JP2003050326A - Optical waveguide part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical waveguide part in which the central wavelength of passing light is kept constant independent of temperature. SOLUTION: An optical waveguide chip 9 on which substrate 1 the optical waveguide circuit of which the light transmissivity varies according to temperature is formed and a temperature adjustment part 8 for the optical waveguide chip 9 are provided, and the temperature adjustment part 8 and the optical waveguide chip 9 are laminated. The optical waveguide chip 9 and the temperature adjustment part 8 are directly joined by a jointing material 7 provided between the joining faces of the optical waveguide chip 9 and the temperature adjustment part 8. The jointing material 7 is, for example, a high thermal conductivity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical waveguide component having a temperature adjusting function used for optical communication such as wavelength division multiplexing optical communication.

[0002]

2. Description of the Related Art In recent years, in optical communication, as a method of dramatically increasing its transmission capacity, research and development of optical wavelength division multiplex communication have been actively carried out and are being put to practical use. In the optical wavelength division multiplexing, for example, a plurality of lights having different wavelengths are multiplexed and transmitted, and the transmission capacity of one optical fiber can be efficiently increased by increasing the number of multiplexed lights. . Recently, wavelength division multiplexing communication systems using 100 or more wavelengths have been commercialized.

An optical wavelength multiplexer / demultiplexer is one of the optical components that plays an important role in this wavelength division multiplexing communication. The optical wavelength multiplexer / demultiplexer is a general term for the optical wavelength multiplexer and the optical wavelength demultiplexer, and many optical wavelength multiplexers and optical wavelength demultiplexers have the other function.

Array waveguide diffraction grating (AWG; Arr) is one of the optical wavelength multiplexers / demultiplexers that have been put into practical use.
ayed Waveguide Grating). FIG. 6 shows an example of an arrayed waveguide type diffraction grating chip in which an optical waveguide circuit of an arrayed waveguide type diffraction grating is formed on the substrate 1. In this specification, a configuration in which an optical waveguide circuit is formed on a substrate is called an optical waveguide chip, and an optical waveguide circuit of an arrayed waveguide type diffraction grating is formed on the substrate of the optical waveguide chip. This structure is called an arrayed waveguide type diffraction grating chip.

The optical waveguide circuit of the arrayed waveguide type diffraction grating includes one or more optical input waveguides 2, a first slab waveguide 3 connected to the emission side of the optical input waveguides 2, and the first slab waveguide 3. Array waveguide 4 connected to the output side of slab waveguide 3
A second slab waveguide 5 connected to the emitting side of the arrayed waveguide 4; and a plurality of optical output waveguides 6 connected in parallel to the emitting side of the second slab waveguide 5. is doing.

The arrayed waveguide 4 propagates the light derived from the first slab waveguide 3 and is formed by arranging a plurality of channel waveguides 4a in parallel, and the adjacent channel waveguides 4a are formed. The lengths of 4a are set by each other (ΔL)
Is different. The waveguide forming region 10 having the above optical waveguide circuit is formed of a silica glass material.

The optical output waveguides 6 are provided corresponding to the number of signal lights of different wavelengths which are demultiplexed or combined by, for example, an arrayed waveguide type diffraction grating. Constituting channel waveguide 4a
Are usually provided in a large number such as 100, but in the figure, for simplification of the figure, the number of each of the channel waveguides 4a, the optical output waveguides 6 and the optical input waveguides 2 is provided. Is simply shown.

An optical fiber (not shown) on the transmission side, for example, is connected to the optical input waveguide 2 so that wavelength-multiplexed light can be introduced. The light introduced into the slab waveguide 3 is spread by the diffraction effect thereof, enters the array waveguide 4, and propagates through the array waveguide 4.

The light propagated through the arrayed waveguide 4 is
Of the array waveguide 4 is reached by the optical output waveguide 6, and all the channel waveguides 4a of the array waveguide 4 have different lengths. After propagating, there is a phase shift of individual light,
The wavefront of the focused light is tilted according to the amount of deviation, and the tilt angle determines the position where light is focused.

In the arrayed waveguide type diffraction grating,
Assuming that the angle (diffraction angle) at which light is condensed when the light enters the second slab waveguide from the arrayed waveguide is φ, this angle φ and the wavelength of the condensed light (light transmission center wavelength) λ There is a relationship as shown in the following equation (1).

