JPS6021006A - Transmitting device of light - Google Patents

Abstract

PURPOSE:To maintain high optical coupling efficiency by supporting an optical fiber opposed to a light source by a fixing material in a penetration hole formed into a supporting body. CONSTITUTION:A laser diode chip 5 is fixed on a sub-mount 4 fixed on a mount 3 through a solder by the solder. The leading end part of the optical fiber 8 is inserted into the hole 20 formed into the supporting body 19 projected on a metallic stem 1, the optical axis of the chip 5 is aligned with that of the optical fiber 8 and then the fixing material 11 is injected into the hole 20 and hardened to support the optical fiber 8. Even if the hardening and contraction of the fixing material 11 starts, the optical fiber 8 is pulled uniformly in the radius direction, so that high optical coupling efficiency with the chip 5 is maintained without changing an axis aligning position.

Description

DETAILED DESCRIPTION OF THE INVENTION [Background Art] The present invention relates to a light propagation device, and particularly to a laser diode device with an optical fiber.

As an optical propagation device, such as an optical communication device.

A combination of a semiconductor laser element and an optical fiber is known. For example, a laser module device using a single mode optical fiber and a semiconductor laser chip is disclosed in Japanese Patent Application Laid-open No. 57-2589.
・Ru. This laser module device has a complicated structure because it uses a condensing lens and the like for optical coupling between the laser chip and the optical fiber.

The applicant of the present application has previously developed a laser diode device with an optical fiber having a structure as shown in FIGS. 1 to 3 as an optical communication device for optical communication. This laser diode device is characterized in that it does not use a condenser lens or the like between the laser chip and the optical fiber, has a simple configuration, and can be miniaturized. This laser diode device is assembled based on a stem 1 of a rectangular plate. That is, the stem 1 is made by cutting one side of a rectangular metal plate to form a ring-shaped sealing wall 2 in the center, and further hollowing out the inside of the ring-shaped sealing wall 2 and having a pedestal part in the center of the bottom surface. It forms 3. A laser diode chip (chip) 5 is fixed by solder onto a submount 4 which is fixed onto this pedestal portion 3 via solder. Furthermore, guide holes 6 and 7 are provided at both ends of the stem 1, respectively, and extend toward the output surface of the chip 5 from which the laser beam is output. A fiber guide 9 in which an optical fiber 8 is inserted and fixed in the center is fitted into one guide hole 6, and is fixed to the °C stem 1 with silver paste 10. The tip of the optical fiber 8 faces one exit surface of the chip 5, and the laser beam is taken into the optical fiber 8. FIG. 3 is an enlarged view showing the part where the tip of the optical fiber is fixed. As also shown in the figure, the tip of the optical fiber 8 is fixed to the pedestal part 3 of the stem 1 with a fixing material 11 such as resin or solder. In this way, consideration is given so that the light intake efficiency (optical coupling efficiency) to the optical fiber 8 does not change due to vibration. In addition, in the case of a single mode fiber in which the core diameter of the optical fiber 8 is about 8 μmφ, in order to obtain a desired optical coupling efficiency that can withstand use, the relative optical axis alignment accuracy of the tip of the optical fiber 8 with respect to the chip 5 is as follows. For example ±
It must be kept within 0.2 to 0.3 μm.

On the other hand, the monitor fiber 1 is placed in the other guide hole 7.
2 is inserted and fixed. This monitor fiber 12
The tip faces the other output surface of the chip 5 and monitors the light intensity of the laser beam. In addition, two leads (terminals) 13 and 14 are arranged on the stem 1.One lead 13 is a ground lead, which is welded to the stem 1, and connects the stem 1 and submount 4.
It is electrically connected to the lower electrode of the chip 5 via.

The other lead 13 is fixed to the stem 1 via a glass (insulator) not shown, and its inner end protrudes from the end surface of the stem 1 into the space inside the ring-shaped sealing wall 2. The inner end of this protrusion and the upper electrode of the chip 5 are electrically connected by a conductive wire 15 made of gold wire. Furthermore, a plate-shaped camp 16 is attached airtightly to the upper surface of the ring-shaped sealing wall 2, rather than a seam weld.

The chip 5 etc. are hermetically sealed.

By the way, the optical axis alignment between the fiber and the laser chip in such a laser diode device is performed by adjusting the optical fiber 8 to a position where the maximum amount of laser light emitted from the fixed laser chip 5 can be taken into the optical fiber.
This is done by accurately measuring °C with a photodetector while moving the temperature, and then fixing the core (-).
According to research conducted by the applicant of the present application, it has been found that even if the optical axes of the optical fiber and the chip are precisely aligned, the optical axis will shift after the optical fiber is fixed and the optical coupling efficiency will deteriorate.

