize an optical coupling which enables high-efficiency optical coupling, miniaturization, and high mass productivity at low processing cost. It is to provide a method and an optical coupling structure.

[0005]

In order to achieve the above object, an optical coupling method according to the present invention provides a photolithography and anisotropic etching on the upper surfaces of both substrates whose front end surfaces are abutted with each other. At the time of butting of the substrates, the V-grooves for optical fibers of the same shape, whose centers coincide with each other along the butting direction and are linear, and the V-grooves for the optical fibers are parallel to each other at a predetermined distance from each other. At the time of abutment, V-grooves for guide pins of the same shape which are aligned at the center with each other and become linear are formed, and the end faces are flush with the V-grooves for optical fibers of the two substrates and the front end surfaces of both substrates. The optical fibers are held and fixed respectively, and the guide pins are held and fixed by projecting a predetermined length from the front end surface of the substrate in the V-grooves for guide pins of the one substrate, and the front end surfaces of both substrates are fixed. Butt At this time, the protruding portions of the guide pins held and fixed to one substrate are inserted into the V-grooves for guide pins of the other substrate, so that the optical axes of the optical fibers of the two substrates are aligned and both are aligned. Wherein the optical fibers are connected to each other. Therefore, according to the present invention, merely abutting the front end surfaces of both substrates,
The protruding portions of the guide pins are inserted into the V-grooves for guide pins on the other substrate, whereby the optical axes of both optical fibers are aligned with the alignment of the V-grooves for both optical fibers, and the Both optical fibers are coupled in a state where the optical axes coincide with each other, so that the work is easy and good optical coupling is obtained.

Further, according to the optical coupling method of the present invention, the butt direction of the two substrates is formed on the upper surface of one substrate by photolithography and anisotropic etching. A V-groove for an optical fiber is formed along the V-groove, and the optical fiber is held and fixed in the V-groove for the optical fiber with the end face flush with the front end face of the substrate. By anisotropic etching, an optical waveguide is formed which coincides with the optical axis of the optical fiber held and fixed in the V-groove of the one substrate when the leading end surfaces of the two substrates are butted, and is formed on the upper surface of the one substrate. A V-groove for a guide pin is formed in parallel with the V-groove for the optical fiber at a predetermined distance by photolithography and anisotropic etching, and a photolithography is formed on the upper surface of the other substrate. V-grooves for guide pins of the same shape that are parallel to the optical waveguide at a predetermined distance and have the same center and a straight line when the front end surfaces of both substrates are abutted by a predetermined distance and anisotropic etching. And V for the guide pin of one of the two substrates.
In the groove, the guide pin is held and fixed by projecting a predetermined length from the front end surface of the substrate, and when the front end surfaces of both substrates are abutted, the protruding portion of the guide pin held and fixed by the one substrate Are inserted into the V-grooves for guide pins of the other substrate so that the optical axes of the optical fiber of the one substrate and the optical waveguide of the other substrate are aligned, and the optical fiber and the optical waveguide are It is characterized in that it is combined. Therefore, according to the present invention, the projecting portions of the guide pins are inserted into the V-grooves for the guide pins of the other substrate by merely abutting the end surfaces of both substrates, whereby the V-grooves for the optical fibers and the V-grooves for the optical fibers are inserted. The optical axes of the optical fiber and the optical waveguide are aligned with the alignment of the optical path, and the optical fiber and the optical waveguide are coupled in a state where the optical axes thereof are aligned with each other.

