JP2002116354A - Laser diode module for communication - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an LD(Laser Diode) module for communication which is easy to assemble, and has high stability against an external force, etc., converges laser beam from an LD by a lens and makes the laser beam incident on an optical fiber. SOLUTION: A relay pipe 13 is fixed by laser welding to an end surface of a heat sink 12 fitted with an LD element 1, one end of a pipe 14 which supports a collimator lens 2 is inserted into the relay pipe 13 and fixed by laser welding, and one end of a pipe 16 which supports a condenser lens 3 is inserted into the other end of the pipe 14 and fixed by laser welding; and one end of a holder 17 is made to abut against the other end of the pipe 16, and a ferrule 18 to which one end of the optical fiber 4 is fitted is inserted into the other end of the holder 17. Further, a ferrule 18 is fixed to the holder 17 by laser welding and the other end of the pipe 16 and one end of the holder 17 are fixed by laser welding.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication laser diode module, and more particularly to a structure of a communication laser diode module which is easy to assemble and has high stability.

[0002]

2. Description of the Related Art A laser diode module for communication is
A laser beam emitted from a laser diode (LD) is condensed by a lens and made incident on an optical fiber. FIG. 4 shows a configuration of a conventional typical butterfly-type communication LD module. The LD element 1 and the collimator lens 2 are axially mounted inside the case 5, and the condenser lens 3 is axially aligned with the collimator lens 2 outside one end of the case 5. The optical fiber 4 is attached to the holder of the condenser lens 3 so that the end of the optical fiber 4 coincides with the light spot. Note that an isolator may be attached to the exit side of the collimator lens 2 inside the case 5.

[0003]

In order to assemble a conventional communication LD module as shown in FIG. 4, optical components such as an LD element 1, a collimator lens 2, and an isolator are put in a case 5 and attached while being adjusted. Do. At present, the space in the case 5 is narrow, and when assembling is to be automated, work efficiency is poor, reproducibility is poor, and automation is difficult at present.

[0004] Moreover, as is apparent from the configuration of FIG.
When the case 5 is deformed due to a temperature change or an impact, the influence is transmitted to the optical components such as the LD element 1 and the collimator lens 2, so that the alignment state is easily broken and the stability is not always high.

The present invention has been made in view of such problems of the prior art, and an object of the present invention is to make it easy to assemble a communication LD module in which laser light from an LD is condensed by a lens and incident on an optical fiber. An object of the present invention is to provide a structure that is highly stable against temperature changes, external forces, and the like.

[0006]

A communication laser diode module according to the present invention that achieves the above object is a communication laser diode module in which laser light from a laser diode is condensed by a lens and incident on an optical fiber. One end of the relay pipe is fixed by laser welding to the end surface of the heat sink to which is attached, and one end of a collimator lens holder pipe supporting a collimator lens is inserted into the other end of the relay pipe to surround the relay pipe. One end of the condenser lens holder pipe supporting the condenser lens is inserted into the other end of the collimator lens holder pipe by laser welding at a plurality of positions of the collimator lens holder pipe. Is fixed by laser welding at the position One end of the optical fiber holder pipe is abutting facing the other end of the condenser lens holder pipe,
And, a ferrule which is attached to the other end of the optical fiber holder pipe, with one end of the optical fiber attached to the center, is inserted, and the ferrule is fixed by laser welding at a plurality of positions around the optical fiber holder pipe by laser welding. Further, the other end of the condenser lens holder pipe and one end of the optical fiber holder pipe are fixed at a plurality of peripheral positions by laser welding.

Another communication laser diode module according to the present invention is a communication laser diode module in which laser light from a laser diode is condensed by a lens and is incident on an optical fiber. One end of the relay pipe is fixed by laser welding, and one end of a condenser lens holder pipe that supports the condenser lens is inserted into the other end of the relay pipe, and laser beams are inserted at a plurality of positions around the relay pipe. A ferrule fixed by welding, one end of the optical fiber holder pipe is abutted on the other end of the condenser lens holder pipe, and one end of the optical fiber is mounted in the other end of the optical fiber holder pipe. Is inserted around the optical fiber holder pipe. The ferrule is fixed by laser welding at a plurality of positions by laser welding, and the other end of the condenser lens holder pipe and one end of the optical fiber holder pipe are fixed by laser welding at a plurality of peripheral positions. It is characterized by having.

In these cases, the Peltier element is fixed at a predetermined position on the bottom of the case box having an opening on one side, and the other end of the optical fiber is inserted into the opening from inside the box. The heat sink is fixed to the Peltier element so that the heat sink is located on the Peltier element, and a protective pipe is placed around the optical fiber holder pipe and ferrule that came out of the opening, and one end is fixed to the side of the box It is desirable to be.

