JP2004109600A - Optical coupling device and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hybrid optical coupling device comprising a plurality of optical waveguides which has optical waveguides mounted by high-precision control of alignment in the height direction and to provide a manufacturing method therefor. <P>SOLUTION: A second optical waveguide to be optically coupled to a first optical waveguide mounted on a substrate is constituted of a plurality of layers having different linear expansion coefficients, and an end part of the second optical waveguide can be displaced to the substrate in the vertical direction. The end part of the second optical waveguide is displaced by heating, and the condition of optical coupling between the first optical waveguide and the second optical waveguide is monitored to perform alignment in the height direction with a high precision. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to optical coupling between optical components when a plurality of optical components used in the field of optical communication are mounted on a single substrate, and more particularly to an optical coupling device with low optical coupling loss and a mounting method thereof. It is.
[0002]
[Prior art]
The demand for high-speed, large-capacity broadband is increasing due to the spread of the Internet.In particular, optical communication that transmits information by optical signals is not affected by radio interference, and is not intercepted because signals are not transmitted in the air like wireless communication, Attention is paid to its high reliability. Conventionally, in the field of optical communication, bulk-type optical components such as semiconductor lasers, optical switches, optical modulators, and optical fibers have been used, and these optical components are optically coupled to each other such as by mechanically moving. Devices, systems, and transmission lines for transmitting optical signals were configured. The bulk type has the advantages of low wavelength dependence and relatively low loss, but the size of each optical component is large, so that when the number of channels is several thousand or more, the device and system become very large. Furthermore, the steps of assembling and mechanically moving each optical component and adjusting the optical axis are complicated, have poor reliability such as environmental resistance, and are not suitable for mass production. is there.
[0003]
Therefore, an optical coupling device that integrates optical components on one substrate using an optical waveguide has been proposed. FIG. 3 shows an example of a type of optical switch for switching an optical path disclosed in Japanese Patent Application No. 2001-40006. The optical waveguide type optical coupling device of this example is one in which a plurality of optical components are formed and mounted on a substrate of about 10 cm square and integrated. In FIG. 3, each of an incident side optical waveguide section 301, a collimating section 302, an incident side optical polarization element section 303, a common optical waveguide 304, an exit side optical polarization element section 305, a condensing section 306, and an exit side optical waveguide section 307 is Each has an individual function as an optical component. Further, the optical waveguide type optical coupling device of the present example is a device in which these are integrated to fulfill the function of an optical switch as a whole. In addition, the optical waveguide type optical coupling device of the present example in which a plurality of optical components are integrated may be referred to as an optical module. However, even when a system is configured by combining such optical modules, it is regarded as an optical coupling device. I have.
In an optical waveguide type optical coupling device, each optical component is integrated on one substrate, and most of them are electrically and optically operated, so there is no mechanically movable part, and it is hardly affected by vibration and heat fluctuation. Because it can construct a system that is strong against the environment, its reliability is high. Furthermore, it is suitable for miniaturization because it is composed of thin-film optical components, and can be mass-produced easily, so that it can be realized at low cost.
[0004]
Here, there are two types of optical waveguides, one is a monolithic type in which optical components are formed on the same substrate, and the other is a hybrid type in which individually formed optical components are mounted on the same substrate. In the monolithic optical waveguide, various optical components are made of the same material as much as possible.Thus, the thickness of each layer and the horizontal position can be controlled with high precision and formed on the same substrate. It can be realized while forming optical components. On the other hand, since they are formed on the same substrate, there are restrictions on the temperature conditions to be formed, the materials of the respective layers, and the like, and it is difficult to realize an optimal optical function. On the other hand, the hybrid optical waveguide can have an optimal optical function for individually forming individual optical components.
[0005]
However, in the hybrid type optical waveguide, alignment at the time of optically coupling the respective optical components is required. Therefore, development for minimizing the optical coupling loss at the optical coupling portion is regarded as important.
