JPH0850218A - Waveguide type optical module - Google Patents

Abstract

PURPOSE:To obviate degradation in reliability against a temp. change and humidity change by fixing planar reinforcing members onto both fiber blocks so as to cross a waveguide substrate. CONSTITUTION:Both incident and exit end faces of the waveguide substrate 20 are optically polished. Both end faces are adhered and fixed by UV curing type adhesives after a single core fiber block 21 and 16-core fiber block 22 of optical polishing agents are optically adjusted. Further, the reinforcing plates 23, 24 as reinforcing materials are adhered and fixed on both of front and rear faces by the UV curing type adhesives so as to cross the waveguide substrate 20, by which a module is formed. The coeffts. of linear expansion of the reinforcing plates 23, 24 fixed to cross the waveguide substrate 20 are confined to >=0.1 times and within 10 times of the coefft. of thermal expansion of the waveguide substrate 20. As a result, tensile and compressive stresses are applied on the module from the adhered parts even if the temp. change arises in the case of adhesion of the reinforcing plates 23, 24 by the adhesives. Increasing of the insertion loss and peeling of the adhered parts of the optical axis is obviated without bending of the module even if the stresses are not symmetrical with the cross-section of the module.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waveguide type optical module, and more particularly to a waveguide type optical module which can obtain good optical characteristics against temperature changes.

[0002]

2. Description of the Related Art In recent years, optical communication technology has advanced, and the demand for optical modules composed of optical branching elements, optical multiplexers / demultiplexers, etc. is increasing. Along with this, high reliability and economical efficiency are required for the waveguide type optical module.

In the waveguide type optical module, a cylindrical waveguide substrate holding block (Japanese Patent Laid-Open No. 4-212113, Japanese Laid-Open Patent Publication No. 5-213113).
-113517), a "U" -shaped holding block (JP-A-5-27139), and a holding plate 2 of the same size on the front surface (or back surface) of the waveguide substrate 1 as shown in FIG. After accommodating the waveguide substrate 1 in another block, for example, by laminating, the end faces are polished and connected to the optical fibers (arrays) 3 and 4. In addition, 5 is a single-core optical fiber, 6
Is a 4-core optical fiber.

The reason why the waveguide substrate is housed in the holding block in this way is as follows.

(1) The cross-sectional dimensions of the waveguide substrate are as small as several mm in width and 1 to 2 mm in thickness, and the core is formed in a flat shape at a depth of several tens of μm below the surface of the substrate, which facilitates handling. To prevent damage to the core.

(2) Since the substrate has a small cross-sectional area, it is housed in a holding block to increase the cross-sectional area so as to secure sufficient adhesive strength with the optical fiber block.

(3) Since the core is formed several tens of μm below the surface of the substrate, the substrate alone is located at the edge portion with respect to the cross section. For this reason, the core end surface is convexly curved (hereinafter referred to as "convex polishing") during mirror polishing using a buff cloth or the like, which causes an increase in connection loss when connecting to an optical fiber. Therefore, the holding block is fixed to the surface of the substrate with an adhesive and collectively polished to prevent the core from being curved.

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

In the figure, the single-core optical fiber 1 on the incident side is shown.
An incident side fiber array 11 to which 0 is connected and a waveguide element 12 that divides incident light into four by using Y branch and emits the light are fixed with a UV adhesive in a state where the optical axes are aligned. 12 output side and output side 4 core tape fiber 1
An optical unit 15 is configured by fixing the output side fiber array 14 to which 3 is connected with a UV adhesive in a state where the optical axes are aligned. This optical unit 15
In this case, when used in a high-temperature and high-humidity atmosphere, the adhesive absorbs water and the joint strength of the joint between the single-core optical fiber 10, the 4-core tape fiber 13 and the optical waveguide of the waveguide element 12 decreases. Therefore, the optical unit is housed in the housings 16 and 17 made of plastic or metal and having recesses therein, and the bottom surface of the optical unit 15 and the housing 17 are adhesively fixed and fixed with an adhesive from above and below. Integrated,
It is hermetically sealed.

There is also an optical module in which only a part of the waveguide element is directly connected to the metal case (Japanese Patent Laid-Open No. 63-20).
5617).

[0011]

However, the waveguide type optical module shown in FIG. 8 has the following problems.

