JP2000031575A - Ld module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remarkably reduce power consumption of electronic cooling element and total power consumption of LD module by mounting, on a single electronic cooling element, a plurality of LD elements, a condensing lens, a monitor PD as a light receiving element for monitoring output beam of LD and a thermistor resistance. SOLUTION: Two sets of LD (semiconductor laser) 10a, 10b are fixed in parallel on an electronic cooling element 21 and is formed through each sleeve 23 and fibers 19a, 19b. A-light receiving element (PD) 13a for monitoring the emitted light beam of LD 10a, thermistor resistance 15a and condensing lens 11a are fixed in direct on a metal substrate 14a. The light emitted from LD 10a is adjusted to obtain the maximum coupling coefficient for the condensing lens 11a and moreover temperature rise by generation of heat from LD 10a is detected by a thermistor resistance 15a and the part on the metal substrate 14a is cooled from the side of electronic cooling element 21. In the same manner, heat generated by LD 10b is also cooled by the metal substrate 14b and it is then radiated via a case 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor laser (hereinafter, referred to as an excitation light source for an optical fiber amplifier).
This is related to the structure of the module.

[0002]

2. Description of the Related Art As a conventional LD module, for example, a configuration as disclosed in Japanese Patent Application No. 09-195554 is known. This type of device includes a light emitting element LD,
A thermistor resistor for detecting the ambient temperature of the LD, an electronic cooler for cooling the heat generated from the LD, an optical lens for focusing the output light from the LD, an optical fiber for transmitting the focused light, and the entire optical system. It consisted of a hermetically sealed case and the like.

The LD module has a configuration in which one LD is arranged in one case. The power consumption of the LD module is mainly the power consumption of the LD and the electronic cooler that cools the heat generated by the LD. The power consumption was added.

[0004]

SUMMARY OF THE INVENTION The conventional LD described above
The module has a configuration in which one LD is arranged in one case. However, as in the case of an excitation LD module used in an optical fiber amplifier, a plurality of, for example, two L
There may be a case where a D module is required.

In such a case, if an LD module having a conventional configuration is used, the power consumption is two LDs (for example, 2 W at 1 W / piece) and two electronic coolers for cooling the heat generated by the LD. Power consumption (for example, 5 V power supply, 5
(W / piece, a total of 10 W) is required, and a large power consumption of 12 W is required in total, which has been a problem in reducing the power consumption of the entire optical fiber amplifier. In addition, there is a problem that the power consumption of the electronic cooler particularly accounts for a large proportion of the power consumption of the entire optical fiber amplifier.

[0006]

In order to solve the above-mentioned problems, an LD module according to the present invention comprises a plurality of LD elements, a condenser lens, and a monitor PD which is a light receiving element for monitoring an output light of the LD. It has a configuration in which a thermistor resistor is mounted on a single thermoelectric cooler.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a top view showing a case mounting example of this embodiment, and FIG. 2 is a side view showing a configuration of a component assembly mounted in the case of FIG.

The LD module according to the first embodiment is shown in FIG.
2 are assembled and fixed in parallel on the electronic cooling element 21 as shown in FIG.
The fiber 19a and the fiber 19b are fixed to the case 22 in parallel via YAG laser welding.

In this subassembly, an LD 10 is soldered to a metal substrate 14 via a heat sink 12 and a header 16, and a light receiving element (hereinafter abbreviated as PD) for receiving and monitoring the light emitted from the LD 10. Is the monitor PD13.
The thermistor resistor 15 is soldered and fixed to the metal substrate 14 via a D header 18, the condenser lens 11 is fixed to the metal substrate 14 via a lens holder 17 by YAG laser welding.

