WO2013157287A1

WO2013157287A1 - Optical module

Info

Publication number: WO2013157287A1
Application number: PCT/JP2013/053008
Authority: WO
Inventors: 建天野; 史雄佐々木; 小森　和弘
Original assignee: 独立行政法人産業技術総合研究所
Priority date: 2012-04-16
Filing date: 2013-02-08
Publication date: 2013-10-24
Also published as: JP2015121568A

Abstract

[Object] An object of the present invention is to provide an optical module that is capable of reducing the effect of laser light loss even when a laser light source and an optical wiring unit are configured to be separated from each other. [Solution] An optical module according to the present invention includes: one square surface where laser light is incident; a truncated pyramid-shaped laser light introduction unit that has another square surface which is in parallel with the one square surface and is larger in size than the one square surface; an optical waveguide unit that is connected to the other square surface of the laser light introduction unit, extends in the incident direction of the laser light, and guides the introduced light inside and emits the light from another cross section; an optical path changing unit that has a reflective surface which reflects the guided light emitted from the optical waveguide unit; and a support substrate that supports the laser light introduction unit, the optical waveguide unit, and the optical path changing unit. When the one square surface of the laser light introduction unit is a right side surface and the other square surface is a left side surface, at least one of the other surfaces is a tapered surface.

Description

Optical module

The present invention relates to an optical module that changes the optical path of incident laser light and emits a surface in an arbitrary direction.

Up to now, optical communication has been carried out over a relatively long transmission distance of several kilometers to several hundred kilometers via a large amount of optical communication traffic for transmission between continents, cities, and between base stations and homes. It was. In the future, in order to process large volumes of data without delay, it will be carried out at a very close transmission distance between each transmission device (several meters to several hundreds of meters) and between members in the transmission device (several centimeters to several tens of centimeters). It is required to be done. In the future, in order to handle high-definition image information in consumer equipment such as televisions and personal computers, it will be essential to increase the speed and capacity of video signal transmission, and optical transmission will also be applied to short-distance signal transmission lines. It is required to be. A surface emitting laser is effective for opticalizing the signal transmission line.

As such a surface emitting laser module, for example, a semiconductor substrate, a light emitting region provided in the semiconductor substrate, a lens integrated in the light emitting region, and the light emitting region in which the lens is integrated are surrounded. A light emitting element that emits light in a direction perpendicular to the main surface of the semiconductor substrate from the light emitting region, and is held in the holding portion to hold the lens. There has been proposed a surface emitting laser module characterized by having an external optical waveguide that guides light transmitted from the light emitting element and a stem to which the light emitting element and the external optical waveguide are fixed (Patent Document) 1).
This surface-emitting laser module functions as a surface-emitting type semiconductor laser and can be miniaturized by integrating the light-emitting element, the mirror structure, and the lens structure.

However, in this surface emitting laser module, the structure of the module itself is used as a laser light source, so that the selectivity of the laser light source is limited. Various types of laser light sources have been developed depending on the application, and a degree of freedom of selection is required depending on the application. Further, when the laser light source fails, it cannot be replaced with another laser light source.
In addition, as a surface emitting type laser module, an electric signal input from an electronic device such as an LSI or a memory element is converted into an optical signal before being attenuated and transmitted to another electronic device. While it is necessary to arrange the laser beam as an optical signal according to the arrangement position of the electronic device on the transmission side, it is necessary to arrange the laser light source and the optical wiring portion in the surface emitting laser module. Are integrally configured, it is impossible to adopt a module configuration corresponding to the arrangement position of such an electronic device.
If the laser light source and the optical wiring part are configured separately, and the modules can be arranged so that they can be arranged in the immediate vicinity of the input side and output side electronic devices, it is very advantageous in terms of device design.
However, if the laser light source and the optical wiring part are separated from each other, there is a problem that the loss effect of the laser light is increased when these are optically coupled.

JP 2010-251649 A

This invention makes it a subject to solve the said various problems in the past and to achieve the following objectives. That is, an object of the present invention is to provide an optical module that can reduce the loss effect of laser light even if the laser light source and the optical wiring portion are separated.

The inventors of the present invention have made extensive studies in order to solve the above problems, and have obtained the following knowledge.
That is, when laser light emitted from a laser light source is directly introduced into an optical wiring portion (optical waveguide portion), the loss efficiency of the laser light is increased. However, when a taper is provided at a portion where the laser light is introduced, We have found that the loss efficiency of laser light can be kept small.