1) When the waveguide substrate and the holding block are fixed by an adhesive, a quality assurance test such as temperature cycle, high temperature, high humidity, etc., shows that a part of the adhesive surface may peel off. When this peeling progresses and spreads to the end face of the substrate, the orthogonal optical coupling surface is peeled off, which causes a serious failure such as an increase in insertion loss of the optical module and a reduction in reflection attenuation.

2) This is a phenomenon observed in a cylindrical or "U" -shaped glass holding block. When a temperature cycle test is performed on an optical module, cracks may be generated at the corners inside the holding block. There is. If the crack reaches the end face of the waveguide substrate, it may cause a serious failure of the optical module as in the above item 1).

3) If the holding block is bonded to the surface of the waveguide substrate with an adhesive having a relatively high elastic modulus, the optical multiplexing / demultiplexing and optical multiplexing / branching characteristics of the optical circuit change due to the contracting stress when the adhesive is cured. This tendency is particularly remarkable in the MZ (Mach-Zehnder) type optical coupling / branching circuit.

4) The price of each holding block varies depending on the shape, the material and the number of manufactured products, but in any case, it becomes a factor of increasing the assembly cost.

Further, in the waveguide type optical module shown in FIG. 9, stress is applied to the optical unit when the constituent metal blocks and the plastic constituting the housing are expanded and contracted due to changes in ambient temperature. However, there is a problem that loss of the optical unit and loss variation due to temperature change become large.

Therefore, an object of the present invention is to solve the above problems and to provide a waveguide type optical module in which reliability is not deteriorated even with changes in temperature and humidity.

[0018]

In order to achieve the above object, the present invention provides a waveguide in which one optical fiber and a plurality of optical fibers are coupled to an input / output end face of a waveguide substrate through fiber blocks. In this optical module, a plate-shaped reinforcing member is fixed on both fiber blocks so as to straddle the waveguide substrate.

In addition to the above structure, the present invention is such that the linear expansion coefficient of the reinforcing member is 0.1 times or more and 10 times or less the linear expansion coefficient of the waveguide substrate and the optical fiber.

According to the present invention, in addition to the above-mentioned constitution, the elastic modulus after curing of the adhesive for fixing the reinforcing member is 100 kg / mm.
^{It is} less than ² .

The present invention provides a waveguide type optical module comprising an optical unit composed of an optical fiber and a waveguide element connected to the optical fiber, and an enclosing member enclosing the optical unit. A pedestal is interposed between the unit and the lower part.

In the present invention, in addition to the above structure, the pedestal is fixed between the surrounding member and the optical unit with an adhesive.

According to the present invention, in addition to the above structure, the pedestal is made of an elastic member, and a reinforcing member made of an elastic member is interposed between the upper portion of the optical unit and the inner surface of the surrounding member.

In the present invention, in addition to the above constitution, the material of the pedestal is
It is equal to or less than the linear expansion coefficient of the waveguide element.

According to the present invention, in addition to the above structure, the pedestal is arranged inside the joint surface between the waveguide element and the optical fiber.

According to the present invention, in addition to the above-mentioned structure, the contact surface between the pedestal and the optical unit and / or the contact surface with the surrounding member is provided with irregularities.

[0027]

According to the above structure, when the linear expansion coefficient of the reinforcing member fixed across the waveguide substrate is 0.1 times or more and 10 times or less that of the waveguide substrate, the reinforcing member is bonded with the adhesive. In this case, even if a temperature change such as a temperature cycle test occurs, tensile or compression stress is applied to the module from the adhesive part,
Even if the stress is not symmetrical with respect to the cross section of the module, the module will not be bent, and the insertion loss will not increase and the optical axis bonded portion will not be peeled off.

The elastic modulus of the reinforcing member adhesive after curing is 100.
If it is less than Kg / mm ² , even if a temperature change such as a temperature cycle test occurs, the stress in the adhesive layer of the reinforcing member is often relieved, the module is bent, the insertion loss is increased, and the optical axis is increased. No peeling of the adhesive part occurs.

By interposing a pedestal between the inner surface of the surrounding member and the lower portion of the optical unit, even if thermal expansion and contraction occurs in the surrounding member, it does not propagate to the optical unit, so that the thermal expansion of the surrounding member occurs. Deformation and destruction of the waveguide element due to contraction and increase in loss are eliminated.

Since the pedestal is fixed between the enclosing member and the optical unit with an adhesive, the optical unit is resistant to mechanical vibration and impact, and the intervention of the pedestal causes deformation or destruction of the waveguide element, The loss increase can also be kept low.

