JPH11295560A - Module for optical communication and inspection method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the temperature of a semiconductor laser element from the outside of a package, to lower the price of a module for optical communication and to miniaturize it. SOLUTION: A Peltier element 101 is provided on the bottom part of the package 100 and a base 102 is fixed on the Peltier element 101. On the base 102, the semiconductor laser element 103 and a photodetector 104 for monitoring are fixed. A recessed groove whose cross section is chevron-shaped is formed on the upper surface of the base 102 so as to be extended in an optical axis direction and the incident part 105a of an optical fiber 105 is fitted to the recessed groove. A fiber pressing member 106 provided with the recessed groove whose cross section is trapezoidal is fixed on the upper side of the base 102 and the incident part 105a of the optical fiber 105 is clamped by the base 102 and the fiber pressing member 106. A notched part 107 extended in a direction perpendicular to an optical axis is formed at the base 102 and the left end face of the optical fiber 105 is abutted on the wall surface on the side of the semiconductor laser element 103 of the notched part 107.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical communication module used in an optical transmission system for transmitting an optical signal bidirectionally through an optical fiber, and a method of inspecting the module.

[0002]

2. Description of the Related Art In recent years, optical signals for transmitting optical signals, such as data and multi-channel image information, from a center station to a subscriber's home or its vicinity (between telephone poles or several houses) using an optical fiber. A subscriber system has been proposed and considered. The optical communication module used in this optical subscriber system is considered to be used not only indoors but also outdoors such as telephone poles. Therefore, it is necessary to stably operate the optical communication module even under severe outdoor temperature conditions compared to indoor conditions. Since the optical output characteristics of the optical communication module have a large temperature dependency, it is necessary to keep the temperature of the optical communication module constant in order to obtain stable optical output characteristics regardless of the environmental temperature.

Therefore, in an optical communication module used in an optical subscriber system, it is preferable that the temperature of a semiconductor laser device that emits laser light can be controlled from outside the package.

Therefore, as an optical communication module used in an optical subscriber system, a module having a structure described in Japanese Patent Application Laid-Open No. 9-21929 and shown in FIG. 11 has been proposed.

Hereinafter, a conventional optical communication module will be described with reference to FIG.

A Peltier device 1 is provided at the bottom of the package 10.
1, a metal lens mount 12 is mounted on the Peltier element 11. A laser mount 13 is fixed to the center of the lens mount 12, and the laser mount 13 is
4 is held. On the right side of the laser mount 13 in the lens mount 12, an aspheric lens 15 for condensing the laser light emitted from the semiconductor laser element 14 is provided.

[0007] An optical isolator 16 is provided at an emission portion 10 a of the package 10.
A glass plate 17 for airtightness is fixed inside the optical isolator 16 in the light emitting portion 10a of the light emitting device. In addition, a cylindrical fiber fixing member 1 is provided at the emission portion 10a of the package 10.
The fiber fixing member 18 is fixed to the optical fiber 1.
9 holds a ferrule 20 fixed to one end.

A monitor mount 21 is fixed on the lens mount 12 on the left side of the laser mount 13, and the monitor mount 21 is mounted on the semiconductor laser device 14.
Holding the monitoring light receiving element 22 for monitoring the laser light emitted from the light emitting device. On the left side of the monitor mount 21 on the laser mount 12, a temperature detector 23 for detecting the temperature of the lens mount 12 is provided.

The package 10 is hermetically sealed by a cap 24 in a state where the above-described members are stored. In this case, the package 10 and the cap 24 are welded to keep the inside of the package 10 airtight for a long period of time, and a metal film is formed around the airtight glass 17. The package 10 is fixed with solder. Further, the space between the optical isolator 16 and the emission section 10a of the package 10 is also hermetically sealed.

In the conventional optical communication module, the laser light emitted from the semiconductor laser element 14 is coupled to one end of an optical fiber 19 by an aspheric lens 15, and then propagates through the optical fiber 19 to be transmitted to the optical fiber. The other end of the signal 19 is output as output signal light.

The optical output of the laser beam emitted from the semiconductor laser element 14 is monitored by the monitoring light receiving element 22 so that the optical output of the semiconductor laser element 14 is controlled and the temperature of the lens mount 12 is controlled by the temperature. It is controlled by the detector 23 and the Peltier element 11.

[0012]

As described above, in the optical communication module used in the optical subscriber system, it is preferable that the temperature of the semiconductor laser device that emits laser light can be controlled from outside the package. With the spread of optical subscriber systems, it is desired to reduce the cost and size of optical communication modules.

However, since the conventional optical communication module has a large number of components, there is a problem that reduction in cost and size are restricted.

In view of the above, it is an object of the present invention to control the temperature of a semiconductor laser device from outside a package and to realize a low-cost and compact optical communication module.

[0015]

In order to achieve the above-mentioned object, an optical communication module according to the present invention has a package whose inside is kept airtight, and is fixed to the bottom of the package, and the temperature is controlled from the outside. Cooling means, a base fixed on the cooling means, a semiconductor laser element fixed on the base and emitting laser light, and a light of the laser light fixed on the base and emitted from the semiconductor laser element A monitor light receiving element for detecting an output; and an optical fiber fixed on the base, the laser light emitted from the semiconductor laser element being incident on one end, and an output signal light being output from the other end. .