The present invention is based on the above knowledge, and means for solving the above problems are as follows. That is,
<1> One rectangular surface into which laser light is incident from a direction substantially orthogonal to the surface, and the one rectangular surface parallel to the one rectangular surface by introducing the laser light incident from the one rectangular surface. A rectangular pyramid-shaped laser beam introducing portion having another square surface having a larger area than the other end surface, and one end surface is connected to the other rectangular surface of the laser beam introducing portion and in the incident direction of the laser beam An optical waveguide that extends and guides the introduced light introduced from the one end face and emits it from the other end face, and reflects the guided light emitted from the optical waveguide and emits the light to the outside. An optical path changing unit having a reflecting surface, and a support substrate that supports the laser light introducing unit, the optical waveguide unit, and the optical path changing unit, and the one rectangular surface of the laser light introducing unit is a right side surface. When the other rectangular surface is the left side surface, An optical module characterized in that at least one of the surfaces is a tapered surface having a slope that spreads from the one rectangular surface toward the other rectangular surface.
<2> When the laser beam introduction part has one rectangular surface as the right side surface and the other rectangular surface as the left side surface, the shape in which the flat surface is a tapered surface, and the incident direction of the laser light in front view and the back surface Any of a shape that is a line-symmetric taper surface with the upper extension line as a symmetry axis, and a shape in which the flat surface is a taper surface and the front surface and the back surface are the line-symmetric taper surface <1> The optical module according to <1>.
<3> When the laser beam introduction portion has one rectangular surface as the right side surface and the other rectangular surface as the left side surface, the laser light introducing portion is formed in a shape in which the flat surface is a tapered surface, and the width of the other rectangular surface is X When the shortest distance between the one rectangular surface and the other rectangular surface is 1.1X to 9X, and the height of the other rectangular surface is Y, the height of the one rectangular surface is The optical module according to <2>, wherein is 0.2Y to 0.9Y.
<4> When the front surface and the back surface are formed in a shape that is a line-symmetric taper surface with an extension line in the incident direction of the laser light in a plan view as a symmetry axis, and the width of the other rectangular surface is X, The light according to <2>, wherein the width of the one rectangular surface is 0.1X to 0.9X, and the shortest distance between the one rectangular surface and the other rectangular surface is 1.1X to 8X. module.
<5> When the laser beam introduction part has one square surface as the right side surface and the other square surface as the left side surface, the plane is a tapered surface and the front and back surfaces are in the laser beam incident direction in plan view. The width of the one rectangular surface is 0.1X to 0.9X, where X is the width of the other rectangular surface. And the shortest distance between the one rectangular surface and the other rectangular surface is 1.1X to 8X, and when the height of the other rectangular surface is Y, the height of the one rectangular surface is The optical module according to <2>, wherein 0.2Y to 0.9Y.
<6> The optical module according to any one of <1> to <5>, wherein the width of the other rectangular surface is 1 μm to 100 μm.
<7> The optical module according to any one of <1> to <6>, wherein the height of the other rectangular surface is 1 μm to 100 μm.
<8> The optical module according to any one of <1> to <7>, wherein the laser beam introduction section and the optical waveguide section are integrally formed.
<9> Any one of the items <1> to <8>, wherein the optical waveguide section is formed of a forming material having an optical waveguide loss with respect to light having a wavelength of 1.3 μm being 0.1 dB / cm to 0.5 dB / cm. The optical module as described in.
<10> The optical module according to any one of <1> to <9>, wherein a laser light source that makes laser light incident on one square surface is disposed on a support substrate.
<11> The optical module according to <10>, wherein the distance L between the laser light emission port of the laser light source and the one rectangular surface satisfies the following expression: 0 μm <L ≦ 40 μm.
<12> The optical module according to any one of <10> to <11>, wherein the laser light source is a quantum dot laser.

According to the present invention, there is provided an optical module that can solve the above-mentioned problems in the prior art and can reduce the loss effect of laser light even if the laser light source and the optical wiring portion are separated. be able to.