In the optical coupling structure of the present invention, the centers coincide with each other when the two substrates are butted by photolithography and anisotropic etching. A V-shaped groove for an optical fiber of the same shape, and a guide pin of the same shape which is parallel to the V-groove for the optical fiber at a predetermined distance, and whose centers coincide with each other when the two substrates are butted, and are linear. V
The optical fibers are respectively held and fixed in the V-grooves for the optical fibers of the two substrates with the end surfaces flush with the end surfaces of the two substrates, and the guide fibers for the guide pins of the one substrate are formed. Guide pins are held and fixed in the V-grooves by projecting a predetermined length from the front end surface of the substrate, and the protruding portions of the guide pins of one substrate are used for the guide pins of the other substrate by abutting the front end surfaces of the two substrates. And the optical fibers of the two substrates are aligned with each other so as to align the optical axes of the optical fibers. Therefore, according to the present invention, the projecting portions of the guide pins are inserted into the V-grooves for the guide pins of the other substrate simply by abutting the end faces of both substrates, thereby forming the V-grooves for both optical fibers. Since the optical fibers are aligned with each other and the optical axes of the optical fibers are aligned with each other, the optical fibers are coupled in a state where the optical axes of both optical fibers are aligned with each other. Is obtained. Further, since the two optical fibers are optically coupled to each other by the alignment of the guide pins and the V-grooves for the guide pins, the structure is simplified and the size can be reduced. Further, since V-grooves can be formed by processing by anisotropic etching utilizing photolithography and crystal orientation, the distance between each V-groove is accurate, and each V-groove is formed.
The angle accuracy and flatness of the groove can be processed with submicron accuracy, and optical coupling between the two optical fibers can be performed with high accuracy. Further, since each V-groove can be processed by photolithography and anisotropic etching, which are the same method as the semiconductor process, each V-groove can be formed at the same time as the semiconductor process is formed. A large amount of processing can be performed, mass productivity can be improved, and processing cost can be reduced.

In the optical coupling structure of the present invention, the top surface of one of the two substrates whose front end surfaces are abutted with each other is formed along the abutting direction of the substrates by photolithography and anisotropic etching. V for optical fiber
A groove is formed, and the optical fiber is held and fixed in the V-groove for the optical fiber with the end face flush with the front end face of the substrate,
An optical waveguide, which coincides with the optical axis of the optical fiber held and fixed in the V-groove of the one substrate when the two substrates are abutted to each other by photolithography and anisotropic etching, on the other substrate. A waveguide is formed, and a V-groove for a guide pin is formed on the upper surface of the one substrate by photolithography and anisotropic etching at a predetermined distance in parallel with the V-groove for the optical fiber, and the other substrate is formed. The upper surface of the substrate is parallel to the optical waveguide at a predetermined distance by photolithography and anisotropic etching. A V-groove for a guide pin having the same shape is formed, and a V-groove for a guide pin of either one of the two substrates is located from the front end surface of the substrate. The guide pins are held long and protrude, and the guide pins are held and fixed. The protruding portions of the guide pins held and fixed in the V-grooves for the guide pins are brought into contact with the end surfaces of the two substrates, and the V pins for the guide pins of the other substrate are fixed. The optical fiber of the one substrate and the optical waveguide of the other substrate are inserted into the groove and are coupled to each other with the optical axes thereof aligned. Therefore, according to the present invention, the projecting portions of the guide pins are inserted into the V-grooves for the guide pins of the other substrate only by abutting the front end surfaces of both substrates, whereby the V Since the groove and the optical waveguide are aligned and the optical axis of the optical fiber and the optical waveguide are aligned with this, the optical fiber and the optical waveguide are coupled with the optical axis of the optical fiber and the optical waveguide aligned. Work is facilitated and good optical coupling is obtained. In addition, since the end face of the optical fiber and the optical waveguide are optically coupled by the alignment of the guide pins and the V-grooves for the guide pins, the structure is simplified and the size can be reduced. Furthermore, since a V-groove and an optical waveguide can be formed by processing by anisotropic etching using photolithography and crystal orientation, the distance between the V-groove for the optical fiber and the V-groove for a pair of guide pins and the pair of the optical waveguide and the optical waveguide are formed. The distance between the V-grooves for the guide pins is accurate, and the angular accuracy and flatness of each V-groove can be processed with submicron accuracy, enabling optical coupling between the optical fiber and the optical waveguide with high precision. Becomes In addition, each V lithography is performed by photolithography and anisotropic etching, which are the same method as the semiconductor process.
Since grooves and optical waveguides can be processed, each V-groove and optical waveguide can be formed simultaneously with the formation of a semiconductor process, and a large amount of processing can be performed per wafer in a single operation, thereby improving mass productivity. Costs can be reduced.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment according to the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing an optical coupling structure according to an embodiment of the present invention, FIG. 2 is a plan view showing one substrate, FIG. 3 is a front view showing one substrate, and FIG.
(A)-(c) is a top view which shows the order of optical coupling. As shown in FIGS. 1 and 4, the optical coupling structure according to the present embodiment includes a pair of optical fiber V-grooves 3 on the upper surfaces of both substrates 1A and 1B where the end surfaces 1a and 1b abut against each other. V-grooves 5 and 5 for guide pins are formed. Optical fibers 9 are held and fixed in the optical fiber V-grooves 3 of both substrates 1A and 1B, respectively.
Guide pins 9, 9 are held and fixed in the V-grooves 5, 5 for the guide pins A, 1B with the tips protruding a required length. Further, the guide pins 9 and 9 are formed to have a considerably larger outer diameter than the optical fiber 7, and accordingly, the V-grooves 5 and 5 for the guide pins are formed in large V-grooves.

