JP2007058233A - Optical path conversion device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an optical path conversion device capable of simplifying a manufacturing process, materializing a low price, and suppressing deterioration in optical coupling efficiency. <P>SOLUTION: Inside a clad 12, there is imbedded a core 11, with a first core end face 11a exposed in the first end face 12a, with a second core end face 11b exposed in the second end face 12b, reaching from the first core end face 11a to a mirror face 13, with the direction changed therein, and then reaching the second core end face 11b to constitute a continuous optical path. In addition, the first core end face 11a and the second core end face 11b of the core 11 are each two-dimensionally arrayed in the first end face 12a and the second end face 12b. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a structure of an optical path conversion device that optically couples components having photoelectric conversion elements and optical waveguides arranged two-dimensionally.

  2. Description of the Related Art In recent years, development of an optical interconnection that communicates within a device at high density has been vigorously conducted toward the development of a high-speed and large-capacity optical communication system and a massively parallel computer that processes parallel signals between a large number of processors. When performing such optical interconnection, processing of the transmitted optical signal is performed by the electronic device. The boundary device that couples these electronic devices requires an optical waveguide, a photoelectric conversion element, an LSI or switch for electronic control, or an optical-electric mixing device with an electrical circuit for driving electronic components. Become. In particular, in order to realize a high-speed broadband communication system, there is an increasing demand for devices including photoelectric conversion elements such as VCSEL (Vertical Cavity Surface Emitting Laser), LD (Laser Diode), and PD (Photo Diode).

  In response to such a requirement, an optical pin with a micromirror is provided on the photoelectric conversion element, a through hole having the same shape as the optical pin is provided on the optical printed circuit board, and the optical pin is fitted into the through hole, so that the photoelectric conversion element and the optical printed circuit board For example, Non-Patent Document 1 proposes a technique for optically coupling the two.

  As shown in FIG. 17, the conventional 90 ° optical path conversion technique in the optical circuit mounting is such that the core 2 serving as an optical waveguide is embedded in the optical printed circuit board 1 and the through-hole 3 cuts the core 2. An optical pin 5 with a micromirror formed on the printed board 1 and fixed to the photoelectric conversion element 4 is fitted into the through hole 3. The through hole 3 is formed on the optical printed circuit board 1 so that the hole center is orthogonal to the optical axis of the core 2, and the tip surface of the optical pin 5 is formed on the micromirror 5 a having an angle of 45 degrees with the optical axis. is doing. Thereby, for example, light propagating through the core 2 is totally reflected by the micromirror 5 a and guided to the optical pin 5, propagates through the optical pin 5, and reaches the photoelectric conversion element 4. That is, the core 2 and the photoelectric conversion element 4 are optically coupled by changing the optical path by 90 degrees.

  By adopting this conventional optical path changing technology, the light emitted from the light emitting element and the optical waveguide caused by the light emitted from the light emitting element into the space and the light emitted from the optical waveguide into the space having a radiation angle spread. It is possible to prevent the coupling and the optical coupling between the optical waveguide and the light receiving element from being lowered. Furthermore, according to this conventional optical path conversion technique, even when light is incident on the core 2 from a light emitting element (photoelectric conversion element) such as VCSEL via the micromirror 5a, a light receiving element (photoelectric element) such as a PD from the core 2 is used. Also when light is emitted to the conversion element), there is an advantage that the photoelectric conversion element 4 and the core 2 can be optically coupled with the same structure.

Journal of Japan Institute of Electronics Packaging "90 degree optical path switching technology in optical circuit packaging" (vol.2, No.5, P368-372, 1999)

Since the conventional optical path conversion technology is configured as described above, the optical pin 5 with a micromirror must be fixed to each of the photoelectric conversion elements 4, and the manufacturing process becomes complicated. The price cannot be reduced.
Further, it is necessary to form the through hole 3 in the optical printed circuit board 1 in order to fit the optical pin 5. This optical pin 5 has a diameter of several μm to several hundred μm, and the through hole 3 must also be formed to have the same diameter as the optical pin 5, and the processing of the through hole 3 is extremely difficult and production Sexuality will deteriorate. This problem becomes more prominent as the number of through holes 3 increases. Further, it is difficult to form the inner wall surface of the fine through-hole 3 without unevenness, and the optical coupling efficiency between the core 2 and the optical pin 5 is caused by the unevenness of the end surface of the core 2 formed by the through-hole 3. It will decline.

Further, in the configuration in which the photoelectric conversion elements 4 are two-dimensionally arranged, the optical pins 5 must be fixed one by one with respect to the large number of photoelectric conversion elements 4, and the positional accuracy of the optical pins 5 deteriorates. Thereby, the optical axis shift of the photoelectric conversion element 4 and the optical pin 5 arises, and the optical coupling efficiency falls.
Further, in the configuration in which the layers in which the cores 2 are two-dimensionally arranged are arranged in multiple layers in order to cope with the increase in the number of the photoelectric conversion elements 4, the length of the optical pin 5 varies from core layer to core layer. 5 is required. The lengthening of the optical pin 5 causes the optical pin 5 to warp, the position accuracy of the micromirror 5a with respect to the optical axis of the core 2 is deteriorated, and the optical coupling efficiency is lowered.

  The present invention has been made to solve the above-described problems, and includes a plurality of optical waveguides for optically coupling two-dimensionally arranged components such as an optical waveguide and a photoelectric conversion element, an optical path conversion mirror surface, and the like. It is an object of the present invention to obtain an optical path conversion device capable of simplifying the manufacturing process, realizing a reduction in price, and suppressing a decrease in optical coupling efficiency.