It has been found that the cause of this is that the tip of the optical fiber 8 (optical coupling end) is pulled down and deviated from its original position due to curing and shrinkage of the fixing material 11.

This situation is shown in FIG. FIG. 4 schematically shows a partial cross-section along the A-H line in FIG. , arrows indicate the direction of the pulling force). This reduction is at most 0,
Since the thickness is as much as 3 to 0.4 μm, the optical coupling efficiency decreases, resulting in a decrease in yield. Especially the diameter of the core 21.

In the case of a single-molded fiber of several micrometers, there was a drawback of almost no light being captured (.5).

[Purpose of the invention]

An object of the present invention is to provide a light propagation device 5, such as a laser diode device with an optical fiber, which can maintain high optical coupling efficiency.

[Summary of the invention]

The present invention is an optical fiber-equipped laser diode device having an optical coupling end of an optical fiber arranged so as to come into contact with a laser beam emitted from an output surface of a laser diode chip, wherein the optical fiber is connected to a groove provided in a support body or It is characterized in that it is supported at the center of a fixing material made of resin or brazing material that is filled and hardened in the hole, and is supported while being pulled in the radial direction around the entire outer periphery of the optical fiber.

[Example 1] A laser diode device of this example is shown in FIGS. 5 to 8. This laser diode device is assembled based on a rectangular metal stem 1, similar to the conventional laser diode device shown in FIGS. 1-3. That is, the stem 1 is made by cutting one side of a rectangular metal plate to form a ring-shaped sealing wall 2 in the center, and further hollowing out the inside of the ring-shaped sealing wall 2 and installing a pedestal in the center of the bottom surface. Then, a laser diode chip (chip) is placed on the submount 4 fixed on the pedestal section 3 via solder.
5 is fixed (・) Also, guide holes 6 and 7 are provided at both ends of the stem 1, respectively, each extending toward the emission surface from which the laser beam of the chip 5 is emitted. A fiber guide 9 in which an optical fiber 8 is inserted and fixed in the center is fitted, and is fixed to the stem 1 with silver paste 10.The tip of the optical fiber 8 faces one exit surface of the chip 5, and the laser beam is emitted from the fiber guide 9. is introduced into the optical fiber 8.

At this time, as shown in FIG. 7, the tip end (optical coupling end) of the optical fiber 8 passes through the hole 20 provided in the support 19 protruding from the pedestal 3, and is fixed with a fixing material such as resin or solder. The core of the optical fiber 8 in this embodiment is fixed to the pedestal part 3 of the stem 1, and is designed so that the light intake efficiency (optical coupling efficiency) to the optical fiber 8 does not fluctuate due to vibration. The diameter 21 has a diameter of 5 to 10 μm.Furthermore, the inner pedestal part of the support 19 has an outflow groove of Q, 5 [1 width] to receive and flow the fixing material 11 overflowing from the circular through hole 20. 23 are provided.

Therefore, the end faces of the submount 4 and the chip 5 are not blocked by the fixing material 11 overflowing from the hole 20, and there is no problem in receiving the laser beam 18. Note that the first
As shown in Figure 3, if a body surface 22 is provided on the upper part of the support 19 so that the fiber fixing material 11 can be easily supplied into the hole 20 of about 5 m111φ, the amount of the fixing material can be adjusted freely. , it is possible to prevent excess fixing material from overflowing.

On the other hand, the monitor fiber 1 is placed in the other guide hole 7.
2 is inserted and fixed. This monitor fiber 12
The tip faces the other output surface of the chip 5 and is adapted to monitor the light intensity of the laser beam. Further, two leads 13 and 14 are arranged on the stem 1.

On the other hand, the lead 13 is a ground lead, and the stem I
It is electrically connected to the lower electrode of the chip 5 via the stem 1 and the submount 4. Further, the other lead 13 is fixed to the stem 1 via a non-oral glass (insulator), and its inner end protrudes from the end surface of the stem 1 into the space within the ring-shaped sealing wall 2. This inner end and the upper electrode of the chip 5 are electrically connected by a conductor (wire) 15 made of gold wire. Further, a plate cap 16 is airtightly attached to the upper surface of the ring-shaped sealing wall 2 by seam welding, thereby airtightly sealing the chip 5 and the like.

〔effect〕

When assembling such a laser diode device, after aligning the optical axes of the chip 5 and the optical fiber 8,
The fixing material 11 is supplied into the hole 20 through which the optical fiber 8 passes, and the fixing material 11 is hardened and pushed.As shown in FIG. will be supported. As a result, even if the fixing material 11 begins to harden and shrink, the entire outer circumference of the optical fiber 8 is pulled uniformly in the radial direction.
The optical coupling efficiency can be maintained at high degrees Celsius.

