JP2001324647A - Optical fiber array, optical waveguide chip and optical module connecting them - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an optical module in which optical fibers and optical waveguides are connected with low loss and low reflection with high accuracy. SOLUTION: The optical module is provided, in which an optical fiber array 14 which is constituted by engraving plural lines of V grooves 12 parallel on a substrate 11 so as to become oblique with respect to the connection end face of the substrate 11 and by housing optical fibers 13 in these V grooves 12 and by grinding the connection end face 14a so as to become a right angle with respect to the upper surface and the bottom surface of the substrate 11 is connected to an optical waveguide chip 35 which is constituted by forming plural lines of optical waveguides 36 on a waveguide substrate 37 and by forming the waveguides so that their axial directions become oblique with respect to the connection end face of the substrate 37 at incidence and emission positions of the optical waveguides 36 and by grinding the connection end face of the substrate 37 so as to become a right angle with respect to the upper surface and the bottom surface of the substrate 37.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of connecting a waveguide type optical component such as a waveguide type optical selector, a waveguide type splitter, a waveguide type optical switch and an optical fiber in an optical communication system. The present invention relates to an optical fiber array, an optical waveguide chip, and an optical module connecting these, which are useful for connecting the optical fiber with low reflection and low loss.

[0002]

2. Description of the Related Art In optical communication, an optical waveguide type optical component such as a modulator and a switch is inserted into a transmission line composed of an optical fiber as required. 2. Description of the Related Art An optical waveguide type optical component is an optical functional component in which an optical waveguide is formed on a substrate, and is widely used because of its features such as small size, high speed, high efficiency, and high reliability. Among the optical waveguide type optical components, the silica glass type optical waveguide type component containing silica glass as a main component has a low optical transmission loss and a low loss connection with a silica glass type optical fiber is possible. Since optical functions can be integrated, they are expected to be used in large quantities in the construction of optical communication networks in the future.
Under these circumstances, there is a need for a technique for connecting the optical waveguide of the optical waveguide type optical component and an optical fiber so as to obtain low reflection, low loss, and the best optical characteristics.

[0003]

In general, when connecting an optical fiber and an optical waveguide type optical component, the connection between the optical fiber and the optical waveguide of the optical waveguide type optical component, that is, the boundary surface of the optical waveguide is connected to the optical fiber. By slightly inclining with respect to the traveling direction of the light, light reflected at the boundary surface of the optical waveguide and returning to the light source, that is, reflected light can be reduced.

As a method of inclining the connection surface between the optical fiber and the optical waveguide, for example, FIGS.
As shown in the figure, the optical fiber array 4 and the optical waveguide chip 7
In connection with the optical fiber array 4, there is a method in which the end face 4a of the optical fiber array 4 and the end face 7a of the optical waveguide chip 7 are polished obliquely to connect them. In the optical fiber array 4, a plurality of V-grooves 2, 2,... Are engraved on the substrate 1 in parallel along the longitudinal direction of the substrate 1, and the optical fibers 3, 3,.
Is housed.

[0005] The optical waveguide chip 7 connected thereto is formed by forming a plurality of optical waveguides 6 on a waveguide substrate 5. In the connection method shown in FIGS. 7 and 8, the connection end face 4 a of the optical fiber array 4 and the connection end face 7 a of the optical waveguide chip 7 are set at their inclination angles (the polished surface 4 b with respect to the connection end face 4 a before polishing). The angle or the angle of the polishing surface 7b with respect to the connection end surface 7a) is polished obliquely so that they are equal to each other and overlap when these end surfaces are opposed to each other.

More specifically, in FIG. 7, the connection end face 4a of the optical fiber array 4 is polished with the connection end face 4a so as to be oblique to the width direction of the substrate 1 and perpendicular to the thickness direction. Polishing is performed so that the angle formed by the surface 4b becomes θ ′. Also, the connection end face 7a of the optical waveguide chip 7 is oblique to the width direction of the substrate 5 and perpendicular to the thickness direction, and the angle formed between the connection end face 7a and the polished surface 7b is θ. Polish so that it becomes. And these polished surfaces 4
b and 7b are connected to face each other to obtain an optical waveguide type optical component.

