JPH06281846A - Optical coupling method for semiconductor laser and optical fiber - Google Patents

Abstract

PURPOSE:To easily and efficiently execute optical coupling of a semiconductor laser and an optical fiber. CONSTITUTION:On the upper side of a sub-mount 26, a semiconductor laser 1 provided with a stripe light emitting part 3 in the inside is provided, and on the right above side of the semiconductor laser 1, an electrode 2 is provided. An optical fiber 4 is arranged so as to be opposed to a stripe emitting end 13 of the semiconductor laser 1, and image pickup cameras 5, 6 observing the stripe emitting end 13 side of the semiconductor laser 1 and an incident side tip 14 side of the optical fiber 4 are provided on the upper face side of the semiconductor laser 1, and the side face side being orthogonal thereto respectively. An image observed by the image pickup cameras 5, 6 is displayed on an image processing part 20, a deviation between an optical axis of the stripe light emitting part 3 and an optical axis of the optical fiber 4 core is detected, and based on its result, an optical fiber driving mechanism 22 is moved in the X and the Y directions under the control of a feedback control part 21, and a deviation of each optical axis is corrected. In such a way, a relative position of the semiconductor laser 1 and the core of the optical fiber 4 is adjusted, and optical coupling of the semiconductor laser 1 and the optical fiber 4 is executed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical coupling method between a semiconductor laser and an optical fiber, which is carried out, for example, in manufacturing a semiconductor module.

[0002]

2. Description of the Related Art When manufacturing an optical semiconductor module,
It is necessary to make an optical coupling between the semiconductor laser and the optical fiber. As shown in FIG. 3, the optical coupling between the semiconductor laser and the optical fiber is performed by first driving the semiconductor laser 1 to oscillate and emit the light of the semiconductor laser 1 from the stripe emission end 13.
While observing with the imaging camera 5 provided on the upper side of the semiconductor laser 1, the tip 14 on the incident side of the optical fiber 4 is brought closer to the stripe emission end 13 via a certain distance A, and the core of the semiconductor laser 1 is placed on the core of the optical fiber 4. Inject light. Next, a light reception detection monitor connected to the end face 15 on the emission side of the optical fiber 4.
The intensity of the light emitted from the core of the optical fiber 4 is measured by means of 16, and the incident side tip 14 side of the optical fiber 4 is moved so that this optical intensity becomes an optimum value. Thereby, the optical axes Z of the semiconductor laser 1 and the core of the optical fiber 4 are aligned, the relative positions of the semiconductor laser 1 and the optical fiber 4 are adjusted, and the semiconductor laser 1 and the optical fiber 4 are optically coupled.

[0003]

However, when the relative position between the semiconductor laser 1 and the core of the optical fiber 4 deviates from the tolerance of the optical fiber (the allowable range of deviation from the optimum position), the semiconductor laser 1 is The light of the stripe light emitting portion 3 cannot be made to enter the core of the optical fiber 4 even a little. Especially, when the optical fiber 4 is a single mode fiber, the tolerance of the optical fiber is as small as several μm, and therefore the semiconductor laser 1 It was difficult to move the incident side tip 14 side of the optical fiber 4 to the position where the light of the striped light emitting portion 3 enters the core of the optical fiber 4.

Further, even after the tip 14 side of the optical fiber 4 is moved to a position where the light of the stripe light emitting portion 3 of the semiconductor laser 1 is incident on the core of the optical fiber 4, the optical fiber detected by the light reception detection monitor 16 is detected. It takes time to move the tip 14 side of the optical fiber 4 so that the intensity of the emitted light of 4 becomes the optimum value and adjust the relative position of the semiconductor laser 1 and the optical fiber 4. When the relative position of the fiber 4 is largely deviated from the optimum position, it takes a very long time to find the optimum peak of the light emitted from the optical fiber 4 detected by the light reception detection monitor 16.

When the relative position between the semiconductor laser 1 and the optical fiber 4 is fixed at the optimum position for the purpose of manufacturing an optical semiconductor module, etc., after adjusting the relative position between the semiconductor laser 1 and the optical fiber 4 to the optimum position. , Before fixing the position
If the position is displaced for some reason, there is no means for immediately detecting the direction of the displacement, and the relative position between the semiconductor laser 1 and the optical fiber 4 must be adjusted again from the beginning, which is a troublesome process. And was inefficient. Further, it is difficult to precisely place an object having a step at a minute distance because the object is out of focus.

The present invention has been made to solve the above-mentioned conventional problems, and an object thereof is to facilitate the optical coupling between the semiconductor laser and the optical fiber, and to efficiently perform the semiconductor laser and the optical fiber. An object is to provide an optical coupling method.

