JPH11183747A - Three-dimensional polymer optical waveguide array and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a three-dimensional polymer optical waveguide array provided with a parallel transmission/parallel processing function capable of performing highly accurate addressing and coping with various system needs by arranging plural cores at prescribed positions. SOLUTION: In this polymer optical waveguide array of a multicore type for which polymer optical waveguide films constituted of the plural cores and the clad of a refractive index smaller than that of the core installed around the cores are laminated, the plural cores are arranged at the prescribed positions. In this case, the polymer optical waveguide film can be provided with female and male fitting parts or an aligning marker part for alignment. Also, the core is formed by the one selected from a group composed of PMMA, deuterated PMMA, UV curing an epoxy resin and a polysiloxane. The clad may be formed by a material having the refractive index smaller than the refractive index of the material of the core. The diagram illustrates an 8×8 three-dimensional polymer optical waveguide array for which 8 sheets of the polymer optical waveguide films are piled up and fixed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical waveguide using a polymer material, and is widely used in the fields of optical communication, optical interconnection, image transmission, optical information processing, micro optics and other general optics. It can be used for various optical waveguides, optical waveguide modules, optical integrated circuits or optical wiring tubes.

[0002]

2. Description of the Related Art An optical waveguide is a special light that confines light by forming a portion having a slightly higher refractive index than the surroundings on the surface of the substrate or immediately below the surface of the substrate, and performs multiplexing / demultiplexing and switching of light. Parts. Specific examples include an optical multiplexing / demultiplexing circuit, a frequency filter, an optical switch, and an optical interconnection component that are useful in the field of communication and optical information processing.

The characteristics of an optical waveguide device are basically as follows.
Compared to optical fiber parts made by processing a single optical fiber, high performance can be realized compactly based on a precisely designed waveguide circuit, mass production is possible, and various types of optical waveguides Can be integrated into one chip.

A brief review of the history of the development of optical waveguides suggests that optical waveguide devices have evolved in tandem with their introduction into optical fiber communication systems. In the 1970's, the early days of optical fiber communication, research was mainly on multi-mode optical waveguides compatible with multi-mode fiber, but in the 1980's, optical communication systems using single-mode fiber became mainstream. Research and development of single mode optical waveguides has been activated.

The advantages of the single-mode optical waveguide are that the control of the guided light is easy, that the device is advantageous in miniaturizing the device, that the optical power density is large, and that it is suitable for high-speed operation. On the other hand, with the rapid rise of multimedia, the momentum of high-speed signal distribution by light is increasing not only in advanced computer communications but also in offices and homes, and multi-mode optical waveguide components are beginning to attract attention as low-cost optical components. . Advantages of the multi-mode optical waveguide are that it is more suitable for mass production than a single-mode optical waveguide, and that handling such as connection is much easier.

Heretofore, inorganic glass having excellent transparency and small optical anisotropy has been mainly used as an optical waveguide material. However, inorganic glass is heavy and easy to break,
Due to problems such as high production cost, recently, instead of inorganic glass, it has extremely excellent transparency in the visible region and is transparent at 1.3 μm and 1.55 μm even in the communication wavelength region. There is a growing movement to manufacture optical waveguide components using conductive polymers. A polymer material is easy to form a thin film by a spin coating method, a dip method, or the like, and is suitable for producing a large-area optical waveguide. Also,
Unlike the case where an inorganic glass material such as quartz is used, when a polymer material is used, a high-temperature heat treatment step is not included in film formation, so that an optical waveguide is formed on a substrate that is not suitable for high-temperature processing such as a plastic substrate. There is an advantage that can be. Further, it is possible to produce a substrate-free polymer optical waveguide film utilizing the flexibility and toughness of the polymer. Also, manufacturing is basically a low temperature process,
An optical waveguide using a polymer material has a high potential for cost reduction as compared with a glass-based or semiconductor-based optical waveguide because it is easy to develop a replication such as mass production using a mold.

