JP2004286895A - Optical waveguide part and optical module using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical module which can be formed in a small and thin type optical module with less number of parts, and further can keep luminescence intensity constant by molding the optical waveguide parts consisting of transparent solid media for splitting into two the light emitted from a light emitting element in a state integrated with plastic, low melting point glass, and the like, and is rich in easy mass-producibility. <P>SOLUTION: The optical waveguide parts are those consisting of the transparent solid media, and has a 1st plane to which the light is made incident, 2nd and 3rd planes for deflecting the incident light toward two different directions, a 4th plane for emitting the 1st light deflected by the 2nd plane, a 5th plane for re-deflecting the 2nd light deflected by the 3rd plane, and a 6th plane for emitting the 3rd light deflected by the 5th plane. The cross sections of the solid media is continuously decreasing along the traveling directions of the 1st and 2nd lights. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an optical module used for optical communication or optical information processing, for example, and more particularly to an optical transmission module having a configuration in which a light emitting element such as a surface emitting laser diode monitors the optical output of the element. .
[0002]
[Prior art]
Conventionally, in a light emitting element, for example, a laser diode, a light receiving element, for example, a photodiode is used to monitor emitted light of a laser diode and feed back to a power supply so that stable optical communication and optical information processing can be performed. The emission light was controlled so as to emit light stably at a desired value.
[0003]
FIG. 5 is a diagram illustrating a configuration example of a conventional optical module. For example, the edge emitting laser 30 which is a typical laser diode has a structure having two light emitting surfaces as shown in FIG. 5 (a). The incident light and the emitted light from the other side can be used by being incident on the light receiving element 3 for monitoring.
[0004]
As described above, since there is no need to split light specially for monitoring, the optical module configuration using the edge-emitting laser 30 is such that the light receiving element 3, for example, a photodiode is merely disposed near the emission surface for monitoring. Is fine.
[0005]
However, since a general photodiode has a surface-type light receiving structure, when an edge emitting laser is mounted on a substrate, it is necessary to dispose the photodiode perpendicular to the substrate. Conversely, when the photodiode is mounted on a substrate, it is necessary to arrange the edge emitting laser perpendicular to the substrate.
[0006]
As described above, when an edge-emitting laser is used, a complicated mounting process is required, which is a problem particularly when an optical module in which a plurality of lasers are arrayed is manufactured.
[0007]
On the other hand, the surface emitting laser can be highly integrated in an array arrangement or the like and is excellent in mountability on a substrate as compared with the conventional edge emitting laser 30. Recently, it has attracted attention as a key component used for optical information processing that requires high integration.
[0008]
In a surface emitting laser, generally, one of the resonance mirrors is formed in a laser die, so that only the light emitted from the other mirror can be used. Therefore, when monitoring the emitted light, it is necessary to separate the light by some method and to guide the light to a photodiode as a light receiving element.
[0009]
As a method of separating light, a method of using a mirror that transmits part of light and reflects the remaining part, that is, a so-called half mirror, has conventionally been proposed (see Patent Document 1).
[0010]
That is, as shown in FIG. 5B, a half mirror 50 is installed at 45 ° above the surface emitting laser 40, a part of the light enters the optical fiber 4 and the like, and the other part is a light receiving element. 3 is incident.
[0011]
In this case, in addition to the necessity of the half mirror 50, the light receiving element 3 needs to be installed at a right angle to the reflected light from the half mirror 50, so that the assembly of the module becomes complicated and the optical axis alignment becomes difficult. .
[0012]
Further, as shown in FIG. 5C, a half mirror 50 is installed at 45 ° in front of the surface emitting laser 40 and another mirror 51 is installed, so that a part of the laser light is There is also proposed a device that is incident on a light receiving element 3 mounted on a device (see Patent Document 2). In this case, the light receiving element 3 can be installed on the same substrate as the surface emitting laser, and mounting is relatively easy. However, since two mirrors are used and the optical path becomes long, optical components such as the lens 60 are required. And the assembly becomes complicated, and the optical axis alignment becomes more difficult.
[0013]
In addition, since these methods emit signal light perpendicular to the substrate, when the signal light is incident on the optical fiber, it is necessary to dispose the optical fiber perpendicular to the substrate, which results in poor mountability. It is difficult to realize a thin optical module.