According to the optical communication module of the present invention, since the semiconductor laser device is directly fixed on the base fixed on the cooling means, the heat generated in the semiconductor laser device is cooled via the base. This eliminates the need for a laser mount that directly transmits to the means and holds the semiconductor laser device between the base and the semiconductor laser device. Further, since the laser light emitted from the semiconductor laser element is directly incident on the optical fiber, a condenser lens for condensing the laser light emitted from the semiconductor laser element becomes unnecessary.

An optical communication module according to the present invention is provided on a base, and an optical splitter for guiding an input signal light propagating in the optical fiber after being input from the other end of the optical fiber, and an optical splitter on the base. And a receiving light receiving element for receiving the input signal light guided upward by the optical splitter.

The optical communication module of the present invention preferably further includes an in-line optical isolator provided on the base and for preventing input signal light propagating in the optical fiber from entering the semiconductor laser device. .

It is preferable that the optical communication module of the present invention further includes an optical fiber positioning means provided on the base and for regulating a position of the optical fiber with respect to the semiconductor laser device.

In this case, the optical fiber positioning means is formed on the base so as to extend in the optical axis direction, and has a concave groove for regulating the position of the optical fiber in a direction perpendicular to the optical axis by fitting the optical fiber. A cut groove formed in the base so as to extend in a direction perpendicular to the optical axis, and restricting the position of the optical fiber in the optical axis direction by contacting one end of the optical fiber with the wall surface on the semiconductor laser element side. Is preferred.

It is preferable that the optical communication module of the present invention further includes a base positioning means provided on the cooling means and for regulating a position of the base with respect to the cooling means.

In this case, the base positioning means is preferably a recess formed on the upper surface of the cooling means and having a shape to which the base can be fitted.

In this case, the base positioning means is
Preferably, it is an alignment mark formed on the upper surface of the cooling means.

In the optical communication module according to the present invention, the cooling means is preferably a Peltier device.

In the optical communication module of the present invention, the semiconductor laser device is preferably a distributed feedback laser device, a pump laser, a narrow radiation angle laser device or a spot size conversion laser device.

In the laser element for optical communication according to the present invention, the optical fiber is preferably a single mode optical fiber having a core diameter substantially equal to the spot diameter of the semiconductor laser element.

In the optical communication module according to the present invention, it is preferable that the semiconductor laser element is fixed to the base by lead-free solder having no lead.

In the optical communication module of the present invention, the base is preferably fixed to the cooling means by a lead-free heat conductive paste.

In the optical communication module of the present invention, it is preferable that a metal deposition layer is formed on the lower surface of the base.

The optical communication module of the present invention is formed on the upper surface of the base and is electrically connected to a first external electrode formed on the upper surface of the base and directly connected to the lower electrode of the semiconductor laser device. And a second external electrode formed on the upper surface of the base and connected to the upper electrode of the semiconductor laser device by a bonding wire and formed on the upper surface of the base. The second inspection electrode is formed on the upper surface of the base and is electrically connected to the third external electrode formed on the upper surface of the base and directly connected to the lower electrode of the light receiving element for monitoring. A third inspection electrode formed on the upper surface of the base and electrically connected to a fourth external electrode formed on the upper surface of the base and connected to the upper electrode of the light receiving element for monitoring by a bonding wire; Preferably further includes a fourth inspection electrodes being.

According to the method for inspecting an optical communication module according to the present invention, a semiconductor laser device fixed on a base and emitting laser light, and a semiconductor laser device fixed on the base and emitted from the semiconductor laser device are provided. A monitor light-receiving element for detecting light output, an optical fiber fixed on the base, laser light emitted from the semiconductor laser element being incident on one end, and outputting output signal light from the other end, A first inspection electrode formed on the upper surface and electrically connected to the lower electrode of the semiconductor laser device; and a second inspection electrode formed on the base and electrically connected to the upper electrode of the semiconductor laser device A third inspection electrode formed on the upper surface of the base and electrically connected to the lower electrode of the monitor light receiving element; and a fourth inspection electrode electrically connected to the upper electrode of the monitor light receiving element. Inspection A method for inspecting an optical communication module having a first probe electrode and a second probe electrode in contact with a first probe electrode and a second probe electrode. A current applying step of applying an inspection current between the probe needle and the second probe needle;
A third probe needle is brought into contact with the third inspection electrode, and a fourth probe needle is brought into contact with the fourth inspection electrode, so that a current flowing between the third probe needle and the fourth probe needle is generated. The method includes a current detection step for detecting, and an inspection step for inspecting electrical characteristics of the semiconductor laser element based on the current detected in the current detection step.

According to the optical communication module inspection method of the present invention, the first inspection electrode and the second inspection needle are applied by applying an inspection current between the first probe needle and the second probe needle. Inspection current can be applied between the inspection electrode and thus between the lower electrode and the upper electrode of the semiconductor laser device, and the current between the third probe terminal and the fourth probe terminal is detected. Thus, the current flowing between the third inspection electrode and the fourth inspection electrode, that is, the current flowing between the lower electrode and the upper electrode of the monitoring light receiving element can be detected.