It is a top view which shows the outline | summary of embodiment of the optical module which concerns on this invention. It is sectional drawing which shows the outline | summary of embodiment of the optical module which concerns on this invention. It is a front view of the laser beam introduction part 5. FIG. 5 is a plan view of a laser beam introducing unit 5. 2 is a front view of a laser beam introducing unit 10. FIG. FIG. 3 is a plan view of a laser beam introducing unit 10. The shortest distance L _tap between one rectangular surface 10a and the other rectangular surface 10b in the laser beam introducing section 10 is changed in the range of 40 μm to 300 μm, and the width W _p of the one rectangular surface 10a is changed in the range of 4 μm to 40 μm. It is a figure which shows the simulation result at the time of making it change. It is a figure which shows the simulation result at the time of fixing the shortest distance L _tap between one square surface 10a and the other square surface 10b to 100 _micrometers , and changing the distance _Lsp . FIG. 3 is a front view of a laser beam introduction unit 15. FIG. 6 is a plan view of a laser beam introducing unit 15. The shortest distance L _tap between one rectangular surface 15a and the other rectangular surface 15b in the laser beam introducing portion 15 is changed in the range of 100 μm to 350 μm, and the height H _p of the one rectangular surface 15a is in the range of 4 μm to 40 μm. It is a figure which shows the simulation result at the time of making it change by. It is a top view which shows the outline | summary of the optical module which concerns on an Example. It is a fragmentary sectional view which shows the outline | summary of the optical module which concerns on an Example.

(Optical module)
The optical module of the present invention includes at least a laser beam introduction unit, an optical waveguide unit, an optical path changing unit, and a support substrate, and includes a laser light source and other members as necessary.

<Laser beam introduction part>
The laser light introducing section includes a rectangular surface into which laser light is incident from a direction substantially orthogonal to a surface, and the laser light incident from the one rectangular surface is introduced and parallel to the one rectangular surface. A quadrangular frustum-shaped member having another square surface having a larger area than one square surface, the one rectangular surface of the laser light introducing portion as a right side surface, and the other square surface as a left side surface In this case, at least one of the remaining surfaces is a tapered surface having a slope that becomes wider from the one rectangular surface toward the other rectangular surface.
With such a tapered surface, it is possible to introduce the laser light into the optical waveguide section while keeping the loss efficiency of the laser light incident from the outside low.

The shape of the laser beam introducing portion is not particularly limited as long as it has the tapered surface, but when the one rectangular surface is the right side and the other rectangular surface is the left side, the plane is a tapered surface. The front surface and the back surface in a plan view, the shape being a line-symmetric taper surface with the extension line in the incident direction of the laser beam as the axis of symmetry, and the flat surface being a taper surface and the front surface and the back surface Is preferably formed in any of the shapes that are the axisymmetric tapered surfaces.
In addition, about these shapes, it mentions later using FIG. 2 (a), (b), FIG. 3 (a), (b) and FIG. 6 (a), (b).

The material for forming the laser beam introduction part is not particularly limited as long as the laser beam can be introduced, and includes a known translucent material, for example, a resin material such as an epoxy resin.

There is no restriction | limiting in particular as a formation method of the said laser beam introducing | transducing part, According to the objective, it can select suitably, For example, the method of forming by a well-known photolithography technique, the cutting process by cutting machines, such as a dicer Is mentioned.

<Optical wave guide>
The optical waveguide section has one end face connected to the other rectangular face of the laser light introducing section and extends in the incident direction of the laser light, and introduces introduced light introduced from the one end face inside. It is a member that is guided and emitted from the other end face.
By adjusting the extension length of such an optical waveguide section, the optical module can be designed so that the laser light is acquired from an arbitrary position and guided to an arbitrary position.
In addition, by separating the laser light introducing section and the optical waveguide section from the laser light source of the laser light, the laser light source can be appropriately selected according to the purpose, and when the laser light source fails Can be replaced with other laser light sources.

The material for forming the optical waveguide part is not particularly limited, but a material having an optical waveguide loss for light having a wavelength of 1.3 μm of 0.1 dB / cm to 0.5 dB / cm is preferable. Examples of the material include a resin material such as an epoxy resin.
By using such a forming material with a small optical waveguide loss, the optical waveguide loss can be suppressed even when the extension length of the optical waveguide portion is relatively long.

The method for forming the optical waveguide is not particularly limited and may be appropriately selected depending on the purpose. Examples thereof include a method for forming the optical waveguide by a known photolithography technique.

The laser beam introduction section and the optical waveguide section may be formed as separate members, but can be easily formed and formed integrally from the viewpoint of suppressing loss of the laser beam. preferable.

The width of each end face of the optical waveguide is not particularly limited, but is preferably 1 μm to 100 μm, and more preferably 5 μm to 50 μm. The height of each end face is preferably 1 μm to 100 μm, more preferably 5 μm to 50 μm.
Forming the optical waveguide part with such a size is preferable in that light can be transmitted over a long distance without impairing the signal capacity.