In recent years, in recent years, in the field of optical wiring, so-called optical interconnection, a multi-port optical transmitting / receiving module using an optical waveguide film has been developed, and is set in parallel with an optical fiber having a multi-core shape in a tape shape. It is becoming a key component of transmission. For these, Usui et al., 199
Proceedings of the 7th IEICE Communications Society Conference, p. 432, Yoshimura et al., Proceedings of the 1997 IEICE OPE / LQE / EMD / CPM Joint Workshop, etc.

[0008] Accordingly, it is possible to manufacture optical waveguide components such as an optical integrated circuit used in the optical communication field and an optical wiring board used in the optical information processing field in a large amount and at a low cost using a polymer optical material. Expected.

On the other hand, in the field of optical parallel transmission, a tape fiber has been used as a transmission medium for a long time, but recently, an image fiber used for an image monitor in an extreme environment such as a medical facility or a nuclear fuel facility has been replaced with a tape fiber. The movement to apply to optical parallel transmission has been activated. For example, high-density optical parallel transmission combining a two-dimensional surface emitting laser array having excellent mountability and integration and an image fiber having excellent parallel transmission has been proposed. A transmission channel of 36 channels with a transmission length of 1 m but a total throughput of 1 Gb / s is equivalent to 47 Tb / s / cm ² in terms of transmission density (Koita et al., Sugimoto, Kasahara, IEICE technical report ( ED 9558-74), 96 (156), 7-1
2, (1995)). Also, Kitayama et al. Converted an image into a space-code division multiplexed signal by an 8 × 8 coding pattern orthogonal to each other, and passed a distance of 16 m while maintaining the spatial arrangement through a 3 × 10 ⁴ quartz image fiber. Has been successfully transmitted in parallel (K. Kitayama
J. Lightwave Technol., 15 (2), 202-212, (1997)
See). Further, a transmission medium in which a normal tape fiber is bundled with a laminated type multi-core connector and the cross section is apparently two-dimensional has appeared.

[0010]

Under such circumstances, a new optical waveguide component for linking a high-density parallel transmission medium such as an image fiber or a laminated tape fiber with a parallel optical signal processing system has been required. . However, to date, no high-density optical waveguide component applicable to such an application has been found.

Although it is conceivable to provide the image fiber or the laminated tape fiber itself with a parallel optical signal processing system and a link function, the application range has to be extremely narrow due to the following circumstances.

That is, the image fiber is not only promising as a high-density multi-core transmission medium, but also has a potential to be applicable to a certain number of address selections. However, the application as a high-density multi-core transmission medium involves problems such as crosstalk and skew between cores at the time of high-density high-speed transmission. There is a problem that the possibility of manufacturing is poor and the application is limited.

[0013] For the multi-core tape fiber, the technology of laminating for each connector has already been established, and it is highly practical in terms of addressing, but there is a limit in terms of increasing the density of the core, and the number of pixels is limited. It is practically impossible to connect to a spatial modulator or the like, in which the dramatic increase in the number of devices is increasing.

Further, in a future advanced parallel optical signal processing system, a part for linking a transmission medium and a processing system also has some signal processing functions (for example, branching / joining,
Filters and switches). However, it is almost impossible to assign such a function to the image fiber or the laminated tape fiber itself.

A three-dimensional optical waveguide having a three-dimensional cross-section with a high-density waveguide core is disclosed in 1983 by Yamada et al. Circuit (T. Yamada, N. Takat
o, T. Kurokawa, J. Appl. Phys. Part2, 22 (10), L63
6-638, (1983)), and an optical waveguide by stereolithography in recent years. However, there is a problem in accuracy and mass productivity, and a practically usable one has not yet been obtained.

Assuming that the three-dimensional optical waveguide will be used in a parallel processing device or as an interface between the parallel processing device and the optical parallel transmission fiber in the future, a three-dimensional optical waveguide excellent in accuracy and mass productivity is provided. It is desired to establish a method for producing the same.

SUMMARY OF THE INVENTION The present invention has been made in view of the above situation, and has as its object the purpose of having a parallel transmission / parallel processing function, enabling high-precision addressing, and responding to various system needs. An object of the present invention is to provide an original polymer optical waveguide array and a method for manufacturing the same.