  An optical path conversion device according to the present invention includes a clad formed with a first end face, a second end face and a mirror surface, embedded in the clad, each first core end face exposed at the first end face, and a second core A plurality of cores whose end faces are exposed at the second end face, and each of the cores reaches from the first core end face to the mirror face and is changed in direction by the mirror face to reach the second core end face. Forming a continuous optical path, wherein the first core end surface and the second core end surface of the core are two-dimensionally arranged on the first end surface and the second end surface, respectively, and at least one of the plurality of cores The optical path from the first core end surface to the mirror surface intersects the optical path from at least one other mirror surface of the plurality of cores to the second core end surface.

  According to the present invention, an optical path conversion device with low cost and high optical coupling efficiency can be obtained.

Embodiments of the present invention will be described below with reference to the drawings.
Embodiment 1 FIG.
FIG. 1 is a perspective view schematically showing an optical path conversion device according to Embodiment 1 of the present invention, and FIG. 2 is a side view for explaining an optical path conversion operation in the optical path conversion device according to Embodiment 1 of the present invention.

In FIG. 1, an optical path conversion device 10 is manufactured by embedding six L-shaped cores 11 serving as an optical path in a clad 12.
The cladding 12 is formed with a first end surface 12a, a second end surface 12b, and a mirror surface 13 for optical path conversion. The first core end surface 11a of the core 11 is arranged in a matrix (two-dimensional) in three columns and two rows on the first end surface 12a of the cladding 12, and the second core end surface 11b is formed on the second end surface 12b of the cladding 12. They are arranged in a matrix of 3 columns and 2 rows (two-dimensional). Each core 11 has an optical path from the first core end surface 11a to the mirror surface 13 and an optical path from the second core end surface 11b to the mirror surface 13 intersecting the optical axis on the mirror surface 13, and the optical axis It is formed in an L shape so as to be symmetric with respect to the normal of the mirror surface 13 at the intersection. The six cores 11 are configured by arranging two cores 11 arranged in parallel on the same plane orthogonal to the mirror surface 13 in three rows at a predetermined pitch parallel to the direction orthogonal to the plane. Has been. On the mirror surface 13, the intersections of the optical axes of the cores 11 are arranged in a matrix of 3 columns and 2 rows (two-dimensional).

The mirror surface 13 is formed on a flat surface having an angle of 45 degrees (mirror angle θ) with respect to the optical axis of the core 11. The first and second end faces 12 a and 12 b are each formed as a flat surface having an angle of 90 degrees with respect to the optical axis of the core 11.
The core 11 and the clad 12 are made of glass having different refractive indexes. The core 11 is made of glass having a higher refractive index than that of the clad 12, and the difference in refractive index between the two is 0.1 to 1.0%.

An optical path changing operation in the optical path changing device 10 configured as described above will be described with reference to FIG.
The light 14 enters the first core end surface 11 a of the core 11 from the first end surface 12 a of the optical path conversion device 10. Since the refractive index of the core 11> the refractive index of the cladding 12, the light 14 travels through the core 11 with low loss and reaches the mirror surface 13. Therefore, the light 14 is reflected by the mirror surface 13, the optical path is converted by 90 degrees, travels through the core 11 with low loss, and is emitted from the second core end surface 11 b of the core 11. As a result, the optical path of the light 14 is converted by 90 degrees by the optical path conversion device 10.
Even when the light 14 enters the second core end surface 11b of the core 11 from the second end surface 12b of the optical path conversion device 10, the light path is similarly converted by 90 degrees and emitted from the first core end surface 11a of the core 11. Is done.

Next, an optical coupling structure using the optical path conversion device 10 will be described with reference to FIG.
3, the array type photoelectric conversion element unit 20 has a photoelectric conversion element 21 including a light emitting element such as a surface emitting laser (VCSEL) and an edge emitting laser (LD) or a light receiving element such as a photodiode (PD). Are appropriately selected according to the two-dimensional arrangement and mounted on the substrate 22. Here, the six photoelectric conversion elements 21 are arranged in a matrix of 3 columns and 2 rows at an arrangement pitch equivalent to the first core end surface 11 a of the core 11 of the optical path conversion device 10.

  The array type optical waveguide unit 25 is manufactured by embedding a core 26 having a rectangular cross section serving as an optical waveguide in a matrix of three rows and two layers, with its optical axis parallel, and embedded in a clad 27. The arrangement pitch of the cores 26 in the array type optical waveguide unit 25 is configured to be equal to the arrangement pitch of the second core end faces 11 b of the cores 11 in the optical path conversion device 10. Both end surfaces of the unit 25 in the length direction of the core 26 are formed as flat surfaces having an angle of 90 degrees with respect to the optical axis of the core 26. Here, for example, fluorinated polyimide is used as the material of the core 26 and the clad 27. The core 26 is made of fluorinated polyimide having a refractive index larger than that of the fluorinated polyimide of the clad 27. And the refractive index difference of both is 0.1 to 1.0%.