[0014]
Further, as a method of facilitating mounting, an example in which a surface emitting laser and a photodiode serving as a light receiving element are mounted on the same substrate, and light emitted from the surface emitting laser is horizontally divided into two by a reflective structure. (See Patent Document 3).
[0015]
In this example, a method is employed in which light emitted from a surface emitting laser is reflected by a mirror on which a metal or the like is deposited, without using a half mirror, and the light is split into two. One of the reflected light divided into two as a spatial beam using air as a medium is used for monitoring, and the other is used as signal light.
[0016]
This mirror is formed by vapor-depositing metal on a component in which a groove has been formed along a specific plane direction on a Si substrate or the like by anisotropic wet etching or the like. Therefore, light can be split by the thin reflective structure without using a half mirror or the like, so that the light receiving element for monitoring can be mounted on the same substrate as the light emitting element.
[0017]
With such a configuration, the spatial beam can be split in the horizontal direction with a small number of components, while using a surface emitting laser, and the thickness can be reduced.
[0018]
[Patent Document 1] USP 5,771,254 (front page)
[0019]
[Patent Document 2] USP 5,761,299 (front page)
[0020]
[Patent Document 3] JP-A-2002-72025 (pages 1 to 5, FIG. 1)
[0021]
[Problems to be solved by the invention]
As described above, when trying to realize an optical module equipped with a monitor means for emitted light by a conventional method using a half mirror or the like as in US Pat. No. 5,771,254 or US Pat. When manufacturing an optical module in which the above surface emitting lasers are arrayed, the number of components such as mirrors and lenses increases.
[0022]
In addition, there has been a problem that as a result, assembly is complicated and cost is increased. Further, there is a problem that it is difficult to highly integrate components, which hinders downsizing of the optical module.
[0023]
Furthermore, with the configuration disclosed in Japanese Patent Application Laid-Open No. 2002-72025, it is difficult to produce a reflecting structure for dispersing light. That is, when the light reflecting structure is formed, it is necessary to accurately form the reflecting surface, so that the etching process becomes extremely difficult. Therefore, there has been a problem that the cost is high and the method is not suitable for mass production.
[0024]
Therefore, an object of the present invention is to form a small and thin optical module with a small number of components, and further to make an optical waveguide component made of a transparent solid medium that divides light emitted from a light emitting element into two into an integrally molded component such as plastic. Accordingly, an object of the present invention is to provide an optical module which is easy to assemble and has high productivity.
[0025]
[Means for Solving the Problems]
In order to achieve the above object, one aspect of the present invention is to provide a light-emitting element and a light-receiving element mounted on a substrate, a first surface on which light from the light-emitting element is incident, and two different light-incident elements. Second and third surfaces that deflect in the directions, a fourth surface that emits the first light deflected by the second surface, and a fifth surface that redeflects the second light deflected by the third surface. And a sixth surface for emitting the third light deflected by the fifth surface to the light receiving element, and the cross-sectional area of the solid medium along the traveling direction of the first light and the second light. And an optical waveguide component made of a transparent solid medium that continuously decreases.
[0026]
As described above, the cross-sectional area of the solid medium is continuously reduced along the traveling direction of the first and second lights, so that the light condensing action of the first and second lights is enhanced, and the light receiving element is further improved. And the coupling efficiency with the optical fiber is increased.
[0027]
Further, another aspect of the present invention resides in that as the optical waveguide component is an integrally molded component such as plastic, assembly is simplified and mass productivity is improved.
[0028]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the scope of protection of the present invention is not limited to the following embodiments, but extends to the inventions described in the claims and their equivalents.
[0029]
FIG. 1 is a diagram showing an embodiment of the optical module of the present invention. FIG. 1A is a sectional view of the optical module, and FIG. 1B is a perspective view of the optical module.
[0030]
First, a light emitting element 2 and a light receiving element 3 are mounted on a substrate, and an optical waveguide component 1 made of a transparent solid medium is fixed on the light emitting element 2 and the light receiving element 3 by a jig (not shown).