[0018]

Means for Solving the Problems A first invention of the present invention is:
A polymer optical waveguide film composed of a plurality of cores and a clad having a lower refractive index than the core disposed around the core (that is, the plurality of waveguide cores are densely arranged in a horizontal plane in the polymer optical waveguide film). A multi-core type polymer optical waveguide array in which the arranged polymer optical waveguide films are laminated, wherein the plurality of cores are arranged at predetermined positions.

Here, the polymer waveguide film can have a male and female fitting portion or a positioning marker portion for positioning.

The core is made of PMMA, deuterated PMM
A, the cladding may be formed of any one selected from the group consisting of an epoxy UV-curable resin and a polysiloxane resin, and the cladding may be formed of a material having a refractive index smaller than that of the core material. That is, in the production of the three-dimensional polymer waveguide array, the material can be appropriately selected according to the use environment conditions that differ for each application.

According to a second aspect of the present invention, there is provided a method of manufacturing a multi-core three-dimensional polymer optical waveguide array including a step of laminating a polymer optical waveguide film comprising a plurality of cores and a clad. The laminating step is characterized in that laminating is performed after positioning with the male and female fitting portions or positioning marker portions formed on the front and back surfaces of the polymer optical waveguide film.

Here, in the laminating step, the lamination can be performed by positioning at the male and female fitting portions and then fixed and fixed by bonding or physical engagement, and an adhesive can be used for bonding.

In the step of laminating, the positioning marker portion and the positioning marker portion of the double-sided pressure-sensitive adhesive sheet having the positioning marker portion and having a precisely controlled thickness are positioned to obtain a polymer. The optical waveguide film and the double-sided pressure-sensitive adhesive sheet can be laminated and integrated.

As described above, according to the present invention, the cores are arranged at predetermined positions. This is because the cores which are addressed with high precision are arranged with a desired core diameter, core interval, and number of cores. Means that they are regularly arranged spatially. Here, “addressed” means that the respective cores are arranged at predetermined positions.

The shape of the waveguide is not limited to a straight line, but can easily realize branching, merging, and the like. The waveguide can be used not only as a transmission medium but also as an optical signal for parallel processing. Therefore, by combining the three-dimensional polymer waveguide array of the present invention with a planar switch or filter, it is possible to configure a large-scale matrix optical device indispensable for optical parallel processing and wavelength multiplexing processing. .

Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A three-dimensional polymer optical waveguide array according to the present invention will be described with reference to FIGS. FIG. 1 is a plan view of a polymer optical waveguide film, and FIG. 2 is a perspective view of an 8 × 8 three-dimensional polymer optical waveguide array in which eight polymer optical waveguide films of FIG. 1 are stacked and fixed. The polymer optical waveguide film 10 includes eight cores arranged in parallel in a clad 15. On the back surface of the polymer optical waveguide film, there are alignment protrusions 2a at four corners and two alignment protrusions 3a in parallel with the core, and alignment recesses 2b and 3b at similar positions on the front surface. And 2a and 2b are in a form of engagement between male and female. As shown in FIG. 3, the polymer optical waveguide film may be provided with an alignment marker 32 instead of an alignment protrusion or a recess in parallel with the eight-core linear optical waveguide core 31.

The three-dimensional polymer waveguide array of the present invention may be laminated with a double-sided adhesive sheet between polymer optical waveguide films. FIG. 4 is a perspective view of an 8 × 8 three-dimensional polymer optical waveguide array in which a polymer optical waveguide film and a double-sided adhesive sheet 41 are alternately bonded.

FIG. 6 shows a (1 × 8) × 8 three-dimensional polymer optical waveguide array in which a tape fiber is connected to an 8 × 8 three-dimensional polymer optical waveguide array. Also, as shown in FIG.
A three-dimensional polymer optical waveguide array module in which two (1 × 8) × 8 three-dimensional polymer optical waveguide arrays are connected can be manufactured.

Example 1 A three-dimensional polymer optical waveguide array of the present invention as shown in FIG. 2 or 4 was manufactured.