<Optical path changing unit>
The optical path changing unit is a member having a reflection surface that reflects the guided light emitted from the optical waveguide unit and emits the light to the outside.
By having such a reflection surface, it is possible to change the optical path of the laser light and to emit the laser light to the surface in an arbitrary direction.

As long as the optical path changing portion has the reflecting surface, the structure is not particularly limited, and the entire member may be formed of a light reflecting material, or only the reflecting surface may be formed of the light reflecting material. Good.
There is no restriction | limiting in particular as said light reflection material, For example, gold | metal | money, copper, etc. are mentioned.
In the case where the entire member is formed of a light reflecting material, examples of the method for forming the optical path changing portion include a method using a dicing saw.
When only the reflection surface is formed of the light reflection material, the light path changing portion may be formed by, for example, applying the light reflection material to the surface of the main material that forms the base of the reflection surface by vacuum deposition or sputtering. And a method of forming a film by a method.

<Support substrate>
The support substrate is a member that supports the laser light introducing section, the optical waveguide section, and the optical path changing section.
The support substrate may directly support each part or indirectly support through another member.
Further, when the laser light introduction part and the optical waveguide part are integrally formed, the laser light introduction part may be indirectly supported by supporting the optical waveguide part.

The support substrate is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a known substrate such as a semiconductor substrate may be used.

<Laser light source>
The laser light source for making the laser light incident on the one rectangular surface of the laser light introducing section may be disposed as a separate member from the optical module, but is disposed on the same support substrate of the optical module. Is preferred.
Thus, by arranging on the same support substrate, it is possible to easily adjust the incident position of the laser beam with respect to the one rectangular surface.

The method of arranging the laser light source on the support substrate is not particularly limited, and examples thereof include a method of fixing and arranging the laser light source on the support substrate by soldering.

The laser light source is not particularly limited, and for example, a known semiconductor laser can be used. Among them, a quantum dot laser is preferably used from the viewpoint that a large capacity signal can be handled at high speed. Since the semiconductor laser generally has a relatively large divergence angle component, the laser light is radiated on the condition that the divergence of light in the laser light introducing portion is a gentler angle than the gradient of the tapered surface. It is preferable to make it enter into a light introduction part.

<Other members>
There is no restriction | limiting in particular as said other member, According to the objective, it can select suitably, For example, when the said optical waveguide part is made into a core part, the clad part which coat | covers the exterior is mentioned. The clad portion has a role of confining the laser light in the core portion due to a difference in refractive index from the core portion. The clad portion may be disposed so as to support the laser light introducing portion, the optical waveguide portion, the optical path changing portion, and the laser light source as the support substrate in manufacturing the optical module.
There is no restriction | limiting in particular as a formation material of the said clad part, For example, well-known resin materials, such as an epoxy resin, are mentioned. Moreover, there is no restriction | limiting in particular as the formation method, It can form by a well-known formation method.

An embodiment of the optical module will be described with reference to the drawings.
FIG. 1A is a plan view showing an outline of an embodiment of an optical module according to the present invention, and FIG. 1B is a sectional view taken along line AA.
In the optical module 1, a laser light source 4, a laser light introducing unit 5, an optical waveguide unit 6, and an optical path changing unit 7 are arranged on a layered clad part 3 a formed on a support substrate 2, and an optical waveguide A clad 3b is formed on the outer periphery of the optical path changing unit 7 excluding the part 6 and the reflecting surface 7a.

The laser light introducing portion 5 and the optical waveguide portion 6 are formed as an integral member, and the laser light introducing portion 5 has a tapered surface, and the optical waveguide portion 6 extends in the incident direction of the laser light. It is formed as a quadrangular columnar member.
The optical path changing unit 7 has a reflecting surface 7a that changes the optical path, and the clad 3b is formed on the optical path changing unit 7 so that the upper part of the reflecting surface 7a is opened.

The laser light incident on the laser light introducing section 5 from the laser light source 4 is introduced into the optical waveguide section 6 from the laser light introducing section 5 while being diffused in the laser light introducing section 5, and guided into the optical waveguide section 6. And is emitted from the optical path changing unit 7 side. At this time, the guided light guided into the optical waveguide 6 is emitted toward the optical path changing unit 7 while being refracted by the optical confinement effect by the

clads

3a and 3b. The emitted light emitted to the optical path changing unit 7 side is changed in its optical path by the reflecting surface 7a of the optical path changing unit 7, and is emitted upward in the illustrated example.