[0007]

In order to achieve the above object, the present invention is constructed as follows. That is, the present invention is linked to a drive mechanism that moves an optical fiber facing the stripe emission end side of a semiconductor laser in the Z-axis direction of the optical axis and in the X-axis and Y-axis directions orthogonal to the Z-axis. Every time, the stripe light emitting portion on the emitting end side of the semiconductor laser and the core of the optical fiber are observed by the imaging camera from two directions, that is, the upper surface side of the semiconductor laser and the side surface side orthogonal to this, and the stripe light emission is performed using the images of each imaging camera. Of the X-axis direction and the Y-axis direction between the section and the optical fiber core is detected, and the drive mechanism is moved in the X and Y directions to correct the deviation to adjust the relative position between the semiconductor laser and the optical fiber core. It is configured as a feature.

[0008]

In the present invention having the above structure, the stripe light emitting portion on the stripe emission end side of the semiconductor laser and the core of the optical fiber are observed by the imaging camera from two directions, that is, the upper surface side of the semiconductor laser and the side surface side orthogonal thereto. . The image of each image pickup camera is displayed on the image processing unit, and the displacement between the stripe light emitting unit and the core of the optical fiber in the X-axis direction and the Y-axis direction is detected by this display. Based on this detection result, the relative position between the semiconductor laser and the optical fiber core is adjusted by moving the drive mechanism in the X and Y directions for correcting the deviation.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. In the description of the present embodiment, the same parts as those of the related art will be designated by the same reference numerals, and the duplicate description thereof will be omitted. FIG. 1 shows an embodiment of an apparatus used for the optical coupling method between a semiconductor laser and an optical fiber according to the present invention. Figure 1
In FIG. 3, the rectangular parallelepiped semiconductor laser 1 is mounted and bonded on the upper side of the submount 26, and the electrode 2 is bonded on the upper side of the semiconductor laser 1. Outer peripheral edge 9 of electrode 2 and upper peripheral edge of semiconductor laser 1
The distance to 10 is 20 μm, and the area of the electrode 2 is smaller than that of the upper surface of the semiconductor laser 1 by that amount.

A stripe light emitting section 3 is provided inside the semiconductor laser 1, and the stripe light emitting section 3 becomes a mirror surface state of the semiconductor laser 1 from the outside of the semiconductor laser 1 by the light emitted when the semiconductor laser 1 is driven. You can see through the outer peripheral surface.

An optical fiber 4 is arranged to face the stripe emission end 13 side of the semiconductor laser 1, and the optical fiber 4 is linked to an optical fiber drive mechanism 22. The optical fiber drive mechanism 22 causes the optical axis of the optical fiber 4 to move. It is configured to be freely movable in the Z direction and the X and Y directions orthogonal to the Z direction. The optical fiber 4 is a spherical single-mode fiber, and the tip side of its core is tapered.

An image pickup camera 5, which is an infrared camera, is provided on the upper surface side (Y direction in the drawing) of the semiconductor laser 1.
The stripe light emitting portion 3 and the optical fiber 4 of the semiconductor laser 1 can be imaged from the upper surface side. Further, the side surface front side (X direction in the drawing) orthogonal to the upper surface side of the semiconductor laser 1
An image pickup camera 6 which is an infrared camera is provided in the device, and like the image pickup camera 5, the stripe light emitting portion 3 and the optical fiber of the semiconductor laser 1 can be observed and imaged from the side surface side.

The image pickup cameras 5 and 6 are connected to an image processing section 20, and the image processing section 20 is connected to a feedback control section 21. The image processing unit 20 simultaneously displays the images captured by the imaging cameras 5 and 6 on the same screen, and the stripe light emitting unit 3
And the function of detecting the deviation between the X-axis direction and the Y-axis direction of the optical fiber 4 core. The feedback control unit 21 is connected to the optical fiber drive mechanism 22, and the feedback control unit 21 shifts the stripe light emitting unit 3 and the optical fiber 4 core detected by the image processing unit 20 in the X-axis direction and the Y-axis direction. The optical fiber driving mechanism 22 is moved in the direction for correcting

The present embodiment is constructed as described above,
Next, the operation will be described. First, the semiconductor laser 1
Is driven to emit laser light from the stripe light emitting portion 3 of the semiconductor laser 1. Next, the focus of the image pickup cameras 5 and 6 is adjusted to the stripe light emitting unit 3, and the images of the image pickup cameras 5 and 6 are displayed on the screen of the image processing unit 20.