The optical coupling loss due to the displacement of the core between the optical waveguides is the square of the displacement value as shown in FIG. In order to minimize the optical coupling loss as much as possible, it is necessary to align the positions of the cores between the optical waveguides with high precision. It is known that the core diameter of an optical waveguide is very small, and in particular, a single-mode optical waveguide generally used in optical communication has a core diameter of about 10 μm (for example, see Non-Patent Document 1). Micron alignment technology is required.
[0006]
Next, as an optical waveguide alignment technique, a passive alignment method and an active alignment method are known.
As a passive alignment method, for example, a mounting method of aligning an optical fiber and a semiconductor laser chip using a marker, and a self-alignment method using surface tension at the time of solder reflow have been proposed.
In the method using a marker, an alignment marker is formed in advance on an optical component to be mounted and a substrate or an adjacent optical component, and positioning is performed while monitoring the marker with an optical device. Also, in solder reflow, solder balls are formed at predetermined positions on the optical component and the board, and even if the solder balls are arranged roughly so that the opposing solder balls are in contact, when the solder is heated and melted, This is a self-alignment method in which the optical component moves by the surface tension and the optical component and the substrate can be automatically positioned.
However, in these methods, there are cases where the alignment of the marker positions is misaligned and the amount of solder varies. Therefore, alignment accuracy is not sufficient, it is difficult to obtain stable and efficient optical coupling, there are problems such as a low yield, and it is necessary to inspect all final products.
[0007]
On the other hand, as an active alignment method, an alignment mechanism using a micrometer has been put to practical use.
In this method, the position of the optical component is finely moved using a micrometer while monitoring the optical coupling efficiency, and alignment is performed so that the optical coupling efficiency becomes highest. Therefore, high optical coupling efficiency can be obtained.
However, in the method using this alignment mechanism, since it is necessary to arrange a micrometer stage around the optical waveguide, it is difficult to align the optical waveguide in a highly integrated portion in the optical device.
In addition, when there are many alignment locations, it is necessary to arrange a micrometer stage for each location, so that there is a problem that it is troublesome and the mountability is low.
[Non-patent document 1]
Tadashi Sueda, "Introduction to Optoelectronics," published by Maruzen Co., Ltd.
December 1998, P78
[0008]
[Problems to be solved by the invention]
Conventional passive alignment technology is simple and does not require a complicated mechanism for positioning.However, it is difficult to stably optically couple optical waveguides in optical components with high accuracy. is there.
In addition, the conventional active alignment technique requires a complicated mechanism for positioning. Since alignment of a highly integrated portion is difficult, it is unsuitable for a small optical coupling device, and low productivity is also a problem.
[0009]
Therefore, the present invention solves the above-mentioned problems, and provides a highly integrated optical coupling device which is mounted easily and stably with high accuracy in controlling the positional accuracy in the height direction between optical waveguides, and a manufacturing method thereof. The purpose is to do.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, in the optical coupling device of the present invention, the first optical waveguide is mounted on a single substrate. Next, a second optical waveguide is disposed so as to face the first optical waveguide, and a recess is provided in the substrate so that an end of the second optical waveguide can be displaced. A second optical waveguide composed of a plurality of layers having different linear expansion coefficients is arranged so as to face the first optical waveguide, and a resin for fixing the second optical waveguide is injected into the recess. While heating the end of the second optical waveguide facing the first optical waveguide, displacing the end, performing alignment with the first optical waveguide with high accuracy, and optically coupling with high optical coupling efficiency The problem is solved by fixing and mounting the second optical waveguide on the substrate.
[0011]
In order to heat the end of the second optical waveguide, a method of providing a heater to the end or irradiating infrared light can be used.
[0012]
Alignment of the first optical waveguide and the second optical waveguide with high precision is achieved by injecting light into the first optical waveguide and monitoring the optical output of the second optical waveguide, and achieving the highest optical coupling efficiency. The problem can be solved by optically coupling as follows.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiments of the present invention will be described with reference to the drawings. 1 and 2 are schematic cross-sectional views of an optical coupling device 7 according to the present invention. FIG. 1 shows a configuration before alignment of optical coupling, and FIG. 2 shows a configuration after alignment of optical coupling.