In this LD module, light emitted from the LD 10a is condensed by the condensing lens 11a, and
Combined in 9a. The LD 10a, the condenser lens 11a, and the fiber 19a are optimally adjusted so that the maximum coupling efficiency can be obtained optically. Further, the PD 13a is fixed to the metal substrate 14 by soldering so that the emitted light of the LD 10a emitted to the side opposite to the fiber side is monitored. And LD10
The temperature rise due to the heat generated from a is detected by the thermistor resistor 15a. The portion on the metal substrate 14a is cooled from the electronic cooling element cooling side of the electronic cooling element 21 so that the temperature detected by the thermistor resistor 15a becomes 25 ° C.

Similarly, light emitted from the LD 10b is condensed by the condenser lens 11b and coupled to the fiber 19b.
The LD 10b, the condenser lens 11b, and the fiber 19b are optimally adjusted so as to obtain the maximum coupling efficiency optically, and the monitor PD 13a is made of metal such that the emitted light of the LD 10b emitted to the opposite side from the fiber side is monitored. It is fixed to the substrate 14 by soldering. The temperature rise due to the heat generated from the LD 10b is detected by the thermistor resistor 15b. The part on the metal substrate 14b is cooled from the thermoelectric cooler cooling side of the thermoelectric cooler 21 so that the temperature detected by the thermistor resistor 15b becomes 25 ° C. This electronic cooling element 2
The heat radiation from the heat radiation side of the electronic cooling element 1 is released to the outside via the case 22.

The power consumption of the LD 10a is about 1 W,
The power consumption of b is also about 1 W, for a total of about 2 W. And
The power consumption of the electronic cooling element 21 is about 5 W when a 5 V power supply is used, which is about 7 W in total. Thus, in the conventional configuration, the total power consumption of 12 W is reduced to about 60%. Furthermore, since the power consumption is reduced, the heat radiation amount of the electronic cooling element is also reduced, the operable environmental temperature when mounting the device can be increased, and the device can be used under high temperature environment conditions. Become. Further, since the power consumption is reduced, the power supply for supplying power can be reduced, and the power consumption of the device is reduced.

(Second Embodiment) Next, a second embodiment will be described with reference to FIGS. FIG. 4 is a top view showing a case mounting example of this embodiment, and FIG. 3 is a side view showing a configuration of a component assembly mounted in the case of FIG.

An excitation LD array 31 in which LDs 30a and 30b are arrayed on a substrate 34 at a pitch between emission centers of 500 μm.
A condensing lens array 33 in which the condensing lenses 32a and 32b are arrayed at a pitch of 500 μm between the condensing centers; a fiber array 36 in which the fibers 35a and 35b have a pitch between fibers of 500 μm; Thermistor resistors 37 for detecting the ambient temperature are each fixed by solder.

The excitation LD array 31, the condenser lens array 33, and the fiber array 36 are optimally adjusted so as to obtain optically maximum coupling efficiency. On the side opposite to the fiber side of the excitation LD array 31, a monitor PD array 39 in which the monitor PDs 38a and 38b are arrayed at a pitch of 500 μm between the light receiving centers so that the emitted light of the excitation LD array 31 is monitored, It is fixed on the substrate 34 with solder.

Then, as shown in FIG. 4, the bottom surface of the component assembly having such a configuration is fixed by soldering the cooling side of the electronic cooling element 21 and the case 22 is fixed by soldering to the heat radiation side of the electronic cooling element 21. . As shown in FIG. 15, the converging lens array 33 is formed by contacting spherical lenses having a diameter of 500 μm in parallel.

The light 50a emitted from the LD 30a in FIG. 3 is condensed by the condensing lens 32a and coupled to the fiber 35a. Similarly, the emitted light 50b from the LD 30b is condensed by the condensing lens b36 and coupled to the fiber 35b. The monitor PD 38a receives the outgoing light of the LD 30a emitted to the side opposite to the fiber side, and is used as an outgoing light monitor of the LD 30a. Similarly, the monitor PD 38a receives the output light of the LD 30b, and is used as an output light monitor of the LD 30a. Since the resistance value of the thermistor resistor 37 changes depending on the temperature, the ambient temperature of the excitation LD array 31 is detected by detecting the resistance value.