The optical path conversion device 10 is disposed in close contact with the array type photoelectric conversion element unit 20 with the optical axis of the first core end face 11 a of each core 11 aligned with the center of the element surface of the photoelectric conversion element 21. The array type optical waveguide unit 25 is disposed in close contact with the optical path conversion device 10 with the optical axis of each core 26 aligned with the optical axis of the second core end surface 11b of each core 11.
Thereby, when the photoelectric conversion element 21 is a light emitting element, the light emitted from the photoelectric conversion element 21 is optically converted by 90 degrees by the optical path conversion device 10, and is transferred from one end side of the array type optical waveguide unit 25 to the core 26. Incident. Since the refractive index of the core 26 is greater than the refractive index of the cladding 27, the light travels through the core 26 with low loss and is emitted from the other end side of the array type optical waveguide unit 25.
On the other hand, when the photoelectric conversion element 21 is a light receiving element, the light incident on the core 26 from the other end side of the arrayed optical waveguide unit 25 enters the core 11 from the second core end surface 11b. Then, the light is converted by the optical path conversion device 10 by 90 degrees, emitted from the first core end surface 11a, and received by the photoelectric conversion element 21.

Next, a mounting example of the optical coupling structure shown in FIG. 3 will be described with reference to FIG.
The IC 16 and the array type photoelectric conversion element unit 20 are mounted on the substrate 17 by solder bumps or wire bonding. Further, the optical path conversion device 10 and the array type optical waveguide unit 25 are mounted on the electric wiring board 19 with the cores 11 and 26 facing each other. Next, the substrate 17 is mounted on the electrical wiring substrate 19 with the solder balls 18 so that the photoelectric conversion element 21 faces the first core end surface 11a of the core 11 of the optical path conversion device 10, thereby the light shown in FIG. A combined structure is realized.
For example, the core 26 of the array type optical waveguide unit 25 is connected to an optical device such as an optical switch or multiplexer / demultiplexer by an optical connector or the like, and is incorporated into an optical communication system or a massively parallel computer.

Here, in FIG. 4, the array type photoelectric conversion element unit 20 is fixed to the substrate 17, but the array type photoelectric conversion element unit 20 may be mounted (fixed) on the optical path conversion device 10.
In addition, the array type photoelectric conversion element unit 20 is electrically connected to the substrate 17 by solder bumps or wire bonding. For the connection between the two, a conductive adhesive, a Pin Grid Array (PGA), a Land Grid Array is used. (LGA) or the like may be used.

Further, the gap between the array type photoelectric conversion element unit 20 and the optical path conversion device 10 and the gap between the array type optical waveguide unit 25 and the optical path conversion device 10 are generally air, but propagation loss is small at the wavelength used. These gaps may be filled with a material that can be efficiently optically coupled to the cores 11 and 26, for example, a resin such as fluorinated polyimide, polymethyl methacrylate (PMMA), silicone resin, or epoxy resin.
The array type optical waveguide unit 25 can be fixed to the electric wiring board 19 by using an adhesive such as fluorinated polyimide, polymethyl methacrylate, silicone resin, epoxy resin, etc. The array type optical waveguide unit 25 may be fixed to the optical path conversion device 10 by using it.

Thus, according to the first embodiment, the cores 11 that are optical waveguides are arranged in a 3 × 2 matrix and embedded in the cladding 12, and the mirror surface 13 for optical path conversion is formed integrally with the cladding 12. Has been.
Therefore, the conventional optical pin 5 with a micromirror and the through hole 3 for fitting the optical pin 5 become unnecessary, the manufacturing process is simplified, the price is reduced, and the unevenness of the inner wall surface of the through hole 3 is reduced. There is no decrease in the optical coupling efficiency due to this.

Further, since the cores 11 can be manufactured in a matrix arrangement with high positional accuracy, optical axis misalignment between the photoelectric conversion elements 21 (cores 26) arranged in the matrix and the cores 11 hardly occurs, and the optical coupling efficiency is reduced. It can be suppressed.
In addition, optical elements arranged in a matrix can be optically coupled with a single optical path conversion device, the configuration is simplified, and the cost is reduced.
Further, since the core 11 is continuous before and after the mirror surface 13, the propagating light can be sufficiently confined, and the loss can be reduced.

In addition, since the core 11 is embedded in the clad 12, the occurrence of the warp of the core due to the lengthening of the core 11 is significantly reduced as compared with the warp generated in the single optical pin 5 as in the prior art. . As a result, even if the cores 11 are arranged in a 3 × 2 matrix, the positional accuracy of the cores 11 is not deteriorated, and the decrease in optical coupling efficiency is remarkably suppressed.
In addition, since the optical path conversion device 10 is a block body, optical coupling between elements such as the array photoelectric conversion element unit 20 and the array optical waveguide unit 25 and the optical path conversion device 10 can be accurately performed by a simple method. it can.

  Here, in the first embodiment, a part of the clad 12 is removed to produce the flat mirror surface 13. However, the mirror surface 13 is covered with gold or a multilayer film having a high reflectance. It may be. In this case, the reflectance at the mirror surface 13 is improved, and a reduction in loss is suppressed. The mirror surface 13 may be covered with a light selective transmission film. In this case, the mirror surface 13 is provided with a filter function, and only light having a predetermined wavelength can be transmitted through the mirror surface 13 and incident on other optical waveguides.

  In the first embodiment, the first and second core end faces 11a and 11b of the core 11 are arranged in a matrix of 3 columns and 2 rows, but the first and second core end faces 11a and 11b The arrangement state is not limited to this, and is appropriately set according to the arrangement state of the photoelectric conversion elements 21 and the arrangement state of the cores 26. Further, the arrangement pitch of the first and second core end faces 11a and 11b is not necessarily equal, and is appropriately set according to the arrangement state of the photoelectric conversion elements 21 and the cores 26. Further, the first and second core end faces 11a and 11b do not necessarily have to be arranged in a complete matrix of 3 columns and 2 rows. For example, two core end faces in one column are core end faces in other columns. May be offset in the row direction, or three core end faces may be arranged in a certain column.

