JP2002182063A - Optical waveguide module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical waveguide module in which the failure caused by the optical damage of an adhesive is avoided and the service life is elongated. SOLUTION: The I/O end surface 1a of an optical fiber 1 and the I/O end surface 2a of an optical waveguide 2 are disposed facing each other via a space, and a lens 3 is provided in the space. The lens 3 controls the light outputted from one I/O end surface so that the light is inputted into the other I/O end surface as luminous flux of the same diameter as that of the other I/O end surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical communication system for connecting an optical fiber to a waveguide type optical component such as a waveguide type optical selection element, a waveguide type splitter, and a waveguide type optical switch. For an optical waveguide type module.

[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.

The above-mentioned optical fiber is usually handled as a fiber array with its connection end held by an optical fiber holding substrate, and the input / output end surface of the optical fiber comes into contact with the connection end surface of the optical fiber holding substrate. I have. The optical waveguide is formed on a substrate (optical waveguide forming substrate) of the optical waveguide type optical component, and an input / output end surface of the optical waveguide is in contact with a connection end surface of the optical waveguide forming substrate.
Then, the optical fiber and the optical waveguide, the connection end face of the optical fiber holding substrate and the connection end face of the optical waveguide forming substrate are opposed to each other, and the optical fiber and the optical waveguide are aligned in a centering connection machine.
It is joined by joining while aligning. At this time, as a method of joining the optical fiber and the optical waveguide, various methods such as bonding with an adhesive, fusion with a laser beam, and mechanical pressure welding are used. The method of closely adhering is widely used because a plurality of optical fibers and an optical waveguide can be easily and accurately connected. As the adhesive at this time, the light loss is small, and the core of the waveguide and the optical fiber (the waveguide portion) is used.
An adhesive having a refractive index similar to that of the adhesive and having high transparency is preferable. For example, an ultraviolet curable adhesive or the like is used.

[0004]

However, when the optical fiber and the optical waveguide are bonded by bonding, an adhesive resin is interposed in the optical path. For this reason, the resin of the adhesive is degraded by the light, and the respective substrates are peeled off, or the adhesive itself is broken, which causes a failure. In particular, when high-power light is inserted, there is a problem that the progress of this deterioration is accelerated, and the life of the connection portion (optical waveguide module) between the optical waveguide and the optical fiber of the optical waveguide optical component is shortened. SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide an optical waveguide module having a longer life by avoiding a failure due to optical damage of an adhesive.

[0005]

Means for Solving the Problems In order to solve the above problems, the present inventors have provided an optical waveguide type module in which an optical fiber and an optical waveguide are optically connected to each other. And the input / output end face of the optical waveguide are opposed to each other via a space, and the optical path control means is provided in the space, whereby the light output from one input / output end face is used for the other input / output end face. Provided is an optical waveguide module, which is controlled so that an end face can be input as a light flux equivalent to the diameter of the other input / output end face.

Here, as the optical path control means, a micro lens such as a selfoc lens (a green lens), a spherical lens, or an aspherical lens can be preferably used. It is also possible to combine a plurality of microlenses and the like. The specific configuration of the optical path control means can be appropriately selected in consideration of the positional relationship and the diameter between the optical fiber and the input / output end face of the optical waveguide.

According to the present invention, it is not necessary to interpose an adhesive causing optical damage in the optical path, so that an optical waveguide module having a high optical damage resistance function and a long life can be obtained. Further, the separated input / output end faces can be connected without loss by the optical path control means.

In the optical waveguide module according to the present invention,
It is desirable that the optical fiber, the optical waveguide, and a fixing means for maintaining a positional relationship among the optical path control means are provided. This makes it possible to stabilize the positional relationship among the optical fiber, the optical waveguide, and the optical path control means, improve the accuracy of light transmission, and improve mechanical strength and earthquake resistance.

The fixing means includes an optical fiber holding substrate for holding an optical fiber, an optical waveguide forming substrate on which the optical waveguide is formed, and a connecting member for connecting these substrates and holding the optical path control means. Can be suitably used. Thus, since the optical fiber and the optical waveguide are each held or formed on the substrate, the accuracy of light transmission, and the mechanical strength and the earthquake resistance can be further improved.

When the fixing means is constructed as described above, the optical fiber holding substrate and the connecting member may be separate and independent members, but are preferably formed integrally. In this case, since the fixing means has a simple configuration, the handling of the entire module becomes easy and the manufacturing cost can be reduced.

In the present invention, it is desirable that an antireflection film is disposed on all or a part of the input / output end face of the optical fiber, the input / output end face of the optical waveguide, and the input / output end face of the optical path control means. Thereby, so-called reflected light (return light)
Can be reduced to cause noise in the communication light by advancing to the input side.