A temperature rise due to heat generated from the excitation LD array 31 is detected by a thermistor resistor 37. The part on the substrate 34 is cooled from the electronic cooling element cooling side 27 of the electronic cooling element 21 so that the temperature detected by the thermistor resistor 37 becomes 25 ° C. The heat radiation from the electronic cooling element heat radiation side 28 of the electronic cooling element 21 is released outside through the case 22.

The power consumption of the LD 30a is about 1 W, and the power consumption of the LD 30b is also about 1 W, for a total of about 2 W. The power consumption of the electronic cooling element 21 is about 5 W when a 5 V power supply is used, which is about 7 W in total. Thus, the power consumption, which is 12 W in the conventional configuration, is reduced to about 60%. Furthermore, since the power consumption is reduced, the heat radiation amount of the electronic cooling element is also reduced, the operable environmental temperature when mounting the device can be increased, and the device can be used under high temperature environment conditions. Become. Further, since the power consumption is reduced, the power supply for supplying power can be reduced, and the power consumption of the device is reduced.

(Third Embodiment) Next, a third embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a top view showing a case mounting example of this embodiment, and FIG. 6 is a side view.

First, two sets of subassemblies to be formed on the electronic cooling element are assembled. The structure of this subassembly is shown in FIG.
Since it is the same as that of the first embodiment shown in FIG. 1, the details are omitted, but the light emitted from the condenser lens 11 is optically adjusted to be a parallel beam.

The two sub-assemblies are assembled on the electronic cooling element 21 by fixing the optical axes of the LDs 10a and 10b in parallel at an interval of 3 mm. The polarization conversion element 41 is placed on the electronic cooling element 21 on the optical path of the parallel beam 51 from the condenser lens 11a, and is fixed with solder. Parallel beam 52 that has passed through this polarization conversion element 41
A polarization plane combining element 42 is arranged on the electronic cooling element 21 on the optical path of the parallel beam 53 from the condenser lens 11b, and is fixed by soldering. A collimator 25 composed of a fiber 26 and a lens 24 is arranged on the optical path of the parallel beam emitted from the polarization plane combining element 42.
Through YAG laser welding, it is fixed. The heat radiation side of the electronic cooling element 21 and the case 22 are fixed by soldering.

LD 10a, condenser lens 11a and collimator 2
5 and the LD 10b, the condenser lens 11b, and the collimator 25 are optimally adjusted so that the maximum coupling efficiency can be obtained optically.

The polarization conversion element 41 uses a Faraday rotator, and the polarization synthesis element 42 uses a birefringent crystal such as rutile (composition formula: TiO ₂ ). A magnet 43 that applies a saturation magnetic field to the polarization conversion element 41 is fixed on the electronic cooling element 21 without interrupting the parallel beam.

The configuration diagram of FIG. 5 is conceptual only, and the description of the configuration of the isolator and the like, which is unrelated to the essence of the present invention, is omitted.

The light emitted from the LD 10b is converted into a parallel beam 53 by the condenser lens 11b, passes through the polarization plane combining element 42, and is output as a part of the parallel beam 54. Also, LD
The light emitted from 10a is converted into a parallel beam 5 by a condenser lens 11a.
Converted to 1. Then, by passing through the polarization plane conversion element 41 and converting the plane of polarization by 90 degrees, the parallel beam 53 is converted into a parallel beam 52 whose polarization plane is orthogonal. Thereafter, the parallel beams 52 and 53 are combined as orthogonal polarization planes by the refractive index difference between ordinary light and extraordinary light of the polarization plane combining element 42 and output as a power-combined parallel beam 54. This parallel beam 54 enters the collimator 25,
The light is condensed by the lens 24, is coupled to the fiber 26, and is output as synthesized excitation light power.

LD 10a emitted to the side opposite to the side of fiber 26
Outgoing light is received by the monitor PD13a,
0a is used as an output light monitor. Similarly LD10
The output light of b is received by the monitor PD 19b,
Used as the output light monitor of 10b.