In the optical module 1, the loss efficiency of the laser light incident from the laser light source 4 can be kept low because the laser light introducing portion 5 has a tapered surface.
Here, the shape of the laser beam introducing portion 5 will be described in more detail with reference to FIGS. 2 (a) and 2 (b). FIG. 2A is a front view of the laser beam introducing section 5, and FIG. 2B is a plan view thereof.
The laser beam introducing section 5 has one rectangular surface 5a on which laser light is incident and another rectangular surface 5b that is parallel to the one rectangular surface and has a larger area than the one rectangular surface 5a. This is a quadrangular frustum-shaped member having the rectangular surface 5b as a bottom surface.
Further, when one square surface 5a is a right side surface and the other square surface 5b is a left side surface, the flat surface is a tapered surface, and the front and back surfaces are extended in the incident direction of laser light in a plan view. It is formed in a shape that is a line-symmetric taper surface with the line as the axis of symmetry. Each taper surface has a slope that spreads from one square surface 5a to another square surface 5b (hereinafter, this shape is referred to as a “three-dimensional taper shape”).

In the three-dimensional tapered laser beam introducing portion 5, when the width of the other rectangular surface 5b is X, the width W _p of one rectangular surface 5a is preferably 0.1X to 0.9X. The shortest distance L _tap between the rectangular surface 5a and the other rectangular surface 5b is preferably 1.1X to 8X. When the height of the other rectangular surface 5b is Y, the height of one rectangular surface 5a it is preferable that H _p is 0.2Y ~ 0.9Y.
That is, with such a shape, the loss efficiency of the laser light incident from the laser light source 4 can be kept extremely low.
This is based on the result of summing up the simulation results for two two-dimensional tapered laser light introducing portions described below. That is, the shape of the front and back surfaces being a line-symmetric taper surface with the extended line in the laser beam incident direction as the axis of symmetry in plan view (see FIGS. 3A and 3B) and the surface is tapered. The simulation results for the shapes of the two laser light introducing portions (hereinafter sometimes referred to as “two-dimensional taper shapes”) and the shapes to be formed (see FIGS. 6A and 6B) Based on the combined result.

First, a simulation result of the laser light introducing unit 10 having a shape in which the front and rear surfaces are line-symmetric taper surfaces with an extension line in the laser light incident direction as a symmetry axis in a plan view will be described.
As shown in FIGS. 3A and 3B, the laser light introducing section 10 has one rectangular surface 10a as a right side surface, and is parallel to the one rectangular surface 10a and has an area larger than that of the one rectangular surface 10a. When the other large rectangular surface 10b is the left side surface, the front and back surfaces have a shape that is a line-symmetric taper surface with the extended line in the laser beam incident direction as the axis of symmetry in plan view. 3A is a front view of the laser beam introducing unit 10, and FIG. 3B is a plan view thereof.

In the simulation, in the optical module 1 shown in FIGS. 1A and 1B, a laser beam emitted from the laser light source 4 when the laser beam introducing unit 10 is arranged instead of the laser beam introducing unit 5 is used. This was performed by calculating the difference between the light intensities of the light and the guided light emitted from the optical waveguide unit 6 as coupling efficiency (Coupling Efficiency (dB)). The coupling efficiency is an index of the loss efficiency of the laser beam.
In addition, in the simulation, a simulator Beamprop (ver. 8.2.RC2) using a beam propagation method (BPM) manufactured by RSsoft is used, and a pad approximation order is used so that a wide-angle divergence angle can be calculated ( 4, 4).
The dimensions of the other rectangular surface 10b of the laser beam introducing portion 10 and the end faces of the optical waveguide 6 are 40 μm square, and the refractive indexes of the optical waveguide 6 and the

cladding portions

3a and 3b are 1.58 and 1.55, respectively. It was.
Further, the divergence angle of the laser light introduced into the laser light introducing portion 10 was 40 ° in the width direction (x-axis direction) of the other rectangular surface 10b and 53 ° in the height direction (y-axis direction).
Further, the laser light is introduced into the rectangular surface 10a of the laser light introducing portion 10 from the orthogonal direction to the center thereof, and the laser light emitting port of the laser light source 4 and the one rectangular surface 10a. And the distance _Lsp to 10 μm.