In the present invention, one end of a relay pipe is fixed to an end surface of a heat sink to which a laser diode is attached by laser welding, and a collimator lens holder pipe supporting a collimator lens in the other end of the relay pipe. One end is inserted and fixed by laser welding at a plurality of positions around the relay pipe, and one end of the condenser lens holder pipe supporting the condenser lens is inserted into the other end of the collimator lens holder pipe. It is fixed by laser welding at a plurality of positions around the collimator lens holder pipe, one end of the optical fiber holder pipe faces the other end of the condenser lens holder pipe, and the other end of the optical fiber holder pipe A ferrule attached to the center of one end of the optical fiber is inserted The ferrule is fixed by laser welding at a plurality of positions around the optical fiber holder pipe by laser welding, and the other end of the condenser lens holder pipe and one end of the optical fiber holder pipe are laser welded at a plurality of positions around the optical fiber holder pipe. Or the collimator lens is omitted, and the condenser lens holder pipe is directly fixed to the relay pipe in the same way, so that assembly is easy to automate, workability is good, and reproducibility is good. Become. In addition, since the support between the holders is fixed by fitting and laser welding at the surrounding axisymmetric position, even if there is a temperature change or impact, there is little effect on the alignment accuracy, and durability against temperature change and impact It has excellent properties.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction and assembling process of an embodiment of a butterfly type communication LD module according to the present invention will be described below with reference to FIGS.

FIG. 1 is a sectional view of the assembled communication LD module, FIG. 2 is a sectional view of a main part of the communication LD module before being inserted into a case, and FIG. 3 is a communication LD module of FIG. FIG. 3 is an exploded perspective view of a main part.

First, referring to FIGS. 2 and 3, a communication LD
The configuration of the main part of the module and the assembly process will be described.

The LD element 1 is mounted on a heat sink 12 made of copper or the like via a mounting substrate 11 so as to be aligned with an end face 12 '. This heat sink 1
The relay pipe 13 is attached to the end face 12 ′ of the second so that the central axis coincides with the light emission center of the LD element 1. A flange 13 ′ is provided at one end of the relay pipe 13 for the attachment. By irradiating YAG laser light to both sides of the flange 13 'as shown by the arrow in FIG.
Is welded to the end face 12 '.

Thereafter, the small diameter portion 14 'of the collimator lens holder pipe 14 is inserted into the other end of the relay pipe 13. The collimator lens holder pipe 14 is the small diameter part 1
The collimator lens 2 is mounted at a predetermined position inside the small-diameter portion 14 ′, and the small-diameter portion 14 ′ is inserted into the relay pipe 13. In this state, the outer periphery of the relay pipe 13 is irradiated with YAG laser light at three places at 120 ° intervals as shown by arrows in FIG. 2 (in FIG. Although it is shown in the figure, it is actually 1
Because of the 20 ° interval, only one location can be shown. Less than,
the same. ), The relay pipe 13 and the collimator lens holder pipe 14 are mutually welded and fixed.

The outer periphery of the large-diameter portion 14 "is inserted in the large-diameter portion 14" of the collimator lens holder pipe 14 welded to the relay pipe 13 with the isolator holder pipe 15 having the isolator 6 fixed therein inserted therein. Figure 2
By irradiating the YAG laser light at three places at 120 ° intervals as indicated by arrows, the isolator 6 is fixed in the collimator lens holder pipe 14 by welding.

In this state, the small diameter portion 16 'of the condenser lens holder pipe 16 is inserted into the large diameter portion 14 "of the collimator lens holder pipe 14. The condenser lens holder pipe 16 is connected to the collimator lens holder pipe 14. Similarly, the small diameter portion 16 'and the large diameter portion 16 "are coaxially connected, and the condenser lens 3 is mounted at a predetermined position inside the small diameter portion 16', and the small diameter portion 16 'is collimated. As shown by an arrow in FIG. 2, in this state, as shown by the arrow in FIG. 2, the outer periphery of the large diameter portion 14 ″ of the collimator lens holder pipe 14
By irradiating the YAG laser light at three places at intervals of 20 °, the collimator lens holder pipe 14 and the condenser lens holder pipe 16 are welded and fixed to each other.