Since the resistance of the thermistor resistor 15a changes depending on the temperature, the ambient temperature of the LD 10a can be detected by detecting the resistance value. Similarly, the ambient temperature of the LD 10b is detected by the thermistor resistor 15b.

Then, the upper part of the electronic cooling element cooling side 27 of the electronic cooling element 21 in FIG. 6 is cooled so that the temperature detected by the thermistor resistance 15a and the thermistor resistance 15b becomes 25 ° C. Electronic cooling element heat radiation side 28 of electronic cooling element 21
Is released to the outside via the case 22.

As described above, by mounting two LDs on one thermoelectric cooling element in one case, the power consumption of one thermoelectric cooling element could be reduced. The amount of heat radiation of the electronic cooling element is also reduced, the operable environmental temperature at the time of mounting the device can be increased, and the device can be used under high temperature environment conditions. Since the power consumption is reduced, the power supply for supplying power can be reduced, and the power consumption of the device is reduced.

FIG. 7 is a block diagram showing a case where the polarization combining LD module 70 of this embodiment is applied to an excitation light source of an optical fiber amplifier.

When it is desired to obtain a high-output signal light from an optical fiber amplifier, an amplification medium fiber (for example, a so-called erbium-doped optical fiber (hereinafter abbreviated as EDF) in which a rare earth element erbium is doped in a fiber core) is used. What is necessary is just to add the excitation light source of power. At this time, if the output light power of one LD is insufficient, two L
A configuration is conceivable in which the output of D is polarization-synthesized, the power is added, and output as pump light. The configuration of FIG. 7 is obtained by applying this embodiment to such a configuration, and the output light of the polarization-combining LD module 70 is output via the pumping light input fiber 71. Then, the wavelengths are combined with the signal light by the function of the wavelength combining coupler 72 and input to the EDF 73. The EDF 73 amplifies the signal light by using the output light of the polarization combining LD module 70 as the pump light.

According to the configuration of this embodiment, the output of the two pumping light source LD modules, which has been a problem in the conventional configuration, is added to the output of the polarization combining module. It is possible to solve the problems of a decrease in output power due to insertion loss, a connection work between two LD modules and a polarization combining module, and an increase in the size of an optical fiber amplifier due to an increase in a mounting area including fiber routing. It becomes possible.

(Fourth Embodiment) Next, a fourth embodiment of the present invention will be described with reference to FIGS. This embodiment also has a configuration suitable for use in an excitation light source LD module as in the third embodiment. FIG. 8 is a top view showing the configuration of a component assembly used in this embodiment, and FIG. 9 is a side view showing the configuration of this embodiment.

As shown in FIG. 8, an excitation LD array 31 in which the LDs 30a and 30b are arrayed at a pitch between emission centers of 500 μm is fixed on a substrate 34 by soldering. A condensing lens array 33, which converts the light emitted from the excitation LD array 31 into a parallel beam and has a condensing lens 32a and a condensing lens 32b arrayed at a pitch of 500 μm between lens centers, is soldered on a substrate 34 by soldering. Fixed. Further, the condenser lens 32a
Polarization plane conversion element 41 only on the optical path of parallel beam 51 from
Are fixed on the substrate 34 with solder. The magnet 43 that applies a saturation magnetic field to the polarization conversion element 41 is fixed on the substrate 34 without interrupting the parallel beam.

A polarization plane combining element 42 is arranged on the optical path of the parallel beam 52 passing through the polarization plane conversion element 41 and the parallel beam 54 from the condenser lens 32b, and is fixed on the substrate 34 by soldering. .

The parallel beam 53 emitted from the polarization plane combining element 42
As shown in FIG. 9, a fiber 26 and a lens 24
Are arranged, and these are the case
YAG laser welding is fixed to 22 via a sleeve 23. In addition, the excitation LD array 31, the condenser lens array 33, and the collimator 25 are optically maximized so that the maximum coupling efficiency is obtained.
Optimal adjustment.