The shortest distance L _tap between one rectangular surface 10a and the other rectangular surface 10b in the laser beam introducing section 10 is changed in the range of 40 μm to 300 μm, and the width W _p of the one rectangular surface 10a is changed in the range of 4 μm to 40 μm. FIG. 4 shows the simulation result when the change is made. Note that when W _p is 40 [mu] m, the simulation result in the absence of the tapered surface.
As shown in FIG. 4, a higher coupling efficiency is obtained than in the case where there is no tapered surface under most conditions. Therefore, even when the laser light source 4 and the optical wiring part (laser light introducing part 10 and optical waveguide part 6) are separated from each other, the loss effect of the laser light when optically coupling them is kept low. be able to.
Therefore, the laser light introducing section 10 having a two-dimensional tapered shape in which the front and rear surfaces are axisymmetric taper surfaces with an extension line in the laser light incident direction as a symmetry axis in plan view (FIGS. 3A and 3). in (b) refer), when the width of the other rectangular surface 10b was set to X, the width _{W p} of one rectangular surface 10a is 0.1X ~ 0.9X, one rectangular surface 10a and the other square The shortest distance L _tap between the surfaces 10b is preferably 1.1X to 8X.

In the simulated laser beam emitting port of the laser source 4, it was performed by fixing the distance L _sp with one rectangular face 10a to 10 [mu] m, the shortest distance between one rectangular surface 10a and the other rectangular surface 10b FIG. 5 shows a simulation result when the L _tap is fixed to 100 μm and the distance L _sp is varied.
As shown in FIG. 5, when the distance L _sp satisfies the following equation, 0 μm <L _sp ≦ 40 μm, by adjusting the width W _p of one rectangular surface 10a, higher coupling than when there is no tapered surface Efficiency can be obtained.
Therefore, it is preferable that the distance L _sp between the laser beam emission port of the laser light source 4 and the one rectangular surface 10a satisfies the following expression: 0 μm <L _sp ≦ 40 μm. Further, from the viewpoint of enabling a design with a higher degree of freedom, it is more preferable to satisfy the following formula: 0 μm <L _sp ≦ 30 μm.

Next, a simulation result of the two-dimensional tapered laser beam introducing unit 15 whose plane is a tapered surface will be described.
As shown in FIGS. 6A and 6B, the laser light introducing portion 15 has one rectangular surface 15a as a right side surface, and is parallel to the one rectangular surface 15a and has an area larger than that of the one rectangular surface 15a. When the other large rectangular surface 15b is the left side surface, the flat surface is a tapered surface. 6A is a front view of the laser beam introducing portion 15, and FIG. 6B is a plan view thereof.

In this simulation, in the optical module 1 shown in FIG. 1A and FIG. 1B, the laser light introducing section is set except that the laser light introducing section 15 is arranged instead of the laser light introducing section 5. Same as the simulation performed for 10.
The shortest distance L _tap between one rectangular surface 15a and the other rectangular surface 15b in the laser beam introducing portion 15 is changed in the range of 100 μm to 350 μm, and the height H _p of the one rectangular surface 15a is in the range of 4 μm to 40 μm. FIG. 7 shows the simulation result when the change is made.
As shown in figure 7, if the _{H p} or more 8 [mu] m, the condition of all the _{L tap,} the coupling efficiency is obtained higher than without the tapered surface _(H p = 40 [mu] m).
Therefore, in the laser beam introducing section 15 (see FIGS. 6A and 6B) having a two-dimensional tapered shape whose plane is a tapered surface, when the width of the other rectangular surface is X, the When the shortest distance L _tap between the rectangular surface 15a and the other rectangular surface 15b is 1.1X to 9X, and the height of the other rectangular surface 15b is Y, the height H _p of one rectangular surface 15a is It is preferably 0.2Y to 0.9Y.

By adding together the simulation results of the above two-dimensional taper shape, the shape of the laser light introducing portion 5 having the three-dimensional taper shape can be set.
Further, in the above simulation of the two-dimensional taper shape, the calculation was performed with the width X and the height Y of the other rectangular surfaces in the laser beam introducing unit 10 and the laser beam introducing unit 15 being 40 μm, respectively. The surface width is preferably 1 μm to 100 μm, more preferably 5 μm to 50 μm.
That is, if the width is less than 1 μm, light scattering is increased, which makes it difficult to transmit light. If the width exceeds 100 μm, the waveguide size increases and the degree of integration does not increase.
The height of the other rectangular surface is preferably 1 μm to 100 μm, and more preferably 5 μm to 50 μm.
That is, if the height is less than 1 μm, light scattering increases, so that light transmission becomes difficult. If the height exceeds 100 μm, the waveguide size increases and the degree of integration does not increase.