[0014]
In FIG. 1, the substrate of the present invention preferably has a flat surface in order to arrange a high-precision optical component on the substrate, and further has a quartz substrate through which ultraviolet rays are transmitted to cure the adhesive. 3 was used. The first optical waveguide 1 is mounted on the quartz substrate 3. The quartz substrate 3 is provided with a depression 31 so that the end 22 of the second optical waveguide 2 facing the first optical waveguide 1 can be displaced in the vertical direction with respect to the quartz substrate 3. The second optical waveguide 2 is arranged on the quartz substrate 3 at a position facing the first optical waveguide 1. The second optical waveguide 2 is characterized in that it is formed of a plurality of layers having different coefficients of linear expansion, and a heater 23 for heating is provided at an end 22 thereof.
[0015]
A curable adhesive 32 is injected into the depression 31 of FIG. 1 and is filled with the adhesive 32 as shown in FIG. The present invention is such that the second optical waveguide 2 is fixed and mounted on the quartz substrate 3 with an adhesive 32 at a position where the end 22 of the second optical waveguide 2 facing the first optical waveguide 1 is aligned. Is a configuration of the optical coupling device 7.
[0016]
Here, as the second optical waveguide 2, it is preferable to use a polymer optical waveguide 21 in which a plurality of layers having different linear expansion coefficients can be easily obtained.
[0017]
Furthermore, since the curable adhesive 32 can be cured and fixed independently of the heat for displacing the end 22 of the second optical waveguide 2, an ultraviolet curable adhesive 32 is preferably used.
[0018]
Next, a method for manufacturing the optical coupling device of the present invention will be described. The first optical waveguide 1 is mounted on the quartz substrate 3. A depression 31 is provided in the quartz substrate 3 so that the end 22 of the second optical waveguide 2 facing the first optical waveguide 1 can be displaced. A curable adhesive for arranging the second optical waveguide 2 composed of a plurality of layers having different linear expansion coefficients so as to face the first optical waveguide 1 and fixing the second optical waveguide 2 to the recess 31. Inject 32. The end 22 of the second optical waveguide 2 facing the first optical waveguide 1 is heated, the end 22 is displaced, and alignment with the first optical waveguide 1 is performed with high accuracy. In a state where the optical coupling is performed at a high optical coupling efficiency, the adhesive 32 is cured by irradiating ultraviolet rays 6 from the back surface of the quartz substrate 3, and the second optical waveguide 2 is fixed to the quartz substrate 3 and mounted. The optical coupling device 7 of the invention is realized.
[0019]
In order to align the end 22 of the second optical waveguide 2 facing the first optical waveguide 1 with high accuracy, light is incident 4 from the first optical waveguide 1 and the end of the second optical waveguide 2 is This is realized by monitoring the emitted light 5 at an end different from the portion 22 and controlling the emitted light 5 to be maximum.
[0020]
Embodiments of the present invention will be described in more detail with respect to detailed embodiments and modifications.
It is desirable that the first optical waveguide 1 and the second optical waveguide 2 arranged on the quartz substrate 3 are arranged such that the deviation of the core position is about ± 2 μm or less. The reason is that the incident light 4 enters the first optical waveguide 1 and the outgoing light 5 of the second optical waveguide 2 is monitored. This can be easily realized if a quartz substrate 3 having a flat surface is used.
[0021]
In the optical coupling device 7 of the present invention, alignment is performed by vertically displacing the end 22 of the second optical waveguide 2 with respect to the first optical waveguide 1 mounted on the quartz substrate 3, and in particular, a slab. It is effective for optical coupling of an optical waveguide having a structure.
Here, an optical waveguide having a slab structure has no specific channel as a path for transmitting light, and therefore has a high degree of freedom in a path through which light propagates, and does not require horizontal alignment with another optical waveguide. There is a feature that highly efficient optical coupling can be achieved by performing only vertical alignment.
