JP2011099905A - Method for manufacturing optical device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an optical device capable of suppressing coupling loss caused by assembly accuracy of an optical module. <P>SOLUTION: The method for manufacturing an optical device for loading, on a substrate 4, an optical module 1 having a base substrate 12 and an optical element 11 installed on the base substrate 12 includes steps of: detecting an angle (a) formed between an incident light 101 entering the optical element 11 and an incident surface 14 through which the incident light 101 enters or an emission surface 14 through which the incident light 101 is emitted after passing the optical element 11; and loading the optical module 1 on the substrate 4 so that the detected angle (a) agrees with a prescribed angle. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an optical device manufacturing method, and more particularly to an optical device manufacturing method in which an optical module is mounted on a substrate.

  With recent developments in optical technology, optical communication systems have grown dramatically. In particular, in order to increase the utilization efficiency of optical fibers, technologies such as speeding up of optical signals and increasing the number of wavelengths have been developed.

  On the other hand, with such technological progress, demands for parts used in optical communication systems are becoming stricter. In particular, with FTTH (Fiber To The Home), cost reduction of parts is required.

  In FTTH, there is an increasing demand for higher speeds, and those that initially had a transmission rate of about 100 Mbps have recently started to be available with a transmission rate of 2.4 Gbps. The FTTH possessed is also being studied.

  As the transmission speed in such optical communication is increased, it is known that the reflected return light reflected from the communication path and returning to the LD (Laser Diode) affects the quality of the transmission signal. In order to suppress reflected return light, an optical isolator is generally mounted in front of an LD element in a transmission module used at a transmission rate of 2.4 Gbps. Here, the optical isolator is an optical module that allows light incident from one side to pass through the optical isolator with low loss, but can generate high loss with respect to light incident from the opposite direction. Therefore, by mounting the optical isolator, the reflected return light returning to the LD element can be removed.

  As an example of use of the optical isolator, a first lens is disposed in front of the LD element, the light emitted from the LD element is converted into a parallel beam and then transmitted through the optical isolator, and the second lens disposed thereafter. In general, the light is condensed and coupled with an optical fiber. A use example in which optical fibers and optical waveguides are arranged on both sides of two lenses is also conceivable.

  As in the above usage example, when an optical isolator is incorporated into a product, it is essential to use a lens. In this case, it is necessary to adjust the optical axis of the optical isolator and the lens. Since this optical axis adjustment requires a great deal of labor and time, it has been difficult to reduce the cost of the optical isolator.

  For this reason, in recent years, techniques for realizing optical coupling without adjusting the optical axis have been studied. For example, Patent Documents 1 to 3 disclose techniques for mounting optical components such as optical isolators and lenses without adjustment and realizing high coupling efficiency. That is, this is a technique in which a groove is provided on the substrate corresponding to the position where the optical component is arranged on the substrate, and the optical component is mounted in the groove. Patent Document 4 discloses a technique for recognizing an image of an end face of an optical fiber and an end face of an optical waveguide module and mounting the optical waveguide module so that the end faces are aligned.

JP 2000-47070 A JP 2001-217171 A JP 2004-61541 A JP-A-8-54535

  Here, FIG. 11 shows a usage example of the optical isolator. In the optical isolator 2, a polarizer 22 is bonded to both ends of a Faraday rotator 21, and these components and a magnet 23 that forms a magnetic field are arranged on a base substrate 24. Therefore, there may be variations in assembly accuracy when the Faraday rotator 21 is disposed on the base substrate 24. Accordingly, since the emission position of the emitted light is shifted due to an angular shift or a positional shift during assembly, the light collected by the lens 312 is shifted from the incident surface of the output optical fiber 322 as shown in FIG. The optimum coupling efficiency could not be obtained.

  The techniques disclosed in Patent Documents 1 to 3 can mount an optical module such as the optical isolator 2 at a predetermined position on the substrate with high accuracy, but as described above, the optical isolator 2 itself is mounted. When the assembly accuracy varies, there is a problem that even if the optical isolator 2 is mounted with high accuracy, it is impossible to prevent coupling loss due to the assembly accuracy.