Further, the mirror angle θ is assumed to be 45 degrees, but the mirror angle θ is not limited to 45 degrees, and the optical path conversion angle can be arbitrarily adjusted if appropriately set.
Needless to say, the mode propagating through the cores 11 and 26 may be a single mode or a multi-mode.

  In the first embodiment, glass such as quartz glass, oxide glass, and halogenated glass is used as the material for the core 11 and the cladding 12, but the material for the core 11 and the cladding 12 is limited to this. Any material may be used as long as the material has low loss with respect to propagation loss. For example, fluorinated polyimide, polymethyl methacrylate, silicone resin, epoxy resin, or the like can be used. And although the refractive index difference of the core 11 and the clad 12 is about 0.1-1.0%, it cannot be overemphasized that it can change suitably with a use.

The wavelengths that can be handled by the photoelectric conversion element 21 are generally 0.85 μm, 1.3 μm, and 1.55 μm. However, the wavelength is not limited to this, and an arbitrary wavelength may be used as necessary. Can do.
Further, the wavelength characteristics of the photoelectric conversion element 21 may be utilized so that a plurality of wavelengths can be handled. In this case, crosstalk of light propagating through the adjacent cores 11 and 26 can be suppressed.

Further, the core 26 and the clad 27 in the array type optical waveguide unit 25 are not limited to fluorinated polyimide, and a material having a refractive index necessary for light propagation and low loss with respect to the propagation wavelength. For example, glass such as quartz glass, oxide glass, and halogenated glass, polymethyl methacrylate, silicone resin, epoxy resin, and the like can be used. And although the refractive index difference of the core 26 and the clad | crud 27 is about 0.1 to 1.0%, it cannot be overemphasized that it can change suitably with a use.
The array type optical waveguide unit 25 is configured by embedding a core 26 in a clad 27. However, the array type optical waveguide unit is configured by bundling a plurality of optical fibers in which the core and the clad are integrally manufactured. May be.

Embodiment 2. FIG.
In the second embodiment, as shown in FIG. 5, a second mirror surface 13a having a mirror angle θ of 45 degrees is formed between the mirror surface 13 and the second end surface 12b.
In the optical path conversion device 10A thus manufactured, the optical path can be converted by 180 degrees, and it is possible to cope with complicated optical path conversion.
In the second embodiment as well, the conversion angle of the optical path can be arbitrarily adjusted by appropriately setting the mirror angle θ.

Embodiment 3 FIG.
In the third embodiment, as shown in FIG. 6, a second mirror surface 13b having a mirror angle θ of 45 degrees is formed between the mirror surface 13 and the second end surface 12b.
In the optical path conversion device 10B manufactured in this way, the optical path can be crank-converted (0 degree conversion), and it is possible to cope with complicated optical path conversion.
In the third embodiment as well, the conversion angle of the optical path can be arbitrarily adjusted by appropriately setting the mirror angle θ.

Embodiment 4 FIG.
FIG. 7 is a schematic diagram showing a mounting structure using an optical path conversion device according to Embodiment 4 of the present invention.
In the fourth embodiment, as shown in FIG. 7, the optical coupling structure between the array type photoelectric conversion element units 20 mounted on different substrates 17 is realized by combining the optical path conversion device 10 and the array type optical waveguide unit 25. is doing.
Therefore, the optical path conversion device 10 can be applied to optical coupling between the array type photoelectric conversion element unit 20 and the array type optical waveguide unit 25 and further to optical coupling between the array type optical waveguide unit 25.

Embodiment 5. FIG.
FIG. 8 is a schematic diagram showing a mounting structure using an optical path conversion device according to Embodiment 5 of the present invention.
In the fifth embodiment, as shown in FIG. 8, an optical coupling structure between array type photoelectric conversion element units 20 mounted on different substrates 17 is realized by an optical path conversion device 10A.
Therefore, the optical path conversion device 10A can be applied to optical coupling between the array type photoelectric conversion element units 20.

Embodiment 6 FIG.
FIG. 9 is a process diagram for explaining a method of manufacturing an optical path conversion device according to Embodiment 6 of the present invention.

Here, a method for manufacturing an optical path conversion device using quartz as a core and a clad material will be described.
First, as shown in FIG. 9A, a thin plate-like substrate 30 is manufactured using quartz glass having a low refractive index. Next, quartz having a high refractive index is deposited on the substrate 30 to a predetermined thickness using a vacuum deposition technique such as sputtering. Then, after applying a photoresist on the high refractive index quartz film and patterning the photoresist using a photoengraving technique, unnecessary portions of the quartz film are removed by reactive ion etching (RIE). Next, the photoresist is removed to obtain four cores 31a and 31b made of a high refractive index quartz film formed on the same plane. The two cores 31a are formed in parallel straight lines, the two cores 31b are formed in parallel straight lines, and the cores 31a and 31b are orthogonal to each other. In addition, the intersection part of the cores 31a and 31b is located on a straight line, and corresponds to the folded part of the core 11.
Then, a low refractive index quartz film is formed on the substrate 30 to a predetermined thickness using a vacuum film forming technique such as sputtering. As a result, as shown in FIG. 9B, a waveguide body 32 in which the cores 31a and 31b are embedded in quartz (clad) having a low refractive index is obtained.