On the screen of the image processing section 20, as shown in FIG. 2, the images of the image pickup cameras 5 and 6 are simultaneously displayed on the same screen. On the upper half surface of the screen, images of the stripe emission end 13 side of the semiconductor laser 1 and the incident side tip 14 side of the optical fiber 4 on the XZ plane (images viewed from the upper side), which are imaged by the imaging camera 5, are displayed. On the lower half surface of the screen, an image of the YZ plane (image viewed from the side) of the stripe emission end 13 side of the semiconductor laser 1 and the incident side tip 14 side of the optical fiber 4 captured by the imaging camera 6 is displayed. It

Next, the optical fiber drive mechanism 22 is activated,
The optical fiber 4 is moved in the Z-axis direction and the optical fiber 4 is incident so that the distance between the tip 14 of the optical fiber 4 and the stripe emission end 13 of the semiconductor laser 1 is 10 μm while observing the screen of the image processing unit 20. The tip 14 side of the side is brought close to the stripe emission end 13 of the semiconductor laser 1.

Next, the deviation between the optical axis 23 of the stripe light emitting section 3 of the semiconductor laser 1 and the optical axis 24 of the core 12 of the optical fiber 4 is detected by the image processing section 20, and the detection result signal is sent to the feedback control section 21. To transmit.

Based on the signal sent from the image processing section 20, the feedback control section 21 corrects the deviation between the optical axis 23 of the stripe light emitting section 3 of the semiconductor laser 1 and the optical axis 24 of the optical fiber core 12 in the XY directions. The optical fiber drive mechanism 22 is moved. By this movement, the optical axes 23 and 24 of the stripe light emitting portion 3 and the optical fiber core 12 are aligned with each other, and the optical fiber 4 is moved in such a direction that the light of the stripe light emitting portion 3 enters the center of the core 12. In this way, the relative positions of the semiconductor laser 1 and the optical fiber core 12 are adjusted, and the semiconductor laser 1 and the optical fiber 4 are optically coupled.

As described above, according to this embodiment, the stripe light emitting section 3 of the semiconductor laser 1 is driven by the image pickup cameras 5 and 6.
The core 12 of the optical fiber 4 and the core 12 of the optical fiber 4 are observed and imaged from two directions of the upper surface side and the side surface side of the semiconductor laser 1, and the captured images are simultaneously displayed on the same screen by the image processing unit 20, and the stripe emission of the semiconductor laser 1 is performed. Optical axis 23 of section 3 and optical fiber 4
To detect the deviation of the optical axis 24 of the core 12 of
The 24 deviations in the X and Y directions can be detected at the same time. Therefore, the signal processing time required to detect the deviation between the optical axes 23 and 24 can be shortened, and the optical axes 2 and 24 can be processed in a short time.
Deviations of 3 and 24 can be detected.

Further, based on the detection result, the feedback control section 21 moves the optical fiber drive mechanism 22 so that the deviation between the optical axes 23 and 24 is corrected, and the optical fiber 4 is moved, thereby facilitating the operation. Optical axis 24 of core 12 of optical fiber 4
Can be aligned with the optical axis 23 of the stripe light emitting portion 3 of the semiconductor laser 1. Therefore, unlike the conventional example, it does not take time to adjust the relative position between the semiconductor laser 1 and the optical fiber core 12, and the adjustment can be performed in a short time.

Further, the semiconductor laser 1 and the optical fiber core 12
After fixing the relative position with, when fixing the optical fiber 4,
Even if the position of the optical fiber 4 is slightly deviated for some reason, the direction of the deviation can be immediately known by observing the imaging cameras 5 and 6, and thus the deviation can be corrected immediately. Semiconductor laser 1 and optical fiber core 12
It is also possible to efficiently correct the positional deviation between and.

Further, the stripe emission end of the semiconductor laser 1
Even when 13 is brought closer to the tip 14 side of the optical fiber 4 on the incident side, it can be observed from two directions by the imaging cameras 5 and 6, so that the stripe exit end 13 and the tip 14 side of the optical fiber 4 on the incident side can be observed. The distance can be measured accurately,
The operation for that can also be performed easily.

The constitution of the present invention is not limited to the above-mentioned embodiment, and various embodiments can be adopted. For example, the optical fiber 4 used in the above embodiment is a spherical single-mode fiber, and the core 12 has a tapered tip end side. However, the optical fiber 4 may be a multimode fiber, and the shape thereof is also spherical. Not limited to optical fiber, core
The present invention can also be applied to the case where the optical fiber 4 other than the one in which the tip end side of 12 is tapered is used. However, the single mode fiber 4 used in this example is
Is extremely fine, and the alignment of the optical coupling with the semiconductor laser 1 is particularly difficult. Therefore, according to the present invention, the optical coupling of such an optical fiber 4 can be easily performed in a short time. Even if you change the type and shape of 4,
Optical coupling with the semiconductor laser 1 can be more easily performed in a short time.

