JP2943629B2 - Optical waveguide module, array thereof, and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical waveguide module, an array thereof, and a method of manufacturing the same.

[0002]

2. Description of the Related Art In the fields of communication, measurement, information processing and the like, optical integrated circuits having various functions such as multiplexing and branching of light have been studied in order to utilize light more highly. An optical waveguide module in which an optical fiber and an optical waveguide are connected is used as an element constituting an optical integrated circuit.

As shown in FIG. 8, a quartz glass or single crystal silicon substrate 1 is used as such an optical waveguide module.
A core region 102 having a high refractive index and a cladding region 103 having a low refractive index are formed on the optical fiber 01, and an optical fiber 105 composed of a core 106 and a clad 107 is connected to an optical waveguide element 104 for confining and propagating light in the core region 102. What has been proposed.

The connection between the optical waveguide element and the optical fiber is performed by attaching the optical fiber 105 to an optical fiber holder 108,
A method of aligning an optical axis with a waveguide core and bonding and fixing both end surfaces with an adhesive 109 is often used.

The optical axis alignment between the optical fiber and the waveguide is
Normally, light is incident on one end of an optical waveguide core, light at the output end is received by an optical fiber, and the position of the optical fiber is adjusted so that the amount of light incident on the optical fiber is maximized. Therefore, the alignment work requires a lot of time, which is a factor of increasing the cost of the module.

In order to reduce the time required for optical axis alignment work, there has been proposed a method of simply performing optical axis alignment using a guide mechanism having a precise positional relationship with the position of the optical waveguide core (Japanese Patent Laid-Open No. HEI 9-163568). 4-128809).

FIG. 9 is a diagram showing another conventional example. As shown in the figure, a guide groove 202 is formed on a single-crystal silicon substrate 201 by anisotropic etching, and further subjected to a flame deposition method and dry etching to form a quartz including a GeO ₂ —SiO ₂ core 203 and a SiO ₂ clad 204. A system optical waveguide element 205 was formed.

The optical fiber holder 206 is formed by arranging optical fibers 208 on an epoxy resin molded body 207 and implanting guide pins 209. In the centering operation of this embodiment, the guide pins 20 of the optical fiber holder 206 are used.
9 is fitted in the guide groove 202 on the optical waveguide element 205 to reduce the alignment time.

[0009]

However, in the conventional example shown in FIG. 9, when an optical fiber is to be mounted without alignment using a guide mechanism, the positional relationship between the guide groove and the core of the optical waveguide is limited. If a deviation from the design value occurs,
There has been a problem that correct alignment with the optical fiber cannot be performed.

[0010] This is because the guide groove for positioning with the optical fiber is formed on the optical waveguide substrate, so that the waveguide core position and the guide groove position cannot be adjusted according to the deviation. ing. Since the positional deviation from the design value is caused by a difference in etching conditions when forming by etching the side groove and a deformation due to a thermal process when forming the optical waveguide, the deviation amount varies from production lot to production lot. There are many cases.

The optical waveguide element having such a positional deviation cannot be corrected for its positional relationship, so that it has a defect in lot units, and has problems such as a reduction in yield and an increase in cost.

Further, in the conventional example shown in FIG. 9, since the positional relationship between the guide groove and the optical waveguide core needs to be arranged three-dimensionally precisely (for example, with an accuracy of 1 μm or less), the guide groove and the optical waveguide core are required. Is required to be precisely formed on the same substrate by using a semiconductor process or the like, and a substrate having independent guide grooves and an optical waveguide
It has been substantially difficult to use them by dimensional positioning and bonding. Therefore, according to the conventional method, two regions of the guide groove portion and the optical waveguide circuit portion are mixed on one wafer, which means that when the same number of optical waveguide devices are manufactured, only the optical waveguide device without the guide groove is used. As compared with the case of manufacturing a semiconductor device, there is a problem that a larger number of wafers must be processed, and the unit price of the optical waveguide device is greatly increased. Moreover, since the optical waveguide element is bonded and fixed to the substrate,
There is also a problem that it cannot be replaced with another optical waveguide element.

Accordingly, an object of the present invention is to solve the above-mentioned problems and to provide a method of manufacturing an optical waveguide module which does not require alignment work with an optical fiber, an optical waveguide module to which an optical fiber can be attached and detached, and an optical waveguide module. And an optical waveguide module array using the same.

[0014]

According to the present invention, there is provided an optical waveguide unit having an optical waveguide formed thereon or an optical waveguide element fixed thereon on a bench having at least two parallel grooves. A plurality of guide holes for positioning with the optical waveguide or the optical fiber connected to the optical waveguide element are formed along the groove in the resin molded body. And
The guide hole is located outside the optical waveguide unit apart from the optical waveguide unit.