In the present invention, all or part of the input / output end face of the optical fiber, the input / output end face of the optical waveguide, and the input / output end face of the optical path control means are formed to be inclined with respect to the optical axis. Is desirable. This can also reduce the phenomenon that so-called reflected light (return light) proceeds to the input side and generates noise in communication light.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
1 and 2 show a first embodiment of the optical waveguide module of the present invention.
FIG. 1 is a perspective view and FIG. 2 is a side view showing an embodiment. As shown in these drawings, the input / output end faces 1a, 1a of the optical fibers 1, 1,... And the input / output end faces 2a, 2a,. The optical paths during this time are lenses 3, 3,... (Optical path control means).
Are connected via These members are fixed to each other at fixed positions by fixing means 6 including a support member 4 and an optical waveguide forming substrate 5. In this figure, the number of the optical fibers 1 is set to four for easy explanation, but actually, it is possible to design more.

The support member 4 is a member made of quartz or the like having an L-shaped cross section, and is formed by integrally forming a thick plate portion 4a (optical fiber holding substrate portion) and a thin plate portion (connection member) 4b. I have. A plurality of grooves (not shown) are formed on the upper surface side of the thick plate portion 4a, and the optical fibers 1 and
.. Are held. In addition, 4
On the upper surface side of b, at a predetermined interval from the thick plate portion 4a,
The connection end surface side of the lower surface of the optical waveguide forming substrate 5 is joined. Further, a concave portion 4c is formed at the center of the thin plate portion 4b in the connection direction and extends perpendicularly to the connection direction, and the lenses 3, 3,. The optical waveguide 2 is formed on the optical waveguide forming substrate 5. A joint portion of these members, that is, the thick plate portion 4a
, The optical fiber 1, 1,..., The thin plate portion 4b and the optical waveguide forming substrate 5, the optical waveguide 2 and the optical waveguide forming substrate 5, and the thin plate portion 4b
, And the joints of the lenses 3, 3,... Are made of resin, solder,
It is fixed by any means such as low melting glass or mechanical fixing.

As the optical fiber 1 housed in the groove of the thick plate portion 4a, for example, as shown in FIG. 3, a multi-core optical fiber tape core wire 19 is divided into optical fiber strands 18, and this strand is An optical fiber (bare wire) 1 having an outer diameter of 125 μm, which is obtained by removing the coating on the tip portion of No. 18 and extruding, can be used. If there are a large number of optical fibers 1 to be connected, for example, as shown in FIG. 3, if there are 16 optical fibers, two 8-core optical fiber tapes are used, and these are divided and led out. By putting two optical fibers (bare wire) 1 in each groove in a state of being superposed, the optical fiber 18 is wider than the width in which one optical fiber (bare wire) 1 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 1 is led out as an optical fiber ribbon 19 so that it can be connected to another optical component. The groove width of the groove of the thick plate portion 4a is larger than the outer diameter of the optical fiber 1 accommodated therein by about 1-2 μm, usually 126-127 μm, and the groove depth is 85 μm.
It has become about.

The input / output end faces 1a, 1a of the optical fibers 1, 1,... And the input / output end faces 2a of the optical waveguides 2, 2,.
, And the input / output end faces of the lenses 3, 3,..., Are each provided with an antireflection film (not shown). Thus, light reflected at each end face and returning toward the light source, that is, so-called reflected light can be reduced to reduce light loss.

In the optical waveguide module according to the present embodiment, the lenses 3, 3,... Are composed of the input / output end faces 1a, 1a of the optical fibers 1, 1,. , And controls the luminous flux so that the light output from one input / output end face can be input to the other input / output end face. On the input side, the light flux is controlled so as to be equal to or smaller than the diameter of the input / output end face, so that light output from one input / output end face is transmitted to the other without loss. .
At this time, since the adhesive does not exist in the optical path between the two input / output end faces, a failure due to optical damage of the adhesive can be avoided, and a long life can be secured. Also, the fixing means 6
Is provided, the positional relationship between the optical fiber 1, the optical waveguide 2, and the lens 3 can be stabilized, the accuracy of light transmission can be improved, and mechanical strength and earthquake resistance can be improved. it can.

FIGS. 4 to 6 show a second embodiment of the optical waveguide module according to the present invention. FIG. 4 is a plan view seen from above, FIG. 5 is a side view, and FIG. It is sectional drawing in -VI. As shown in these figures, the optical fiber 1
, The input / output end faces 11a, 11a,.
The input / output end faces 12a, 12a,... Of the lenses 2, 12,.
3, 13... (Optical path control means). These members are fixed to each other at fixed positions by fixing means 17 including an optical fiber holding substrate 14, an optical waveguide forming substrate 15, and a connecting member 16. In this figure, the number of the optical fibers 11 is set to four for easy explanation, but actually, it is possible to design more.