[0022]
The first optical waveguide 1 mounted on the quartz substrate 3 is an optical waveguide having a slab structure. The first optical waveguide 1 is composed of a quartz plate 10 also serving as an under clad, a core portion 12, and an over clad portion 13. The thickness of the quartz plate 10 is 1 mm, the thickness of the core portion 12 is 10 μm, The thickness of the portion 13 was 18 μm. Incidentally, the refractive index of the quartz plate 10 also serving as the under cladding is 1.445, the refractive index of the core 12 is 1.449, and the refractive index of the over cladding 13 is 1.445. In the present invention, in a state where the first optical waveguide 1 is formed, the over clad portion 13 is on the uppermost layer, and the quartz plate 10 is on the lowermost layer. When mounting the first optical waveguide 1 on the quartz substrate 3, the first optical waveguide 1 is turned upside down so that the over clad portion 13 is the lowermost layer and is mounted so as to be in contact with the quartz substrate 3.
[0023]
Next, in order to adjust the displacement of the end 22 of the second optical waveguide 2 disposed opposite to the first optical waveguide 1, the depression 31 lower than the horizontal plane of the quartz substrate 3 is formed on the quartz substrate 3. Provide. As a method of forming the recessed portion 31, reactive ion etching that combines chemical reaction and physical action, which enables fine processing and obtains a smooth processed surface, was used.
[0024]
The second optical waveguide 2 mounted on the quartz substrate 3 is also an optical waveguide having a slab structure. The second optical waveguide 2 includes a silicon plate 20 as a substrate, a polymer optical waveguide 21, and a heater 23 for heating. Here, the polymer optical waveguide 21 is a general term for an optical waveguide portion made of an epoxy-based or polyimide-based polymer material. First, a heater 23 is provided on the back surface of the silicon plate 20 by vapor deposition. The thickness of the silicon plate 20 is 0.5 mm, the coefficient of linear expansion is 4 ppm / ° C., and the elastic modulus is 10E12 dyn / cm 2. As the polymer optical waveguide 21, an epoxy-based optical waveguide forming resin (manufactured by NTT-AT) was used. The linear expansion coefficient is 40 ppm / ° C., the elastic modulus is 10E10 dyn / cm 2, and the thickness of the under cladding part 211, the thickness of the core part 212 is 10 μm, and the thickness of the over cladding part 213 is 20 μm. A 20 μm epoxy-based optical waveguide forming resin (manufactured by NTT-AT) is laminated. Incidentally, the refractive index of the under cladding part 211 is 1.565, the refractive index of the core part 212 is 1.570, and the refractive index of the over cladding part 213 is 1.565. Next, when it is thermally cured at 200 ° C., it becomes the second optical waveguide 2.
[0025]
A structure in which such materials having different linear expansion coefficients are laminated is warped due to a change in temperature.
The amount of warpage (the amount of displacement) is determined by the coefficient of linear expansion, the thickness of the layer, the elastic modulus, and the amount of change in temperature, and the equation for calculating the amount of warpage is described in the literature (S. Timoshenco, J. Opt. Amer., 11, No. 23).
According to this calculation formula, if a material having an appropriate coefficient of linear expansion and elasticity, an appropriate layer thickness, and an amount of temperature change are selected, the amount of warpage (sub-micron displacement) required for alignment of a single mode optical waveguide is obtained. Can be controlled. FIG. 5 shows the calculation results when the silicon plate 20 and the polymer optical waveguide 21 were used. In FIG. 5, 200 ° C. indicates the amount of warpage of the second optical waveguide 2 in a thermosetting state, and the amount of warpage is 0 μm, indicating that the amount of warpage becomes slightly more than 4 μm at room temperature. .
That is, in the state where the second optical waveguide 2 is formed, the heater 23 on the back surface of the silicon plate 20 is in the lowermost layer, and the over clad portion 213 is in the uppermost layer, and slightly warps in a concave shape at room temperature. When the second optical waveguide 2 is disposed on the quartz substrate 3, the second optical waveguide 2 is disposed upside down so as to be in contact with the quartz substrate 3 with the over clad portion 213 as the lowermost layer. The second end 22 enters the depression 31.
[0026]
Next, an adhesive 32 is filled in the recess 31 between the end 22 of the second optical waveguide 2 and the quartz substrate 3.
In the present invention, an epoxy-based NA4291 (manufactured by NTT-AT), which is an ultraviolet-curing type and has a small curing shrinkage and is cured by ultraviolet irradiation, is used as the adhesive 32.