Then, the waveguide body 32 is stacked with the cores 31a and 31b aligned as shown in FIG. 9C, and the stacked waveguide bodies 32 are bonded together to obtain the waveguide unit 33.
Next, by dicing, the waveguide unit 33 is cut and removed together with a part of the intersecting portion of the cores 31a and 31b to form a mirror surface 34 as shown in FIG. 9D, thereby obtaining an optical path conversion device. The mirror surface 34 is formed so as to pass through the intersection of the optical axis of the core 31a and the optical axis of the core 31b.

In the optical path conversion device manufactured in this way, the core 31a and the core 31b are folded back by the mirror surface 34 to constitute the continuous core 11, the low refractive index quartz constitutes the cladding 12, and the mirror surface 34 is the mirror. A surface 13 is formed.
Each core 11 includes a core 31a extending from the first core end surface 11a to the mirror surface 13 (34) and a core 31b extending from the second core end surface 11b to the mirror surface 13 (34). It is formed so as to be symmetric with respect to the perpendicular line of the mirror surface 13 (34) at the intersection. The eight cores 11 are arranged in four rows in parallel to a direction (stacking direction) perpendicular to the plane, with the two cores 11 arranged in parallel on the same plane orthogonal to the mirror surface 13 (34). It is arranged and arranged. The first core end surface 11a and the second core end surface 11b are arranged in a matrix of 4 columns and 2 rows on the first end surface 12a and the second end surface 12b, respectively.

In the manufacturing method according to the sixth embodiment, since the core 11 is produced by combining photolithography and reactive ion etching, the positional accuracy of the core 11 is ensured, and the light from the photoelectric conversion element 21 and the core 26 is obtained. The optical coupling efficiency in coupling can be increased.
In addition, since a plurality of cores 31a and 31b can be produced in the waveguide body 32, the cost can be reduced.

In the sixth embodiment, the waveguide unit 33 is cut by dicing to produce the mirror surface 34. However, after cutting by dicing, polishing is performed to increase the flatness of the mirror surface 34. Also good. Further, instead of dicing, the mirror surface may be formed by reactive ion etching or polishing.
In the sixth embodiment, a high refractive index quartz film is formed, and then the core is formed by etching. However, a core that has been prepared in a predetermined shape may be attached to the substrate 30 in advance. .

In the sixth embodiment, if only one waveguide body 32 is formed with three cores 31a and 31b, two-dimensional arrangement of the first and second core end faces 11a and 11b in three rows only in one column. A state is obtained. In this case, it is necessary to form the three cores 31a and 31b in the waveguide body 32 so that the intersections of the optical axes of the cores 31a and 31b constituting the core 11 are arranged on a straight line. Further, if the cores 31a and 31b are produced one by one for only one waveguide body 32, a two-dimensional arrangement state of the first and second core end faces 11a and 11b in one row for only one column can be obtained.
In the sixth embodiment, if the four waveguide bodies 32 are alternately offset and bonded, a two-dimensional arrangement state in which the first and second core end faces 11a and 11b are arranged in a staggered pattern can be obtained. . In this case, it is necessary to laminate the waveguide bodies 32 so that straight lines passing through the intersections of the optical axes of the cores 31 a and 31 b constituting the core 11 in each waveguide body 32 overlap in the lamination direction of the waveguide bodies 32.

Embodiment 7 FIG.
In the sixth embodiment, the mirror surface 34 is manufactured after the waveguide body 32 is bonded, but in the seventh embodiment, the mirror surface is formed at the stage of manufacturing the substrate.

Here, a method of manufacturing the optical path conversion device according to the seventh embodiment will be described with reference to FIG.
First, as shown in FIG. 10A, a thin plate-like substrate 30A on which a mirror surface 34a is formed is manufactured using quartz glass having a low refractive index. Next, a quartz film having a high refractive index is formed on the substrate 30A to a predetermined thickness by using a vacuum film formation technique such as sputtering. Then, after applying a photoresist on the high refractive index quartz film and patterning the photoresist using a photoengraving technique, unnecessary portions of the quartz film are removed by reactive ion etching (RIE). Then, the photoresist is removed to obtain four cores 31a and 31b made of a high refractive index quartz film formed on the same plane. The two cores 31a are formed in parallel straight lines, the two cores 31b are formed in parallel straight lines, and the cores 31a and 31b are orthogonal to each other on the mirror surface 34a. Then, a low-refractive-index quartz film is formed to a predetermined thickness on the substrate 30A using a vacuum film formation technique such as sputtering. As a result, as shown in FIG. 10B, a waveguide body 32A is obtained in which the cores 31a and 31b are embedded in quartz (clad) having a low refractive index.

Next, the waveguide body 32A is stacked with the mirror surfaces 34a aligned as shown in FIG. 10C, and the stacked waveguide bodies 32A are bonded together to obtain the waveguide unit 33. Thereby, the optical path changing device shown in FIG. 10D is obtained. In addition, the mirror surface 34 is comprised by the mirror surface 34a, and is formed so that it may pass through the intersection position of the optical axis of the core 31a, and the optical axis of the core 31b.
As described above, also in the seventh embodiment, an optical path conversion device similar to that of the sixth embodiment is manufactured.