Since the pedestal is made of an elastic member and the elastic member is interposed between the upper portion of the optical unit and the inner surface of the surrounding member, the optical unit is resistant to vibration and impact,
In addition, since the thermal expansion and contraction of the surrounding member is not directly transmitted to the optical unit, it is possible to eliminate the deformation and destruction of the waveguide element and the increase in loss.

Since the material of the pedestal is equal to or less than the linear expansion coefficient of the waveguide element, it is possible to prevent the waveguide element from being affected by thermal expansion and thermal contraction of the pedestal.

Since the pedestal is arranged inside the joint surface between the waveguide element and the optical fiber, stress on the optical unit due to thermal expansion and contraction of the surrounding member is not applied to the joint surface between the waveguide element and the fiber array. It is possible to suppress an increase in loss due to axis deviation of the joint surface and peeling.

Since the contact surface of the pedestal with the optical unit and / or the contact surface with the enclosing member is made uneven and fixed by adhesion, the contact portion between the waveguide element and the enclosing member is reduced, so that the heat of the enclosing member is reduced. It is possible to suppress the deformation and breakage of the waveguide element and the increase in loss due to the expansion thermal contraction.

[0035]

An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a conceptual diagram of one embodiment of the waveguide type optical module of the present invention.

In the figure, 20 is a width of about 5 mm and a length of about 5
This is a single waveguide substrate in which a 2 × 16 branch waveguide is formed on a quartz substrate having a thickness of 0 mm and a thickness of about 2 mm. The waveguide substrate 20 has its both input and output end faces optically polished, and both end faces have optical-polished single-core fiber blocks 21 and 1.
After the optical axis of the 6-core fiber block 22 is adjusted, it is adhesively fixed with a commercially available UV (ultraviolet) curable adhesive.
However, in order to prevent the convex surface from being polished by the buff cloth, substrate polishing is performed not with a single body but with a dummy plate overlaid on the substrate surface.

Further, reinforcing plates 23 and 24 as a reinforcing member having a width of about 5 mm, a length of about 65 mm and a thickness of about 1 mm are bonded and fixed to the upper and lower surfaces with a UV curable adhesive so as to straddle the waveguide substrate 20. It is modular. The UV-curable adhesive may have an elastic modulus after curing of about 50 kg / mm ² . Thereafter, this module is put into a metal PKG (package) (or a plastic elastic body PKG, neither of which is shown) to obtain a final form. In addition,
Reference numeral 25 represents a single-core optical fiber, and 26 represents a 16-core optical fiber.

Next, the operation of the embodiment will be described.

The linear expansion coefficient of the reinforcing plates 23 and 24 fixed across the waveguide substrate 20 is 0.1 of that of the waveguide substrate 20.
When the reinforcing plates 23 and 24 are bonded with an adhesive in the case of 10 times or more and 10 times or less, even if a temperature change such as a temperature cycle test occurs, tensile or compressive stress is applied to the module from the bonded portion, Even if the stress is not symmetrical with respect to the cross section of the module, the module is not bent, and the insertion loss does not increase and the optical axis bonded portion does not separate.

When the elastic modulus of the adhesive for fixing the reinforcing plates 23 and 24 after curing is less than 100 Kg / mm ² , the reinforcing plate adhesive layer can be formed even if a temperature change such as a temperature cycle test occurs. Since the stress of 1 is relaxed, the module is not bent, the insertion loss is not increased, and the optical axis adhesive portion is not peeled off.

FIG. 2 is a diagram showing the relationship between the insertion loss and the temperature characteristic of the waveguide type optical module shown in FIG. 1 and the waveguide type optical module shown in FIG. 8, respectively, and FIG. 2 is an insertion loss characteristic at the # 1 port of the waveguide type optical module shown in FIG. 1, and FIG. 2B is an insertion loss characteristic at the # 16 port of the waveguide type optical module shown in FIG.
FIG. 2C is an insertion loss characteristic at the # 1 port of the waveguide type optical module shown in FIG. 8, and FIG. 2D is an insertion loss characteristic at the # 16 port of the waveguide type optical module shown in FIG. (E) is a figure which shows the relationship between time and a temperature change.