In the optical communication module inspection method of the present invention, the first inspection electrode is electrically connected to a first external electrode formed on the base and directly connected to the lower electrode of the semiconductor laser device. The second inspection electrode is electrically connected to a second external electrode formed on the base and connected to an upper electrode of the semiconductor laser device by a bonding wire, and is connected to the second inspection electrode. The test electrode is electrically connected to a third external electrode formed on the base and directly connected to the lower electrode of the monitor light receiving element, and the fourth test electrode is formed on the base. Further, it is preferable to be electrically connected to the fourth external electrode connected to the upper electrode of the monitoring light receiving element by a bonding wire.

[0034]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) An optical communication module according to a first embodiment of the present invention will be described below with reference to FIGS. 1 is a side sectional view of the optical communication module, FIG. 2 is a plan view of the optical communication module with a cap removed, and FIG.
FIG. 4 is a sectional view taken along line VI-VI in FIG. 1.

A Peltier device 101 as a cooling means is provided at the bottom of the package 100, and a rectangular plate-like base 102 is fixed on the Peltier device 101. As a method for fixing the base 102 to the Peltier element 101, soldering or an adhesive such as a resin may be used. However, if lead-free solder or lead-free paste containing no lead is used, an adverse effect on the human body can be prevented.

The base 102 is connected to the Peltier device 101.
To the base 102,
When a metal deposition layer is formed on the lower surface of
And the Peltier element 101 can be improved in thermal conductivity.

On the left side of FIGS. 1 and 2 on the base 102, for example, a semiconductor laser device 103 for emitting a laser beam in a wavelength band of 1.3 μm, and the semiconductor laser device 10
A monitoring light receiving element 104 composed of a photodiode for monitoring the intensity of the laser light emitted from the laser light 3 is mounted with high accuracy by image recognition.

On the right side of the upper surface of the base 102 on which the semiconductor laser element 103 is mounted, FIG.
As shown in FIG. 7, a concave groove having a V-shaped cross section is formed so as to extend in the optical axis direction, and the incident portion 105a of the single mode optical fiber 105 is fitted into the concave groove.

A fiber pressing member 106 having a concave groove having a trapezoidal cross section is fixed above the central portion of the base 102. The incident portion 105a of the optical fiber 105 is connected to both wall surfaces of the concave groove of the base 102 and the fiber. Holding member 10
6 and 3 points.

Semiconductor laser device 1 on base 102
A cutout portion 107 extending in a direction perpendicular to the optical axis is formed on the right side of the portion where 03 is mounted. The left end face (incident end face) of the optical fiber 105 is in contact with the wall surface of the cutout portion 107 on the semiconductor laser element 103 side, and thereby the distance between the semiconductor laser element 103 and the left end face (incident end face) of the optical fiber 105 is increased. Is regulated.

Since the incident portion 105a of the optical fiber 105 is sandwiched by three points and the incident end face of the optical fiber 105 is in contact with the wall surface of the notch 107, a sub-micron order passive alignment method is used. The optical axis can be adjusted.

Notch 10 on the upper surface of base 102
7, an external electrode 108 for applying a current to the semiconductor laser element 103 or detecting a current generated in the monitoring light receiving element 104 is provided. The external electrode 108 is connected to an external lead 109. Are electrically connected to each other by a bonding wire 110. Further, the Peltier element 101 and the external lead 109 are also electrically connected by the bonding wire 110.

A cylindrical portion 111 for holding the optical fiber 105 is provided integrally with the package 100 on the right wall of the package 100.
Jacket portion 10 of optical fiber 105 inserted through
5b is fixed to the cylindrical portion 111 by a fixing resin 112. In order to improve the airtightness inside the package 100, the jacket 105 of the optical fiber 105 is required.
forming a metal layer (not shown) on the surface of b.
It is preferable that the metal layer and the cylindrical portion 111 be fixed by soldering.

After mounting each of the above-described members inside the module 100, the upper opening of the module 100 is hermetically sealed with a cap 113. Cap 113
As a means for fixing the module to the module 100, an adhesive such as welding, soldering, or resin may be used. The order of welding, soldering, and the adhesive is inferior in airtightness but is advantageous in cost. In this case, the use of lead-free solder or lead-free paste containing no lead can prevent adverse effects on the human body.

By the way, in order to mount the semiconductor laser element 103, the light receiving element 104 for monitoring, and the optical fiber 105 on the base 102 with high accuracy, alignment marks for image recognition (not shown) are provided on the base 102. And a concave groove having a V-shaped cross section must be machined with high precision. Further, it is necessary to efficiently dissipate heat generated from the semiconductor laser element 103 to the Peltier element 101 via the base 102.

Therefore, the material constituting the base 102 is preferably a single crystal of silicon which is easy to process and has good thermal conductivity. The silicon single crystal can be processed into a very high-precision shape by utilizing semiconductor processes such as photolithography, anisotropic etching, and metal deposition. In addition, since silicon single crystal has good thermal conductivity, it can play a sufficient role as a heat sink of the semiconductor laser element 103.

As the semiconductor laser device 103, a device having a large spot size such as a narrow radiation angle laser device is preferable in order to couple the laser beam to the incident end face of the optical fiber 105 with high coupling efficiency.