Embodiment 8 FIG.
In the sixth embodiment, it is described that quartz, which is an inorganic material, is used as the core and the clad material. In this eighth embodiment, fluorinated polyimide, which is an organic material, is used as the core and the clad material. It is.
First, a first fluorinated polyimide solution having a low refractive index is spin-coated on a quartz substrate and baked to form a first cladding layer. Next, a second fluorinated polyimide solution having a high refractive index is spin-coated and baked to form a core layer on the first cladding layer.

And a photoresist is apply | coated on a core layer, a photoresist is patterned by the photoengraving technique, and the unnecessary part of a core layer is removed by reactive ion etching after that. Then, the photoresist is removed to obtain a core composed of the core layer. Next, the first fluorinated polyimide solution is spin-coated and baked to form a second cladding layer.
Thereby, a waveguide body (corresponding to the above-described waveguide body 32) in which the core is embedded in the first and second cladding layers is obtained. The core is configured similarly to the cores 31a and 31b in the sixth embodiment. Thereafter, in the same manner as in the sixth embodiment, this waveguide body is laminated and bonded to produce a waveguide unit, and a mirror surface is formed to obtain an optical path conversion device.
Therefore, in the eighth embodiment, the same effect as in the sixth embodiment can be obtained.

In the eighth embodiment, fluorinated polyimide is used as the core and the clad material. However, this manufacturing method is also used when polymethyl methacrylate, silicone resin, epoxy resin or the like is used as the core and clad material. Is applicable.
In the eighth embodiment, the core layer is patterned by reactive ion etching. However, if photocurability is imparted to the second fluorinated polyimide solution, the core layer can be patterned only by photolithography, The manufacturing process can be simplified.

In the eighth embodiment, the mirror surface is prepared after the waveguide bodies are bonded together. However, as in the seventh embodiment, the first and second fluorinated polyimide solutions are applied to the substrate. A mirror surface may be formed in advance.
In the eighth embodiment, the core layer is formed by etching after the second fluorinated polyimide solution is applied and cured to form the core layer. You may affix on a clad layer.

Embodiment 9 FIG.
FIG. 11 is a process diagram for explaining a method for manufacturing an optical path conversion device according to Embodiment 9 of the present invention, and FIG. 12 is a diagram for explaining a core formation method.

Here, a manufacturing method of an optical path conversion device using halogenated glass as a core and a clad material will be described.
First, as shown in FIG. 11A, a flat substrate 40 made of a halogenated glass is produced.
Next, as shown in FIG. 12, the laser beam of 810 nm emitted from the laser generator 38 is condensed by the condenser lens 39 and irradiated to a predetermined depth position of the substrate 40 as energy of 100 MJ / cm ^2. . At this time, the substrate 40 is moved in the direction of the arrow in FIG. 12, and one core 41 b is formed at the laser beam condensing position in the substrate 40. After one core 41b is formed, the substrate 40 is shifted by a predetermined amount in the direction orthogonal to the core 41b, and the second core 41b is formed while moving the substrate 40 in the same manner. In this way, the three cores 41 b are formed in parallel on the same plane in the substrate 40.

Subsequently, the condensing position in the substrate 40 by the condensing lens 39 is made shallow by a predetermined amount, and similarly, three cores 41 b are arranged in parallel in the substrate 40. As a result, as shown in FIG. 11B, a substrate 40 (waveguide body) in which six cores 41b are arranged in three rows and two layers is obtained.
Next, the position of the substrate 40 is rotated by 90 degrees, and the six cores 41a are arranged in three rows and two layers in the same manner using the laser generator 38 and the condenser lens 39, and formed in the substrate 40. . As a result, as shown in FIG. 11C, a substrate 40 (waveguide body) formed so that the core 41a and the core 41b intersect each other at right angles is obtained. In addition, the intersection of the corresponding core 41a and core 41b is located on the same plane.
Next, by dicing, the substrate 40 is cut and removed together with a part of the intersecting portion of the cores 41a and 41b to form a mirror surface 42 as shown in FIG. 11D, thereby obtaining an optical path conversion device. The mirror surface 42 is formed so as to pass through the intersection of the optical axis of the core 41a and the optical axis of the core 41b.

In the optical path conversion device manufactured in this way, the core 41a and the core 41b are folded at the mirror surface 42 to form the core 11, the substrate 40 forms the clad 12, and the mirror surface 42 forms the mirror surface 13. ing.
Each core 11 includes a core 41a extending from the first core end surface 11a to the mirror surface 13 (42), and a core 41b extending from the second core end surface 11b to the mirror surface 13 (42), and the mirror surface 13 (42). They are formed so as to intersect with each other and to be symmetric with respect to the perpendicular of the mirror surface 13 (42) at the intersection. The core 11 is configured by arranging two cores 11 arranged in parallel on the same plane orthogonal to the mirror surface 13 (42) in three rows parallel to the direction orthogonal to the plane. .

In the manufacturing method according to the ninth embodiment, laser light is focused on the substrate 40 using the laser generator 38 and the condensing lens 39, and a refractive index change is caused inside the substrate 40 to produce the cores 41a and 41b. is doing. Therefore, as compared with the sixth to eighth embodiments, the bonding process of the waveguide bodies 32 and 32A becomes unnecessary, the manufacturing process is simplified, and the cost is reduced.
Further, in the manufacturing methods according to the above sixth to eighth embodiments, the core is formed in a rectangular cross section, but in the ninth embodiment, a core having a circular cross section can be formed, so that there is little loss during propagation, Optical coupling can be performed efficiently.