The method of Kaneko et al. (Proc. Of POF '96, pp. 113)
-119, (1996).).
A polymer optical waveguide film having a relative refractive index difference of 1.2%, comprising a deuterated PMMA core and an epoxy-based UV curable resin clad, was manufactured with a design of m, the number of cores and the core pitch of 127 μm. The thickness was exactly 127 μm, and the core was fabricated so as to be located exactly at the center in the thickness direction of the polymer optical waveguide film. This polymer optical waveguide film has a square alignment projection at the four corners on the back surface and two alignment projections in the longitudinal direction, and the alignment is performed at the same position on the front surface of the polymer optical waveguide film. There is a dent.
The alignment dents on the surface were formed by photolithography (equivalent dents could be formed by machining), and the alignment projections were traces of the dents formed on the polymer optical waveguide film fabrication substrate. is there. Eight polymer optical waveguide films cut out from the same chip were precisely aligned by male and female (concavo-convex) engagement portions (male and female fitting portions) to produce a three-dimensional polymer optical waveguide array (I). . In addition, a three-dimensional polymer optical waveguide array (II) in which an adhesive was applied to the engagement portion was also manufactured at the same time. Thus, an 8 × 8 three-dimensional polymer optical waveguide array as shown in FIG. 2 was obtained.

Further, a polymer optical waveguide film as shown in FIG. 3 was prepared as shown in FIG. 3 having a core thickness of 50 μm, a cladding thickness both above and below the core of 15 μm, and a positioning marker having no unevenness for positioning. Thereafter, a 47 μm-thick double-sided pressure-sensitive adhesive sheet with a positioning marker was prepared. These polymer optical waveguide films and the double-sided pressure-sensitive adhesive sheet were alternately stuck together while positioning under a microscope to obtain an 8 × 8 three-dimensional polymer optical waveguide array (III) as shown in FIG.

Next, light having a wavelength of 830 nm was input from one end face, and the light intensity was measured at the other end to determine the optical waveguide characteristics. In the three-dimensional polymer optical waveguide array (I) in which the engagement portion is only physically fixed, the 50 × 50 μm core, 50 μm
mm length loss is in the range of 0.2-0.4 dB and 8 ×
The average loss value in the eight 64-channel optical waveguide array was 0.3 dB. From this result, it was found that a 64-channel multi-core three-dimensional waveguide having optical waveguide characteristics at a practical level can be manufactured.

In a three-dimensional polymer optical waveguide array (II) in which an adhesive is applied to the engagement portion, a 50 mm long 50 ×
The average loss value (wavelength 830 nm) in the optical waveguide array of 64 channels with a 50 μm core was 0.4 dB.

64 laminated and integrated using an adhesive film
50 × 50 μm for a three-dimensional optical waveguide array of channels
The average loss value of a 50 mm long optical waveguide is 0.3 dB.
Met.

Example 2 Similarly, a core diameter of 35 × 35 μm and a core pitch of 127
A three-dimensional polymer optical waveguide having a thickness of 50 μm was prepared.
Evaluation was performed in the same manner as in the case of μm.

Table 1 shows the measurement results of Example 1 and Example 2 together.

[0038]

[Table 1]

Example 3 Instead of the deuterated PMMA core shown in Example 1, ordinary PMMA not deuterated, commercially available optical polymers such as ARTON (manufactured by Nippon Synthetic Rubber) and ZEONEX (manufactured by Nippon Zeon) ), An 8 × 8 three-dimensional polymer optical waveguide was produced in the same manner as in Example 1 using a heat-resistant epoxy UV-curable resin and a silicone resin as a core material. As the clad material, a special heat-resistant epoxy UV curable resin also used as the core material was used. 1. The relative refractive index difference is 1.
The composition of the heat-resistant epoxy UV curable resin was adjusted to be 2 ± 0.2%. The core diameter was set to 50 × 50 μm, and an adhesive engagement method was used for three-dimensionalization.

With respect to these five types of three-dimensional polymer optical waveguide arrays, the average loss value of 64 ports at a wavelength of 830 nm and the heat resistance temperature were measured. The heat-resistant temperature is represented by a temperature at which the loss value becomes 130% or more compared to the initial value by heating for 1 hour. Table 2 shows the results.