N _s · d · sin φ + n _c · ΔL = m · λ (1)

N _s is the equivalent refractive index of the first and second slab waveguides, d is the distance between the end portions of the channel waveguides on the side of the first and second slab waveguides, φ is the diffraction angle, and n _c Is the equivalent refractive index of the arrayed waveguide, ΔL is the difference in length between adjacent arrayed waveguides, and m is the diffraction order.

By the way, since the refractive index of glass material such as quartz generally changes with temperature, the refractive indices n _s and n _{c of the} waveguide change with temperature, and the relationship between λ and φ in equation (1). Changes. Therefore, when the temperature changes, the combined / demultiplexed wavelength of the arrayed waveguide diffraction grating changes.

This amount of change is about 0.01 nm in the case of a circuit using a silica-based material such as an arrayed waveguide type diffraction grating.
/ C, which is a practically nonnegligible value because the amount of change is 0.7 nm or more in the temperature range of 0C to 70C, which is the operating temperature range required for optical communication.

For this reason, when the arrayed-waveguide diffraction grating is used, the temperature of the arrayed-waveguide diffraction grating is controlled by providing a temperature adjusting component on the arrayed-waveguide diffraction grating chip as an optical waveguide chip. I have to. That is, FIG.
As shown in, the temperature control component 8 and the optical waveguide chip 9 of the arrayed waveguide type diffraction grating chip are superposed, and
A soaking plate 12 is provided between the joint surface of the optical waveguide chip 9 and the joint surface of the temperature control component 8 to form the optical waveguide component. As shown in FIG. 8, this optical waveguide component has a package 20
It is housed inside and modularized.

The temperature adjusting component 8 has at least a function of generating heat or absorbing heat, and in the example shown in FIGS. 7 and 8, it is formed of a Peltier module having a plurality of Peltier elements 25.

In the Peltier module, a plurality of Peltier elements 25 are arranged between the upper substrate 23 and the lower substrate 24. The upper substrate 23 and the lower substrate 24 are generally formed of ceramic substrates. The Peltier element 25 is made of P-type and N-type semiconductors, and these P-type semiconductors and N-type semiconductors are arranged so as to be electrically alternately connected. When the Peltier module is energized via the lead wire 26 by a temperature controller (not shown), P
Electric current flows through the type semiconductor and the N-type semiconductor, and endothermic and exothermic reactions are obtained.

The soaking plate 12 is a plate made of a material having high thermal conductivity such as copper or aluminum as a main material, and is usually made of a silicone oil compound (silicone grease) having excellent thermal conductivity. The soaking plate 12, the optical waveguide chip 9, and the temperature control component 8 are joined together. As an example of the silicone grease, a product name SC102 manufactured by Toray Dow Corning Co., Ltd. or the like is applied.

On the upper surface of the optical waveguide chip 9, a chip upper plate 19 is joined to the end side of the optical waveguide chip 9 and the end surface is polished, and the end surface-polished optical fiber array 21 is connected to the optical waveguide chip 9. There is. By this connection, the optical waveguides of the optical waveguide chip 9 (in this case, the optical input waveguide 2 and the optical output waveguide 6) are optically connected to the optical fibers of the optical fiber array 21, respectively.

The temperature adjusting component 8 is adjusted by the temperature controller so that the temperature detected by a temperature detecting element such as a thermistor or a resistance temperature detecting element (not shown) becomes a preset temperature. Then, the temperature of the optical waveguide chip 9 is configured to be uniform and constant throughout due to heat diffusion by the heat equalizing plate 12.

[0021]

However, as described above, in the structure in which the heat equalizing plate 12 is provided between the optical waveguide chip 9 and the temperature adjusting component 8, the temperature adjusting component 8 and the optical waveguide chip 9 are used to equalize the temperature. Since both of the temperatures of the plate 12 are controlled, there is a problem that the power consumption during the temperature control becomes large.