The conventional waveguide type optical module shown in FIG. 8 has a modulus of elasticity of 240 kg / mm after being cured on the surface of the waveguide substrate.
^This is a product obtained by bonding a quartz plate of the same size as the substrate with the UV curable adhesive of item 2. In the conventional waveguide type optical module, the curing shrinkage force of the adhesive remains in the core through the clad film with a thickness of several tens of μm on the surface of the substrate, which is increased on the high temperature side and further increased on the low temperature side by the temperature cycle. It will be.

Since the 2 × 2 coupling / branching portion on the incident side of the waveguide substrate is of the MZ type, the branching ratio changes sensitively to stress. Therefore, the conventional waveguide type optical module is shown in FIG. As shown in FIG. 2D, the # 1 port and the # 16 port exhibit a large forward and reverse ± 1.5 dB insertion loss. On the other hand, the waveguide type optical module of the present embodiment exhibits good loss and temperature characteristics within ± 0.2 dB.

As described above, the present embodiment is characterized in that the holding block and the like are not bonded and fixed to the outer surface other than the end faces of the substrate before the optical fiber is coupled to the both input and output end faces of the waveguide substrate. This eliminates the deterioration of the optical multiplexing / demultiplexing and the optical multiplexing / branching characteristics, the insertion loss due to the peeling of the adhesive at the connection portion with the optical fiber, and the deterioration of the reflection attenuation characteristics.

Further, as described above, in the case where the strength of the module remains unsatisfactory when the end face is bonded only to the waveguide substrate, a reinforcing plate or the like is attached so as to cross the waveguide substrate by avoiding the surface portion of the waveguide substrate as much as possible. If fixed by
Higher module strength can be achieved. It is desirable that the reinforcing plate used in this case has a linear expansion coefficient close to that of the waveguide substrate and the optical fiber block, and when the reinforcing plate is bonded, the Young's modulus after curing of the adhesive is low.

Although the reinforcing plate is adhered to the back surface of the waveguide substrate in the embodiment shown in FIG. 1, the adhering portion is not limited to this, and the side surface of the substrate may be used.

FIG. 3 is a conceptual view of another embodiment of the waveguide type optical module of the present invention.

The incident side fiber array 31 to which the incident side single-core optical fiber 30 is connected and the incident side of the waveguide element 32 which divides the incident light into four by using the Y-branch and outputs the light are aligned. Is fixed with a UV adhesive in the closed state, and the 4-side tape fiber 3 on the emission side of the waveguide element 32 and on the emission side
An optical unit 35 is formed by fixing the output side fiber array 34 to which 3 is connected with a UV adhesive in a state where the optical axes are aligned.

When this optical unit 35 is used in a high temperature and high humidity atmosphere, the adhesive absorbs moisture to form the single core optical fiber 30, the four core tape fiber 33 and the optical waveguide of the waveguide element 32. Since the joint strength of the joint portion is reduced, the pedestals 36 and 37 are adhered to the bottom surface of the waveguide element 32, and the optical unit 35 is provided inside the casing 38 as an enclosure member.
The housing 36 is housed, the pedestals 36 and 37 and the housing 38 are bonded and fixed, and both ends of the housing 38 are hermetically sealed by the lids 39 to package the single core optical fiber 30 and the four core tape fiber 33. It is reinforced with a rubber tube 40 to prevent it.

The pedestals 36 and 37 are arranged so that the linear expansion coefficient of the pedestals 36 and 37 matches the linear expansion coefficient of the waveguide element 32.
It is desirable that the same material as that of No. 2 be used and that the casing 38 be made of Invar having a low linear expansion coefficient.

Next, the waveguide type optical module will be described with reference to numerical values, but the present invention is not limited to this.

In the waveguide type optical module of the embodiment, a single core incident side fiber array 31 having a length of about 10 mm is UV-bonded to the incident side of a quartz waveguide having a length of about 50 mm, a width of about 10 mm and a thickness of about 4 mm. And a 4-core output side fiber array 34 is attached to the output side with a UV adhesive, and a pedestal 36 having a length of about 10 mm, a width of about 10 mm, and a thickness of about 1 mm is attached to the bottom surface of the waveguide element 32 made of quartz. , 37, two optical units 35, which are bonded and fixed with UV adhesive at positions equidistant from the center
About 90 mm in length, about 12 mm in width, about 12 mm in height,
Stored in a metal casing 38 having a thickness of about 0.5 mm,
The pedestals 36 and 37 and the metal casing 38 were fixed with a thermosetting epoxy adhesive, the both ends were covered with lids 39, and airtightly sealed with the thermosetting epoxy adhesive.