[0031]
Light emitted from the light emitting element 2, for example, a surface light emitting element, first enters the first surface 10 of the optical waveguide component 1 made of a transparent solid medium. At this time, in order to obtain high optical coupling, it is desirable that the area of the first surface 10 is larger than the light emitting area of the light emitting element.
[0032]
Thus, the light incident on the optical waveguide component made of the transparent solid medium is deflected by the second surface 11 and the third surface 12 provided on the optical waveguide component. Here, the light deflected on the second surface 11 is referred to as a first light, and the light deflected on the third surface 12 is referred to as a second light.
[0033]
First, when the first light propagates from the second surface 11 to the fourth surface 13, the cross-sectional area of the optical waveguide component made of a transparent solid medium is continuously reduced. Since the waveguide is narrowed in a tapered shape, it is condensed and has a feature that attenuation of light intensity can be suppressed.
[0034]
The first light emitted from the fourth surface 13 of the optical waveguide component 1 is efficiently optically coupled to, for example, the core 5 of the optical fiber 4 and propagates an optical signal. At this time, if the area of the fourth surface 13 is smaller than the area of the core portion 5 of the optical fiber, most of the light emitted from the fourth surface 13 can be incident on the core portion 5, so that the coupling efficiency can be further improved. Can be raised.
[0035]
Similarly, when the second light also propagates from the third surface 12 to the fifth surface 14, the cross-sectional area of the optical waveguide component 1 made of a transparent solid medium is continuously reduced. The attenuation of the light intensity is suppressed, and the light is deflected again by the fifth surface 14, and becomes the third light.
[0036]
Then, the third light exits from the sixth surface 15 of the optical waveguide component, efficiently enters the light receiving element 3 mounted on the same substrate as the light emitting element 2, and its intensity is monitored. At this time, if the area of the sixth surface 15 is smaller than the light receiving diameter of the light receiving element 3, most of the light emitted from the sixth surface can be incident on the light receiving portion, so that the coupling efficiency can be further improved. Can be. Then, the monitored light is fed back to the surface emitting element 2 so that the intensity is stabilized at a desired value.
[0037]
Normally, the ratio of the light split on the second surface 11 and the third surface 12 is such that the first light deflected by the second surface 11 is about 95% of the total emitted light, The second light deflected by the surface 12 is about the remaining 5%.
[0038]
FIG. 6 is a diagram illustrating an example of a method of controlling the ratio of split light. In this example, it is assumed that all light incident from the first surface 10 is incident on the second surface 11 and the third surface 12. FIG. 6A shows a case where the area 11a of the second surface 11 and the area 12a of the third surface 12 are the same. In this case, the amount of light to be split is the same, that is, 50%.
[0039]
However, when the area 11b of the second surface 11 is different from the area 12b of the third surface 12 as shown in FIG. 6B, the amount of light split according to the ratio of the area 11b to the area 12b. Is changed, and the larger the area, the greater the amount of light to be split. Therefore, in the case shown in FIG. 6B, since the area of the second surface 11 is large, the amount of light to be deflected is large. As described above, when all the emitted light is incident on the second surface 11 and the third surface 12 of the optical waveguide component 1, the area ratio between the second surface 11 and the third surface 12 is changed. By doing so, the amount of light to be split can be controlled. Since a large amount of light for monitoring is not required, the amount of light deflected on the third surface 12 may be small.
[0040]
From the above configuration, the optical module according to the present embodiment can be obtained. Next, an optical waveguide component made of a transparent solid medium according to an embodiment of the present invention will be described in detail below. The optical waveguide component made of the transparent solid medium is applicable to other than the optical module described above.
[0041]
The optical waveguide component made of a transparent solid medium is made of a material such as plastic or low-melting glass, and is poured into a mold in a state where the material is molten, and is integrally molded. Since such a forming method is used, complicated optical axis alignment, difficult etching, and the like are unnecessary as in the related art, and an extremely precise optical waveguide component can be easily and mass-produced.
[0042]
Further, even though it is a single component, the cross-sectional area continuously decreases toward the light emitting surface or the light deflecting surface, so that the light condensing function works to efficiently transmit the signal light to a transmission medium such as an optical fiber. In addition to good incidence, it is also possible to efficiently enter the monitor light receiving element.