Further, in general, an optical waveguide module in which an optical waveguide chip 9 such as an arrayed waveguide type diffraction grating is housed in a housing is required to be small in size, and particularly, the size in the thickness direction is small. Is desired, soaking plate 12
However, there is a problem in that the thickness of the optical waveguide module becomes large when using. For example, an optical waveguide module incorporated in an optical communication system device is required to have a thickness (A shown in FIG. 8) of 8.5 mm or less. Is very difficult to satisfy.

Further, since the soaking plate 12 is required to have high thermal conductivity, it is desirable to form the soaking plate 12 from copper, but the soaking plate 12 using copper is expensive. Further, since it is necessary to plate with nickel or the like in order to prevent copper from being oxidized, the price of the optical waveguide module formed using the heat equalizing plate 12 made of copper becomes high.

The present invention has been made to solve the above problems, and an object thereof is to stabilize the temperature control of an optical waveguide chip such as an arrayed waveguide type diffraction grating without using a soaking plate. It is to provide an optical waveguide component that can be performed.

[0025]

In order to achieve the above object, the present invention has the following constitution as means for solving the problem. That is, the first invention comprises an optical waveguide chip having an optical waveguide circuit whose light transmission characteristics change depending on temperature, formed on a substrate, and a temperature adjusting component for the optical waveguide chip. And the optical waveguide chip are overlapped with each other, and the optical waveguide chip and the temperature control component are directly bonded by a bonding agent interposed between the bonding surface of the optical waveguide chip and the bonding face of the temperature control component. As a means to solve.

In addition to the structure of the first invention, the second invention is such that the bonding agent has a thermal conductivity of 0.4 W / (m.multidot.m).
K) The above configuration is used as a means for solving the problem.

Further, in the third invention, in addition to the constitution of the first or second invention, the bonding agent has a Young's modulus of 2.0.
A structure of × 10 ⁷ Pa or less is a means for solving the problem.

Further, in the fourth invention, in addition to the constitution of the first, second or third invention, the bonding agent is an adhesive containing silicone as a main component, which is a means for solving the problems. .

Further, a fifth invention is the above-mentioned first to fourth inventions.
In addition to the structure of any one of the above aspects, the bonding agent has a structure in which the average thickness is 0.1 mm or more as means for solving the problem.

Further, a sixth invention is the above-mentioned first to fifth inventions.
In addition to the structure of any one of the inventions, the temperature control component has a structure formed with a Peltier element or a heater element as means for solving the problem.

Further, a seventh invention is the above-mentioned first to sixth inventions.
In addition to the configuration of any one of the above aspects, the substrate of the optical waveguide chip is made of a material having a thermal conductivity of 50 W / (m · K) or more as a means for solving the problem.

Further, in addition to the structure of the seventh invention, the eighth invention has a structure in which the substrate of the optical waveguide chip is made of silicon as means for solving the problem.

Further, a ninth invention is the above-mentioned first to eighth inventions.
In addition to the configuration of any one of the inventions, the optical waveguide circuit of the optical waveguide chip includes one or more optical input waveguides and a first slab waveguide connected to the emission side of the optical input waveguides. ,
An array waveguide, which is connected to the emission side of the first slab waveguide and is composed of a plurality of channel waveguides arranged in parallel with each other having different set amounts, and a second array waveguide connected to the emission side of the array waveguide. An optical waveguide circuit of an arrayed waveguide type diffraction grating having a slab waveguide and a plurality of optical output waveguides connected in parallel on the emission side of the second slab waveguide is used as means for solving the problem. .

In the present invention having the above-mentioned structure, since the optical waveguide chip and the temperature control component are directly bonded to each other via the bonding agent (without providing the heat equalizing plate), the optical waveguide chip is connected via the heat equalizing plate. It is possible to suppress an increase in the thickness of the optical waveguide component, an increase in power consumption during temperature control, and an increase in the cost of the optical waveguide component, as in the case of joining the optical waveguide component and the temperature adjustment component.

[0035]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In the description of the example of the present embodiment, the same names as those in the conventional example are denoted by the same reference numerals, and the duplicate description thereof will be omitted. FIG. 1 is a sectional view showing the configuration of the essential parts of an embodiment of an optical waveguide component according to the present invention.