In FIG. 8, the connection end face 4a of the optical fiber array 4 is perpendicular to the width direction and oblique to the thickness direction.
b is polished so as to form an angle θ ′, and the connection end face 7 a of the optical waveguide chip 7 is perpendicular to the width direction of the substrate 5 and oblique to the thickness direction, and Polishing is performed so that the angle between the connection end surface 7a and the polishing surface 7b becomes θ ′, and the polishing surfaces 4b and 7b are connected to face each other.

However, in such a connection method, it is necessary to polish the connection end face 4a of the optical fiber array 4 and the connection end face 7a of the optical waveguide chip 7 obliquely. Therefore, these connection end faces 4a and 7a are polished. The polishing machine or the mounting jig of the polishing machine is polished at a polishing angle (the angle of the connection end face after polishing with respect to the substrate end face before polishing, that is, the angle θ and the angle θ ′ are the polishing angles).
Had to be remodeled. When the optical fiber array 4 and the optical waveguide chip 7 are connected, the optical fiber 3 and the optical waveguide 6 are connected while being aligned, but the alignment connector used in this case or the mounting of the alignment connector is used. It was also necessary to modify the jig according to the polishing angle (angle θ, angle θ ′). Therefore, it takes time, and in such a connection method, the polishing accuracy of the connection surface between the optical fiber array 4 and the optical waveguide chip 7 is poor, and the reproducibility is poor.

On the other hand, as another method of connecting an optical fiber to an optical waveguide type optical component, Japanese Patent Application Laid-Open No. 8-122561 discloses a method of connecting a non-quartz optical waveguide formed on the same substrate to a quartz optical fiber. A method for doing so is described. In this method, the optical waveguide formed on the substrate has an end face of the optical waveguide facing the tip end face of the optical fiber, a flat surface inclined with respect to the axis of the optical waveguide, and the axis of the optical waveguide and the optical fiber. A guide groove for an optical fiber is prepared on the substrate so that the axis intersects the end face at an intersection angle corresponding to the light bending at the end face, and in this state, the optical fiber and the optical waveguide are connected. is there.

However, this method is difficult to apply when a plurality of optical fibers are connected to a plurality of optical waveguides, and the end face of the optical waveguide is aligned with the connection end face of the optical fiber as in the above-described connection method. It is necessary to work diagonally, and the accuracy of the polishing angle on the connection surface is poor, and there is a problem that connection loss increases. In addition, there is a problem that reproducibility is poor. The present invention has been made in view of the above circumstances, and has as its object to easily obtain an optical module in which an optical fiber and an optical waveguide of an optical waveguide type optical component are connected with low loss and low reflection.

[0011]

To solve this problem, the present invention provides a plurality of V-grooves on the upper surface of a plate-like substrate.
From the side surface which is the connection end surface of the substrate to the other side surface opposite thereto, the V grooves are engraved in parallel so that the axial direction is oblique to the connection end surface, and the optical fibers are inserted into these V grooves. Provided is an optical fiber array which is housed such that the front end surface is in contact with the connection end surface of the substrate, and polished the connection end surface of the substrate and the front end surface of the optical fiber so as to be perpendicular to the top and bottom surfaces of the substrate. I do. Also, a plurality of optical waveguides are formed on the upper surface of the plate-like substrate from the side surface which is the connection end surface of the substrate to the other opposite side surface, and at the input / output position of the optical waveguide leading to the connection end surface, the optical waveguide Is formed such that its axial direction is oblique to the connection end surface of the substrate, and the connection end surface of the substrate and the tip end surface of the optical waveguide are polished so as to be perpendicular to the top and bottom surfaces of the substrate. An optical waveguide chip is provided. With such an optical fiber array and an optical waveguide chip, by polishing these connection end faces at right angles, the connection end faces of the optical fiber and the optical waveguide can be processed obliquely and accurately.