Therefore, a laser diode device with good optical coupling efficiency can be manufactured with high yield.

[Example 2] The present invention is not limited to the above example. For example, as shown in FIG. 9, a groove 24 is provided in the support 19 that supports the optical fiber 8, the optical fiber 8 passes through the center of the groove 24, and the fixing material 11 filled in the groove 24 is used to secure the optical fiber 8. Even if the entire outer periphery is supported, the optical fiber 8 is fixed while maintaining the optical axis alignment state as in the previous embodiment.

[Example 3] As shown in FIG. 1O, the support 19 that supports the optical fiber 8 is provided with a cutout (narrow groove) 25 and a hole 26 connected to this.
The entire outer periphery of the optical fiber 8 may be supported by the fixing material 11 that penetrates through the center of the optical fiber 8 and fills the groove 26 . As shown, the width W of the groove 26 is smaller than the diameter of the hole 26. Therefore, Embodiment
As in case 1, the entire outer periphery of the optical fiber 8 is pulled uniformly in the radial direction, so that it can be fixed without changing its position during optical axis alignment.

In this case, there is an advantage that the fixing material 11 for fixing the optical fiber can be efficiently injected from the narrow groove 25 into the hole 26.

The external appearance of the support body 19 shown in FIG. 10 has a structure in which a groove 25 connected to a hole 26 is formed, as shown in FIG. Note that the support body 19 may have a structure having an injection port 27 for injecting the fixing material as shown in FIG. If this is done, the optical fiber 8 can be guided through the groove 26 to the hole 26 when assembling the laser diode device, which is convenient. It goes without saying that the holes 26 may be provided in the lateral portions of the support 19 instead of in the upper portion.

As described above, according to the present invention, it is possible to provide a laser diode device with an optical fiber that can maintain high optical coupling efficiency.

The present invention is applicable to optical propagation devices using fibers for acoustics and communications, and is most effective when applied to laser diode devices with single-mode fibers in which the core diameter of the optical fiber is small.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway plan view of a laser diode device with an optical fiber that was previously developed by the present inventor, and FIG. 2 is a cross-sectional view taken along the line ■-■ in FIG. FIG. 3 is an enlarged sectional view showing a part of FIG. 2. FIG. 4 is a sectional view taken along the line I-I in FIG. 1 to explain the drawbacks of the prior art, and FIG. 5 is a partially cutaway view of a laser diode device with an optical fiber, which is an embodiment of the present invention. Figure 6 is a cross-sectional view taken along line V-V in Figure 4, Figure 7 is a plan view of the
An enlarged sectional view showing a part of the figure, FIG. 8 is III- of FIG.
FIG. 9 is an enlarged sectional view showing an optical fiber support section taken along line III. FIG. 9 is an enlarged sectional view showing an optical fiber support section in a laser diode device with an optical fiber according to another embodiment of the present invention. FIG. 10 is an enlarged sectional view showing an optical fiber support portion in a laser diode device with an optical fiber, which is still another embodiment of the present invention. FIG. 11 is a perspective view of the optical fiber support section shown in FIG. 10. FIG. 12 is a perspective view showing another modification of the optical fiber support section. FIG. 13 is a sectional view showing a modification of the optical fiber support section. DESCRIPTION OF SYMBOLS 1... Stem, 3... Base part, 4... Submount, 5... Chip, 8... Optical fiber, 11...
・Fixing material, 12°° monitor fiber, 13.14
...Lead, 15...Wire, 16...Cap, 18...Laser light, 19...Support, 20...
- Hole, 21... Core diameter, 22... Slope, 23...
outflow groove. Figure 1 Figure 3 / Figure 14 Figure 7 Figure S Figure 9 Figure 10 Figure 13

Claims (1)

[Scope of Claims] 1. A light emitting means, an optical fiber for propagating the light emitted from the light emitting means, and a support for supporting the optical fiber, the support for passing the optical fiber through the support. A light propagation device characterized in that a through hole is provided, and the optical fiber is supported within the through hole by a fixing member. 2. The upper part of the support body is connected to the through hole. 2. The light propagation device according to claim 1, further comprising a groove for injecting the fixing material along the through hole. 3. The light propagation device according to claim 1 or 2, wherein the width of the groove is smaller than the diameter of the through hole. 4. The light propagation device according to claim 1, wherein an injection port for injecting a fixing material connected to the through hole is provided in the upper part of the support body.