On the opposite side of the excitation LD array 31 from the lens side, a PD for monitoring light emitted from the excitation LD array 31 is provided.
A monitor PD array 39 in which the monitor PD 38a and the monitor PD 38b are arrayed at a pitch of 500 μm between the light receiving centers is fixed on the substrate 34 by soldering. Further, a thermistor resistor 37 is fixed to the substrate 34 by soldering.

The component assembly of FIG. 8 is, as shown in FIG.
The bottom surface and the cooling side 27 of the electronic cooling element 21 are fixed with solder,
The heat radiation side 28 of the electronic cooling element 21 and the case 22 are fixed with solder.

The light emitted from the LD 30b is converted into a parallel beam 54 by the condenser lens 32b, passes through the polarization plane combining element 42, and is output as a part of the parallel beam 53. The light emitted from the LD 30a is converted into a parallel beam 51 by the condenser lens 32a, passes through the polarization plane conversion element 41, and is converted by 90 degrees in the plane of polarization, so that the parallel beam is orthogonal to the parallel beam 54. Converted to 52. Further, the parallel beam 54 and the parallel beam 52 are combined by the polarization plane combining element 42 at orthogonal polarization planes, and output as a power-combined parallel beam 53.

As shown in FIG. 9, the parallel beam 53 enters the collimator 25, is focused by the lens 24, and is focused on the fiber 26.
And output as combined pump light power.

The outgoing light of the LD 30a emitted to the side opposite to the fiber side is received by the monitor PD 38a and used as an outgoing light monitor of the LD 30a. Similarly, the output light of the LD 30b is received by the monitor PD 38b and used as a monitor of the output light of the LD 30b. Since the resistance value of the thermistor resistor 37 changes depending on the temperature, the ambient temperature of the excitation LD array 31 can be detected by detecting the resistance value.

As a result, a temperature rise due to heat generation from the excitation LD array 31 is detected by the thermistor resistor 37. The part on the substrate 34 is cooled from the electronic cooling element cooling side 27 of the electronic cooling element 21 so that the temperature detected by the thermistor resistor 37 becomes 25 ° C. The heat radiation from the electronic cooling element heat radiation side 28 of the electronic cooling element 21 is released outside through the case 22.

According to the configuration of this embodiment, it is possible to combine the output light powers of the two pumping light sources LD in a single case in a parallel beam state, and the optical system related to the loss of the fiber output is required. Since it can be made almost common with the LD module, the insertion loss of the polarization combining module can be eliminated. Furthermore, by using the array LD,
The configuration on the electronic cooling element can be reduced, and power consumption can be reduced.

Also, there is no connection work between the two LD modules and the polarization combining module, and a high output can be obtained in one case for two LD modules composed of the same case. In addition, by mounting two LDs on one electronic cooling element in one case, it is possible to reduce the power consumption of one electronic cooling element, and the amount of heat dissipation of the electronic cooling element is also reduced. The operable environmental temperature at the time of mounting the device can be increased, and it is possible to cope with the device under high temperature environment conditions. Further, since the power consumption is reduced, the power source for supplying power can be reduced, and the power consumption of the device is reduced.

(Fifth Embodiment) Next, a fifth embodiment of the present invention will be described with reference to FIG. FIG. 10 is a top view showing a case mounting example of this embodiment.

First, two sets of subassemblies to be formed on the electronic cooling element are assembled. The structure of this subassembly is shown in FIG.
Since it is the same as that of the first embodiment shown in FIG. 1, the details are omitted, but the light emitted from the condenser lens 11 is optically adjusted to be a parallel beam. The oscillation wavelength of each LD of the two subassemblies is 1460 nm.
And 1480 nm.