Further, the present invention provides an optical module in which such an optical fiber array and an optical waveguide chip are connected. In this optical module, the connection end face of the optical fiber array and the connection end face of the optical waveguide chip are polished so as to be perpendicular to the bottom surface of each substrate, and the connection end faces polished at right angles are opposed to each other. The optical fibers of the optical fiber array are connected to the optical waveguides of the optical waveguide chip, and a boundary surface between the optical fibers and the optical waveguides is inclined with respect to the light traveling direction of the optical fibers. ing. Further, in the optical module, an angle θ1 of a traveling direction of light of the optical fiber with respect to a plane perpendicular to a boundary surface between the optical fiber and the optical waveguide, and an angle θ2 of a traveling direction of light in the optical waveguide with respect to the plane are defined as: Equal (θ1 = θ2), or the angle θ1 and the angle θ2 indicate that the effective refractive index of light propagating through the optical fiber is n1,
When the refractive index of light propagating through the optical waveguide is n2, n
It is preferable to satisfy the relationship of 1 · sin θ1 = n2 · sin θ2. Further, an antireflection film can be interposed on the connection surface between the optical fiber array and the optical waveguide chip. Such an optical module can connect an optical fiber and an optical waveguide with low loss and low reflection.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
First, an optical fiber array and an optical waveguide chip used for an optical module in which an optical fiber and an optical waveguide component of the present invention are connected will be described. 1A and 1B are schematic diagrams for explaining an example of an optical fiber array according to the present invention. FIG. 1A is a plan view seen from above, FIG. 1B is a side view, and FIG. 1C is a sectional view seen from a connection end face. It is. In this figure, the number of the V-grooves 12 and the number of the optical fibers 13 accommodated in the V-grooves 12 are set to four for ease of explanation, but actually, it is possible to design more.

In the figure, reference numeral 11 denotes a substrate.
Is a rectangular plate-like object made of quartz or the like,
One of the side surfaces is perpendicular to the bottom surface and the top surface of the substrate 11, and the connection end surface 11 with the optical waveguide type optical component.
a. On the upper surface of the substrate 11, a plurality of V
Are formed in parallel from the connection end face 11a of the substrate 11 to the other side face 11b so as to be oblique to the connection end face 11a of the substrate 11. Each of these V-grooves 12, 12... Has an optical fiber 13, 13.
1a are accommodated one by one so as to be in contact with 1a. Then, the connection end face 11a of the substrate 11 and the optical fibers 13, 1
3 are polished so as to be perpendicular to the bottom surface of the substrate 11, and are used as connection end surfaces 14a of the optical fiber array 14. Hereinafter, the polished optical fiber array 14
The angle of the connection end surface 14a with respect to the bottom surface of the substrate 11 is defined as a polishing angle.

Here, the term "obliquely with respect to the connection end face 11a of the substrate 11" means that the axial direction of the V-groove 12 corresponds to the connection end face 11a.
Has an inclination of an angle θ1 with respect to the vertical plane. The angle θ1 at this time is defined as an inclination angle. This inclination angle θ
1 are the inclination angles of the optical fibers 13, 13,... Accommodated in the V-grooves 12, 12,.
3 shows the inclination of the light traveling direction (axial direction) of the optical fiber with respect to the vertical plane of the front end face 13a of the optical fiber. The inclination angle θ1 is
The angle is required to secure a sufficient amount of return loss of light, preferably in the range of 7 to 9 °, and more preferably 8 ± 0.1 °. If the angle θ is less than 7 °, the inclination angle at the tip of the optical fiber 13 housed in the V-groove 12 is not sufficient, and when the optical fiber 13 is connected to an optical waveguide type optical component, the end surface (boundary surface) Light reflection increases. On the other hand, when the angle exceeds 9 °, the inclination angle of the end face increases, and it becomes difficult to optically connect the optical waveguide type optical component to the optical waveguide.

Optical fiber 13 housed in V-groove 12
As shown in FIG. 2, for example, a multi-core optical fiber ribbon 19 is divided into optical fiber strands 18,
It is preferable to use an optical fiber (bare wire) 13 having an outer diameter of 125 μm, which is obtained by removing the coating of the tip of the wire 18 and extruding the wire. For example, when the optical fiber array 14 contains 16 optical fibers 13, two 8-core optical fiber ribbons are used, divided and exited, and V When the optical fibers (bare wires) 13 are arranged in the grooves 12, 12,..., The optical fiber 18 is wider than the width in which one optical fiber (bare wire) 13 is arranged in a line, which is convenient. Of course, the multi-core optical fiber ribbon 19 can be used as it is. The other end of the optical fiber 13 is led out from the rear of the optical fiber array 14 as an optical fiber ribbon 19 as a lead wire, and is connected to another optical component.