The optical fiber holding substrate 14 is, for example, a plate-like material made of quartz or the like and having a rectangular planar shape, and the connection end surface 14 a is perpendicular to the bottom, top, and side surfaces of the optical fiber holding substrate 14. Is formed. On the upper surface side of the optical fiber holding substrate 14, as shown in FIG.
A plurality of grooves 14a are formed, and the optical fibers 11, 11 ... are held in the respective grooves. In the present embodiment, the optical fibers 11, 11.
Are arranged at an angle of θ from a direction perpendicular to the connection end surface 14a, and as a result, the connection end surface 11a of the optical fiber 11 is inclined with respect to the optical axis.

The optical waveguide forming substrate 15 is a plate-like object made of, for example, quartz and having a rectangular planar shape.
A connection end face 15a that is spaced apart from and faces the connection end face 14a of the optical fiber holding substrate 14 is formed so as to be perpendicular to the bottom, top, and side surfaces of the optical waveguide forming substrate 15. The optical waveguide 12 is formed on the optical waveguide forming substrate 15. In the present embodiment, the optical waveguides 12, 12
Are arranged at an angle of θ from a direction perpendicular to the connection end face 15a, and as a result, the connection end face 12a of the optical waveguide 12 is inclined with respect to the optical axis.

The connection member 16 is a plate-like member having a rectangular planar shape, which is joined to the lower surface side of the optical fiber holding substrate 14 and extends beyond the connection end surface 15 a of the optical waveguide formation substrate 15. 15 and a part of the lower surface side. Further, a concave portion 16c is formed at the center of the connection member 16 in the connection direction, and extends in a direction perpendicular to the connection direction, and the lenses 13, 13,. The end faces of the lenses 13, 13,... Are substantially perpendicular to the optical axis, but may be slightly inclined. .., The optical waveguide 12 and the optical waveguide forming substrate 15, the connecting portion 16 and the optical fiber holding substrate 14, the optical waveguide forming substrate 15, and the like. Each joint between the connecting portion 16 and the lenses 13, 13,... Is fixed by any means such as an adhesive, solder, low-melting glass, or mechanical fixing.

The thick-plate portion optical fiber 11 is also the same as the optical fiber 1 shown in FIG. 3, and a detailed description thereof will be omitted. The input / output end faces 11 of the optical fibers 11, 11,...
, and the input / output end faces 1 of the optical waveguides 12, 12,.
Also, the anti-reflection film (not shown) is provided on the input / output end faces of the lenses 2a, 12a... And the lenses 13, 13.

The optical waveguide module according to the present embodiment includes:
In addition to the same functions and effects as the first embodiment, the optical fiber 1
The input / output end faces 11a, 11a.
2 are formed so as to be inclined with respect to the optical axis, so that the effect of reducing so-called reflected light and reducing light loss can be further enhanced in combination with the antireflection film. it can.

[0024]

As described above, according to the present invention, it is not necessary to interpose an adhesive causing optical damage in the optical path, and therefore, the optical waveguide module having a high light damage resistant function and a long life can be obtained. It can be.

[Brief description of the drawings]

FIG. 1 is a perspective view of an optical waveguide module according to a first embodiment of the present invention.

FIG. 2 is a side view of the optical waveguide module according to the first embodiment of the present invention.

FIG. 3 is a perspective view showing an example of an optical fiber used in the present invention.

FIG. 4 is a plan view of an optical waveguide module according to a second embodiment of the present invention.

FIG. 5 is a side view of an optical waveguide module according to a second embodiment of the present invention.

FIG. 6 is a sectional view taken along the line VI-VI in FIG. 4;

[Explanation of symbols]

1 ... optical fiber for optical amplification, 2 ... optical waveguide, 3
..Lens, 4 ... Support member, 5 ... Optical waveguide forming substrate, 6 ... Fixing means

 ──────────────────────────────────────────────────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 BA23 DA04 DA05 DA06

Claims (4)

[Claims] An optical waveguide module comprising an optical fiber and an optical waveguide optically connected to each other, wherein an input / output end face of the optical fiber and an input / output end face of the optical waveguide are opposed to each other via a space. Together with an optical path control means in the space,
The light path control means is controlled so that light output from one input / output end face can be input to the other input / output end face as a light flux equivalent to the diameter of the other input / output end face. Optical waveguide module. 2. The optical waveguide module according to claim 1, further comprising fixing means for maintaining a positional relationship between said optical fiber, said optical waveguide, and said optical path control means. 3. The fixing means connects an optical fiber holding substrate holding the optical fiber, an optical waveguide forming substrate on which the optical waveguide is formed, these substrates, and holds the optical path control means. The optical waveguide module according to claim 2, comprising a connecting member. 4. The optical waveguide module according to claim 3, wherein the optical fiber holding substrate and the connection member are integrally formed.