When the semiconductor laser device 103 having a normal spot size is used, the semiconductor laser device 103
Optical fiber 1 with a core diameter about the same as the spot size
By using the laser beam 05 to directly couple the laser beam to the incident portion 105a of the optical fiber 105, high coupling efficiency can be obtained. For example, when the difference between the diameter of the core of the optical fiber 105 and the spot size of the semiconductor laser element 103 is set to about 3.0 μm or less, a coupling efficiency of about 80% can be obtained.

Further, as the semiconductor laser element 103,
When the optical communication module is used as an optical signal output source of a wavelength division multiplexing system and needs to oscillate at a single wavelength, a DFB (distributed feedback) laser element having a narrow radiation angle function is preferable. When a very high output is required as in the case of a fiber amplifier, a pump laser element having a long cavity length is preferable.

As the light receiving element 104 for monitoring, it is preferable to use an end face incident type photodiode such as a waveguide type or an etching chamfered mirror type.

(First Modification of First Embodiment) In order to improve the airtightness of the interior of the package 100, the cylindrical portion 111 and the jacket 1 of the optical fiber 105 are required.
The gap between the base 102 and the Peltier element 05b is preferably adjusted with high precision in order to reduce the gap.
01 must be implemented.

Therefore, in a first modification, as shown in FIG.
A positioning recess 120 having a size that can be fitted is provided, and an alignment mark 121 for image recognition is formed on the bottom surface of the positioning recess 120.

Although not shown, the package 100
May be provided at the bottom with a positioning recess having a size to which the Peltier element 101 can be fitted, or an alignment mark for image recognition may be provided.

With this arrangement, the positional accuracy of the base 102 with respect to the package 100 is improved. Therefore, the gap between the cylindrical portion 111 of the package 100 and the jacket 105b of the optical fiber 105 is reduced, and the airtightness inside the package 100 is reduced. Can be improved.

(Second Modification of First Embodiment) In the optical communication module according to the first embodiment, the pigtail of the optical fiber 105 is
It protrudes from zero. Therefore, it is necessary to fix the incident portion 105a of the optical fiber 105 to the base 102 in a state where the pigtail of the optical fiber 105 protrudes from the package 100, so that the productivity is impaired, and the optical communication module is reduced. However, there is a problem that the occupied area becomes large and mass productivity is impaired.

Therefore, in the second modification, as shown in FIG. 6, the cylindrical portion 111 of the package 100 in the first optical fiber 105A (the optical fiber constituting the optical communication module) having no jacket 105b is provided. While fixing the first ferrule 131 to the part to be inserted,
Second optical fiber 105B having jacket 105b
The second ferrule 13 is provided at the end of the (optical fiber constituting the optical transmission line) from which the jacket 105b has been removed.
2 is fixed, and the first ferrule 131 and the second ferrule 132 are fixed by the split sleeve 133.
Further, the second optical fiber 105B and the second ferrule 1
32 is integrated with a cylindrical connecting member 134.

In this way, the first optical fiber 10
When the 5A incident portion 105a is fixed to the base 102, the first optical fiber 105A and the second optical fiber 10A are fixed.
5B can be separated, so that the productivity is improved, and the area occupied by the optical communication module is reduced, so that the mass productivity is also improved.

Further, the first ferrule 131 and the second optical fiber 105 fixed to the first optical fiber 105A.
Since the second ferrule 132 fixed to B is integrated with the split sleeve 133, the first optical fiber 105A and the second optical fiber 105B can be connected with a low loss of 0.3 dB or less. it can.

Therefore, according to the second modification, the space for the production line of the optical communication module can be saved, and the handling of the optical communication module becomes easy, so that the automation rate of the production line can be improved. it can.

(Second Embodiment) An optical communication module according to a second embodiment of the present invention will be described below with reference to FIG. FIG. 7 is a side sectional view of the optical communication module. However, in FIG. 7, the package and the cap are not shown.

The optical communication module according to the second embodiment is a multifunctional optical communication module having both an optical transmission function of outputting signal light and an optical reception function of receiving signal light.

In the second embodiment, as in the first embodiment, a transmission base 202 having a rectangular plate shape is provided on the Peltier element 201.
A semiconductor laser element 203 and a light receiving element for monitoring 204 are mounted on the device 2 with high accuracy. Further, a concave groove having a V-shaped cross section is formed on the upper surface of the transmitting base 202 so as to extend in the optical axis direction, and a single mode optical fiber 205 is fitted into the concave groove. A fiber holding member 206 having a concave groove having a trapezoidal cross section is fixed above the central portion of the transmitting base 202, and the optical fiber 205 is connected to both wall surfaces of the concave groove of the transmitting base 202 and the fiber holding member 206. It is sandwiched by three points with the bottom. Further, a cutout portion 207 extending in a direction perpendicular to the optical axis is formed on the transmission base 202 on the right side of the portion where the semiconductor laser device 203 is mounted, and the semiconductor laser device 203 of the cutout portion 207 is formed. The left end surface (incident end surface) of the optical fiber 205 is in contact with the side wall surface.

As a feature of the second embodiment, a receiving base 210 is mounted on the Peltier element 201, and an optical fiber 20 is provided at the center of the receiving base 210.
The optical splitter 211 is inserted so as to have a predetermined angle with respect to 5. The optical splitter 211 is provided for the semiconductor laser device 20.
3, the output signal light propagating from the left to the right through the core of the optical fiber 205 is passed therethrough.
The input signal light propagating from the right to the left in the core portion 05 is guided upward. Above the optical splitter 211 on the upper surface of the receiving base 210, a receiving light receiving element 212 for receiving the input signal light guided upward by the optical splitter 211 is provided.