  The technique disclosed in Patent Literature 4 can also easily determine the positional relationship between the optical fiber and the optical module by image recognition, and can prevent the coupling loss due to the positional relationship. No measures are taken for the coupling loss due to the assembly accuracy of the optical module itself.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide an optical device manufacturing method capable of suppressing coupling loss due to assembly accuracy of an optical module.

  An optical device manufacturing method according to the present invention is an optical device manufacturing method in which an optical module having a base substrate and an optical element installed on the base substrate is mounted on a substrate, Detecting an angle formed by incident light and an incident surface on which the incident light is incident or an exit surface on which the incident light passes through and exits the optical element; and the detected angle is a predetermined angle. And mounting the optical module on the substrate.

  According to the present invention, it is possible to provide an optical device manufacturing method capable of suppressing the coupling loss due to the assembly accuracy of the optical module.

1 is a diagram illustrating a configuration example of an optical device according to a first embodiment. 3 is a flowchart of a manufacturing method of the optical device according to the first embodiment. FIG. 6 is a diagram illustrating a configuration example of an optical isolator according to a second embodiment. FIG. 6 is a diagram illustrating a configuration example of an optical device according to a second embodiment. 6 is a flowchart of an optical device manufacturing method according to the second exemplary embodiment; 10 is a flowchart of an optical device manufacturing method according to the third embodiment. FIG. 10 is a top view for explaining the manufacturing process for the optical device according to the third embodiment. 10 is a side view for explaining a manufacturing process of the optical device according to the third embodiment; FIG. FIG. 10 is a top view for explaining the manufacturing process for the optical device according to the third embodiment. FIG. 6 is a diagram illustrating a configuration example of an optical device according to a fourth embodiment. It is a figure which shows the structural example of a related optical device.

Embodiment 1
Embodiments of the present invention will be described below with reference to the drawings. In the optical device shown in FIG. 1, the optical module 1 is mounted on a substrate 4. The optical module 1 includes an optical element 11 and a base substrate 12, and the optical element 11 is installed on the base substrate 12.

  In FIG. 1, light 101 indicated by an arrow enters the optical element 11, passes through the optical element 11, and emits light 102 from the optical element 11. At this time, the optical module 1 is mounted on the substrate 4 so that the optical coupling efficiency between the light 101 and the light 102 is optimized. The reason why the incident surface 13 of the optical element 11 is not perpendicular to the incident light 101 is to remove the influence of the reflected light reflected by the incident surface 13.

  Next, the manufacturing method according to the present embodiment will be described using the flowchart of FIG. First, an angle formed between incident light and an incident surface is detected (S101). If it demonstrates using FIG. 1, the angle a which the incident light 101 and the incident surface 13 of the optical element 11 make is detected. Since the incident surface 13 and the exit surface 14 of the optical element 11 are substantially parallel, the angle between the incident light 101 and the exit surface 14 may be detected.

  Next, the mounting angle of the optical module 1 is adjusted so that the detected angle a is a predetermined angle, that is, as described above, the coupling efficiency between the light 101 and the light 102 is optimal, and the optical module is adjusted. 1 is mounted on the substrate 4.

  Thus, in the present embodiment, the incident surface 13 of the optical element 11 and the incident light 101 incident on the incident surface 13 are not mounted without mounting the optical module 1 based on the position of the base substrate 12. The optical module 1 is mounted on the substrate 4 based on the angle a formed. That is, regardless of the assembly accuracy of the optical module 1, the relationship between the incident light 101 and the incident surface 13 that affects the optical coupling efficiency can be adjusted and mounted. Therefore, even when the assembly accuracy of the base substrate 12 and the optical element 11 provided thereon varies, the light is angled at such an angle that optimum optical coupling efficiency can be obtained without adjusting the optical axis. The module 1 can be mounted on the substrate 4. As a result, labor and cost for adjusting the optical axis can be reduced.