[0041]

[Table 2]

Example 4 First, a 1 × 8 splitter-type polymer optical waveguide film 50 made of a deuterated PMMA core shown in FIG. 5 was produced in the same manner as the method in which the adhesive film in Example 1 was laminated. did. In FIG. 5, reference numeral 51 denotes a 1 × 8 splitter type optical waveguide core, and reference numeral 52 denotes a positioning marker. However, the core diameter was 40 × 40 μm, and the pitch between the upper, lower, left and right cores was 250 μm.

By stacking eight polymer optical waveguide films, a three-dimensional polymer optical waveguide array shown in FIG. 6 was prepared.
In FIG. 6, reference numeral 61 denotes an 8-core fiber pigtail with a connector.

In the three-dimensional polymer optical waveguide array manufactured in this manner, one end portion 62 has 8 ports, the other end portion 63 has 8 × 8 ports, and the 8 port side of one end portion is a bonding method. With this, it was connected to an 8-core tape fiber.
The average insertion loss of eight splitters stacked in parallel is
At a wavelength of 830 nm, it was 0.8 dB.

Next, as shown in FIG. 7A, two parallel splitter-type three-dimensional optical waveguide modules shown in FIG. 6 were prepared, and the respective 64-port sides were collectively exposed by dicing. Then, as shown in the enlarged partial view of FIG. 7B, both surfaces were arranged in a multiply-accumulate manner and bonded.

For each one of the eight-core tape fibers,
Light having different wavelengths but uniform power was input, and the output from each of the other eight-core tape fibers was separated to measure the output intensity. As a result, it was confirmed that a WDM signal multiplexed into eight waves was output uniformly from any port.

Example 5 A high-density version of the product-summation arrangement module of the (1 × 8) × 8 three-dimensional polymer optical waveguide array shown in Example 4 was produced. The core diameter of the used 1 × 8 splitter type polymer optical waveguide film was 40 × 40 μm, the cladding thicknesses of the upper and lower cores were both 18 μm, and the core interval was 80 μm pitch.
However, the length of the waveguide from the input side to immediately before the first Y-branch is twice as long as that of the fourth embodiment in view of the lamination process described later.

An adhesive method was used on the output side of the polymer optical waveguide film, and a wedge-shaped adhesive film having a tapered thickness was used on the input side. The thickness of one end of the wedge-shaped adhesive film is 1
70 μm, the thickness at the other end was 40 μm, and the length was 45% of the length of the polymer optical waveguide film.

The polymer optical waveguide film and the adhesive film were alternately bonded so that one end of the wedge-shaped adhesive film having a thickness of 170 μm and the input end of the polymer optical waveguide film matched. At the output end of the polymer optical waveguide film, the polymer optical waveguide films were bonded to each other.

The three-dimensional optical waveguide fabricated in this manner has eight ports on one end and 8 × 8 ports on the other end. The 8-port side at one end has a pitch of 250 μm, and the 8 × 8-port side at the other end has a pitch of 250 μm. The core spacing was 80 μm pitch. Example 4
Connect an 8-core tape fiber to the 8-port side as in
A high-density parallel splitter type three-dimensional optical waveguide module was fabricated.

Next, two high-density parallel splitter type three-dimensional optical waveguide modules are prepared, and the respective 64-port sides are collectively exposed by dicing. Then, both surfaces of the adhesive surfaces 71 and 72 in FIG. As shown in FIG. 7 (b), they were arranged in a product-sum manner and adhered.

For each one of the eight-core tape fibers,
Light having different wavelengths but uniform power was input, and the output from each of the other eight-core tape fibers was separated to measure the output intensity. As a result, 8
It was confirmed that a wave-multiplexed WDM signal was output.

[0053]

As described above in detail, the three-dimensional polymer optical waveguide array according to the present invention is capable of arranging cores addressed with very high precision in a desired core diameter, core interval, and number of cores. An optical link component for parallel processing. further,
The shape of the waveguide can easily realize not only a straight line, but also a branch and a junction, and has a potential beyond the mere parallel link function and capable of coping with parallel manipulation of optical signals. Therefore, by combining the three-dimensional polymer waveguide array of the present invention with a planar switch or filter, it is possible to configure a large-scale matrix optical device that is indispensable for optical parallel processing and wavelength multiplexing processing. It can be an important element in realizing a large-capacity communication system or a large-scale optical information processing system in the future.