In the present invention, in addition to the above configuration, the bench may be made of Si.

In addition to the above configuration, the present invention is such that an optical waveguide is formed in the middle of two grooves on a bench or an optical waveguide element is fixed.

In addition to the above configuration, the present invention is that the groove on the bench and the optical axis of the optical waveguide are formed to be parallel or the optical waveguide element is fixed.

In addition to the above structure, the present invention provides a method of forming an optical waveguide on a bench having at least two parallel grooves or fixing an optical waveguide element to form an optical waveguide unit; Forming a groove block having parallel grooves, of which at least two grooves are formed at the same pitch as the two grooves of the optical waveguide unit;
Positioning two opposing grooves of the groove block and the optical waveguide unit using two guide pins; and forming a guide hole for positioning an optical fiber in the remaining groove of the groove block. And molding the resin around the optical waveguide unit and the pins.

In addition to the above configuration, the present invention is to form a positioning index on both the bench and the waveguide element, and position the bench groove and the optical waveguide core by matching the indexes.

In addition to the above configuration, the present invention is to position and fix the bench and the optical waveguide element using solder bumps.

In addition to the above configuration, the present invention changes the outer diameter of two guide pins for positioning the groove block and the optical waveguide unit, thereby changing the position of the guide hole for positioning the optical fiber and the position of the optical waveguide core. Is to adjust.

The present invention comprises an optical waveguide and a resin molded body surrounding the outer periphery of the optical waveguide, and the resin molded body is provided with a plurality of guide holes for positioning the optical waveguide and the optical fiber or the optical waveguides. Is housed in one housing.

In addition to the above-described structure, the present invention is such that a plurality of molded optical waveguides are connected via a guide pin fitted into a guide hole.

[0024]

According to the above construction, since a guide hole is formed in the resin molded body of the optical waveguide module, a guide pin is inserted into this guide hole and inserted into a guide hole of another module. Connected without adjusting the optical axis. When exchanging the optical waveguide module, the optical waveguide module can be removed by pulling out the guide pins from the guide holes.

When positioning indices are formed on both the bench and the waveguide element, positioning can be easily performed by matching these indices.

By changing the outer diameter of the two guide pins for positioning the groove block and the optical waveguide unit, the height and inclination of the optical waveguide unit are changed. The position of the waveguide core can be changed.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

FIGS. 1 to 4 are explanatory views for explaining one embodiment of a method of manufacturing an optical waveguide module according to the present invention.

First, the optical waveguide type unit shown in FIG. 1 is manufactured. Single crystal silicon substrate 301 having a thickness of about 0.7 mm
(This is referred to as a “bench.”) Anisotropic etching is performed using a KOH solution to form two V-grooves 302 having a large depth.
And one V-groove 303 having a shallow depth is formed. Each V-groove 30
2 and 303 are parallel to each other. (In the present embodiment, the groove is a V-shaped groove, but the groove is not limited to this, and may be trapezoidal or U-shaped. Here, these are collectively referred to. This is referred to as “V-groove”.)

The distance between the vertices of the two V grooves 302 is 2.4 m.
m, the depth is 0.35 mm, and one V-groove 303 is formed at a position 0.5 mm away from the bisecting center line 320 of the V-groove 302 so as to have a depth of 0.04 mm.

Here, the V-groove 302 is referred to as a "first guide groove", and this first guide groove is for positioning with a V-groove block described later. The V-groove 303 is referred to as an “index”, and serves as a mark for positioning and fixing an optical waveguide element described later on a bench. Although the V-groove was used for the index, the index is not limited to this, and any other index mark such as a circle, a polygonal concave shape, or a metal coating may be used. Is also good.

Next, an optical waveguide element is formed. In the optical waveguide element, one index V groove 305 having a depth of 0.04 mm is first formed on a silicon single crystal substrate 304 having a thickness of 0.5 mm by anisotropic etching using a KOH solution. 306 and clad 3 made of TiO ₂ —SiO ₂ by using a dry etching method
07 is formed. The optical circuit formed is an optical waveguide circuit with four light inputs and four outputs. The four cores are the substrate center line 308
Are formed at a pitch of about 0.25 mm with respect to the symmetry line, and the index V groove 305 is formed at a position about 0.5 mm away from the center line 308 so as to be parallel to the optical axis. As shown in FIG. 2, the bench and the optical waveguide element formed in this manner are such that the index V-groove 303 on the bench and the index V-groove 305 on the optical waveguide element are viewed from the upper surface of the bench 301 and the plate thickness of the optical waveguide element. The optical waveguide unit 800 is formed by performing alignment using an infrared light source and an infrared microscope so as to coincide with each other, and bonding and fixing using an ultraviolet curable resin. The material for fixing the optical waveguide element to the bench 301 may be an adhesive or a solder. Further, the alignment method is not limited to the alignment using the index, and a self-alignment method using solder bumps may be used.