Embodiment 2
A second embodiment according to the present invention will be described. FIG. 3 shows a configuration example of the optical isolator 2 as an example of the optical module. The optical isolator 2 includes an optical element, a magnet 23, and a base substrate 24. Here, the optical element includes a Faraday rotator 21 and a polarizer 22 disposed close to the incident surface side and the exit surface side of the Faraday rotator 21. The Faraday rotator 21 is one of optical rotators having a property of rotating light passing therethrough among optical elements.

  The configuration of the optical isolator 2 shown in FIG. 3 will be described. The optical isolator 2 has a configuration in which a Faraday rotator 21, a polarizer 22, and a magnet 23 are installed on a base substrate 24. Polarizers 22 are arranged close to both sides of the Faraday rotator 21, and magnets 23 are arranged on both sides of the Faraday rotator 21 where the polarizer 22 is not arranged.

  FIG. 4 is a diagram illustrating a configuration example of an optical device in which the optical isolator 2 illustrated in FIG. 3 is mounted on the substrate 4. Lenses 31 (311 and 312) are disposed on both sides of the optical isolator 2, and optical fibers 32 (321 and 322) are disposed on both sides thereof. The light emitted from the input optical fiber 321 enters the incident surface 26 of the polarizer 22 through the lens 311. The light that has passed through the Faraday rotator 21 is emitted from the exit surface 27 of the polarizer 22 and is incident on the output optical fiber 322 via the lens 312. At this time, if the mounting of the optical isolator 2 is not arranged at an appropriate position and angle, the position of the emitted light from the optical isolator 2 is shifted as shown in FIG.

  Next, a manufacturing method of the optical device shown in FIG. 4 will be described using the flowchart of FIG. First, the boundary line 25 between the Faraday rotator 21 and the polarizer 22 located on the incident surface side of the optical isolator 2 is detected (S201).

  Next, an angle b (see FIG. 4) formed by the detected boundary line 25 and the incident light 103 incident on the polarizer 22 of the optical isolator 2 is detected (S202). Then, the optical isolator 2 is mounted so that the angle b becomes a predetermined angle (S203).

  That is, as in the first embodiment, the angle formed by the incident surface 26 of the polarizer 22 and the incident light 103 may be detected, but the incident surface 26 of the polarizer 22 and the boundary line 25 are substantially parallel. Therefore, the mounting angle of the optical isolator 2 can also be adjusted by using the angle b formed by the boundary line 25 and the incident light 103 as in the present embodiment.

Embodiment 3
A third embodiment according to the present invention will be described. In the present embodiment, image recognition is used when arranging the optical module. For example, the optical device is imaged by a camera, and the image processing apparatus processes the acquired image data, thereby determining the optimum angle of the optical module.

  With reference to the configuration of the optical device in FIG. 4, the flowchart according to the present embodiment shown in FIG. 6 will be described. First, the boundary line 25 between the Faraday rotator 21 and the polarizer 22 is imaged by a camera or the like, and image data is acquired (S301). Similarly, the external shape of the input optical fiber 321, that is, the external line 3211 of the optical fiber 321 is imaged to obtain image data (S 302).

  Next, the acquired image data is subjected to image processing, and an angle formed by the detected boundary line 25 and the outline 3211 of the input optical fiber 321 is detected (S303). That is, since it is considered that the outline 3211 of the input optical fiber 321 and the incident light 103 to the polarizer 22 are substantially parallel, the angle formed by the outline 3211 of the input optical fiber 321 and the boundary line 25. By detecting this, the angle formed by the incident light 103 and the incident surface 26 is detected.

  Then, the angle of the optical isolator 2 is adjusted so that the detected angle (the angle of the boundary line 25 with respect to the outline 3211 of the input optical fiber 321) becomes a predetermined angle, and the optical isolator 2 is mounted on the substrate 4 (S304).

  Thus, in the present embodiment, the optical module 2 may be mounted so that the outer line 3211 of the optical fiber 321 and the boundary line 25 form a predetermined angle. Therefore, the optical module 2 can be mounted on the substrate 4 without using the incident light 103 emitted from the optical fiber 321. Furthermore, since the outline 3211 and the boundary line 25 are lines detected from the optical fiber 321, the Faraday rotator 21, and the polarizer 22 that are tangible optical components, they are compared with the incident light 103 that is an intangible laser beam or the like. Thus, it is possible to easily take an image using a camera or the like. Of course, even if this embodiment is used, it can be mounted at an angle at which optimum coupling efficiency can be obtained without adjusting the optical axis.