The optical waveguide component of this embodiment also includes an optical waveguide chip 9 having an optical waveguide circuit of an arrayed waveguide type diffraction grating and a Peltier module, as in the conventional optical waveguide component shown in FIGS. It has a temperature control component 8. In this embodiment, the optical waveguide chip 9 and the temperature control component 8 are overlapped with each other, and the optical waveguide chip 9 and the optical waveguide chip 9 are bonded to each other by a bonding agent 7 interposed between the bonding face of the optical waveguide chip 9 and the bonding face of the temperature control component 8. It is characterized in that the temperature control component 8 is directly joined.

Also in the present embodiment, the configuration shown in FIG. 1 is accommodated in an appropriate package and modularized as needed. Further, in the present embodiment example, the temperature control component 8 is a Peltier module similar to the conventional example. The substrate 1 of the optical waveguide chip 9 has a thermal conductivity of 5
The substrate 1 is formed of single crystal silicon having a material of 0 W / (m · K) or more, and the thickness of the substrate 1 is 1 mm.

The thermal conductivity of silicon is 125.6 m.
W / (m · K), which is 100 times or more higher than the thermal conductivity value of 1.2 W / (m · K) of glass, and the thermal conductivity value of iron is 355. It is higher than 9 mW / (m · K) and the value of the thermal conductivity of solder 33.5 mW / (m · K).

The value of the thermal conductivity of silicon is 335.9 mW, which is the value of the thermal conductivity of copper used as the heat equalizing plate 12.
/ (M · K) and thermal conductivity of aluminum 234.5mW
Compared with / (m · K), it is about one-third. As described above, since the thermal conductivity of silicon is very good, using silicon as the substrate 1 is effective for keeping the temperature of the optical waveguide chip 9 substantially uniform.

The bonding agent 7 is a silicone RTV (silicone room temperature vulcanized rubber) which is an adhesive having elasticity as a main component and having silicone as a main component. The bonding agent 7 is a product name SE448 of Toray Dow Corning Co., Ltd.
6 and the thermal conductivity of this bonding agent 7 is 0.84 W /
(M · K), Young's modulus is 0.6 × 10 ⁷ Pa. Further, in the present embodiment, the average thickness of the bonding agent 7 is 0.33 mm, and the bonding agent 7 is provided on almost the entire area of the upper surface of the temperature control component 8.

In addition to this, as an application example of the bonding agent 7, for example, SE series (SE4 of Toray Dow Corning Co., Ltd.)
400, SE4410, SE4420, SE4422,
There are thermally conductive silicone RTVs such as SE4440, SE4450, SE9184). These thermal conductive RTV
Has a thermal conductivity of 0.75 W / (m · K)
1.05 W / (mK), a general silicone R
Thermal conductivity of TV (0.17W / (mK) ~ 0.33W
It is several times as large as / (m · K).

By the way, the temperature control component 8 applied to the optical waveguide component of the present embodiment is a Peltier module, and the Peltier module causes an endothermic reaction and an exothermic reaction by energizing the Peltier module as described above. I will get it. When the Peltier module is in operation, one of the upper substrate 23 and the lower substrate 24 serves as a heat absorption surface,
The opposite substrate serves as a heat generating surface.

Therefore, when the Peltier module is operated, the temperature difference between the upper substrate 23 and the lower substrate 24 changes significantly, and the upper substrate 23 and the lower substrate 24 warp due to the thermal contraction. Further, the amount of warpage is determined by the upper substrate 23 and the lower substrate 2
It changes with the temperature difference of 4.

For example, FIG. 5 shows the temperature dependence of the warp of the Peltier module. This figure shows the results of measuring the warp of the Peltier module with a surface roughness meter when the Peltier module is placed on the heat radiation fins and the surface temperature of the upper substrate 23 is energized by the temperature controller so as to reach the set temperature. is there. (A), (b) of FIG.
(C) shows the set temperatures of 0 ° C., 20 ° C.,
These are the measurement results when the temperature is 70 ° C., and the measurement lengths are all 14 mm.

As shown in FIG. 5A, when the surface temperature of the upper substrate 23 is 0 ° C., the concave shape is warped by about 2 μm, and as shown in FIG. 5C, the surface temperature of the upper substrate 23. Is 70
It can be seen that the convex shape warps by about 1 μm at a temperature of ℃.