A small in-line isolator 213 is inserted into the right side of the receiving base 202 to prevent the input signal light propagating through the optical fiber 205 from entering the semiconductor laser element 203. Inserting the small in-line isolator 213 into the transmission path of the optical fiber 205 is particularly effective when a DFB laser element that is easily affected by light incident from the outside is used as the semiconductor laser element 203.

In the second embodiment, by selecting the wavelength of the input signal light, the wavelength of the output signal light, and the type of the optical splitter 211, it is possible to realize an optical communication module that can support various uses. it can. Hereinafter, the use of the optical communication module, the wavelength of the input signal light and the output signal light, and the type of the optical splitter 211 will be described.

(1) In the case of an optical communication module having both a transmitter function for transmitting signal light in the 1.3 μm wavelength band and a receiving function for receiving signal light in the 1.55 μm band,
The oscillation wavelength of the semiconductor laser element 203 is set to the 1.3 μm band, the reception wavelength of the light receiving element for reception 212 is set to the 1.55 μm band, and the optical splitter 212 allows light of the 1.3 μm band to pass therethrough, while the 1.55 μm band It is sufficient that the small isolator 213 has a transmission direction such that the light emitted from the semiconductor laser element 203 is emitted to the outside, using a WDM filter (multiplex transmission filter) that reflects the light. Further, as the light receiving element 212 for reception,
It is preferably a pass band type that does not sense light in the 1.55 μm band.

(2) In the case of an optical communication module having both a transmitter function of transmitting signal light in the wavelength band of 1.55 μm and a receiving function of receiving signal light in the wavelength band of 1.3 μm,
The oscillation wavelength of the semiconductor laser element 203 is set to the 1.55 μm band, the reception wavelength of the reception light-receiving element 212 is set to the 1.3 μm band, and the optical splitter 212 allows the light of the 1.55 μm band to pass therethrough, while the 1.3 μm band It is sufficient that the small isolator 213 has a transmission direction such that the light emitted from the semiconductor laser element 203 is emitted to the outside.

(3) In the case of an optical communication module having both a transmitter function for transmitting a 1.3 μm wavelength signal light and a receiving function for receiving a 1.3 μm wavelength signal light, a semiconductor laser device The oscillation wavelength of 203 is set to 1.3 μm band,
The receiving wavelength of the receiving light receiving element 212 is also set to 1.3 μm band,
As the optical branching device 212, a half mirror that allows 1.3 μm band light to pass at a predetermined ratio and reflects the light at a predetermined ratio is used. As the small isolator 213, light emitted from the semiconductor laser element 203 is emitted to the outside. What is necessary is just to have a suitable transmission direction.

(4) In the case of an optical communication module having both a transmitter function of transmitting signal light in the wavelength band of 1.55 μm and a receiving function of receiving signal light in the wavelength band of 1.55 μm, the semiconductor laser element The oscillation wavelength of 203 is 1.55 μm
Band, and the receiving wavelength of the receiving light receiving element 212 is 1.55 μm.
The light splitter 212 uses a half mirror that transmits 1.55 μm band light at a predetermined ratio and reflects the light at a predetermined ratio as the optical splitter 212, and the light emitted from the semiconductor laser element 203 is externally used as the small isolator 213. What is necessary is just to have the transmission direction which is emitted.

(Third Embodiment) An inspection method for an optical communication module according to a third embodiment of the present invention will be described below with reference to FIGS. 8 is a partial plan view of the optical communication module, FIG. 9 is a partially enlarged perspective view showing an inspection method, and FIG. 10 is an overall perspective view showing the inspection method.

First, a planar structure of an optical communication module to which the inspection method according to the third embodiment is applied will be described.

In the third embodiment, as in the first embodiment, the semiconductor laser device 3 is mounted on a rectangular base 302 provided on a Peltier device (not shown).
03 and the monitor light receiving element 304 are mounted with high precision. Further, a concave groove 305 having a V-shaped cross section is formed on the upper surface of the base 302 so as to extend in the optical axis direction.
A single-mode optical fiber (not shown) is fitted into the concave groove 305. A cutout portion 307 extending in a direction perpendicular to the optical axis is formed on the right side of the portion of the base 302 where the semiconductor laser element 303 is mounted, and a cutout 307 is formed on the wall surface of the cutout portion 307 on the semiconductor laser element 303 side. Is in contact with the left end face of a single mode optical fiber not shown.

Notch 30 on the upper surface of base 302
7, a first external electrode 308A directly connected to the lower electrode of the semiconductor laser element 303, and a second external electrode connected to the upper electrode of the semiconductor laser element 303 by the first bonding wire 309. 308B, a third external electrode 308C directly connected to the lower electrode of the monitoring light receiving element 304, and a fourth external electrode 308D connected to the upper electrode of the monitoring light receiving element 304 by the first bonding wire 309, respectively. Is provided.