The width of the V-groove 12 is larger than the outer diameter of the optical fiber 13 accommodated in the V-groove 12 by about 1-2 μm, usually 126-127 μm, and the groove depth is 85 μm.
It has become about. Further, the number and the interval d2 of the V-grooves 12, 12,... Are appropriately determined by the number and the interval d1 of the optical fibers 13, 13 accommodated, and the interval d2 is calculated by the following equation (1). d2 = d1 / cos θ (1) For example, if the bare optical fiber 13 protruded from the eight-core optical fiber ribbon 19 shown in FIG. The spacing d2 is usually equal to the spacing d1 of the bare optical fiber.
Since it is designed at 50 μm, d2 = 250 / cos θ. Further, as shown in FIG. 2, if 16 optical fibers 13 in which 8 optical fiber ribbons are superimposed are accommodated, the distance d1 between them is usually 127 μm, so that d2 = 127. / Cos θ. As described above, it is practical to form the V-grooves 12 in accordance with the standard of the generally used optical fiber ribbon, and it is convenient to mass-produce the optical fiber array 14.

In such an optical fiber array 14, the inclination angle .theta.1 of the V-groove 12 is determined in advance so as to be equal to the desired inclination angle .theta.1 of the optical fiber 13, and the inclination angle .theta.
1 and accommodates the optical fiber 13 along the V-groove 12 so that the tip 13a is
By polishing vertically with respect to the bottom surface of the substrate 11 together with the one connection end surface 11a, the front end surface 13a of the optical fiber 13 can be easily polished so as to have the inclination angle θ1. Therefore, unlike the method of polishing an optical fiber array shown in the conventional example, it is not necessary to change the polishing angle of the connection end face by the inclination angle of the optical fiber, and the polishing angle may be always a right angle. There is no need to modify the mounting jig of the polishing machine depending on the inclination angle of the optical fiber 13, and the connection end surface 14a of the optical fiber array 14 can be easily polished. In addition, the accuracy is good and the reproducibility is good. Therefore, if such an optical fiber array 14 is connected to an optical waveguide chip described below, an optical module with low loss and low reflection can be configured.

Next, an optical waveguide chip connected to the optical fiber array 14 will be described. FIG. 3 is a schematic view showing an example of the optical waveguide chip of the present invention.
FIG. 2 is a plan view as viewed from above, FIG. 2B is a side view, and FIG. 1C is a cross-sectional view as viewed from a connection end face. In this figure, the number of the optical waveguides 16 is set to four for easy explanation, but actually, it is possible to design more. The optical waveguide chip 17 has the optical waveguide 1 on the waveguide substrate 15.
6, 16... Are formed in plurality. The waveguide substrate 15 is, for example, a plate-like material made of quartz or the like and having a rectangular planar shape.
Are perpendicular to the bottom and top surfaces of the optical fiber array 14, and are used as connection end surfaces 15a with the optical fiber array 14. A plurality of optical waveguides 16 are formed on the upper surface of the waveguide substrate 15, and at least at the input / output position of the optical waveguide 16, that is, at the connection portion with the optical fiber 13, the optical waveguides 16, 16,. Connection end surface 15 of waveguide substrate 15
It is formed parallel to and oblique to a. Then, the connection end face 15 a is polished together with the tip end face 16 a of the optical waveguide 16 so as to be perpendicular to the bottom surface of the waveguide substrate 15, thereby forming the connection end face 17 a of the optical waveguide chip 17. Hereinafter, similarly to the optical fiber array 14, the angle between the polished connection end face 17a of the optical waveguide chip 17 and the bottom surface of the waveguide substrate 15 is referred to as a polishing angle.