In the ninth embodiment, a halogenated glass is used as the substrate 40. However, the material of the substrate is not limited to the halogenated glass, and any material may be used as long as it causes a change in refractive index by light irradiation. For example, oxide glass or quartz glass can be used.
In the ninth embodiment, the mirror surface 42 is manufactured by cutting the substrate 40 by dicing. However, after cutting by dicing, polishing may be performed to increase the flatness of the mirror surface 42. . Further, instead of dicing, the mirror surface may be formed by reactive ion etching or polishing.

  In the ninth embodiment, the cores 41a and 41b arranged in three rows and two layers are formed in the substrate 40 by light irradiation. However, the core 41b is formed in three rows and two layers by other methods. After the arrayed substrate 40 is manufactured, the cores 41a arranged in three rows and two layers may be formed in the substrate 40 by light irradiation. Here, the substrate 40 in which the cores 41b are arranged in three rows and two layers forms, for example, three rows of concave grooves in the substrate 40, and accommodates two quartz waveguides and two optical fibers in each concave groove, Thereafter, an adhesive such as fluorinated polyimide is filled in the concave groove and integrated.

Embodiment 10 FIG.
In the ninth embodiment, the mirror surface 42 is formed on the substrate 40 on which the cores 41a and 41b are formed. In the tenth embodiment, the mirror surface 42 is formed on the substrate 40A before the cores 41a and 41b are formed. Is formed.

Here, a method of manufacturing the optical path conversion device according to the tenth embodiment will be described with reference to FIG.
First, as shown in FIG. 13A, a flat substrate 40A on which a mirror surface 42 is formed is produced using a halogenated glass.
Next, the laser beam of 810 nm emitted from the laser generator 38 is condensed by the condenser lens 39 and irradiated to a predetermined depth position of the substrate 40A as energy of 100 MJ / cm ² . At this time, the substrate 40A is moved in the direction of the arrow in FIG. 12, and one core 41b is formed at the condensing position of the laser light in the substrate 40A. After one core 41b is formed, the substrate 40A is shifted by a predetermined amount in a direction orthogonal to the core 41b, and the second core 41b is formed while moving the substrate 40A in the same manner. In this way, a substrate 40A (waveguide body) in which the three cores 41b are formed in parallel on the same plane is obtained.

Next, the condensing position in the substrate 40A by the condensing lens 39 is made shallow by a predetermined amount, and similarly, three cores 41b are arranged in parallel in the substrate 40A. As a result, as shown in FIG. 13B, a substrate 40A (waveguide body) in which six cores 41b are arranged in three rows and two layers is obtained.
Next, the position of the substrate 40A is rotated 90 degrees, and the six cores 41a are arranged in three rows and two layers in the same manner using the laser generator 38 and the condenser lens 39, and formed in the substrate 40A. . The core 41a is formed such that each optical axis intersects the optical axis of the corresponding core 41b at right angles on the mirror surface 42, as shown in FIG.
Thereby, an optical path changing device is obtained. The mirror surface 42 is formed so as to pass through the intersection point between the optical axis of the core 41a and the optical axis of the core 41b.
Thus, also in the tenth embodiment, an optical path conversion device similar to that in the ninth embodiment is manufactured.

Embodiment 11 FIG.
FIG. 14 is a side view showing an optical path conversion device according to Embodiment 11 of the present invention.
The optical path conversion device 10C according to the eleventh embodiment is formed such that the optical path cross section of the core 45 gradually increases from the mirror surface 13 toward the first core end surface 45a.
Other configurations are the same as those in the first embodiment.

  According to the eleventh embodiment, since the optical path cross section of the core 45 is formed so as to gradually expand from the mirror surface 13 toward the first core end face 45a, the cross-sectional area of the first core end face 45a increases. When the first core end surface 45a is used as the incident end surface, the positioning accuracy of the photoelectric conversion element 21 or the core 26 and the optical path conversion device 10C is relaxed.

Note that changing the optical path cross section of the core 45 can be easily achieved by changing the mask shape in reactive ion etching, the laser condensing method, and the like.
In the eleventh embodiment, the optical path cross section of the core 45 is formed so as to gradually expand in the entire region from the mirror surface 13 to the first core end face 45a. The cross-sectional area of the one core end surface 45a may be maximized, and it may be formed so as to gradually expand toward the first core end surface 45a at least in the vicinity of the first core end surface 45a.
In the eleventh embodiment, the optical path cross section of the core 45 is formed so as to gradually expand from the mirror surface 13 toward the first core end surface 45a. May be formed so as to gradually expand toward the second core end surface 45b.

Embodiment 12 FIG.
FIG. 15 is a side view showing an optical path conversion device according to Embodiment 12 of the present invention.
The optical path conversion device 10D according to the twelfth embodiment is formed so that the optical path cross section of the core 46 gradually decreases from the mirror surface 13 toward the first core end surface 46a.
Other configurations are the same as those of the eleventh embodiment.

  According to the twelfth embodiment, since the optical path cross section of the core 46 is formed so as to be gradually reduced from the mirror surface 13 toward the first core end face 46a, the cross-sectional area of the first core end face 46a is reduced, When the first core end surface 46a is used as the emission end surface, the positioning accuracy of the photoelectric conversion element 21 or the core 26 and the optical path conversion device 10D is relaxed.