This is because when the surface temperature of the upper substrate 23 is 0 ° C., the lower substrate 24 becomes high in temperature, so that the upper substrate 23 contracts and the lower substrate 24 expands due to thermal contraction, so that the concave substrate warps. When the surface temperature of the upper substrate 23 is 70 ° C., the lower substrate 24 becomes a low temperature.
Is expanded and the lower substrate 24 is contracted, so that it warps in a convex shape. Also, the difference in warp between 0 ° C and 70 ° C is about 3
μm.

The change in the warp also applies to the change in the warp when the surface temperature of the Peltier module is changed while the external atmosphere is kept constant (for example, room temperature). That is, for example, the upper substrate 23 of the Peltier module
When the outside temperature reaches 70 ° C. with the surface temperature of the substrate kept constant at 40 ° C., the surface of the upper substrate 23 of the Peltier module becomes a heat absorbing surface, so the temperature becomes lower than that of the lower substrate 24 which becomes a heat generating surface The concave shape is warped.

On the contrary, for example, when the outside temperature becomes 0 ° C. with the surface temperature of the upper substrate 23 of the Peltier module being constant at 40 ° C., the surface of the upper substrate 23 of the Peltier module becomes a heat generating surface. As a result, the temperature rises above the lower substrate 24, which is the heat absorbing surface, and the convex shape is warped.

When the optical waveguide chip 9 is attached to the Peltier module, if the Peltier module warps as described above, the warp is transmitted to the optical waveguide chip 9 and the optical waveguide chip 9 also warps. become.

Even when the temperature adjusting component 8 having a heater element is applied, a bimetal effect is generated due to the difference in thermal expansion coefficient between the temperature adjusting component 8 and the optical waveguide chip 9, and warpage occurs. .

Since the refractive index of the optical waveguide changes depending on the stress applied to the optical waveguide, when the optical waveguide chip 9 is warped, the following formula (2) is used even if the temperature of the optical waveguide chip 9 is kept constant. The refractive index n shown in () changes, and the wavelength λ shown in the equation (1) changes. Then, in the optical waveguide circuit such as the arrayed waveguide type diffraction grating in which the optical waveguide chip 9 is formed, the light transmission center wavelength of the light output from each optical output waveguide 6 changes.

N = C · σ (2)

In the equation (2), n is the refractive index of the optical waveguide, C is the photoelastic constant of the optical waveguide, and σ is the stress applied to the optical waveguide. Here, when the stress applied to the optical waveguide is a compressive stress, the value of σ becomes + (plus), and when the stress applied to the optical waveguide is a tensile stress, the value of σ becomes − (minus). Further, the value of the photoelastic constant C of the optical waveguide made of the silica glass material is a negative value.

Therefore, when compressive stress is applied to the optical waveguide, the refractive index of the optical waveguide decreases from the relationship shown in the equation (2), and the light transmission center wavelength in the equation becomes short wavelength side from the relationship shown in the equation (1). Shift to. On the contrary, when a tensile stress is applied to the optical waveguide, the refractive index of the optical waveguide increases from the relationship shown in equation (2), and the optical transmission center wavelength is
It shifts to the long wavelength side from the relationship shown in Expression (1).

As described above, the fact that the optical transmission center wavelength of the optical waveguide chip 9 changes due to the influence of the warp of the temperature control component 8 poses a problem in practical use. The person paid attention to the property of the bonding agent 7 of the heat conductive silicone RTV as a rubber.

Then, an optical waveguide circuit of an arrayed waveguide type diffraction grating having a function of multiplexing / demultiplexing light at 16 dh at 100 GHz intervals is formed on the optical waveguide chip 9, and the thickness t of the bonding agent 7 shown in FIG. As shown in Figure 3, 0 to 0.5m
The variation of the central wavelength of the light transmission of the arrayed waveguide type diffraction grating when it was changed to m was obtained. This examination was performed while controlling the temperature of the optical waveguide chip 9 to 40 ° C. while changing the environmental temperature from 20 ° C. to 70 ° C. The characteristic line a in FIG. 3 indicates a regression curve expected from the experimental results, and the broken lines on both sides of the characteristic line a indicate the range of variation.