As a feature of the third embodiment, the base 30
On the right side of the notch 307 on the upper surface of
External electrode 308A and second bonding wire 311
A first inspection electrode 310A and a second external electrode 308B connected by a second bonding wire 311 are provided respectively, and a third external electrode 310B on the upper surface of the base 302 is provided. Electrode 3
08C, a third inspection electrode 310C connected to the third external electrode 308C by a second bonding wire 311 is provided, and on the upper surface of the base 302, outside the fourth external electrode 308D. Fourth external electrode 3
A fourth inspection electrode 310 </ b> D connected to the second bonding wire 311 is provided.

Hereinafter, a method for inspecting an optical communication module according to the third embodiment will be described with reference to FIGS. 9 and 10.

As shown in FIGS. 9 and 10, the inspection substrate 320 is formed with a positioning recess 321 large enough to allow the base 302 to be inserted.
1 is provided with a base 302. Although the positioning concave portion 321 is formed one-dimensionally in FIG. 10, the positioning concave portion 321 may be formed two-dimensionally.

After setting the inspection substrate 320 at a predetermined position of an inspection device (screening device) not shown, the photodetector 322 for screening is adjusted so that the light receiving portion 322 a of the photodetector 322 coincides with the optical axis of the semiconductor laser element 303. As close as you can. next,
A first probe needle 323A and a second probe needle 323B connected to a drive circuit for applying a test current to the semiconductor laser element 303 are brought into contact with the first test electrode 310A and the second test electrode 310B, respectively. Let me
Third probe needle 3 connected to an inspection circuit for detecting a monitor current output from monitor light receiving element 304
23C and the fourth probe needle 323D are brought into contact with the third inspection electrode 310C and the fourth inspection electrode 310D, respectively. Next, in a state where a test current is applied between the lower electrode and the upper electrode of the semiconductor laser element 303 from the first probe needle 323A and the second probe needle 323B,
Third probe needle 323C and fourth probe needle 324D
Is detected, and the electrical characteristics of the semiconductor laser element 303 are inspected based on the detected current. In this way, the electrical characteristics of the semiconductor laser element 303 can be inspected without complicating the structure of the optical communication module.

In the third embodiment, the output of the laser light emitted from the semiconductor laser element 303 is detected by the monitoring light receiving element 304. However, the output of the laser light emitted from the semiconductor laser element 303 is monitored. It may be detected by the light receiving element 304 and the photo detector 322. By doing so, the semiconductor laser element 303
In addition, the electrical characteristics of the monitor light receiving element 304 can be inspected at the same time.

[0079]

According to the optical communication module of the present invention,
Since the heat generated in the semiconductor laser element is directly transmitted to the cooling means via the base, the heat dissipation is improved and the temperature of the semiconductor laser element can be directly controlled by the cooling means. In addition, since a laser mount for holding the semiconductor laser element between the base and the semiconductor laser element is not required, and a condenser lens for condensing laser light emitted from the semiconductor laser element is not required, an optical communication module is provided. Can be reduced in cost and size.

An optical communication module according to the present invention is provided on a base, an optical splitter for guiding an input signal light propagating through an optical fiber after being input from the other end of the optical fiber, and an optical splitter on the base. And a receiving light receiving element for receiving the input signal light guided upward by the optical branching device, the input signal light guided upward by the optical branching device can be received by the receiving light receiving device. In addition, the size of the optical communication module used in the bidirectional transmission system can be reduced.

When the optical communication module of the present invention includes an in-line optical isolator provided on the base and for preventing input signal light propagating in the optical fiber from entering the semiconductor laser device, the optical fiber The input signal light input from the other end does not enter the semiconductor laser device. Therefore, it is possible to use a DFB laser element that is easily affected by light incident from the outside as the semiconductor laser element.

When the optical communication module of the present invention is provided on the base and includes optical fiber positioning means for regulating the position of the optical fiber with respect to the semiconductor laser element, the position of the optical fiber with respect to the semiconductor laser element is adjusted with respect to the optical axis. Therefore, the optical fiber can be mounted by the passive alignment method because it can be regulated only by the mechanical accuracy without performing.

In this case, the optical fiber positioning means is formed on the base so as to extend in the optical axis direction, and has a concave groove for regulating the position of the optical fiber in the direction perpendicular to the optical axis by fitting the optical fiber. A cut groove formed in the base so as to extend in a direction perpendicular to the optical axis, and restricting the position of the optical fiber in the optical axis direction by contacting one end of the optical fiber with the wall surface on the semiconductor laser element side. You have
Since the optical axis of the laser light emitted from the semiconductor laser element and the central axis of the core of the optical fiber can be easily matched, and the distance between the semiconductor laser element and one end of the optical fiber can be regulated. Further, the coupling efficiency at one end of the optical fiber mounted by the passive alignment method can be further improved.

If the optical communication module of the present invention is provided with the cooling means and includes a base positioning means for regulating the position of the base with respect to the cooling means, the position of the base with respect to the cooling means can be regulated accurately. .

When the base positioning means is formed on the upper surface of the cooling means and is a recess having a shape in which the base can be fitted, the position of the base with respect to the cooling means can be easily and accurately regulated.

When the base positioning means is an alignment mark formed on the upper surface of the cooling means, the position of the base with respect to the cooling means can be further restricted by image recognition.

In the optical communication module according to the present invention, if the cooling means is a Peltier device, the temperature of the base and thus the temperature of the semiconductor laser device can be easily and accurately controlled from the outside.