More specifically, as shown in FIGS. 2 and 3, the V-groove 3 for the optical fiber is abutting direction of the tip surfaces 1a and 1b of the substrates 1A and 1B, that is, the substrate 1
A, 1B are provided linearly along a direction orthogonal to the tip surfaces 1a, 1b. The pair of V-grooves 5 for guide pins are linearly provided in parallel on both sides of the V-groove 3 for optical fiber at a predetermined distance L from each other. The V-grooves 3 for optical fibers and the V-grooves 5 and 5 for guide pins formed on the upper surfaces of both substrates 1A and 1B serve as optical fibers when both substrates 1A and 1B are abutted. V
The V-grooves 5 and 5 for guide pins are formed in the same V-groove so that the centers of the grooves 3 and the guide pins coincide with each other and become straight.

As shown in FIG. 3, when the optical fiber 7 is held and fixed, the center O of the cross section of the core of the optical fiber 7 is set to the substrate 1A, as shown in FIG.
The guide pins V are formed to have a width flush with the upper surface of the guide pins 1B, and the V-grooves 5 for the guide pins are also formed at the center of the cross section of the guide pins 9 when the guide pins 9 are held and fixed. P is formed to have a width such that P is flush with the upper surfaces of the substrates 1A and 1B.

Further, the optical fibers V-grooves 3 of the two substrates 1A and 1B are connected to the optical fibers 7 connected to each other.
The end surfaces of the cores are the front end surfaces 1a, 1a of the substrates 1A, 1B.
Each optical fiber 7 is held and fixed to each surface of the V groove by using an optical adhesive or the like so as to be flush with b. In addition, as shown in FIG.
In each of the V-grooves 5 for guide pins of one of the substrates 1A and 1B, guide pins 9 and 9 formed in a columnar shape having a predetermined length are provided with approximately half of the entire length of the front surface of the substrate 1A. 1a
And is held and fixed to each surface of the V-groove using an optical adhesive or the like.

For the substrates 1A and 1B, for example, silicon (Si) is used as a base material, and anisotropic etching using the crystal orientation of the substrates 1A and 1B is performed by using photolithography. V-grooves 3, 5, 5 for optical fibers and guide pins 9, 9
Are formed at the same time. Therefore, because of the anisotropic etching using the crystal orientation,
Each of the V-grooves 3, 5, 5 is formed with high accuracy in terms of angular accuracy and flatness. Further, since the photolithography method is used, the width of each of the V-grooves 3, 5, 5 and the distance between the pin guides 9, 9 and the optical fiber 7 are formed with submicron accuracy equivalent to that of a semiconductor process.

Further, the core of the optical fiber 7 is generally formed of glass having a smooth cylindrical surface with a standard outer shape of 125 ± 1 μm. The guide pins 9 and 9 are each formed of a column-shaped metal fitting having a flat surface with a sufficiently small straightness and a small surface roughness.

The projecting portions of the pair of guide pins 9, 9 projecting from one of the substrates 1A, 1B are
A and 1B are inserted into the V-grooves 5 and 5 provided while sliding, and the tip surfaces 1a and 1b of both substrates 1A and 1B are abutted to align the optical axes of both optical fibers. The end faces of the cores of the optical fibers 7 fixed to the V-grooves 3 of both the substrates 1A and 1B are connected in a state where the optical axes of the optical fibers 7 are aligned.

Next, the case where the optical fiber 7 having the optical coupling structure is optically coupled will be described. First, as shown in FIG. 4A, the end surfaces 1a and 1b of both substrates 1A and 1B face each other, and as shown in FIG.
When B is moved in the butting direction, the projecting portions of the pair of pin guides 9, 9 fixed to one substrate 1A are inserted into the V-grooves 5, 5 of the other substrate 1B while sliding, respectively, as shown in FIG. As shown in (1), the tip surfaces 1a and 1b of both substrates 1A and 1B are butted. In this case, the insertion of the tip portions of the guide pins 9, 9 causes the two substrates 1A, 1
The V-grooves 5, 3 for the optical fibers of both substrates 1A, 1B are aligned with the centers of the V-grooves 5, 5 for the guide pin B and located at the same distance L from the pair of V-grooves 5, 5. Are aligned so that the optical axes of the two optical fibers 7 held and fixed in the V-grooves 3 for the optical fibers coincide with each other. Then, as shown in FIG.
The end faces of the two optical fibers 7 fixed flush with the end faces 1a and 1b of the substrates 1A and 1B are joined together with the optical axes of the two optical fibers 7 aligned with each other.
A good optical coupling between the two optical fibers 7 can be obtained without adjustment by merely abutting A and 1B.