Here, that the optical waveguide 16 is inclined with respect to the connection end face 15 a of the waveguide substrate 15 means that the connection end face 15
This means that the traveling direction of light in the optical waveguide 16 has an inclination of an angle θ2 with respect to a plane perpendicular to a. This angle θ2 is defined as the inclination angle θ2 of the optical waveguide 16. This inclination angle θ2 is
Optical fiber array 14 connected to optical waveguide chip 17
(Θ2 = θ1)
Alternatively, it is desirable that the value be determined so as to satisfy the following equation (2) derived from Snell's law (refraction law) generally known. n1 · sin θ1 = n2 · sin θ2 (2) Here, n1 is the effective refractive index of light propagating through the optical fiber 13, and n2 is the effective refractive index of light propagating through the optical waveguide 16. For example, the inclination angle θ1 = 8 °, n1 = 1,4
5 (silica type optical fiber), n2 = 3, 21 (optical waveguide 1)
If (6 is an InP waveguide), then θ2 will be 3,6 ° according to equation (2). If the inclination angle θ2 satisfies such a condition, the optical fiber 13 of the optical fiber array 14 and the optical waveguide 16 of the optical waveguide chip 17 can be optically connected, and the light generated by the connection can be obtained. Losses can be minimized.

The optical waveguide 16 is made of quartz glass, a polymer, LiNbO ₃ , a semiconductor, or the like. The formation of a glass film by a generally used flame deposition method and the formation of a glass film by reactive ion etching are combined. It can be formed by a method, a method combining crystal growth and dry etching, or the like. Further, the number of the optical waveguides 16 is set to be the same as the number of the optical fibers 13 in the optical fiber array 14, and the interval d2 is preferably set to be the same as the interval d1 of the optical fibers 13 in the optical fiber array 14. An optical waveguide 16 in the optical waveguide 16,
The interval d3 (interval between the axes) of 16 is d3 = d2
cosθ2 = d1cosθ2 / cosθ1. In addition, in order to form the optical waveguide 16 obliquely, it is possible to easily form the optical waveguide 16 by changing the pattern of the mask used in the above-described ion etching, and to increase the accuracy of the angle.

With such an optical waveguide chip 17,
Since the optical waveguide 16 is previously formed on the waveguide substrate 15 so as to have an inclination angle θ2 at the connection end face with the optical fiber 13, the connection end face 17a of the optical waveguide chip 17 must be polished at a right angle. Thereby, the end face of the optical waveguide 16 can be processed so as to have a desired inclination angle θ2. Therefore, unlike the optical waveguide polishing method shown in the conventional example, it is not necessary to change the polishing angle of the connection end face 17a of the optical waveguide chip 17 depending on the inclination angle of the optical waveguide, and the polishing angle is always a right angle. So good
The polishing machine or the mounting jig of the polishing machine is
There is no need to modify the optical fiber array 14 at the inclination angle of 6, and the connection end surface 14a of the optical fiber array 14 can be easily polished. Also, the accuracy is good and the reproducibility is improved. Further, with such an optical waveguide chip 17, by connecting to the optical fiber array 14 having the above structure, low loss,
An optical module with low reflection can be configured.

Next, a method for connecting the optical fiber array 14 and the optical waveguide chip 17 will be described. The connection between the optical fiber array 14 and the optical waveguide chip 17 is based on the substrate 1
Optical fiber array 1 polished at right angles to the bottom of 1
4 and the connection end face 17a of the optical waveguide chip 17 polished at right angles to the bottom surface of the waveguide substrate 15.
Are opposed to each other, and the optical fiber 13 and the optical waveguide 16 are connected while being centered by the centering connector. At this time, as a joining method of the optical fiber 13 and the optical waveguide 16, various methods such as fusion with a laser beam, adhesion with an adhesive, and mechanical pressure welding can be considered. A connection with a small and highly accurate adhesive is preferred. As the adhesive at this time, an ultraviolet curable adhesive or the like may be used.