In the optical communication module of the present invention, if the semiconductor laser element is a distributed feedback type laser element, the wavelength and output of the output signal light can be stabilized in a wide temperature range, and the semiconductor laser element can be pumped. With a laser, the output of the output signal light can be increased,
When the semiconductor laser element is a narrow radiation angle laser element or a spot size conversion laser element, laser light emitted from the semiconductor laser element can be coupled to one end of the optical fiber with high coupling efficiency.

In the optical communication laser device of the present invention, if the optical fiber is a single mode optical fiber having a core diameter substantially equal to the spot diameter of the semiconductor laser device, the laser light emitted from the semiconductor laser device is emitted. The optical fiber can be coupled to one end of the optical fiber with high coupling efficiency.

In the optical communication module according to the present invention, if the semiconductor laser element is fixed to the base by lead-free solder, it is possible to prevent the human body from being adversely affected in the manufacturing process.

In the optical communication module according to the present invention, if the base is fixed to the cooling means by a heat conductive paste, the heat generated in the semiconductor laser device can be efficiently radiated to the cooling means via the base. .

In the optical communication module of the present invention, if a metal deposition layer is formed on the lower surface of the base, the efficiency of heat exchange between the base and the cooling means is improved, so that the heat generated in the semiconductor laser device is reduced. The heat can be efficiently dissipated to the cooling means via the base. When the optical communication module of the present invention includes the first, second, third, and fourth inspection electrodes, an inspection current flows between the first inspection electrode and the second inspection electrode. By applying the current and detecting the current flowing between the third inspection electrode and the fourth inspection electrode,
The electrical characteristics of the semiconductor laser device can be easily inspected. In this case, since the first to fourth inspection electrodes are formed on the upper surface of the base, the electrical characteristics of the semiconductor laser device can be inspected without hindering the miniaturization of the optical communication module.

According to the optical communication module inspection method of the present invention, by applying an inspection current between the first probe needle and the second probe needle, the lower electrode and the upper electrode of the semiconductor laser device are connected to each other. The inspection current can be applied during the measurement, and the current between the third probe terminal and the fourth probe terminal is detected. Since the flowing current can be detected, the electrical characteristics of the semiconductor laser device can be easily and reliably inspected.

In the optical communication module inspection method according to the present invention, the first inspection electrode and the first external electrode, the second inspection electrode and the second external electrode, the third inspection electrode and the third Of the first and second inspection electrodes and the lower electrode and the upper electrode of the semiconductor laser device, when the first external electrode and the fourth inspection electrode and the fourth external electrode are electrically connected to each other. Since the electrical connection and the electrical connection between the third and fourth inspection electrodes and the lower electrode and the upper electrode of the monitoring light receiving element can be easily performed, without reducing the size of the optical communication module, The electrical characteristics of the semiconductor laser device can be inspected.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing an optical communication module according to a first embodiment.

FIG. 2 is a plan view showing a state in which a cap of the optical communication module according to the first embodiment is removed.

FIG. 3 is a sectional view of the optical communication module according to the first embodiment, taken along line III-III in FIG. 1;

FIG. 4 is a sectional view of the optical communication module according to the first embodiment, taken along line VI-VI in FIG. 1;

FIG. 5 is a perspective view showing an assembling process of an optical communication module according to a first modification of the first embodiment.

FIG. 6 is a side sectional view showing an optical communication module according to a second modification of the first embodiment.

FIG. 7 is a side sectional view showing an optical communication module according to a second embodiment.

FIG. 8 is a partial plan view showing a method for inspecting an optical communication module according to a third embodiment.

FIG. 9 is a partially enlarged perspective view illustrating a method for inspecting an optical communication module according to a third embodiment.

FIG. 10 is an overall perspective view showing a method for inspecting an optical communication module according to a third embodiment.

FIG. 11 is a side sectional view showing a conventional optical communication module.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 Package 101 Peltier element 102 Base 103 Semiconductor laser element 104 Monitor light receiving element 105 Optical fiber 105A First optical fiber 105B Second optical fiber 105a Incident part 105b Jacket part 106 Fiber pressing member 107 Notch part 108 External electrode 109 External Lead 110 Bonding wire 111 Cylindrical part 112 Fixing resin 113 Cap 120 Positioning recess 121 Alignment mark 131 First ferrule 132 Second ferrule 133 Split sleeve 134 Connecting member 201 Peltier element 202 Transmission base 203 Semiconductor laser element 204 Monitor Light receiving element 205 optical fiber 206 fiber pressing member 207 notch 210 receiving base 211 optical splitter 212 receiving Light receiving element 213 Small isolator 302 Base 303 Semiconductor laser element 304 Light receiving element for monitoring 305 Concave groove 307 Notch 308A First external electrode 308B Second external electrode 308C Third external electrode 308D Fourth external electrode 309 First Bonding wire 310A First inspection electrode 310B Second inspection electrode 310C Third inspection electrode 310D Fourth inspection electrode 320 Inspection substrate 321 Positioning recess 322 Photodetector 322a Light receiving portion 323A First probe needle 323B Second probe needle 323C Third probe needle 323D Fourth probe needle

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kenichi Matsuda 1006 Kazuma Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd.