These two sets of assembled sub-assemblies are
An LD with an oscillation wavelength of 1460 nm is placed on the thermoelectric cooler 21.
10a and the optical axis of the LD 10b having an oscillation wavelength of 1480 nm are 3
It is configured to be fixed in parallel at mm intervals. Reflection mirror that changes the optical path of parallel beam 51a from condensing lens 11a by 90 degrees
44 is installed on the electronic cooling element 21 and is fixed with solder. The bandpass filter 24 is arranged on the optical path of the parallel beam 52 reflected by the reflection mirror 44 and the parallel beam 53 from the condenser lens 11b, and is fixed on the electronic cooling element 21 by soldering. A collimator 25 composed of a fiber 26 and a lens 24 is arranged on the optical path of the parallel beam emitted from the band-pass filter 24, and is fixed to the case 22 via a sleeve 23 by YAG laser welding.

The LD 10a, the condenser lens 11a, and the collimator 25, and the LD 10b, the condenser lens 11b, and the collimator 25 are optimally adjusted so as to obtain optically maximum coupling efficiency. The reflection mirror 44 and the band-pass filter 45 are composed of a dielectric multilayer film. Reflection mirror
Reference numeral 44 indicates total reflection irrespective of wavelength, and the band-pass filter 45 reflects light having a wavelength of 1460 nm and a wavelength of 1480 nm.
nm light.

The bottom surface of the component assembly and the cooling side of the electronic cooling element 21 are fixed by solder, and the heat radiation side of the electronic cooling element 21 and the case 22 are also fixed by solder.

LD for emitting excitation light having a wavelength of 1480 nm
The light emitted from 10b is collimated by a condenser lens 11b.
It is converted to 53, passes through a bandpass filter 45, and is output as a part of a parallel beam 54. On the other hand, the wavelength 1460n
The light emitted from the LD 10a that emits the excitation light of m is converted into a parallel beam 51 by the condenser lens 11a, and is reflected by the reflection mirror 44.
Is converted into a parallel beam 52 whose optical path is changed by 90 degrees. Further, the parallel beam 52 is connected to a band-pass
The parallel beam 52 and the parallel beam 53 are wavelength-combined and output as a power-combined parallel beam 54.

The parallel beam 54 enters the collimator 25, is condensed by the lens 24, is coupled to the fiber 26, and is output as the combined excitation light power.

The light emitted from the LD 10a emitted to the opposite side from the fiber side is received by the monitor PD 13a,
It is used as the output light monitor of a. Similarly, LD10b
Outgoing light is received by the monitor PD 13b and the LD 10b
Used as an output light monitor. Thermistor resistance 15a
Since the resistance value changes with temperature, the ambient temperature of the LD 10a can be detected by detecting the resistance value. Similarly, by the thermistor resistance 15b, LD
The ambient temperature of 10b is detected.

The upper part of the electronic cooling element cooling side 27 of the electronic cooling element 21 is cooled so that the temperature detected by the thermistor resistance 15a and the thermistor resistance 15b becomes 25 ° C. The heat radiated from the heat radiation side 28 of the electronic cooling element 21 is radiated outside through the case 22.

As described above, by mounting two LDs on one thermoelectric cooling element in one case, the power consumption of one thermoelectric cooling element could be reduced. The amount of heat radiation of the electronic cooling element is also reduced, the operable environmental temperature at the time of mounting the device can be increased, and the device can be used under high temperature environment conditions. Since the power consumption is reduced, the power supply for supplying power can be reduced, and the power consumption of the device is reduced.

FIG. 12 shows a wavelength multiplexing LD of this embodiment.
FIG. 14 is a configuration diagram when a module 74 is applied to an excitation light source of an optical fiber amplifier.

When it is desired to obtain a high-output signal light from the optical fiber amplifier, a high-power pumping light source may be added to the EDF. At this time, if the output light power of one LD is insufficient, a configuration is conceivable in which the wavelengths of the outputs of the two LDs are combined, and the powers are added and output as pump light.
The configuration of FIG. 12 is obtained by applying this embodiment to such a configuration, and the output light of the wavelength combining LD module 74 is output via the pumping light input fiber 71. Then, the wavelengths are combined with the signal light by the function of the wavelength combining coupler 72 and input to the EDF 73. The EDF 73 amplifies the signal light by using the output light of the polarization combining LD module 70 as the pump light.