[Brief description of the drawings]

FIG. 1 is a diagram showing a polymer optical waveguide film with alignment male and female engagement for producing a three-dimensional polymer optical waveguide array.

FIG. 2 is a diagram showing a three-dimensional polymer optical waveguide array obtained by stacking and fixing the polymers shown in FIG. 1;

FIG. 3 is a diagram illustrating a polymer optical waveguide film with a positioning marker for producing a three-dimensional polymer optical waveguide array.

4 is a diagram showing a three-dimensional polymer optical waveguide array obtained by alternately laminating and fixing the polymer optical waveguide film and the double-sided pressure-sensitive adhesive sheet shown in FIG. 3;

FIG. 5 is a view showing a 1 × 8 splitter type polymer optical waveguide film with a positioning marker for producing a three-dimensional polymer optical waveguide array.

6 is a view showing a (1 × 8) × 8 three-dimensional polymer optical waveguide array obtained by alternately laminating and fixing the 1 × 8 splitter type polymer optical waveguide film and the double-sided pressure-sensitive adhesive sheet shown in FIG. 5; It is.

FIG. 7A is a diagram showing a three-dimensional polymer optical waveguide array module in which (1 × 8) × 8 three-dimensional polymer optical waveguide arrays are connected in a product-sum arrangement, and FIG. FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Polymer optical waveguide film 11 8-core linear optical waveguide core 12a Positioning protrusion 12b Positioning concave 13a Positioning protrusion 13b Positioning concave 15 Cladding 31 8-core linear light waveguide core 32 Positioning marker part 41 Positioning marker Double-sided adhesive sheet having a portion 50 1 × 8 splitter-type polymer optical waveguide film 51 1 × 8 splitter-type waveguide core 52 Alignment marker section 61 8-core fiber pigtail with connector 62 One end 63 Other end 71 Adhesive surface 72 Adhesive surface

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Naoki Oba 3-19-2 Nishishinjuku, Shinjuku-ku, Tokyo Inside Nippon Telegraph and Telephone Corporation (72) Inventor Hisao Tabei 1-3-1 Gotenyama, Musashino City, Tokyo Inside NTT Advanced Technology Co., Ltd.

Claims (6)

[Claims] 1. A multi-core type polymer optical waveguide array in which a polymer optical waveguide film composed of a plurality of cores and a clad having a smaller refractive index than the core disposed around the core is laminated. The three-dimensional polymer optical waveguide array, wherein the plurality of cores are arranged at predetermined positions. 2. The three-dimensional polymer optical waveguide array according to claim 1, wherein the polymer optical waveguide film has a male and female fitting portion or a positioning marker portion for alignment. 3. The method according to claim 1, wherein the core is PMMA, deuterated PMM.
A, formed of any one selected from the group consisting of an epoxy UV-curable resin and a polysiloxane resin, wherein the cladding is formed of a material having a refractive index smaller than the refractive index of the material of the core. 3. The three-dimensional polymer optical waveguide array according to claim 1. 4. A method for manufacturing a multi-core type three-dimensional polymer optical waveguide array, comprising a step of stacking a polymer optical waveguide film composed of a plurality of cores and a clad, wherein the step of stacking is performed by the step of stacking. A method for manufacturing a three-dimensional polymer optical waveguide array, comprising: positioning the polymer optical waveguide film at the male and female fitting portions or positioning marker portions formed on the front and rear surfaces thereof; 5. The three-dimensional polymer optical waveguide array according to claim 4, wherein, in the laminating step, the alignment is performed at the male and female fitting portions, and then the lamination is performed by bonding or physically fixing. Production method. 6. The step of laminating includes aligning the alignment marker portion and the alignment marker portion of a double-sided pressure-sensitive adhesive sheet having a precisely controlled thickness having an alignment marker portion, The method for manufacturing a three-dimensional polymer optical waveguide array according to claim 4, wherein the polymer optical waveguide film and the double-sided pressure-sensitive adhesive sheet are laminated and integrated.