Claims (17)

[Claims] A package having an airtight interior; a cooling unit fixed to a bottom of the package and temperature-controlled from the outside; a base fixed on the cooling unit; A semiconductor laser device that is fixed and emits a laser beam; a light receiving device for monitoring that is fixed on the base and detects an optical output of laser light emitted from the semiconductor laser device; and that is fixed on the base. An optical fiber for receiving laser light emitted from the semiconductor laser element at one end and outputting output signal light from the other end. 2. An optical splitter provided on the base and guiding input signal light propagating through the optical fiber after being input from the other end of the optical fiber, and fixed on the base. The optical communication module according to claim 1, further comprising: a light receiving element for receiving an input signal light guided upward by the optical splitter. 3. An in-line type optical isolator provided on the base and for preventing input signal light propagating in the optical fiber from entering the semiconductor laser device. 3. The optical communication module according to item 2. 4. The optical communication module according to claim 1, further comprising an optical fiber positioning means provided on said base for regulating a position of said optical fiber with respect to said semiconductor laser device. 5. The optical fiber positioning means is formed so as to extend in the optical axis direction on the base, and regulates the position of the optical fiber in a direction perpendicular to the optical axis by fitting the optical fiber. A concave groove, formed in the base so as to extend in a direction perpendicular to the optical axis, and restricting the position of the optical fiber in the optical axis direction by contacting one end of the optical fiber with a wall surface on the semiconductor laser element side. The optical communication module according to claim 4, further comprising: 6. The optical communication module according to claim 1, further comprising a base positioning means provided on said cooling means for regulating a position of said base with respect to said cooling means. 7. The optical communication module according to claim 6, wherein the base positioning means is a recess formed on an upper surface of the cooling means and having a shape to which the base can be fitted. . 8. The optical communication module according to claim 6, wherein said base positioning means is an alignment mark formed on an upper surface of said cooling means. 9. The optical communication module according to claim 1, wherein said cooling means is a Peltier device. 10. The laser device for optical communication according to claim 1, wherein said semiconductor laser device is a distributed feedback laser device, a pump laser, a narrow radiation angle laser device, or a spot size conversion laser device. . 11. The optical communication module according to claim 1, wherein the optical fiber is a single mode optical fiber having a core diameter substantially equal to a spot diameter of the semiconductor laser device. 12. The optical communication module according to claim 1, wherein the semiconductor laser device is fixed to the base by lead-free solder having no lead. 13. The optical communication module according to claim 1, wherein the base is fixed to the cooling means with a lead-free heat conductive paste. 14. The optical communication module according to claim 1, wherein a metal deposition layer is formed on a lower surface of the base. 15. Formed on the upper surface of the base,
A first inspection electrode formed on an upper surface of the base and electrically connected to a first external electrode directly connected to a lower electrode of the semiconductor laser element; and a first inspection electrode formed on the upper surface of the base. A second inspection electrode formed on the upper surface of the base and electrically connected to a second external electrode connected to an upper electrode of the semiconductor laser device by a bonding wire; and a second inspection electrode formed on the upper surface of the base. A third inspection electrode formed on the upper surface of the base and electrically connected to a third external electrode directly connected to the lower electrode of the light receiving element for monitoring; A fourth inspection electrode formed on the upper surface of the base and electrically connected to a fourth external electrode connected to an upper electrode of the monitor light-receiving element by a bonding wire; Optical communication module according to claim 1, characterized by further comprising and. 16. A semiconductor laser device fixed on a base and emitting laser light, and a monitor light receiving device fixed on the base and detecting an optical output of the laser light emitted from the semiconductor laser device. An optical fiber fixed on the base, the laser light emitted from the semiconductor laser element is incident on one end, and an output signal light is output from the other end, and the optical fiber is formed on the upper surface of the base, A first electrode electrically connected to a lower electrode of the semiconductor laser device;
A second inspection electrode formed on the base and electrically connected to an upper electrode of the semiconductor laser device; and a second inspection electrode formed on the upper surface of the base and An inspection method for an optical communication module, comprising: a third inspection electrode electrically connected to a lower electrode; and a fourth inspection electrode electrically connected to an upper electrode of the monitor light receiving element. Contacting a first probe needle with the first inspection electrode and bringing a second probe needle into contact with the second inspection electrode, wherein the first probe needle and the second probe needle A current applying step of applying a test current during the test, and bringing a third probe needle into contact with the third test electrode, and bringing a fourth probe needle into contact with the fourth test electrode, The third probe needle and the fourth probe A light detection step of detecting a current flowing between the needle and a needle; and an inspection step of inspecting electrical characteristics of the semiconductor laser element based on the current detected in the current detection step. Inspection method for communication modules. 17. The semiconductor device according to claim 17, wherein the first inspection electrode is electrically connected to a first external electrode formed on the base and directly connected to a lower electrode of the semiconductor laser device. The second inspection electrode is electrically connected to a second external electrode formed on the base and connected to an upper electrode of the semiconductor laser device by a bonding wire, and the third inspection electrode is A third external electrode formed on the base and directly connected to a lower electrode of the monitor light-receiving element, and the fourth inspection electrode is provided on the base. 17. The method for inspecting an optical communication module according to claim 16, wherein the optical communication module is electrically connected to a fourth external electrode formed and connected to an upper electrode of the light receiving element for monitoring by a bonding wire.