As described above, in the present embodiment, the protruding portions of the guide pins 9, 9 are only required to abut the end surfaces 1a, 1b of the two substrates 1A, 1B.
1B are inserted into the V-grooves 5 and 5 for guide pins, whereby the V-grooves 3 for both optical fibers are aligned with each other, and are held and fixed in each V-groove 3 with the alignment of the V-grooves 3 together. The optical axes of the optical fibers 7 are aligned, and the optical fibers 7 are aligned with the optical axes of the two optical fibers 7 aligned.
Are bonded to each other to easily obtain good optical coupling. Also, guide pins 9 and 9 and V-grooves 5 for guide pins,
Since the optical fibers 7 can be optically coupled by the alignment by 5, the structure can be simplified and the size can be reduced. Further, since the V-grooves 3 and 5 can be formed by processing by photolithography and anisotropic etching utilizing the crystal orientation, the distance between the V-grooves is accurate, and the angular accuracy and flatness of each V-groove 3 and 5 are obtained. Can be processed with submicron accuracy, and both optical fibers 7 can be optically coupled with high precision. In addition, since each V-groove can be processed by photolithography and anisotropic etching, which are the same method as the semiconductor process, each V-groove can be formed at the same time as the semiconductor process is formed. A large amount of processing can be performed, mass productivity can be improved, and processing cost can be reduced.

Next, a second embodiment of the present invention will be described with reference to FIGS. In the present embodiment, a plurality of optical fibers V-grooves 3 are provided in both substrates 1A and 1B so that a plurality of optical fibers 7 can be held and fixed to the substrates.
B, a plurality of optical fibers 7
It is possible to combine them.

That is, as shown in FIGS. 5 and 6,
V-grooves 3 for three optical fibers are formed on both substrates 1A and 1B, which are abutted with each other, at a predetermined distance l. V-grooves 5, 5 for guide pins are formed with L therebetween. V-grooves 5 for a pair of guide pins of one substrate 1A,
The guide pins 9 and 9 project and hold a predetermined length to 5, respectively, and are fixed to the V-grooves 3 for the optical fibers of both substrates 1A and 1B. It is held and fixed flush with the surfaces 1a and 1b. Then, the tip surfaces 1 of both substrates 1A, 1B
By abutting a and 1b, a plurality of optical fibers 7 are simultaneously optically coupled. In this case, in addition to the effects of the above embodiment, without increasing the number of additional components,
It is possible to optically couple a plurality of optical fibers 7 while maintaining a small structure.

Next, a third embodiment of the present invention will be described with reference to FIGS. In the present embodiment, of the two substrates whose leading end surfaces are butted against each other,
On the other hand, the optical fiber 7 is inserted into the V groove 3 for the optical fiber of the substrate 1A.
Are held and fixed, and an optical waveguide 11 for confining and propagating light is formed on the other substrate 1B.

The optical waveguide 11 is provided on a crystal substrate by epitaxy, which is conventionally used, so that the center of the core of the optical fiber 11 is located at the center of the core of the optical fiber 7 as shown in FIGS. Is formed on the other substrate 1B such that the. And both substrates 1
By abutting A and 1B, both optical axes are aligned by the guide pins 9, 9 and the V-grooves 5, 5 for guide pins, and the optical fiber 7 and the optical waveguide 11 are optically coupled. Therefore, a new effect that the optical coupling structure of the optical waveguide module can be simplified and the optical coupling structure can be downsized can be obtained.