As a result, as shown in FIG. 3, as the thickness of the bonding agent 7 increases, the absolute value of the fluctuation amount of the light transmission center wavelength decreases, and when the thickness of the bonding agent 7 is 0.33 mm, the light The variation of the transmission center wavelength became zero. Therefore, in the present embodiment, as described above, the thickness of the bonding agent 7 is set to 0.33.
mm.

If the thickness of the bonding agent 7 is too large, the thermal conductivity from the temperature control component 8 to the optical waveguide chip 9 deteriorates, and the temperature of the optical waveguide chip 9 cannot be controlled to a desired temperature. Therefore, it is considered that the center wavelength of light transmission is shifted to the long wavelength side.

The example of the present embodiment is configured as described above, and the optical waveguide chip 9 and the temperature control component 8 are bonded by the bonding agent 7.
Via the heat soaking plate 12, the optical waveguide chip 9 and the temperature adjusting component 8 are directly connected to each other through the soaking plate.
As in the conventional example of joining and, it is possible to suppress the thickness of the optical waveguide component from increasing, and it is possible to suppress an increase in power consumption during temperature control and an increase in the cost of the optical waveguide component, The temperature of the optical waveguide chip 9 can be accurately controlled by the temperature adjusting component 8.

The optical waveguide component of this embodiment is shown in FIG.
When it is housed in a package 20 as shown in Fig. 8 and modularized, its thickness (thickness of a portion corresponding to A in Fig. 8)
Is 8.5 mm or less.

Further, in this embodiment, the bonding agent 7 is formed of highly elastic heat conductive silicone RTV, and the thickness thereof is accurately determined based on the examination result shown in FIG. It is possible to suppress the waveguide chip 9 from being affected by the warp of the temperature control component 8 and set the light transmission center wavelength of the optical waveguide chip 9 to the set wavelength.

Further, in this embodiment, the bonding agent 7 is formed of the adhesive of the heat conductive silicone RTV, so that the optical waveguide chip 9, the heat equalizing plate 12 and the temperature can be controlled by the silicone oil compound as in the conventional case. It is possible to prevent the optical waveguide chip 9 and the temperature adjusting component 8 from being peeled off or displaced from each other as in the case where the adjusting component 8 is joined, and a stable operation can be realized.

It should be noted that the present invention is not limited to the above-mentioned embodiments, but can take various modes. For example,
In the above embodiment, the bonding agent 7 is SE4486 manufactured by Toray Dow Corning Co., Ltd. However, the bonding agent 7 may be various silicone RTV such as SE series manufactured by Toray Dow Corning Co., Ltd. described above. You can

The bonding agent 7 may be a bonding agent other than silicone RTV, and has a thermal conductivity of 0.4 W /
By using the bonding agent of (m · K) or more, it is possible to favorably control the temperature of the optical waveguide chip 9 by the temperature control component 8. The Young's modulus of the bonding agent 7 is 2.0.
As long as it has a configuration of × 10 ⁷ Pa or less, the influence of the warpage of the temperature control component 8 can be suppressed by appropriately setting the thickness of the bonding agent 7 as in the above-described embodiment.
It is suitable.

Further, it is preferable that the bonding agent 7 is composed of an adhesive containing silicone as a main component because it is possible to prevent the optical waveguide chip 9 and the temperature control component 8 from being displaced and peeled off. .

Further, in the above embodiment, the average thickness of the bonding agent 7 is about 0.33 mm, but the average thickness of the bonding agent 7 is not always about 0.33 mm. For example, by applying the bonding agent 7 applied to the above-described embodiment and setting the average thickness of the bonding agent 7 to 0.1 mm or more, the fluctuation amount of the optical transmission center wavelength of the arrayed waveguide diffraction grating is 0.05 nm. You can: In this way, the thickness of the bonding agent 7 is set appropriately.

Further, in the above embodiment, the bonding agent 7 is provided on almost the entire area of the upper surface of the temperature adjusting component 8. However, even if the area where the bonding agent 7 is disposed is smaller than the area of the upper surface of the temperature adjusting component 8. It may be large or large, and may be provided in the entire region of the optical waveguide chip 9 on the substrate 1 side.

Further, the bonding agent 7 may be a silicone compound. When the bonding agent 7 is a silicone compound, for example, as shown in FIG. 4A, if an adhesive 27 for fixing the optical waveguide chip 9 and the temperature adjusting component 8 is provided, the optical waveguide chip 9 and the temperature adjusting member 8 can be adjusted. The position of the component 8 can be fixed, and stable operation can be realized.