With the configuration of this embodiment, the insertion loss of the wavelength combining module when the output optical power of the two pumping light source LD modules is added by the wavelength combining module, which is a problem in the conventional configuration. Can reduce the problems of the output power reduction, the connection work between the two LD modules and the wavelength combining module, and the enlargement of the optical fiber amplifier due to the increase in the mounting area including the fiber routing. .

(Sixth Embodiment) Next, FIGS.
The sixth embodiment of the present invention will be described with reference to FIG. This embodiment also has a configuration suitable for use in an excitation light source LD module as in the fifth embodiment. FIG. 13 is a top view showing the structure of a component assembly used in this embodiment.
FIG. 4 is a side view showing the configuration of this embodiment.

As shown in FIG. 13, the oscillation wavelength 1460n
pump LD array 31 in which m LDs 30a and LD 30b having an oscillation wavelength of 1480 nm are arrayed at an emission center pitch of 500 μm.
Are fixed on the substrate 34 with solder. Then, the light emitted from the excitation LD array 31 is converted into a parallel beam.
The condensing lens 32a and the condensing lens 32b have a pitch between the lens centers of 5
The condensing lens array 33 arrayed at 00 μm
It is fixed on the top with solder. Further, a reflection mirror 44 for converting the optical path of the parallel beam 51 from the condenser lens 32a by 90 degrees is arranged, and is fixed on the substrate 34 by soldering.

The parallel beam reflected by the reflecting mirror 44
A bandpass filter 45 is arranged on the optical path of 52 and the parallel beam 54 from the condenser lens 32b, and is fixed on the substrate 34 by soldering.

A collimator 25 composed of a fiber 26 and a lens 24 is arranged on the optical path of the parallel beam 53 emitted from the band-pass filter 45, as shown in FIG. , Fixed by YAG laser welding. The excitation LD array 31 and the condenser lens array
33 and the collimator 25 are optimally adjusted so that the maximum coupling efficiency can be obtained optically.

The reflection mirror 44 and the bandpass filter 45 used here are composed of a dielectric multilayer film. The reflection mirror 44 performs total reflection irrespective of the wavelength, and the bandpass filter 45 reflects light having a wavelength of 1460 nm and transmits light having a wavelength of 1480 nm.

On the side opposite to the lens side of the excitation LD array 31, a PD for monitoring the light emitted from the excitation LD array 31 is provided.
A monitor PD array 39 in which the monitor PD 38a and the monitor PD 38b are arrayed at a pitch of 500 μm between the light receiving centers is fixed on the substrate 34 by soldering. Further, a thermistor resistor 37 is fixed to the substrate 34 by soldering.

In the component assembly shown in FIG. 13, the bottom surface and the cooling side 27 of the electronic cooling element 21 are fixed by soldering, and the heat radiation side 28 of the electronic cooling element 21 and the case 22 are fixed by soldering, as shown in FIG. I have.

The light emitted from the LD 30b having an oscillation wavelength of 1480 nm is converted into a parallel beam 54 by the condenser lens 32b, passes through the bandpass filter 45, and is output as a part of the parallel beam 53. LD30a with oscillation wavelength of 1460nm
Is converted by the condenser lens 32a into a parallel beam 51, which is reflected by the reflection mirror 44 and converted into a parallel beam 52 whose optical path is changed by 90 degrees. Further, the parallel beam 52 is reflected by the band-pass filter 45, and the parallel beam 54 and the parallel beam 52 are wavelength-combined and output as a power-combined parallel beam 53.

As shown in FIG. 14, the parallel beam 53 enters the collimator 25, is condensed by the lens 24, and
26, and output as the combined pump light power.