Thereafter, the small diameter portion 17 'and the flange-shaped large diameter portion 17 "
Large diameter part 1 of optical fiber holder pipe 17 made of
The 7 ″ end face is connected to the large diameter portion 1 of the condenser lens holder pipe 16.
A ferrule 18 attached to the end face of the 6 ″ optical fiber holder pipe 17 and having one end of the single mode optical fiber 4 attached to the small diameter portion 17 ′ of the optical fiber holder pipe 17 is inserted, and the LD element 1 emits light in that state. While monitoring the light coupled to the optical fiber 4 at the other end of the optical fiber 4, the position of the optical fiber holder pipe 17 is adjusted vertically with respect to the central axis, and the direction along the central axis within the small diameter portion 17 'of the optical fiber holder pipe 17. The position of the end of the optical fiber 4 is adjusted to find a position where the laser light from the LD element 1 can be coupled with the least loss. By irradiating the outer periphery with three YAG laser beams at 120 ° intervals as shown by arrows in FIG. The ferrule 18 is welded and fixed to the chromatography holder pipe 17. Then, a flange-like large-diameter portion 17 "
Then, as shown by arrows in FIG. 2, the optical fiber holder pipe 17 is welded and fixed to the large-diameter portion 16 ″ of the condenser lens holder pipe 16 by irradiating YAG laser light at three places at 120 ° intervals. .

As described above, the heat sink 12 and the relay pipe 13 (), the relay pipe 13 and the collimator lens holder pipe 14 (), the collimator lens holder pipe 14 and the isolator holder pipe 15
(), The collimator lens holder pipe 14 and the condenser lens holder pipe 16 (), the condenser lens holder pipe 16 and the optical fiber holder pipe 17 (), the optical fiber holder pipe 17 and the ferrule 18 () supporting the optical fiber 4 are mutually connected. It is fixed by welding with a YAG laser beam. To facilitate welding, the relay pipe 13, the collimator lens holder pipe 14, the isolator holder pipe 15, the condenser lens holder pipe 16, and the optical fiber holder pipe 17 are made of metal such as stainless steel. It is preferable that the outer periphery of the ferrule 18 be made of a similar metal integrated.

The communication L assembled as described above
The main part of the D module is inserted into a box 21 for a case 20 having an opening 23 on one side as shown in FIG. The LD module is completed. More specifically, a Peltier element (thermoelectric conversion element utilizing the Peltier effect) 19 is fixed at a predetermined position on the bottom of the box 21.
Open the other end of the optical fiber 4 from the inside of the box 21 to the side opening 2
2, the main part of the communication LD module assembled as shown in FIG. 2 is put in the box 21 and the heat sink 12 is fixed on the Peltier element 19 so that the heat sink 12 is located on the Peltier element 19. I do. On the other hand, a protective pipe 24 is placed around the small-diameter portion 17 ′ of the optical fiber holder pipe 17 that has come out of the opening 23 and the ferrule 18, and one end thereof is fixed to the side surface of the box 21.
A rubber foot 25 is fitted between the other end of the protection pipe 24 and the optical fiber 4 and the ferrule 18 protruding therefrom so as to protect the base of the optical fiber 4.
Then, the lid 22 is fixed to the box 21. In this way,
The exterior of the communication LD module of the present invention is completed. Note that, in FIG. 1, a small circle indicates a YAG laser welded portion corresponding to the circles in FIG.

As is clear from the above description, in the communication LD module of the present invention, the mounting and adjusting work of the optical parts in the conventional horizontal case is eliminated, and the optical part holders are sequentially fitted in the axial direction. By performing adjustment and fixing in the case, and then integrally moving it into the case, assembly can be easily automated, workability is good, and reproducibility is good. Further, since the support fixing between the optical component holders is performed by laser welding at a position axisymmetric around the optical component holder, even if there is a temperature change or a shock, the influence on the alignment accuracy is small, and specifically, -40 ° C or more. Even if the cycle strength stability test is performed 20 times in the temperature range of + 80 ° C., no problem occurs, and the durability against temperature change and impact is excellent. In addition, since such a communication LD module body is assembled and fixed and then integrally mounted in the case, even if the case is deformed due to a temperature change or an impact, it is difficult for the influence to be transmitted to the communication LD module body. From this point, the durability is excellent.

By the way, in the above embodiment, the LD
Is collimated by the collimator lens 2 and then focused on the end of the optical fiber 4 by the condenser lens 3. However, the collimator lens 2 is omitted and the condenser lens 3
The present invention can also be applied to a case where the laser light emitted from the LD is focused on the end of the optical fiber 4 only by the laser beam. In that case, the collimator lens holder pipe 14 is omitted and the relay pipe 1
The condenser lens holder pipe 16 is directly welded and fixed to 3. Further, the mounting of the isolator 6 may be omitted, or another optical component other than the isolator 6 may be mounted in the same manner.

Although the communication laser diode module of the present invention has been described based on the embodiments, the present invention is not limited to these embodiments, and various modifications can be made.