The connection end surface 14 of the optical fiber array 14
a and the connection end face 17a of the optical waveguide chip 17 are polished at right angles as described above, so that these connections are easy and have high precision. Therefore, like the connection method between the optical fiber array and the optical waveguide chip shown in the conventional example, the aligning machine or the mounting jig of the aligning connector is modified depending on the inclination angle (polishing angle) of the optical fiber and the optical waveguide. There is no need and the optical fiber 13
And the optical waveguide 16 can be connected. Also, the connection accuracy is good and the reproducibility is improved.

FIGS. 4 to 6 show examples of an optical module in which the optical fiber array 14 and the optical waveguide 17 are connected. FIG. 4 shows an example in which the optical fiber array 14 and the silica-based optical waveguide chip 27 are connected to each other by setting the inclination angle of the optical fiber 13 and the inclination angle of the optical waveguide 26 to θ1. In this case, since the traveling direction (axis) of the light in the optical fiber 13 is equal to the traveling direction of the light in the optical waveguide 26, they can be connected with low loss.

FIG. 5 shows an example in which the optical fiber array 14 and the non-quartz optical waveguide chip 37 are connected to each other with an optical fiber inclination angle θ1 and an optical waveguide 36 inclination angle θ2. The inclination angle θ2 is calculated by the above equation (2) derived from Snell's law (refraction law) generally known.
So that the optical fiber 1
3 and the optical waveguide 36 can be connected.

FIG. 6 shows a case where the antireflection film 8 is provided and connected between the optical fiber array 14 and the optical waveguide chip 37 in the connection module of FIG. As described above, when the antireflection film 8 is formed on the connection surface between the optical fiber array 14 and the optical waveguide chip 37, light reflection at the boundary between the optical fiber 13 and the optical waveguide 37 can be further reduced. As the non-reflective film 8, for example, a commonly used AR coat or the like can be used. AR
The coat is, for example, a thin film made of SiO ₂ and a thin film made of TiO ₂ alternately formed on the connection end face 14a of the optical fiber array 14 by a vapor deposition method to form the anti-reflection film 8 having a thickness of several μm. It is. Even when the antireflection film 8 is formed as described above, the connection between the optical fiber array 14 and the optical waveguide chip 37 can be easily performed by the above-described alignment connector.

In such an optical module, the so-called interface between the optical fiber 13 and the optical waveguide 36 is inclined with respect to the light traveling direction of the optical fiber 13. , The light reflection of the optical waveguide can be reduced. Therefore, in the case of such an optical module in which the optical fiber array 14 and the optical waveguide chip 17 are connected, light loss is small and light reflection is small.

The optical module shown in FIGS.
This is a schematic view of the connection between the optical fiber array and the optical waveguide chip.The size of each substrate and the waveguide substrate is different, and there is a step at the connection, but there is no such step. It is also possible to adjust the shape of the substrate and the waveguide substrate.

[0030]

As described above, according to the optical fiber array of the present invention, by polishing the connection end face at a right angle, the desired inclination angle (the vertical end face of the optical fiber after polishing with respect to the vertical plane) can be easily obtained. The connection end faces of the plurality of optical fibers can be easily processed so as to have the inclination angle in the light traveling direction (axial direction) of the optical fibers. If such an optical fiber array is connected to the following optical waveguide chip, an optical module with low loss and low reflection can be constructed. Further, according to the optical waveguide chip of the present invention, by polishing the connection end faces at right angles, the end faces of the plurality of optical waveguides can be easily inclined at a desired inclination angle (with respect to the vertical plane of the end faces of the optical waveguide with respect to the vertical plane).
It can be easily processed to have an inclination angle in the light traveling direction (axial direction) of the optical waveguide. Further, with such an optical waveguide chip, an optical module with low loss and low reflection can be configured by connecting to the optical fiber array having the above structure. According to the optical module of the present invention, the end face of the optical fiber on the optical fiber array and the end face of the optical waveguide on the optical waveguide chip are formed by using the optical fiber array and the optical waveguide chip with high processing accuracy. Processing is performed with high precision so that an inclination angle can be obtained. Further, in the optical module, since the connection end surface between the optical fiber and the optical waveguide, that is, the boundary surface is slightly inclined with respect to the traveling direction of light of the optical fiber, light reflection is reduced and low reflection occurs. Further, in the above optical module, light reflection can be further reduced by interposing a non-reflective film between the optical fiber array and the optical waveguide chip.