  At this time, in S301, not the boundary line 25 between the Faraday rotator 21 and the polarizer 22, but the entrance surface 26 or the exit surface 27 of the polarizer 22 may be imaged to obtain image data. However, the entrance surface 26 or the exit surface 27 of the polarizer 22 may be a cut surface for cutting out the optical isolator 2 when the optical isolator 2 is manufactured. May be misrecognized. On the other hand, the boundary line 25 is a surface on which the polarizer 22 and the Faraday rotator 21 are bonded together, so that erroneous recognition due to chipping or the like is not caused. Therefore, it is desirable to detect the boundary line 25 because the boundary line 25 is easier to image than the incident surface 26 or the exit surface 27.

  Here, the manufacturing method of the entire optical device as shown in FIG. 4 will be described in detail with reference to FIGS. First, as shown in FIG. 7, a quadrangular pyramid shape for mounting the V-groove 41 (411, 412) for mounting the input / output optical fiber 32 and the ball lens 33 (331, 332) on the substrate 4 is provided. Grooves 42 (421, 422) are formed. At this time, in order to keep the positions of the optical fiber 32 and the ball lens 33 to be mounted in a later process with high accuracy, it is necessary to suppress the positional deviation of these grooves as much as possible. The reason why the ball lens 33 is used instead of the convex lens such as the lens 31 shown in FIG. 4 is that the ball lens 33 can be mounted in the quadrangular pyramid-shaped grooves 421 and 422 more stably. is there. Further, the shape of the groove is not limited to the V shape and the quadrangular pyramid shape as long as the position and angle of the optical fiber 32 and the ball lens 33 are stably fixed.

  In general, as a method for forming the V-groove 41 and the groove 42 with high accuracy, a method using anisotropic etching is known. For example, in the case of a Si substrate, the V-groove 41 and the groove 42 can be easily produced by utilizing the fact that the etching rate differs with respect to an alkaline etching solution depending on the Si crystal orientation.

  Next, as shown in FIG. 8, the input / output optical fiber 32, the ball lens 33, and the optical isolator 2 are mounted on the substrate 4 on which the grooves are formed, but there is no particular limitation on the mounting order. Note that the input / output optical fiber 32 and the ball lens 33 are mounted in the V-groove 41 and the groove 42, respectively, so that the position can be determined with high accuracy without particularly adjusting the position.

  Here, as to the mounting of the optical isolator 2, as described above, the boundary line 25 at the joint portion of the Faraday rotator 21 and the polarizer 22 is imaged to obtain image data, and the image of the boundary line 25 and the input light Using the image data of the fiber 321, the angle formed by the outer line 3211 of the optical fiber 321 and the boundary line 25 is adjusted to be an optimum angle. As a result, the optical device shown in FIG. 9 can be obtained. At this time, in addition to the image data of the input / output fiber 32, image data of the edge 4111 of the V-groove 41 or image data of the edge 4211 of the quadrangular pyramid-shaped groove 42 may be used. In addition, although there exist the method by an adhesive agent or solder as a fixing method of components, it is not limited to these.

Embodiment 4
A fourth embodiment according to the present invention will be described. The optical device shown in FIG. 10 includes GRIN lenses (gradient index distribution lenses) 34 (341, 342) instead of the ball lens 33 shown in FIG.

  Since the GRIN lens is generally composed of a GI (Graded Index) fiber, if a GI fiber having the same fiber diameter as the input / output optical fiber 32 is used, a V-groove 41 for mounting the input / output optical fiber 32 is used. The same V-groove can be used.

  This eliminates the need to separately etch the groove 42 for disposing the ball lens 33, thereby reducing the optical device manufacturing process.