(Example)
As an example, an optical module according to the present invention was prototyped with the configuration shown in FIGS. FIG. 8 is a plan view showing an outline of the optical module according to the embodiment, and FIG. 9 is a partial cross-sectional view taken along line AA of FIG. In the optical module according to this embodiment, in order to measure the loss efficiency of the laser light in the laser light introducing section and the optical waveguide section, the formation of the optical path changing section is omitted, and an optical fiber is used instead of the optical path changing section. Forming.
That is, as shown in FIG. 8, in the optical module according to the embodiment, a layered clad portion 23a is arranged on a support substrate 22, and the laser light integrally formed with the laser light source 24 on the clad portion 23a. The introduction portion 25, the optical waveguide portion 26, and the optical fiber 30 are disposed, and further, the cladding portion 23 b is disposed on the optical waveguide portion 26.

The optical module according to this example was manufactured as follows.
First, a clad forming polymer (Cosmo Shine A4100 manufactured by Toyobo Co., Ltd.) was applied on the support substrate 22 to form a clad portion 23a.
Next, a core-forming photosensitive polymer (phenoxy resin (using phenotote YP-70 manufactured by Toto Chemical Co., Ltd.)) having a refractive index different from that of the cladding-forming polymer is applied on the cladding portion 23a. Using the photomask on which the shapes of the laser beam introduction section 25 and the optical waveguide section 26 are drawn and an exposure machine, pattern transfer and development of the shapes are performed to form the laser beam introduction section 25 and the optical waveguide section 26. At this stage, the laser beam introducing section 25 has a two-dimensional tapered shape in which the front and back surfaces are two-dimensionally tapered with a line extending symmetrically in the incident direction of the laser light as a symmetry axis in plan view. And formed integrally.
Next, after coating the clad forming polymer on the optical waveguide 26, pattern transfer and development were performed in the same manner as the formation of the optical waveguide 26 to form the clad 23b.
Next, a dicer was used to cut the upper portion of the laser beam introducing portion 25 to form a tapered surface on the upper portion, thereby obtaining a three-dimensional tapered shape.
Here, the dimensions of the optical waveguide section 26 were a diameter of 40 μm square and a length (optical waveguide length) of 2 cm. Further, the dimensions of the laser light introducing section 25 are such that the height of one rectangular surface on the laser light source 24 side is 15 μm, the width is 5 μm, and the height and width of the other rectangular surface connected to the optical waveguide section 26 are as follows. The thickness was 40 μm. As the formation position of the taper surface, a symmetrical taper surface on the front surface and the back surface is formed at a position of 450 μm from one square surface of the laser beam introduction portion 25 to the other square surface, and the flat taper surface is one rectangular surface. To the other rectangular surface at a position of 200 μm. Note that the boundary between the laser beam introducing section 25 and the optical waveguide section 26 is a position 450 μm from one rectangular plane on which the symmetrical tapered surface is formed (the position indicated by the dotted line in FIGS. 8 and 9). Bordered by presence or absence.
Next, the laser light source 24 was soldered on the clad portion 23a. As the laser light source 24, a quantum dot laser having the same configuration as the quantum dot laser (see Japanese Patent Application Laid-Open No. 2007-53322) filed in the past by the applicant of the present application was used.
Finally, an optical fiber 30 for measuring the loss efficiency was disposed on the cladding part 23a.
The optical module which concerns on an Example was produced by the above.

(Comparative example)
In the production of the optical module according to the example, the optical module according to the comparative example was produced in the same manner as the optical module according to the example, except that the tapered surface was not provided in the region to be the light introducing portion 25.

Each loss efficiency of the optical module which concerns on an Example and a comparative example was computed.
The loss efficiency of the optical module according to the embodiment is measured by making the laser light incident on the laser light introducing section 25, guiding the guided light emitted from the optical waveguide section 26 to the optical fiber 30, and connecting to the optical fiber 30. The light intensity was measured with a power meter, and the loss efficiency of the laser light was calculated from the light intensity and the light intensity of the laser light emitted from the laser light source 24.
Further, the loss efficiency of the optical module according to the comparative example was calculated in the same manner.
The calculation results of the loss efficiencies of the optical modules according to the examples and the comparative examples are shown in Table 1 below.