In the twelfth embodiment, the optical path cross section of the core 46 is formed so as to be gradually reduced in the entire region from the mirror surface 13 to the first core end face 46a. The cross-sectional area of the 1st core end surface 46a should be made into the minimum, and it should just be formed so that it may reduce gradually toward the 1st core end surface 46a at least in the 1st core end surface 46a vicinity.
In the twelfth embodiment, the optical path cross section of the core 46 is formed so as to be gradually reduced from the mirror surface 13 toward the first core end surface 46a. However, the optical path cross section of the core 46 is the mirror surface 13. May be formed so as to be gradually reduced from the end toward the second core end face 46b.

Embodiment 13 FIG.
FIG. 16 is a side view showing an optical path changing device according to Embodiment 13 of the present invention.
The optical path conversion device 10E according to the thirteenth embodiment is formed so that the branch cores 48a and 48b branch from the middle portion of the core 47 between the second end face 12b and the mirror face 13 and are exposed to the second end face 12b. .
Other configurations are the same as those in the first embodiment.

According to the thirteenth embodiment, since the core 47 is branched into the two branch cores 48a and 48b, two lights are collected into one light and emitted, or one light is converted into two lights. The light can be branched and emitted, and the application can be expanded.
In this case, the number of first core end faces 47a two-dimensionally arranged on the first end face 12a of the optical path conversion device 10E and the number of second core end faces 47b two-dimensionally arranged on the second end face 12b Will be different.
The number of cores 47 to be branched is appropriately set according to the specifications of optical coupling. Moreover, you may make it branch from the middle part of the core 47 of the 1st end surface 12a and the mirror surface 13, and may be exposed to the 1st end surface 12a.
Further, if a filter is formed in the middle of the branch cores 48a and 48b, light can be selectively transmitted through the branch cores 48a and 48b. Furthermore, if a thermo-optic switch is provided in the middle of the branch cores 48a and 48b, the optical path can be selectively switched.

It is a perspective view which shows typically the optical path changing device which concerns on Embodiment 1 of this invention. It is a side view explaining the optical path changing operation in the optical path changing device concerning Embodiment 1 of this invention. It is a schematic diagram explaining the optical coupling structure using the optical path changing device which concerns on Embodiment 1 of this invention. It is a schematic diagram which shows the example of mounting of the optical coupling structure using the optical path changing device which concerns on Embodiment 1 of this invention. It is a schematic diagram explaining the optical path conversion operation | movement in the optical path conversion device concerning Embodiment 2 of this invention. It is a schematic diagram explaining the optical path changing operation | movement in the optical path changing device concerning Embodiment 3 of this invention. It is a schematic diagram which shows the mounting structure using the optical path changing device which concerns on Embodiment 4 of this invention. It is a schematic diagram which shows the mounting structure using the optical path changing device which concerns on Embodiment 5 of this invention. It is process drawing explaining the manufacturing method of the optical path changing device which concerns on Embodiment 6 of this invention. It is process drawing explaining the manufacturing method of the optical path changing device which concerns on Embodiment 7 of this invention. It is process drawing explaining the manufacturing method of the optical path changing device concerning Embodiment 9 of this invention. It is a figure explaining the core formation method in the manufacturing method of the optical path changing device concerning Embodiment 9 of this invention. It is process drawing explaining the manufacturing method of the optical path changing device concerning Embodiment 10 of this invention. It is a side view which shows the optical path changing device concerning Embodiment 11 of this invention. It is a side view which shows the optical path changing device concerning Embodiment 12 of this invention. It is a side view which shows the optical path changing device concerning Embodiment 13 of this invention. It is a side view which shows the conventional optical path changing device.

Explanation of symbols

  10, 10A, 10B, 10C, 10D, 10E Optical path conversion device, 11, 45, 46, 47 Core, 11a, 45a, 46a, 47a First core end face, 11b, 45b, 46b, 47b Second core end face, 12 Clad , 12a First end surface, 12b Second end surface, 13 Mirror surface, 32, 32A Waveguide body, 33 Waveguide unit, 40, 40A Substrate (waveguide body).

Claims (4)

A clad having a first end face, a second end face and a mirror surface, embedded in the clad, each first core end face is exposed at the first end face, and the second core end face is exposed at the second end face. With multiple cores,
Each of the cores forms a continuous optical path from the first core end surface to the mirror surface, the direction of the mirror surface being changed to the second core end surface,
The first core end surface and the second core end surface of the core are two-dimensionally arranged on the first end surface and the second end surface, respectively, and
An optical path from at least one first core end surface of the plurality of cores to the mirror surface intersects with an optical path from at least one other mirror surface of the plurality of cores to the second core end surface. An optical path conversion device characterized by comprising:   2. The optical path conversion device according to claim 1, wherein at least two of the plurality of cores are configured to have the same optical path length by converting the optical path by 90 ° on the mirror surface.   The mirror surface is composed of a first mirror surface and a second mirror surface, and the plurality of cores reach the first mirror surface from the first core end surface and can be changed in direction by the first mirror surface. A continuous optical path that reaches the second mirror surface and is changed in direction by the second mirror surface to reach the second core end surface; and the second core end surface is flush with the first core end surface. The optical path conversion device according to claim 1.   The mirror surface is composed of a first mirror surface and a second mirror surface, and the plurality of cores reach the first mirror surface from the first core end surface and can be changed in direction by the first mirror surface. A continuous optical path that reaches the second mirror surface and is changed in direction by the second mirror surface to reach the second core end surface, and the second core end surface is opposite to the first core end surface. The optical path conversion device according to claim 1.

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