[0027]
In the optical coupling device 7 of the present invention, the second optical waveguide 2 having such a laminated structure is disposed on the quartz substrate 3 so that the end portion 22 can be displaced in the vertical direction, and the second optical waveguide 2 changes according to the temperature change. It is displaced.
The temperature change can be controlled by heating with a heater 23 installed around the end 22 of the second optical waveguide 2.
[0028]
The determination of the optimal alignment position is a so-called active alignment method in which the power of the light propagated from the first optical waveguide 1 to the second optical waveguide 2 is monitored and maximized. For example, the incident light 4 is input from an external light source to the first optical waveguide 1 by an optical fiber or the like, and the emitted light 5 from the second optical waveguide 2 is detected by a power meter.
[0029]
The fixing at the position of the optimum alignment is performed by filling the recess 31 between the end 22 of the second optical waveguide 2 and the quartz substrate 3 in advance while maintaining the state where the end 22 is displaced to the optimum position. The adhesive 32 is irradiated with ultraviolet rays 6 from the back surface of the quartz substrate 3 to cure the adhesive 32.
[0030]
Although the first optical waveguide 1 and the second optical waveguide 2 have been described as embodiments of the present invention, an optical coupling device in which a plurality of optical components are integrated can be realized by repeating the embodiments of the present invention. . In other words, if a quartz substrate with a flat surface is used, the optical component can be arranged on the substrate with a deviation of the core position of about ± 2 μm or less. The emitted light can be monitored, and the highest optical coupling efficiency between adjacent optical components can be determined. Therefore, if the optical components are mounted while being sequentially optically coupled, a plurality of optical components can be mounted with the highest optical coupling efficiency.
[0031]
Here, in the state where the optical waveguides are simply arranged on the substrate, if the deviation amount of the core position between the first optical waveguide 1 and the second optical waveguide 2 differs by ± 2 μm or more, the substrate may be provided with a terrace or a pedestal. It is desirable that the amount of deviation of the core position be adjusted to about ± 2 μm or less by the spacer.
[0032]
As an example of the method of forming the recess 31, an example using reactive ion etching has been described. Other examples include wet etching and dry etching using a chemical reaction, ion etching for cutting the surface by a physical action, and sand blast. .
[0033]
Here, the polymer optical waveguide 21 is of an epoxy type or a polyimide type and has various characteristics. When light passes through the optical waveguide, it is hardly scattered or absorbed, and has high transparency. Even when exposed to high temperatures, there is little deformation and heat resistance. It is necessary to form the core part and the clad part by delicately controlling the refractive index, but the refractive index can be easily controlled by the additive. Here, the additive for adjusting the refractive index is easily dissolved and has high compatibility. Further, an apparatus for forming a film constituting an optical waveguide is simple, film forming conditions are not strict, and good film forming properties such as good wettability and adhesion to a quartz or silicon plate as a base material. In the present invention, attention has been paid to the fact that a large linear expansion coefficient can be obtained in addition to these. Since such various characteristics can be selected, the degree of freedom in design is increased, and the material is suitable for realizing a high-performance, high-performance optical coupling device.
[0034]
Furthermore, the case where the optical waveguide itself is made of a material having a different linear expansion coefficient as the second optical waveguide 2 has been described. However, as a modification of the present invention, the optical component itself is made of a material that is difficult to thermally deform. Even so, if the optical component is mounted and mounted on a substrate exhibiting a bimetal effect by infrared rays, the same effect as in the present invention is produced, so that high-precision optical coupling can be performed.
[0035]
Also, although the method has been described in which the heater 23 is previously formed by vapor deposition on the back surface of the silicon plate 20, the heater 23 may be formed on the silicon plate 20 after forming the silicon plate 20 on the polymer optical waveguide 21. Good. Further, as a method of forming the heater 23, sputtering or CVD can be used.
[0036]
Further, the temperature change has been described with the method of heating with the heater 23 provided at the end 22 of the second optical waveguide 2, but it can be controlled by irradiating the end 22 with radiation such as infrared rays. is there. By using a laser as infrared light, it is possible to heat a fine region, which is suitable for realizing an optical coupling device with high integration and fine dimensions.