As shown in Table 1, in the optical module according to the example, the loss efficiency can be suppressed to 3.6 dB smaller than the optical module according to the comparative example.

As described above, the optical module of the present invention can reduce the loss effect of the laser light even if the laser light source and the optical wiring portion are separated, and can connect the distant electronic devices by making them light. Therefore, in various fields that have been connected by electrical wiring so far, this can be suitably converted into light.

DESCRIPTION OF SYMBOLS 1

Optical module

2,22

Support substrate

3a, 3b, 23a,

23b Cladding part

4,24 Laser

light source

5a, 10a, 15a One

square surface

5b, 10b, 15b Other

square surfaces

5, 10, 15, 25 Laser

beam introduction Portions

6, 26 Optical waveguide portion 7 Optical path changing portion 7a Reflecting surface 30 Optical fiber

Claims

One rectangular surface into which laser light is incident from a direction substantially orthogonal to the surface, and the laser light incident from the one rectangular surface is introduced and is parallel to the one rectangular surface and has an area larger than that of the one rectangular surface. A quadrangular pyramid-shaped laser light introducing portion having another rectangular surface with a large
One end surface is connected to the other rectangular surface of the laser light introducing portion and extends in the incident direction of the laser light, and guides the introduced light introduced from the one end surface to the other. An optical waveguide to be emitted from the end face;
An optical path changing unit having a reflection surface that reflects the guided light emitted from the optical waveguide unit and emits the light to the outside;
A support substrate that supports the laser beam introduction section, the optical waveguide section, and the optical path changing section,
When the one rectangular surface of the laser beam introducing portion is a right side surface and the other square surface is a left side surface, at least one of the other surfaces is changed from the one rectangular surface to the other rectangular surface. An optical module characterized in that the optical module has a taper surface having a slope that becomes wider toward the bottom.
When the laser beam introduction part has one square surface as the right side surface and the other square surface as the left side surface, the flat surface is a tapered surface, and the front and back surfaces are extended in the laser light incident direction in plan view. A shape that is a line-symmetric taper surface with a line as an axis of symmetry, and a shape in which the plane is a taper surface and the front surface and the back surface are a line-symmetric taper surface. The optical module according to claim 1.
When the laser light introducing portion is a right side surface of one square surface and a left side surface of the other square surface, the laser light introducing portion is formed in a shape having a flat surface as a tapered surface,
When the width of the other rectangular surface is X, the shortest distance between the one rectangular surface and the other rectangular surface is 1.1X to 9X, and the height of the other rectangular surface is Y The optical module according to claim 2, wherein a height of the one rectangular surface is 0.2Y to 0.9Y.
The front and back are formed in a shape that is a line-symmetric taper surface with an extension line in the incident direction of the laser beam as a symmetry axis in plan view,
When the width of the other rectangular surface is X, the width of the one rectangular surface is 0.1X to 0.9X, and the shortest distance between the one rectangular surface and the other rectangular surface is 1. The optical module according to claim 2, which is 1X to 8X.
When the laser beam introduction part has one square surface as the right side surface and the other square surface as the left side surface, the flat surface is a tapered surface and the front and back surfaces are extended lines in the laser light incident direction in plan view. Is formed in a shape that is a line-symmetric taper surface with the axis of symmetry as
When the width of the other rectangular surface is X, the width of the one rectangular surface is 0.1X to 0.9X, and the shortest distance between the one rectangular surface and the other rectangular surface is 1. 3. The optical module according to claim 2, wherein the height of the one rectangular surface is 0.2Y to 0.9Y, where Y is 1X to 8X, and Y is the height of the other rectangular surface.
6. The optical module according to claim 1, wherein the width of the other rectangular surface is 1 μm to 100 μm.
7. The optical module according to claim 1, wherein the height of the other rectangular surface is 1 μm to 100 μm.
The optical module according to any one of claims 1 to 7, wherein the laser beam introducing section and the optical waveguide section are integrally formed.
9. The optical module according to claim 1, wherein the optical waveguide section is formed of a forming material having an optical waveguide loss for light having a wavelength of 1.3 μm of 0.1 dB / cm to 0.5 dB / cm.
The optical module according to any one of claims 1 to 9, further comprising a laser light source that allows laser light to be incident on one rectangular surface.
The optical module according to claim 10, wherein the distance L between the laser light emission port of the laser light source and the one rectangular surface satisfies the following expression: 0 μm <L ≦ 40 μm.
The optical module according to claim 10, wherein the laser light source is a quantum dot laser.