Next, as shown in FIG. 3, V-shaped grooves 402a, 40a having a vertex angle of 90 ° are formed in a box-shaped zirconia block 401.
2b, 403a, 403b, 404a, 404b, 40
Eight portions 5a and 405b are formed. Of these, V groove 40
2a, 402b, 405a, and 405b have the same coaxial shape and a depth of about 0.5 mm.
b, 404a and 404b are coaxial and have the same shape and a depth of about 0.28 mm. Each V groove 402a, 402b, 40
3a, 403b, 404a, 404b, 405a, 40
5b are arranged symmetrically with respect to the V groove block center line 406,
V of grooves 402a, 405a and V grooves 402b, 405b
The groove apex distance is 4.6 mm, and the V groove apex distance of the V grooves 403a and 404a and the V grooves 403b and 404b is about 2.4 mm.
And These V grooves 402a, 402b, 403a, 4
Of the three grooves 03b, 404a, 404b, 405a, and 405b, the inner V-grooves 403a and 404b are the “first guide grooves” on the V-groove block, and the outer V-grooves 402a and 402b and the V-grooves 405a and 405b are the “second guide”. Groove ”.

Next, the above-mentioned optical waveguide unit was set to a diameter of 0.4.
Positioning is performed using two first guide pins 407a and 407b of 2 mm, and the first guide groove on the V-groove block and the first guide groove on the waveguide unit are placed so as to face each other.

Next, two second guide pins 408a and 408b having an outer diameter of about 0.7 mm are mounted on the V-shaped grooves 402a and 402b and the V-shaped grooves 405a and 405b, and three holding blocks 409a, 409b and 409c are mounted. Using the first guide pins 407a, 407b and the second guide pins 408a,
408b is a holding resin molding die. The resin injection port 410 is formed in the holding block 409b.

FIG. 4 shows a cross section of the resin mold thus assembled.

V-groove block 401 and holding block 409
a, 409b and 409c are resin molding dies, and a cavity (resin injection space) 501 is formed inside.
In the cavity 501, the optical waveguide unit 8 described above is provided.
00 is positioned and arranged by the first guide pin and the first guide groove. Next, after the epoxy resin containing glass filler is transferred and molded from the resin injection port 410, the first resin is formed.
Guide pin 407a and second guide pins 408a, 40
8b is removed and the end face is polished to form a waveguide molded body 601 as an optical waveguide module as shown in FIG.
Is obtained. FIG. 5 is an explanatory diagram for explaining a connection state between the optical waveguide module shown in FIGS. 1 to 4 and another module.

An optical fiber positioning guide hole 801 formed by the second guide pin of the optical waveguide molded body 601.
The position of the optical waveguide core 306 can be easily adjusted by changing the diameter of the first guide pin in the resin molding of the next product if there is a positional deviation from the design value. Can be done.

The optical fiber array 603 has a diameter of 0.7 mm.
The two guide pins 602 and the four-fiber tape fiber were transferred and molded with an epoxy resin containing glass filler. The guide pin interval was about 6.4 mm, and the arrangement pitch of the optical fibers was 0.25 mm. When the two guide pins of the optical fiber array body 603 are inserted into the guide holes 801 of the optical waveguide molded body 601, the optical fiber and the optical waveguide core are formed so as to face each other.

As shown in FIG. 5, an optical waveguide module having an optical fiber pigtail can be obtained by fitting the optical waveguide molded body 601 and the optical fiber array body 603 using the guide pins 602. Since this optical waveguide type module can attach and detach an optical fiber, an application system as shown in FIG. 6 can be configured. FIG. 6 shows an optical waveguide array 702 in which a plurality of optical waveguide molded bodies 601 are arranged using a housing 701. Housing 7
The optical circuit of the optical waveguide molded body 601 installed in the optical module 01 can be applied to an apparatus having various functions such as optical multi-branching and optical multiplexing / demultiplexing as in the above-described embodiment. Such an optical waveguide array 702 can distribute input information from an optical fiber only by exchanging pigtails according to a request situation of a receiver. For example, if waveguide molded bodies having different numbers of branches, such as 1 × 4 branches, 1 × 8 branches, and 1 × 16 branches, are prepared as the optical waveguide array body, the optical fiber array body 602 can be replaced simply by replacing the optical fiber array body 602. The number of distributions can be selected.

As another modified example, it is conceivable that a plurality of optical waveguide circuits having different demultiplexing wavelengths are installed as an optical waveguide array, and a plurality of wavelengths are multiplexed and transmitted to an input optical fiber. In this system, optical information of a specific wavelength can be obtained by replacing the optical fiber array 602. In addition, a composite function combining these functions can be obtained by arranging optical waveguide molded bodies having functions such as multiplexing / demultiplexing, branching, and filtering, and connecting them by an optical fiber array.