Comparative Example A waveguide type optical module according to the conventional method was manufactured as follows.

Length about 50 mm, width about 10 mm, thickness about 4
An optical unit formed by adhering a single-core fiber array having a length of about 10 mm to a quartz waveguide made of mm with a UV adhesive and adhering a 4-core optical fiber array to an emission side with a UV adhesive. Is about 90 mm long and about 15 m wide
m, a height of about 15 mm, and a thickness of about 0.5 mm are housed in a metal housing, the bottom surface of the waveguide and the metal housing are fixed with a thermosetting epoxy adhesive, both ends are covered with a thermosetting epoxy. It was hermetically sealed with an adhesive.

5 to 7 show the results of measuring the temperature characteristics of the waveguide type optical module shown in FIG.

FIG. 5A shows the temperature characteristic measurement result of the waveguide type optical module manufactured by the conventional method, and FIG. 5B shows FIG.
5C shows the temperature characteristic measurement results of the waveguide type optical module shown in FIG. 5, and FIG. 5C shows the temperature change during the temperature characteristic measurement. 5A to 5C, the horizontal axis represents time (s), the vertical axis in FIGS. 5A and 5B represents loss fluctuation, and the vertical axis in FIG. 5C represents temperature change. Shown respectively.

From FIG. 5B, it is understood that the waveguide type optical module of the present embodiment has a smaller loss fluctuation width than the waveguide type optical module according to the conventional method.

FIG. 6 is a diagram showing the relationship between the linear expansion coefficient of the pedestal and the temperature characteristic in the waveguide type optical module shown in FIG. FIG. 6A shows the coefficient of linear expansion of the pedestal as α = 0.44.
× 10 ⁻⁶ , FIG. 6B shows the coefficient of linear expansion of the pedestal α = 0.5.
5 × 10 ⁻⁶ , FIG. 6C shows the coefficient of linear expansion of the pedestal α = 1.
The value is 0 × 10 ⁻⁶ , the horizontal axis represents time, and the vertical axis represents loss fluctuation. FIG. 6D shows the temperature change at that time.

From FIGS. 6 (a) to 6 (d), it is understood that the material of the pedestal has a small loss fluctuation range when the linear expansion coefficient is equal to or less than that of the optical unit.

FIG. 7 is a diagram showing the relationship between the pedestal spacing and temperature characteristics in the waveguide type optical module shown in FIG. 7A shows a pedestal interval of 5 mm, FIG. 7B shows a pedestal interval of 10 mm, and FIG. 7C shows a pedestal interval of 30 m.
The horizontal axis represents time, the vertical axis represents loss fluctuation, and FIG. 7D shows the temperature change at that time.

From FIGS. 7 (a) to 7 (d), it can be seen that the width of loss fluctuation becomes smaller by narrowing the pedestal interval. However, if the pedestal spacing is made narrower, the impact on the waveguide type optical module will increase the amount of moment applied to both ends, which may destroy the waveguide element. 5mm-25m
Adhesion between m is desirable.

FIG. 4 is a sectional view showing another embodiment of the waveguide type optical module of the present invention.

In the figure, the incident light is divided into four beams by using the Y branch.
The incident-side fiber array 31 of the waveguide element 32, which is divided and emitted, and the single-core optical fiber 30 are fixed with a UV adhesive in a state where the optical axes are aligned. An optical unit 35 is formed by fixing a core tape fiber 33 and an emission side fiber array 34 with a UV adhesive in a state where their optical axes are aligned with each other.

The optical unit 35 is placed on the pedestals 36 and 37 which are made of plastic (or metal) and fixed inside a housing 38 having a concave portion inside, and further pressed down by elastic bodies 41 and 42. It is hermetically sealed by attaching it and integrating it in the vertical direction. At this time, since the optical unit 35 of the waveguide type optical module 43 is supported by the pedestals 36 and 37 and the elastic bodies 41 and 42, which are elastic materials, from above and below, No stress is directly transmitted to the waveguide element 32, so that the optical unit 35 is prevented from being deformed, destroyed, or increased in loss.

[0066]

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

(1) Peeling of the optical axis joint caused by peeling of the holding plate adhered to the surface of the waveguide substrate, that is, deterioration of the reflection attenuation characteristic of the module and increase of insertion loss are eliminated, and temperature change and humidity change are prevented. A waveguide type optical module whose reliability is not deteriorated can be obtained.