  Note that the present invention is not limited to the above-described embodiment, and can be changed as appropriate without departing from the spirit of the present invention. In the above embodiment, a line substantially parallel to the incident light (for example, the outline 3211 of the input optical fiber 321 shown in FIG. 4 or the edge 4111 of the groove 411 shown in FIG. 9) is used as a reference. Although the angle of the entrance surface or the exit surface with respect to the line is detected, the present invention is not limited to this. For example, the present invention can also be achieved by detecting the angle formed between the incident light and the incident surface or the exit surface with reference to a line substantially parallel to the incident light provided in advance on the substrate or the outline of the substrate itself. It can be implemented. Further, instead of the entrance surface and the exit surface, among the surfaces of the optical element, a side surface provided with a certain angle (for example, a right angle) with respect to the entrance surface or the exit surface may be used. The present invention can also be implemented by detecting the angle of incident light or the like with respect to the side surface.

DESCRIPTION OF SYMBOLS 1 Optical module 2 Optical isolator 4 Board | substrate 11 Optical element 12 Base base material 13 Incidence surface 14 Outgoing surface 21 Faraday rotator 22 Polarizer 23 Magnet 24 Base base material 25 Boundary line 26 Incident surface 27 Outgoing surfaces 31, 311, 312 Lens 32 , 321, 322 Optical fiber 3211 Optical fiber outline 33, 331, 332 Ball lens 34, 341, 342 GRIN lens 41, 411, 412 V groove 4111 V groove edge 42, 421, 422 groove 4211 groove edge 101-103 light

Claims (8)

An optical device having an optical module having a base substrate and an optical element placed on the base substrate, which is mounted on a substrate,
Detecting an angle formed between incident light incident on the optical element and an incident surface on which the incident light is incident or an exit surface on which the incident light passes through and exits the optical element;
Mounting the optical module on the substrate so that the detected angle is a predetermined angle;
An optical device manufacturing method comprising: The optical element includes an optical rotator and a polarizer provided close to an incident surface side and an output surface side of the optical rotator,
Detecting an angle formed by the incident light and the incident surface or the exit surface;
Detecting a boundary line between the optical rotator and the polarizer;
Detecting an angle formed between incident light incident on the polarizer and the detected boundary line;
The optical device manufacturing method according to claim 1, further comprising: detecting an angle formed between the incident light and the incident surface or the output surface based on an angle formed between the detected incident light and the boundary line. Method. Detecting an angle formed by the incident light and the boundary line,
Detecting an outline of an optical waveguide that emits the incident light; and
Detecting an angle formed by the detected outline and the boundary;
The method of manufacturing an optical device according to claim 2, further comprising: detecting an angle formed by the incident light and the boundary line based on the detected angle formed by the outline and the boundary line. Detecting an angle formed by the incident light and the boundary line,
Detecting an edge of a groove where an optical waveguide for emitting the incident light is installed; and
Detecting an angle formed by the detected edge and the boundary line;
The method for manufacturing an optical device according to claim 2, further comprising: detecting an angle formed between the incident light and the boundary line based on the detected angle formed between the edge and the boundary line. Detecting an angle formed by the incident light and the boundary line,
Detecting an edge of a groove where a lens positioned between the optical waveguide emitting the incident light and the optical module is disposed;
Detecting an angle formed by the detected edge and the boundary line;
The method for manufacturing an optical device according to claim 2, further comprising: detecting an angle formed by the incident light and the detected boundary line based on an angle formed by the detected edge and the boundary line. The step of detecting the boundary line detects the boundary line by imaging the boundary line and processing the acquired image data,
The step of detecting the outline of the optical waveguide comprises:
The method of manufacturing an optical device according to claim 3, wherein the outline is detected by imaging the outline and processing the acquired image data. The step of detecting the boundary line detects the boundary line by imaging the boundary line and processing the acquired image data,
Detecting the edge of the groove in which the optical waveguide is installed,
The method for manufacturing an optical device according to claim 4, wherein the edge is detected by imaging the edge and processing the acquired image data. The step of detecting the boundary line detects the boundary line by imaging the boundary line and processing the acquired image data,
Detecting the edge of the groove in which the lens is installed,
The method of manufacturing an optical device according to claim 5, wherein the edge is detected by imaging the edge and processing the acquired image data.

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