FIG. 7 is a view showing another embodiment of the optical waveguide array of the present invention.

The system shown in FIG. 6 includes a plurality of optical waveguide molded bodies 601a 601b, 601c having different functions.
Are connected using guide pins. As the respective functions, multiplexing / demultiplexing, splitting, filtering, and the like as described above can be applied, and various combined functions can be obtained by combining these.

As described above, according to this embodiment, the alignment of the optical axis between the optical waveguide and the optical fiber, which was conventionally required, can be omitted, and the deviation of the core position of the optical waveguide is determined by the outer diameter of the first guide pin. As a result, the yield can be improved,
The manufacturing of the optical waveguide module is facilitated, and the cost is greatly reduced. In addition, since the optical fiber becomes detachable,
The application range of the optical waveguide module can be expanded.

[0045]

In summary, according to the present invention, the following excellent effects are exhibited.

It is possible to realize a method of manufacturing an optical waveguide module that does not require alignment work with an optical fiber, an optical waveguide module to which an optical fiber can be attached and detached, and an optical waveguide module array using the optical waveguide module. it can.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram for explaining one embodiment of a method for manufacturing an optical waveguide module of the present invention.

FIG. 2 is an explanatory diagram for explaining one embodiment of a method of manufacturing an optical waveguide module according to the present invention.

FIG. 3 is an explanatory diagram for explaining one embodiment of a method for manufacturing an optical waveguide module of the present invention.

FIG. 4 is an explanatory diagram for explaining one embodiment of a method for manufacturing an optical waveguide module of the present invention.

FIG. 5 is an explanatory diagram for explaining a connection state between an optical waveguide module and another module according to the manufacturing method described in FIGS. 1 to 4;

FIG. 6 is a view showing one embodiment of an optical waveguide array according to the present invention.

FIG. 7 is a view showing another embodiment of the optical waveguide array according to the present invention.

FIG. 8 is a diagram showing a conventional example of an optical waveguide module.

FIG. 9 is a diagram showing another conventional example of an optical waveguide module.

[Explanation of symbols]

 301 Bench (silicon substrate) 302 Groove 800 Optical waveguide unit 801 Guide hole

Continuation of front page (58) Fields surveyed (Int.Cl. ⁶ , DB name) G02B ⁶ /24-6/43 G02B 6/12

Claims (10)

(57) [Claims] 1. An optical waveguide unit having an optical waveguide formed or an optical waveguide element fixed on a bench having at least two parallel grooves, and a resin molded body surrounding the outer periphery of the optical waveguide unit. In the resin molded body, a plurality of guide holes for positioning with the optical fiber connected to the optical waveguide or the optical waveguide element are formed along the groove, and the guide hole is formed from the optical waveguide unit. An optical waveguide type module, which is located outside at a distance. 2. The optical waveguide module according to claim 1, wherein said bench is made of Si. 3. The optical waveguide module according to claim 1, wherein an optical waveguide is formed in the middle of the two grooves on the bench or an optical waveguide element is fixed. 4. The optical waveguide module according to claim 1, wherein the groove on the bench and the optical axis of the optical waveguide are formed to be parallel or the optical waveguide element is fixed. 5. A step of forming an optical waveguide on a bench having at least two parallel grooves or fixing an optical waveguide element to form an optical waveguide unit; and having at least four parallel grooves. Forming a groove block in which at least two grooves are formed at the same pitch as the two grooves of the optical waveguide unit; and opposing two grooves of the groove block and the optical waveguide unit to each other. Positioning using two guide pins, placing a pin for forming a guide hole for positioning an optical fiber in the remaining groove of the groove block, and surrounding the optical waveguide unit and the pin. And molding the resin. 6. The optical waveguide module according to claim 5, wherein a positioning index is formed on both the bench and the waveguide element, and the bench groove and the optical waveguide core are positioned by matching the indexes. Method. 7. The method of manufacturing an optical waveguide module according to claim 5, wherein said bench and said optical waveguide element are positioned and fixed using solder bumps. 8. The position of an optical fiber positioning guide hole and the position of an optical waveguide core by changing the outer diameter of two guide pins for positioning the groove block and the optical waveguide unit. Item 6. The method for manufacturing an optical waveguide module according to Item 5. 9. An optical waveguide comprising a resin molded body surrounding the outer periphery of the optical waveguide, wherein the resin molded body is provided with a plurality of guide holes for positioning the optical waveguide and the optical fiber or the optical waveguides. An optical waveguide type module array comprising a plurality of optical waveguide molded bodies housed in one housing. 10. The optical waveguide module according to claim 9, wherein the plurality of optical waveguide molded bodies are connected via a guide pin fitted into a guide hole.