[0037]
The type of the adhesive 32 used in the present invention is not limited, but in the present invention, a material that hardly advances due to heat is preferable because the end 22 of the second optical waveguide 2 is heated to control the displacement. . In particular, an ultraviolet-curing type, which can control curing by irradiating ultraviolet rays independently of heat and has a small amount of curing shrinkage, is desirable.
As the UV-curable resin, besides AT-429 manufactured by NTT-AT, which is an epoxy system used for describing the embodiment of the present invention, AT9575 manufactured by NTT-AT, and epoxy-manufactured by NTT-AT are used. AT6001 and AT6177 can be used.
[0038]
The adhesive 32 desirably has a viscosity of 100 Ps or less for smooth displacement when the end portion 22 of the second optical waveguide 2 is heated and displaced.
[0039]
Further, the method of monitoring the power of light propagating in the direction from the first optical waveguide 1 to the second optical waveguide 2 has been described for determining the optimal alignment position. The same effect can be obtained by monitoring the power of light propagating from the optical waveguide 2 to the first optical waveguide 1.
[0040]
In addition, it is preferable that the highest optical coupling efficiency of the corresponding portion in the optical coupling device to be mounted is checked in advance, the state where the predetermined optical coupling efficiency is obtained is determined, and the alignment position is determined.
[0041]
(Supplementary Note 1) An optical coupling device comprising: a first optical waveguide mounted on a substrate; and a second optical waveguide optically coupled to the first optical waveguide and mounted on the substrate. ,
The second optical waveguide is composed of a plurality of layers having different coefficients of linear expansion, and the second optical waveguide is fixed by a curable adhesive, so that the end of the first optical waveguide and the second optical waveguide are fixed. An optical coupling device, wherein the optical coupling device is mounted on the substrate such that ends of two optical waveguides face each other.
[0042]
(Supplementary Note 2) The optical coupling device according to Supplementary Note 1, wherein a heater for controlling a temperature is provided at an end of the second optical waveguide.
[0043]
(Supplementary note 3) The optical coupling device according to supplementary note 1, wherein the second optical waveguide is a polymer optical waveguide disposed on a silicon plate.
[0044]
(Supplementary Note 4) The optical coupling device according to Supplementary Note 1, wherein the curable adhesive is an ultraviolet curable adhesive.
[0045]
(Supplementary Note 5) A step of mounting the first optical waveguide on the substrate, a step of forming the second optical waveguide with a plurality of layers having different linear expansion coefficients, and disposing the second optical waveguide on the substrate. And the step of filling the gap between the end of the second optical waveguide and the substrate with a curable adhesive, and at the time of alignment of optical coupling between the first optical waveguide and the second optical waveguide. Controlling the temperature of the end of the second optical waveguide to displace the end, and curing the adhesive while maintaining the state in which the end is displaced; A method for manufacturing an optical coupling device, comprising a step of mounting a waveguide.
[0046]
(Supplementary Note 6) The method for manufacturing an optical coupling device according to Supplementary Note 5, wherein the end of the second optical waveguide is heated to control the temperature of the end during the alignment of the optical coupling. .
[0047]
(Supplementary note 7) The method for manufacturing an optical coupling device according to Supplementary note 6, wherein the temperature of the end portion is controlled by using infrared rays to heat the end portion of the second optical waveguide.
[0048]
(Supplementary Note 8) At the time of the alignment of the optical coupling, light is incident from the first optical waveguide to monitor an optical output at an end different from the end of the second optical waveguide, and the optical output is maximized. The method of manufacturing an optical coupling device according to claim 5, wherein the displacement of the end portion is controlled so as to be as follows.
[0049]
(Supplementary Note 9) Supplementary note 5 characterized by including a step of irradiating ultraviolet rays in order to cure the adhesive while keeping the end portion displaced so that the light output is maximized. 3. The method for manufacturing an optical coupling device according to claim 1.