In this case, the fixing adhesive 27 is
By using an adhesive having elasticity like the bonding agent 7 applied in the above-described embodiment example, it is possible to suppress the warp of the temperature control component 8 from being transmitted to the optical waveguide chip 9, and the same effect as in the above-described embodiment example. Can be played.

Further, although the optical waveguide chip 9 is the arrayed waveguide type diffraction grating chip in the above embodiment, the optical waveguide chip 9 is not limited to the arrayed waveguide type diffraction grating chip and may be set appropriately. The present invention can be formed by applying an optical waveguide chip 9 having an optical waveguide circuit whose light transmission characteristics change depending on temperature, such as an optical waveguide circuit using a well-known Mach-Zehnder circuit. .

In FIG. 4B, an example of the Mach-Zehnder circuit is shown in a plan view. As shown in this figure, the Mach-Zehnder circuit has, for example, two optical waveguides 14 and 15 arranged side by side. A plurality of directional coupling portions 16 and 17 which are provided to bring the optical waveguides 14 and 15 close to each other.
5 are formed at intervals in the longitudinal direction.

Further, in the above embodiment, the temperature adjusting component 8 is joined to the substrate 1 side of the optical waveguide chip 9, but the temperature adjusting component 8 may be joined to the optical waveguide circuit forming region side of the optical waveguide chip 9. Good.

Further, in the above embodiment, the substrate 1 of the optical waveguide chip 9 is made of silicon.
The substrate 1 may be a substrate other than silicon. However, the substrate 1 is made of silicon or the like and has a thermal conductivity of 50 W / (m ·
K) When formed of the above materials, when the temperature adjusting component 8 is provided on the substrate 1 side as in the above embodiment, the temperature controlling of the optical waveguide chip 9 by the temperature adjusting component 8 can be more favorably performed. .

Further, in the above embodiment, the temperature control component 8 is a Peltier module, but the temperature control component 8 applied to the present invention is not particularly limited and may be appropriately set, such as a heater element. It may be configured to have.

[0075]

According to the present invention, since the optical waveguide chip and the temperature control component are directly bonded via the bonding agent, when the optical waveguide chip and the temperature control component are bonded via the heat equalizing plate. As described above, it is possible to suppress the thickness of the optical waveguide component from increasing, the power consumption during the temperature control to increase, and the optical waveguide component from becoming expensive.

In the present invention, if the bonding agent has a thermal conductivity of 0.4 W / (m · K) or more, the thermal conductivity between the temperature control component and the optical waveguide chip can be improved, The temperature of the optical waveguide chip can be controlled very well by the temperature control component.

Further, in the present invention, when the bonding agent has a Young's modulus of 2.0 × 10 ⁷ Pa or less, even if the temperature control component warps during operation, the warp affects the optical waveguide chip. Can be suppressed.

Further, in the present invention, when the bonding agent is an adhesive containing silicone as a main component, the positional deviation between the temperature control component and the optical waveguide chip can be suppressed and the temperature control component and the optical waveguide chip can be suppressed. Since the heat conduction with the chip can be made good, the temperature control of the optical waveguide chip by the temperature adjusting component can be more excellently performed.

Further, in the present invention, when the average thickness of the bonding agent is 0.1 mm or more, even if the temperature control component warps during operation, the warp affects the optical waveguide chip. Can be suppressed more reliably, and fluctuations in the specific value of the optical waveguide circuit of the optical waveguide chip can be suppressed.

Further, in the present invention, according to the constitution in which the temperature adjusting component is formed by having the Peltier element or the heater element, the temperature adjusting component can be constituted by using a small element, and a good temperature adjusting operation can be achieved. Can be done.

Further, according to the present invention, the substrate of the optical waveguide chip is made of a material having a thermal conductivity of 50 W / (m · K) or more, so that the temperature adjusting component is provided on the substrate side of the optical waveguide chip. By providing it, heat conduction between the temperature control component and the optical waveguide chip can be performed well.