[0043]
FIG. 2 is a sectional view of an optical module on which an optical waveguide component made of a transparent solid medium having a convex lens is mounted. As shown in FIG. 2, by providing lenses on the entrance surface and the exit surface of the optical waveguide component made of the transparent solid medium, the light coupling efficiency can be further increased.
[0044]
For example, by providing the convex lens 7 on the first surface on which the light from the surface light emitting element is incident, the coupling efficiency of the incident light can be increased. Further, if the convex lens 8 is provided on the fourth surface, which is the light emitting surface, the coupling efficiency with the optical fiber is increased. Similarly, if the convex lens 9 is provided on the sixth surface, the coupling efficiency with the light receiving element 3 is provided. Rises.
[0045]
FIG. 3 is a perspective view of an optical module in which a plurality of optical waveguide components 1 made of a transparent solid medium are arranged in parallel. As shown in FIG. 3, an optical waveguide component made of a transparent solid medium can be applied to an array structure in which a plurality of light emitting elements 2 and light receiving elements 3 are arranged in parallel on the same substrate. It is. By assembling a plurality of sets of the optical waveguide component 1 made of the transparent solid medium shown in FIG. 1 (b) and connecting a single part to the single solid medium, assembly can be facilitated.
[0046]
Here, the continuous portion of the adjacent transparent solid medium is desirably the side surface of the first surface 10. This is because, in the vicinity of the first surface 10, even if it is optically connected to the adjacent transparent medium, the light leaks to the adjacent transparent solid medium because it is a region where the spread of incident light from the light emitting element is small. Is not generated. It is desirable that the optical waveguide portion where the cross-sectional area of each optical waveguide component continuously decreases is separated in a comb-like shape.
[0047]
FIG. 4 is a diagram showing an optical module using a support made of a second transparent solid medium. As shown in FIG. 4A, in order to reinforce and support the mechanical strength of the optical waveguide component, if the optical waveguide component 1 made of the transparent solid medium described above is used as the first solid medium, its upper surface ( (Not shown) or a support 6 made of a second transparent solid medium on the lower surface.
[0048]
Here, the first solid medium and the second solid medium may be one physically connected component or may be separate components. However, in order to maintain the performance of the optical waveguide component 1 made of the first transparent solid medium, the support 6 made of the second transparent solid medium has a lower refractive index than that of the first transparent solid medium. It is desirable.
[0049]
Further, as shown in FIG. 4B, the optical waveguide component 1 made of the transparent solid medium includes a structure for fixing an optical fiber, for example, a structure 21 having a V-groove 20 formed therein, and a fourth structure. It may be provided in the vicinity of the extension of the surface.
[0050]
Alternatively, the support 6 made of the second transparent solid medium described above places the structure for fixing the optical fiber, for example, the structure 21 having the V-groove 20 near the extension of the fourth surface. You may have.
[0051]
By adopting such a configuration, it is not necessary to separately prepare a component for fixing the fiber, and the optical axis of the fourth surface and the optical fiber can be easily aligned.
[0052]
As described above, the embodiments are summarized as follows.
[0053]
(Supplementary Note 1) An optical waveguide component made of a transparent solid medium,
A first surface on which light is incident;
Second and third surfaces for deflecting the incident light in two different directions;
A fourth surface for emitting the first light deflected by the second surface,
A fifth surface for re-deflecting the second light deflected by the third surface;
A sixth surface that emits third light deflected by the fifth surface,
An optical waveguide component, wherein a cross-sectional area of the solid medium continuously decreases along a traveling direction of the first light and the second light.
[0054]
(Supplementary Note 2) In Supplementary Note 1,
The optical waveguide component is a molded product made of plastic or low melting point glass.
[0055]
(Supplementary Note 3) A light emitting element and a light receiving element mounted on a substrate,
A first surface on which light from the light emitting element is incident, second and third surfaces for deflecting the incident light in two different directions, and a first light deflected by the second surface. A fourth surface, a fifth surface for re-deflecting the second light deflected by the third surface, and a sixth surface for emitting the third light deflected by the fifth surface to the light receiving element. And an optical waveguide component comprising a transparent solid medium in which a cross-sectional area of the solid medium continuously decreases along a traveling direction of the first light and the second light. Optical module.