Next, a fourth embodiment of the present invention will be described with reference to FIGS. In the present embodiment, the end shapes of the guide pins 9, 9 held and fixed in the V-grooves of the substrates 1A, 1B respectively are made easy to insert. That is, as shown in FIG.
Chamfering the edge of the end face over the entire outer circumference,
As shown in FIG. 10, the ends of the guide pins 9, 9 are formed in a spherical shape bulging outward. When the guide pins 9, 9 formed in such an end shape are held and fixed to the substrates 1A, 1B, when the two substrates 1A, 1B are abutted, the two substrates 1A, 1B are slightly positioned. Even if it is shifted, the guide pins 9 held and fixed to one substrate 1A,
9 can be easily inserted into the V-grooves 5, 5 of the other substrate 1 </ b> B, and the displacement of the substrates 1 </ b> A, 1 </ b> B when the guide pins 9, 9 are inserted can be allowed. The ends of the guide pins 9, 9 are not limited to the spherical surface bulging outward, but may be formed in a bulging curved surface.

Next, a fifth embodiment of the present invention will be described with reference to FIG. In the present embodiment, the substrate 1
The amount of protrusion of the guide pins 9, 9 held and fixed in the V-grooves A, 1B can be easily set. That is, as shown in FIG. 11, the length of the V-grooves 5, 5 for the guide pins to which the guide pins 9, 9 are held and fixed is
The V-grooves 5 are formed at predetermined base lengths at the time of formation, and inclined surfaces 5a and 5b extending from the bottom of the V-grooves 5 and 5 to the upper surface of the substrate 1A are formed on the base end side of the V-grooves 5 and 5. And
The rear ends of the guide pins 9, 9 mounted on the V-grooves 5, 5 formed to a predetermined length are formed on the inclined surfaces 5a, 5b of the V-grooves 5, 5.
, The amount of protrusion of the guide pins 9 from the front end surface 1a of the substrate 1A is set.

Therefore, the amount of protrusion of the guide pins 9, 9 can be determined by setting the lengths of the V-grooves 5, 5, so that the amount of protrusion of the guide pins 9, 9 can be set arbitrarily.
The amount of protrusion of the guide pins 9, 9 can be easily changed, and the rear ends of the guide pins are locked to the inclined surfaces 5a, 5b. 9 has a new effect that it can be prevented from retracting backward from the front end surface 1a of the substrate 1A.

Next, a sixth embodiment of the present invention will be described with reference to FIG. In the present embodiment, the substrate 1
The strength of the substrates 1A and 1B with respect to the stress concentrated on the acute angles of the V-grooves 3, 5 and 5 provided in A and 1B is improved. That is, as shown in FIG.
The flat portions 5b, 5b are formed at the bottom of the V-grooves 3, 5, 5 provided for the guide pins and the V-grooves 5, 5 for the guide pins provided to deep portions in the substrates 1A, 1B. The bottom portions 5b and 5b are formed by adjusting the etching amount when forming the V-grooves 5 and 5 by anisotropic etching to leave the flat portions 5b and 5b at the bottom. Therefore, by providing the flat portions 5b and 5b at the bottoms of the V-grooves 5 and 5, the stress concentrated on the acute corners at the bottoms of the V-grooves 5 and 5 can be reduced, and the strength of the substrates 1A and 1B can be increased. It becomes possible.

In each of the above-described embodiments, the case where the guide pins 9 and 9 are formed in a cylindrical shape has been described. However, the present invention is not limited to this, and the guide pins 9 and 9 may be formed in a cylindrical shape. Also,
The substrates 1A and 1B are not limited to silicon and may be formed of ceramic, metal, or the like. Further, a flat portion 5b is provided at the bottom of the V-grooves 5, 5 for guide pins.
Although 5b is provided, a flat portion may be provided at the bottom of the V-groove 3 for the optical fiber.

[0027]

As described above, according to the present invention, the optical coupling of both optical fibers can be performed only by abutting the end surfaces of both substrates, so that the optical coupling operation is facilitated, and furthermore, the guide pin is provided. When the protruding portion of the optical fiber is inserted into the V-groove for the guide pin of the other substrate, the optical axes of both optical fibers and the optical axis of the optical fiber are aligned with the optical axis of the optical fiber. It is possible to couple the fiber and the optical waveguide in a state where their optical axes are aligned, and good optical coupling is obtained. In addition, since the two optical fibers and the optical fiber and the optical waveguide can be optically coupled by alignment by the guide pin and the V groove for the guide pin, the structure is simplified,
The size can be reduced. Furthermore, since V-grooves can be formed by processing by anisotropic etching utilizing photolithography and crystal orientation, the distance between each V-groove is accurate, and the angular accuracy and flatness of each V-groove are in submicron units. And optical coupling between the two optical fibers can be performed with high precision. In addition, since each V-groove can be processed by photolithography and anisotropic etching, which are the same method as the semiconductor process, each V-groove can be formed at the same time as the semiconductor process is formed. A large amount of processing can be performed, mass productivity can be improved, and processing cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an optical coupling structure according to a first embodiment of the present invention.