[Brief description of the drawings]

FIG. 1A is a plan view showing an example of an optical fiber array according to the present invention. (B) It is a side view of (a). (C) It is sectional drawing in the connection end surface of (a).

FIG. 2 is a perspective view showing an example of an optical fiber used for the optical fiber array of the present invention.

FIG. 3A is a plan view illustrating an example of the optical waveguide chip of the present invention. (B) It is a side view of (a).

FIG. 4 is a plan view showing a first embodiment of the optical module of the present invention.

FIG. 5 is a plan view showing a second embodiment of the optical module of the present invention.

FIG. 6 is a plan view showing a third embodiment of the optical module of the present invention.

FIG. 7A is a plan view showing a connection portion between an optical fiber array and an optical waveguide chip in an example of a conventional optical module. (B) It is a side view of (a). (C) It is sectional drawing in the connection end surface in the optical fiber array of (a).

FIG. 8A is a plan view showing a connection portion between an optical fiber array and an optical waveguide chip in an example of a conventional optical module. (B) It is a side view of (a). (C) It is sectional drawing in the connection end surface in the optical fiber array of (a).

[Explanation of symbols]

 Reference Signs List 11 substrate 12 V groove 13 optical fiber 14 optical fiber array 15 waveguide substrate 16 optical waveguide 17 optical waveguide chip

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Kenichiro Asano 1440, Mukurosaki, Sakura City, Chiba Prefecture Inside Fujikura Sakura Office (72) Inventor Hideyuki Hosoya 1440, Musaki, Sakura City, Chiba Prefecture Fujikura Sakura Office F-term (reference) 2H037 AA01 BA24 CA10 CA34 DA01 DA12 DA18 2H047 KA03 KA15 MA05 RA08 TA32 TA47

Claims (6)

[Claims] An axial direction of the V-groove is oblique with respect to the connection end surface, wherein a plurality of V-grooves are formed on an upper surface of the plate-like substrate from a side surface serving as a connection end surface of the substrate to another opposite side surface. The optical fibers are engraved in parallel so that the optical fibers are accommodated in these V-grooves such that the distal end surfaces thereof are in contact with the connection end surfaces of the substrate. An optical fiber array, which is polished so as to be perpendicular to a bottom surface. 2. A plurality of optical waveguides are formed on an upper surface of a plate-shaped substrate from a side surface, which is a connection end surface of the substrate, to the other side surface opposite to the connection end surface. The optical waveguide is formed so that its axial direction is oblique to the connection end face of the substrate, and the connection end face of the substrate and the tip end face of the optical waveguide are perpendicular to the top and bottom surfaces of the substrate. An optical waveguide chip characterized by being polished. 3. The optical fiber array according to claim 1, wherein:
An optical module connected to the optical waveguide chip according to claim 2, wherein a connection end surface of the optical fiber array and a connection end surface of the optical waveguide chip are perpendicular to a bottom surface of each substrate. The connection end faces polished at right angles are opposed to each other to connect the optical fiber of the optical fiber array to the optical waveguide of the optical waveguide chip, and the interface between the optical fiber and the optical waveguide is an optical fiber. An optical module, wherein the optical module is inclined with respect to a traveling direction of light of a fiber. 4. The optical module according to claim 3, wherein an angle of a light traveling direction of the optical fiber with respect to a plane perpendicular to a boundary surface between the optical fiber and the optical waveguide, and a light intensity of the light in the optical waveguide with respect to the plane. An optical module, wherein the angle of the traveling direction is equal. 5. The optical module according to claim 3, wherein an angle θ1 of a traveling direction of light of the optical fiber with respect to a plane perpendicular to a boundary surface between the optical fiber and the optical waveguide, and light in the optical waveguide with respect to the plane. Is the effective refractive index of the light propagating through the optical fiber, n1,
When the refractive index of light propagating through the optical waveguide is n2, n
An optical module characterized by satisfying a relationship of 1 · sin θ1 = n2 · sin θ2. 6. The optical module according to claim 3, wherein an antireflection film is interposed on a connection surface between the optical fiber array and the optical waveguide chip.