[0056]
(Supplementary Note 4) In supplementary note 3,
An optical module, wherein at least one of the first surface, the fourth surface, and the sixth surface has a convex lens shape.
[0057]
(Supplementary Note 5) In Supplementary note 3 or 4,
Further, the optical module, wherein the optical waveguide component made of the transparent solid medium has a concave portion for fixing an optical fiber to be coupled with light emitted from the fourth surface.
[0058]
(Supplementary Note 6) In any one of Supplementary Notes 3 to 5,
An optical module, wherein a plurality of the optical waveguide components made of a transparent solid medium are arranged in parallel in the direction of emitted light, and the plurality of components are integrally formed.
[0059]
(Supplementary Note 7) In any one of Supplementary Notes 3 to 6,
Further, the optical module is characterized in that the optical waveguide component made of the transparent solid medium has a support made of a transparent solid medium having a lower refractive index than the component.
[0060]
(Supplementary Note 8) In any one of Supplementary Notes 3 to 7,
An optical module, wherein the optical waveguide component is a molded product of plastic or low-melting glass.
[0061]
【The invention's effect】
As described above in detail, in the optical module according to the present embodiment, the light-emitting element and the light-receiving element are mounted on the same substrate, and only one optical waveguide component made of a transparent solid medium is disposed. The optical module having the means can be easily assembled.
[0062]
In addition, all of the light emitting element, the light receiving element, the optical waveguide component made of a transparent solid medium, and the optical fiber can be arranged in parallel to the substrate, and the component mounting is excellent. Further, high integration is possible, and the optical module can be reduced in size and thickness.
[Brief description of the drawings]
FIG. 1 is a diagram showing an embodiment of an optical module according to the present invention.
FIG. 2 is a sectional view of an optical module on which an optical waveguide component made of a transparent solid medium having a convex lens is mounted.
FIG. 3 is a perspective view of an optical module in which a plurality of optical waveguide components made of a transparent solid medium are arranged in parallel.
FIG. 4 is a diagram showing an optical module using a support made of a second transparent solid medium.
FIG. 5 is a diagram illustrating a configuration example of a conventional optical module.
FIG. 6 is a diagram illustrating an example of a method of controlling the ratio of split light.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 optical waveguide component 2 made of transparent solid medium 2 light emitting element 3 light receiving element 4 optical fiber 5 core section 6 second transparent solid medium 7, 8, 9 convex lens 10 first surface 11 second surface 12 third Surface 13 Fourth surface 14 Fifth surface 15 Sixth surface 20 V-groove 21 Structure 100 having V-groove formed thereon Substrate

Claims (5)

An optical waveguide component made of a transparent solid medium,
A first surface on which light is incident;
Second and third surfaces for deflecting the incident light in two different directions;
A fourth surface for emitting the first light deflected by the second surface,
A fifth surface for re-deflecting the second light deflected by the third surface;
A sixth surface that emits third light deflected by the fifth surface,
An optical waveguide component, wherein a cross-sectional area of the solid medium continuously decreases along a traveling direction of the first light and the second light. A light emitting element and a light receiving element mounted on a substrate,
A first surface on which light from the light emitting element is incident, second and third surfaces for deflecting the incident light in two different directions, and a first light deflected by the second surface. A fourth surface, a fifth surface for re-deflecting the second light deflected by the third surface, and a sixth surface for emitting the third light deflected by the fifth surface to the light receiving element. And an optical waveguide component comprising a transparent solid medium in which a cross-sectional area of the solid medium continuously decreases along a traveling direction of the first light and the second light. Optical module. In claim 2,
Further, the optical module, wherein the optical waveguide component made of the transparent solid medium has a concave portion for fixing an optical fiber to be coupled with light emitted from the fourth surface. In claim 2 or claim 3,
An optical module, wherein a plurality of optical waveguide components made of a transparent solid medium are arranged in parallel in the direction of emitted light, and the plurality of components are integrally formed. In any one of claims 2 to 4,
Furthermore, the optical module is characterized in that the optical waveguide component made of the transparent solid medium has a support made of a transparent solid medium having a lower refractive index than the component.

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