(2) There is no change in the optical coupling / splitting characteristic due to temperature, and a waveguide type optical module with good insertion loss and temperature characteristics can be obtained.

(3) Since the number of parts and the number of assembling steps are reduced, the cost and weight of the waveguide type module can be easily reduced.

(4) At least one pedestal having a linear expansion coefficient equal to or less than that of the optical unit is used.
By bonding the optical unit to the bottom surface of the optical unit and further bonding the pedestal and the housing to prevent the optical unit and the housing from directly contacting each other, deformation of the optical unit due to distortion of the housing, destruction, It is possible to prevent an increase in loss.

(5) The optical unit is placed on a pedestal, which is an elastic material, in a housing made of plastic or metal and having a recess therein, and is further pressed down by an elastic material to be integrated in the vertical direction. By tightly sealing,
Even if the housing is thermally expanded or contracted due to temperature change, stress is not directly transmitted to the waveguide element, resulting in deformation or destruction of the optical unit.
It is possible to prevent an increase in loss.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of an embodiment of a waveguide type optical module of the present invention.

2 is a waveguide type optical module shown in FIG. 1 and FIG.
FIG. 6 is a diagram showing a relationship between insertion loss and temperature characteristics of the waveguide type optical module shown in FIG.

FIG. 3 is a conceptual diagram of another embodiment of the waveguide type optical module of the present invention.

FIG. 4 is a cross-sectional view showing another embodiment of the waveguide type optical module of the present invention.

5 is a waveguide type optical module shown in FIG. 3 and FIG.
FIG. 7 is a diagram showing temperature characteristic results of the waveguide type optical module shown in FIG.

6 is a diagram showing a relationship between a linear expansion coefficient of a pedestal and temperature characteristics in the waveguide type optical module shown in FIG.

7 is a diagram showing a relationship between pedestal intervals and temperature characteristics in the waveguide type optical module shown in FIG.

FIG. 8 is a conventional example of a waveguide type optical module.

FIG. 9 is another conventional example of a waveguide type optical module.

[Explanation of symbols]

 20 Waveguide Substrate 21 Incident Side Fiber Block (Fiber Block) 22 Output Side Fiber Block (Fiber Block) 23, 24 Reinforcing Member (Reinforcing Plate) 25 Single-Core Optical Fiber (Optical Fiber) 26 16-Core Optical Fiber (Optical Fiber)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takayuki Kamoi 5-1-1 Hidaka-cho, Hitachi-shi, Ibaraki Hitachi Cable Company, Ltd., Optro System Laboratories (72) Inventor Ryuta Takahashi Hidaka-cho, Hitachi-shi, Ibaraki 5-1-1, Hitachi Cable Ltd., Optoro System Laboratories

Claims (9)

[Claims] 1. A waveguide type optical module in which a single optical fiber and a plurality of optical fibers are coupled to an input / output end face of a waveguide substrate via fiber blocks, respectively, and both fibers are provided so as to straddle the waveguide substrate. A waveguide type optical module in which a plate-shaped reinforcing member is fixed on a block. 2. The waveguide type optical module according to claim 1, wherein the linear expansion coefficient of the reinforcing member is 0.1 times or more and 10 times or less the linear expansion coefficient of the waveguide substrate and the optical fiber. 3. The waveguide type optical module according to claim 1, wherein an elastic modulus of the adhesive for fixing the reinforcing member after curing is less than 100 kg / mm ² . 4. A waveguide type optical module comprising an optical unit including an optical fiber and a waveguide element connected to the optical fiber, and an enclosing member enclosing the optical unit, wherein an inner surface of the enclosing member is provided. A waveguide type optical module, characterized in that a pedestal is interposed between the optical unit and a lower portion of the optical unit. 5. The waveguide type optical module according to claim 4, wherein the pedestal is fixed between the surrounding member and the optical unit with an adhesive. 6. The waveguide type optical module according to claim 1, wherein the pedestal is made of an elastic member, and a reinforcing member made of an elastic member is interposed between the upper portion of the optical unit and the inner surface of the surrounding member. . 7. The waveguide type optical module according to claim 1, wherein the material of the pedestal is equal to or less than the linear expansion coefficient of the waveguide element. 8. The waveguide type optical module according to claim 1, wherein the pedestal is arranged inside a joint surface between the waveguide element and the optical fiber. 9. The waveguide type optical module according to claim 4, wherein unevenness is provided on a contact surface between the pedestal and the optical unit and / or a contact surface with the surrounding member.