FIG. 2 is a plan view showing one substrate according to the first embodiment of the present invention.

FIG. 3 is a front view showing one substrate according to the first embodiment of the present invention.

FIGS. 4A to 4C are plan views showing the order of optical coupling according to the first embodiment of the present invention.

FIG. 5 is a plan view showing an optical coupling structure according to a second embodiment of the present invention.

FIG. 6 is a front view showing an optical coupling structure according to a second embodiment of the present invention.

FIG. 7 is a plan view showing an optical waveguide provided on the other substrate according to the third embodiment of the present invention.

FIG. 8 is a front view showing an optical waveguide provided on the other substrate according to the third embodiment of the present invention.

FIG. 9 is a plan view showing an optical coupling structure according to a fourth embodiment of the present invention.

FIG. 10 is a plan view showing an optical coupling structure according to a fourth other embodiment of the present invention.

FIG. 11 is a plan view showing an optical coupling structure according to a fifth embodiment of the present invention.

FIG. 12 is a front view showing an optical coupling structure according to a sixth embodiment of the present invention.

[Explanation of symbols]

1A: One substrate, 1a: Tip surface of one substrate, 1
B: the other substrate, 1b: the end surface of the other substrate, 3 ...
... V-groove for optical fiber, 5 ... V-groove for guide pin, 5
b: flat part, 7: optical fiber, 9: guide pin,
11 Optical waveguide.

Claims (15)