[0023]

As is clear from the above description, according to the communication laser diode module of the present invention, one end of the relay pipe is fixed to the end face of the heat sink to which the laser diode is attached by laser welding, One end of the collimator lens holder pipe supporting the collimator lens is inserted into the other end of the collimator lens, and is fixed by laser welding at a plurality of positions around the relay pipe, and condensed in the other end of the collimator lens holder pipe One end of the condenser lens holder pipe supporting the lens is inserted and fixed by laser welding at several positions around the collimator lens holder pipe, and the optical fiber holder faces the other end of the condenser lens holder pipe One end of the pipe is abutted and the other end of the fiber optic holder pipe Ferrule is inserted that is attached to the center of one end of the optical fiber, and the ferrule is fixed by laser welding by laser welding at a plurality of positions around the optical fiber holder pipe, further,
Either the other end of the condenser lens holder pipe and one end of the optical fiber holder pipe are fixed by laser welding at a plurality of positions in the surrounding area, or the collimator lens is omitted and the condenser lens holder pipe is directly fixed to the relay pipe in the same way As a result, the assembly can be easily automated, the workability is good, and the reproducibility is good. In addition, since the support between the holders is fixed by fitting and laser welding at the surrounding axisymmetric position, even if there is a temperature change or impact, there is little effect on the alignment accuracy, and durability against temperature change and impact It has excellent properties.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an assembled communication LD module according to one embodiment of the present invention.

FIG. 2 is a sectional view of a main part of a communication LD module before being inserted into and attached to the case of the embodiment of FIG. 1;

FIG. 3 is an exploded perspective view of a main part of the communication LD module of FIG. 2;

FIG. 4 is a diagram showing a configuration of a conventional typical butterfly-type communication LD module.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... LD element 2 ... Collimator lens 3 ... Condenser lens 4 ... Single mode optical fiber 5 ... Case 6 ... Isolator 11 ... Mounting board 12 ... Heat sink 12 '... Heat sink end face 13 ... Relay pipe 13' ... Relay pipe flange 14 ... Collimator lens holder pipe 14 '... Small diameter part of collimator lens holder pipe 14 "... Large diameter part of collimator lens holder pipe 15 ... Isolator holder pipe 16 ... Condenser lens holder pipe 16' ... Small diameter part of condenser lens holder pipe 16" ... Large diameter part of condenser lens holder pipe 17 ... Optical fiber holder pipe 17 '... Small diameter part of optical fiber holder pipe 17 "... Large diameter part of optical fiber holder pipe 18 ... Ferrule 19 ... Peltier element 20 ... Case 21 ... Box 22 ... Lid 23 ... opening 24 ... protection pipe 25 ... foot

Claims (3)

[Claims] 1. A communication laser diode module in which laser light from a laser diode is condensed by a lens and made incident on an optical fiber, wherein one end of a relay pipe is fixed to an end surface of a heat sink to which the laser diode is attached by laser welding. One end of a collimator lens holder pipe supporting a collimator lens is inserted into the other end of the relay pipe, and is fixed by laser welding at a plurality of positions around the relay pipe; One end of a condenser lens holder pipe supporting the condenser lens is inserted into the other end, and is fixed by laser welding at a plurality of positions around the collimator lens holder pipe. One end of the fiber optic holder pipe facing the end A ferrule which is in contact with and is attached to the other end of the optical fiber holder pipe with one end of the optical fiber as the center is inserted, and the ferrule is fixed by laser welding at a plurality of positions around the optical fiber holder pipe by laser welding. A communication laser diode module, wherein the other end of the condenser lens holder pipe and one end of the optical fiber holder pipe are fixed at a plurality of peripheral positions by laser welding. 2. A communication laser diode module in which laser light from a laser diode is condensed by a lens and made incident on an optical fiber, wherein one end of a relay pipe is fixed to an end face of a heat sink to which the laser diode is attached by laser welding. One end of a condenser lens holder pipe supporting the condenser lens is inserted into the other end of the relay pipe, and is fixed by laser welding at a plurality of positions around the relay pipe; One end of the optical fiber holder pipe is in contact with the other end of the holder pipe, and a ferrule attached around the one end of the optical fiber is inserted into the other end of the optical fiber holder pipe. The ferrule is laid by laser welding at several locations around it. A laser diode module for communication, wherein the other end of the condenser lens holder pipe and one end of the optical fiber holder pipe are fixed by laser welding at a plurality of peripheral positions. . 3. A Peltier element is fixed at a predetermined position at the bottom of a case box provided with an opening on one side, and the other end of the optical fiber is inserted into the opening from the inside of the box. The heat sink is fixed to the Peltier element so that the heat sink is located on the Peltier element, and a protection pipe is placed around the optical fiber holder pipe and the ferrule that have come out of the opening, and one end of the protection pipe is covered with the protection pipe. 3. The communication laser diode module according to claim 1, wherein the communication laser diode module is fixed to a side surface of the box.