In the above embodiment, the distance between the outer peripheral edge 10 of the upper surface of the semiconductor laser 1 and the outer peripheral edge 9 of the electrode 2 is 20 μm.
However, this distance may be 20 μm or more, and if the area of the electrode 2 is large enough to fulfill the function of the electrode 2, the outer peripheral edge 9 of the electrode 2 and the outer peripheral edge of the upper surface of the semiconductor laser 1 are defined.
The 10 distances can be widely separated.

Furthermore, in the above embodiment, the image pickup camera 6 is provided on the front side of the side surface orthogonal to the upper surface side of the semiconductor laser 1, but the image pickup camera 6 is provided on the side surface orthogonal to the upper surface side of the semiconductor laser 1 of the semiconductor laser 1. You may comprise so that it may be provided in the back side.

Further, in the above embodiment, the semiconductor laser 1 was mounted on the submount 26 and bonded, but
The semiconductor laser 1 is not necessarily mounted on the submount 26, may be mounted on a stem or the like, may not be bonded after mounting, and may be mounted by, for example, solder or the like. .

Further, in the above embodiment, the image pickup camera 5,
The image No. 6 is displayed on the image processing unit 20, and the optical fiber drive mechanism 22 is driven and controlled by the control of the feedback control unit 21, but the feedback control unit 21 is not necessarily provided, and the display of the image processing unit 20 is displayed. Accordingly, the optical fiber drive mechanism 22 may be manually driven.

Furthermore, in the above embodiment, the images of the image pickup cameras 5 and 6 are simultaneously displayed on the same screen by the image processing section 20, but they are separately displayed on the same screen by switching a switch or the like. Also, the imaging camera 5
It is also possible to provide and display separate screens for the camera and the imaging camera 6. However, in these cases, the optical axis 23 of the stripe light emitting portion 3 of the semiconductor laser 1 and the optical axis 24 of the core 12 of the optical fiber 4 are used.
The time of the signal processing performed to detect the deviation from
It takes a little longer than the case where the images of the imaging cameras 5 and 6 are simultaneously displayed on the same screen.

[0029]

According to the present invention, the semiconductor laser is observed from two directions, that is, the upper surface side and the side surface orthogonal to the upper surface side of the semiconductor laser, by using the images of the respective imaging cameras, and the stripe emission part and the X-ray of the optical fiber core are observed. Since the deviation between the axial direction and the Y-axis direction is detected, this deviation can be easily detected in a short time. Further, based on the inspection result, the drive mechanism is moved in the X and Y directions for correcting the displacement to adjust the relative position between the semiconductor laser and the optical fiber core, so that the adjustment is easy and the adjustment time is short. I need time.

When the semiconductor laser and the optical fiber are fixed, once the relative position between the semiconductor laser and the optical fiber core is adjusted, and if the position is slightly deviated before the fixing, the deviation is immediately detected by the image pickup camera. It is possible to detect and correct the shift immediately. Therefore, by using the present invention, the optical coupling between the semiconductor laser and the optical fiber can be easily and efficiently performed, and the time for assembling can be greatly saved when manufacturing an optical semiconductor module. it can.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an apparatus used for optical coupling between a semiconductor laser and an optical fiber according to the present invention.

FIG. 2 is an explanatory diagram showing an image of an image pickup camera displayed on a screen of an image processing unit of the apparatus.

FIG. 3 is an explanatory diagram showing a conventional optical coupling method of a semiconductor laser and an optical fiber.

[Explanation of symbols]

 1 semiconductor laser 2 electrode 3 stripe light emitting part 4 optical fiber 5, 6 imaging camera 12 cores

Claims (1)

[Claims] 1. An optical fiber facing the stripe emission end side of a semiconductor laser is linked to a drive mechanism that moves in the Z-axis direction of the optical axis and in the X-axis and Y-axis directions orthogonal to the Z-axis. The stripe light emitting part on the emitting end side of the semiconductor laser and the core of the optical fiber are observed by an imaging camera from two directions, that is, the upper surface side of the semiconductor laser and the side surface orthogonal to the upper surface side of the semiconductor laser. And a semiconductor laser that detects a shift between the X-axis direction and the Y-axis direction of the optical fiber core, and moves the drive mechanism in the X and Y directions to correct the shift and adjusts the relative position between the semiconductor laser and the optical fiber core. Optical coupling method with optical fiber.