[Claims] 1. A photolithography process and an anisotropic etching process are performed on the upper surfaces of both substrates whose front end surfaces abut each other so that their centers coincide with each other along the abutting direction when the two substrates abut each other, and are linearly formed. And a V-groove for an optical fiber having the same shape, and a V-groove for the same shape that is parallel to the V-groove for the optical fiber at a predetermined distance and has the same center and a linear shape when the two substrates are butted. Grooves are formed respectively, and the optical fibers are respectively held and fixed in the V-grooves for the optical fibers of the two substrates, with the end surfaces flush with the end surfaces of the two substrates, and the guide pins for the guide pins of the one substrate are formed. A guide pin protrudes from the front end surface of the substrate by a predetermined length and is held and fixed to the V-groove, and when the front end surfaces of both substrates abut against each other, the protruding portion of the guide pin held and fixed to one substrate But others The optical coupling is characterized in that the optical fibers of the two substrates are aligned by aligning the optical axes of the optical fibers of the two substrates by being inserted into the V-grooves for the guide pins of the other substrate. Method. 2. An optical fiber V-shaped optical fiber is formed on the upper surface of one of the two substrates whose front end surfaces are abutted with each other by photolithography and anisotropic etching along the abutting direction of the two substrates. Forming a groove, holding and fixing the optical fiber in the V-groove for the optical fiber with the end face flush with the end face of the substrate, and performing photolithography and anisotropic etching on the other substrate, Forming an optical waveguide that coincides with the optical axis of the optical fiber held and fixed in the V-groove of the one substrate at the time of abutting the front end surfaces of the substrates; and photolithography and anisotropic etching on the upper surface of the one substrate. A V-groove for a guide pin is formed in parallel with the V-groove for the optical fiber at a predetermined distance, and photolithography and anisotropic etching are performed on the upper surface of the other substrate. Thereby, a V-groove for a guide pin of the same shape which is parallel to the optical waveguide at a predetermined distance and has the same center when the front end surfaces of both the substrates abut each other and becomes linear is formed. Of these, the guide pin is held and fixed in a V-groove for a guide pin of one of the substrates by projecting a predetermined length from the front end surface of the substrate, and when the front end surfaces of the two substrates are abutted, By inserting the protruding portion of the guide pin held and fixed to one substrate into the V-groove for the guide pin of the other substrate,
An optical coupling method, wherein an optical axis of the optical fiber of the one substrate and an optical axis of the optical waveguide of the other substrate are aligned to couple the optical fiber and the optical waveguide. 3. An optical fiber for optical fibers of the same shape, whose centers coincide with each other and become linear when the two substrates are butted by photolithography and anisotropic etching on the upper surfaces of both substrates whose tip surfaces are butted against each other. And a V-groove for a guide pin, which is parallel to the V-groove for the optical fiber at a predetermined distance and has the same shape and becomes linear when the two substrates are butted together, respectively. The optical fibers are held and fixed to the optical fiber V-grooves of the two substrates, respectively, with the end faces flush with the end surfaces of the two substrates, and the substrate is fixed to the V-grooves for guide pins of the one substrate. The guide pins protrude a predetermined length from the front end surfaces of the two substrates, and the guide pins are held and fixed. When the front end surfaces of the two substrates abut, the protruding portions of the guide pins of one substrate are V
An optical coupling structure, wherein the optical coupling structure is inserted into the groove and aligned with the optical axes of the optical fibers of the two substrates so as to be coupled to each other. 4. A V-groove for an optical fiber is formed on the upper surface of one of the two substrates whose front end surfaces abut each other by photolithography and anisotropic etching along the abutting direction of the substrates. An optical fiber is formed and fixed in the V-groove for the optical fiber with the end face flush with the front end face of the substrate. Photolithography and anisotropic etching are performed on the other of the two substrates. Thereby, an optical waveguide is formed which coincides with the optical axis of the optical fiber held and fixed in the V-groove of the one substrate at the time of abutting of the two substrates, and photolithography and anisotropy are formed on the upper surface of the one substrate. By etching, a V-groove for a guide pin is formed in parallel with the V-groove for the optical fiber at a predetermined distance, and photolithography and a different pattern are formed on the upper surface of the other substrate. By the reactive etching, for the same shape of the guide pin, the center and the V-groove for the guide pin of the one substrate coincide with each other and become linear when the two substrates are abutted. A V-groove is formed, and a guide pin is held and fixed by protruding a predetermined length from a front end surface of the substrate in a V-groove for a guide pin of one of the two substrates. The protruding portions of the guide pins held and fixed in the V-grooves for the guide pins are inserted into the V-grooves for the guide pins of the other substrate so that the optical fiber of the one substrate and the optical fiber of the other substrate are joined. An optical coupling structure wherein the optical axes of the substrate and the optical waveguide are aligned and coupled to each other. 5. The optical fiber V-groove is formed such that the center of the optical fiber when held and fixed in the V-groove is flush with the upper surface of the substrate, and the guide pin is formed in the V-groove. 5. The optical coupling structure according to claim 3, wherein the V-groove is formed so that the center of the guide pin when held and fixed in the V-groove is flush with the upper surface of the substrate. . 6. The optical coupling according to claim 3, wherein a plurality of said optical fiber V-grooves and a plurality of optical fibers held and fixed in said V-grooves are provided on both of said substrates. Construction. 7. A plurality of optical fiber V-grooves and a plurality of optical fibers held and fixed in the V-groove are provided on the one substrate, and a plurality of optical waveguides coupled to the plurality of optical fibers are provided on the other substrate. The optical coupling structure according to claim 4, wherein the optical coupling structure is provided on a substrate. 8. The optical coupling according to claim 3, wherein the V-groove for the guide pin is provided on both sides of the V-groove for the optical fiber and the optical waveguide, respectively. Construction. 9. The optical fiber according to claim 3, wherein said guide pin and said optical fiber are held and fixed in respective V-grooves by bonding using an optical adhesive or the like.
The optical coupling structure as described. 10. The guide pin according to claim 3, wherein the guide pin is formed in a cylindrical shape.
The optical coupling structure as described. 11. The guide pin according to claim 3, wherein a peripheral edge of an end of the guide pin is chamfered.
11. The optical coupling structure according to 8, 9, or 10. 12. The guide pin according to claim 3, wherein an end portion of the guide pin is formed in a curved surface bulging outward.
The optical coupling structure according to 5, 6, 7, 8, 9 or 10. 13. An end portion of the guide pin is formed in a spherical shape bulging outward.
The optical coupling structure according to 5, 6, 7, 8, 9 or 10. 14. The V-groove for the guide pin is formed with a predetermined length, and the amount of protrusion of the guide pin held and fixed in the V-groove from the front end surface of the substrate is defined by the length of the V-groove. Claims 3, 4, 5, 6, 7, 8,
The optical coupling structure according to 9, 10, 11, 12 or 13. 15. The device according to claim 3, wherein a flat portion is provided at a bottom portion of the V-groove for the guide pin or the optical fiber. 12, 1
15. The optical coupling structure according to 3 or 14.