Further, in the present invention, according to the structure in which the substrate of the optical waveguide chip is made of silicon, by providing the temperature adjusting component on the substrate side of the optical waveguide chip, heat conduction between the temperature adjusting component and the optical waveguide chip can be achieved. It can be performed favorably, and the optical waveguide chip can be easily formed using the silicon substrate.

Further, according to the present invention, the optical waveguide circuit of the optical waveguide chip is the optical waveguide circuit of the arrayed waveguide type diffraction grating, so that the light transmission center wavelength of the arrayed waveguide type diffraction grating does not depend on the temperature. An optical waveguide component that can be kept constant and suitable for wavelength division multiplexing transmission can be realized.

[Brief description of drawings]

FIG. 1 is a configuration diagram of essential parts showing an embodiment of an optical waveguide component according to the present invention.

FIG. 2 is an explanatory diagram schematically showing the manufacturing method according to the embodiment.

FIG. 3 is a graph showing the relationship between the thickness of a bonding agent interposed between the optical waveguide chip and the temperature control component and the fluctuation of the light transmission center wavelength of the optical waveguide chip.

FIG. 4 is a configuration diagram (a) of a main part showing another embodiment of the optical waveguide component according to the present invention, and an optical waveguide circuit example applied to another embodiment of the optical waveguide component according to the present invention. It is a plane explanatory view (b).

FIG. 5 is an explanatory diagram showing a warped state depending on the temperature of the Peltier module.

FIG. 6 is an explanatory diagram showing an arrayed waveguide type diffraction grating.

FIG. 7 is an explanatory view showing a conventional optical waveguide component in an exploded state.

FIG. 8 is a cross-sectional view showing a conventional optical waveguide component.

[Explanation of symbols]

1 substrate 2 Optical input waveguide 3 First slab waveguide 4 Array waveguide 4a channel waveguide 5 Second slab waveguide 6 Optical output waveguide 7 Bonding agent 8 Temperature control parts 9 Optical waveguide chip

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tomohiro Watanabe             2-6-1, Marunouchi, Chiyoda-ku, Tokyo             Kawa Electric Industry Co., Ltd. (72) Inventor Toshihiko Ota             2-6-1, Marunouchi, Chiyoda-ku, Tokyo             Kawa Electric Industry Co., Ltd. F term (reference) 2H047 KA03 KA12 LA19 MA05 QA07                       TA11

Claims (9)

[Claims] 1. An optical waveguide chip having an optical waveguide circuit whose light transmission characteristics change depending on temperature, formed on a substrate, and a temperature adjusting component for the optical waveguide chip. An optical waveguide characterized in that the optical waveguide chip and the temperature control component are directly bonded to each other with a bonding agent interposed between the waveguide chip and the bonding face of the optical waveguide chip and the bonding face of the temperature control component. Waveguide component. 2. The bonding agent has a thermal conductivity of 0.4 W / (m.multidot.m).
K) or more, The optical waveguide component of Claim 1 characterized by the above-mentioned. 3. The bonding agent has a Young's modulus of 2.0 × 10 ⁷ Pa.
The optical waveguide component according to claim 1 or 2, wherein: 4. The optical waveguide component according to claim 1, wherein the bonding agent is an adhesive containing silicone as a main component. 5. The optical waveguide component according to any one of claims 1 to 4, wherein the bonding agent has an average thickness of 0.1 mm or more. 6. The optical waveguide component according to claim 1, wherein the temperature control component is formed to have a Peltier element or a heater element. 7. The substrate of the optical waveguide chip has a thermal conductivity of 50.
The optical waveguide component according to any one of claims 1 to 6, which is formed of a material having a W / (m · K) or more. 8. The optical waveguide component according to claim 7, wherein the substrate of the optical waveguide chip is silicon. 9. The optical waveguide circuit of the optical waveguide chip comprises one or more optical input waveguides, a first slab waveguide connected to the emission side of the optical input waveguides, and the first slab waveguide. An arrayed waveguide connected to the output side of the waveguide, the arrayed waveguide including a plurality of channel waveguides arranged in parallel and having different set amounts from each other; a second slab waveguide connected to the output side of the arrayed waveguide; 9. An optical waveguide circuit of an arrayed waveguide type diffraction grating having a plurality of optical output waveguides connected in parallel on the emission side of the second slab waveguide. The optical waveguide component described in one.