[0050]
【The invention's effect】
As described above, according to the present invention, it is possible to simply and easily align various optical components without using a conventional active alignment mechanism using a micrometer or the like. Is easy to implement, and greatly contributes to the realization and spread of highly integrated optical coupling devices.
[0051]
Further, according to the present invention, even when there are many optical coupling points, a special alignment mechanism is not required, so that expensive mounting equipment is not required, and the mounting can be performed easily, so that low cost and high productivity can be expected. be able to.
[0052]
Further, by using a polymer as the material of the optical waveguide, the degree of freedom in designing conditions of the optical waveguide is increased, so that a high-performance and high-performance optical coupling device can be realized.
[0053]
Further, by using infrared rays instead of the heater for heating the end of the optical waveguide, the number of steps for forming the optical waveguide is reduced, and the optical coupling device can be realized at low cost.
[0054]
Also, at the time of alignment of the optical coupling between the optical waveguides, light is incident on one optical waveguide and light emitted from the other optical waveguide is monitored, so that a highly efficient light coupling device can be realized.
[0055]
Furthermore, when the optical waveguide is fixed to the substrate, by using an ultraviolet curing resin, the curing can be controlled by ultraviolet rays independently of the heating for displacing the end of the optical waveguide in the present invention. And a high-performance optical coupling device can be realized.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view before alignment of optical coupling in an optical coupling device according to an embodiment of the present invention.
FIG. 2 is a schematic cross-sectional view after alignment of optical coupling in the optical coupling device according to the embodiment of the present invention.
FIG. 3 is an example of an optical coupling device in which a plurality of optical components are integrated.
FIG. 4 is a diagram illustrating a relationship between a deviation between fibers and an optical coupling loss.
FIG. 5 is a graph of a calculation result showing a relationship between the amount of warpage of the second optical waveguide and the temperature in the embodiment of the present invention.
[Explanation of symbols]
1 First optical waveguide
2 Second optical waveguide
3 Quartz substrate
4 Incident light
5 Emitted light
6 UV
7 Optical coupling device
10 Quartz plate of first optical waveguide 1
12 core part of first optical waveguide 1
13 Overcladding part of the first optical waveguide 1
20 Silicon plate of second optical waveguide 2
21 Polymer Optical Waveguide of Second Optical Waveguide 2
22 End of Second Optical Waveguide 2
23 heater
31 hollow
32 adhesive
211 Underclad portion of second optical waveguide 2
212 Core of Second Optical Waveguide 2
213 Over clad portion of second optical waveguide 2
301 Incident side optical waveguide
302 Collimating part
303 Incident light polarization element
304 common optical waveguide
305 Outgoing side light polarizing element
306 Condenser
307 Output side optical waveguide

Claims (5)

A first optical waveguide mounted on a substrate, an optical coupling device comprising a second optical waveguide optically coupled to the first optical waveguide and mounted on the substrate,
The second optical waveguide is composed of a plurality of layers having different coefficients of linear expansion, and the second optical waveguide is fixed by a curable adhesive, so that the end of the first optical waveguide and the second optical waveguide are fixed. An optical coupling device, wherein the optical coupling device is mounted on the substrate such that ends of two optical waveguides face each other. The optical coupling device according to claim 1, wherein the second optical waveguide is a polymer optical waveguide arranged on a silicon plate. The optical coupling device according to claim 1, wherein the curable adhesive is an ultraviolet curable adhesive. A step of mounting the first optical waveguide on the substrate, a step of forming the second optical waveguide with a plurality of layers having different linear expansion coefficients, and a step of disposing the second optical waveguide on the substrate, A step of filling the gap between the end of the second optical waveguide and the substrate with a curable adhesive, and at the time of alignment of optical coupling between the first optical waveguide and the second optical waveguide, Controlling the temperature of the end of the optical waveguide to displace the end, and curing the adhesive while maintaining the state where the end is displaced, and mounting the second optical waveguide. A method for manufacturing an optical coupling device, comprising the steps of: At the time of the alignment of the optical coupling, light is incident from the first optical waveguide to monitor the optical output at an end different from the end of the second optical waveguide, so that the optical output is maximized. 5. The method according to claim 4, wherein the displacement of the end is controlled.

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