The outgoing light of the LD 30a emitted to the side opposite to the fiber side is received by the monitor PD 38a and used as an outgoing light monitor of the LD 30a. Similarly, the output light of the LD 30b is received by the monitor PD 38b and used as a monitor of the output light of the LD 30b. Since the resistance value of the thermistor resistor 37 changes depending on the temperature, the ambient temperature of the excitation LD array 31 can be detected by detecting the resistance value.

As a result, a temperature rise due to heat generation from the excitation LD array 31 is detected by the thermistor resistor 37. The part on the substrate 34 is cooled from the electronic cooling element cooling side 27 of the electronic cooling element 21 so that the temperature detected by the thermistor resistor 37 becomes 25 ° C. The heat radiation from the electronic cooling element heat radiation side 28 of the electronic cooling element 21 is released outside through the case 22.

According to the configuration of this embodiment, it is possible to combine the output light powers of the two pumping light sources LD in one case in a parallel beam state, and the optical system related to the loss of the fiber output is an LD. Since it can be made almost common with the module, the insertion loss of the wavelength combining module can be eliminated. Furthermore, by using the array LD,
The configuration on the electronic cooling element can be reduced, and power consumption can be reduced.

Also, there is no connection work between the two LD modules and the wavelength synthesizing module, and a high output can be obtained in one case for two LD modules composed of the same case. In addition, by mounting two LDs on one electronic cooling element in one case, it is possible to reduce the power consumption of one electronic cooling element, and the amount of heat dissipation of the electronic cooling element is also reduced. The operable environmental temperature at the time of mounting the device can be increased, and it is possible to cope with the device under high temperature environment conditions. Further, since the power consumption is reduced, the power source for supplying power can be reduced, and the power consumption of the device is reduced.

In each of the above embodiments, the configuration in which the fiber is fixed to the case has been described. However, the same effect can be obtained by mounting two sets of subassemblies in which the fiber is fixed to the metal substrate. .

In the second embodiment and the like, a spherical lens having a diameter of 500 μm is formed in an array as a condenser lens.
Although a spherical lens array was used, other configurations can be applied. For example, a Fresnel lens array shown in FIG. 16 or a computer generated hologram (Com
puter generated hologram:
Hereinafter, it is abbreviated as CGH. ) Lens (Japanese Patent Application No. 09-33)
It is also possible to use a CGH lens array shown in FIG. If such a configuration is used, a lens array can be formed at a higher precision pitch, and a lens with less aberration is formed. Therefore, the coupling efficiency between the LD output light and the fiber increases, and the same output power is obtained. LD power consumption for obtaining optical power can be reduced.

Further, in the above embodiment, the excitation LD,
The monitor PD, the condenser lens, and the fiber have been described by forming an array at a pitch of 500 μm in order to reduce the substrate area. However, this pitch is not limited to 500 μm, and is unified among the components. Good.

Similarly, in each embodiment, a two-core array has been described. However, if the number of cores is further increased, an LD can be further mounted in the same case.

[0076]

As described above in detail, according to the present invention, since a plurality of LDs are cooled by a single electronic cooling element, the power consumption of the electronic cooling element when cooling a plurality of LDs is reduced. The power consumption of the entire LD module can be greatly reduced as compared with the conventional configuration.

Further, since the power consumption is reduced, the heat radiation amount of the electronic cooling element is also reduced, the operable environmental temperature at the time of mounting the device can be increased, and the device can be used under high temperature environment conditions. Becomes possible. Further, since the power consumption is reduced, the power supply for supplying power can be reduced, and the power consumption of the device is reduced.

[Brief description of the drawings]

FIG. 1 is a top view showing a case mounting example of a first embodiment.

FIG. 2 is a side view showing a configuration of a component assembly mounted in the case of FIG. 1;

FIG. 3 is a top view showing a configuration of a component assembly mounted in the case of FIG. 4;

FIG. 4 is a side view showing a case mounting example of the second embodiment.

FIG. 5 is a top view showing a case mounting example of the third embodiment.

FIG. 6 is a side view showing a case mounting example of the third embodiment.

FIG. 7 is an overall configuration diagram when the polarization-combining LD module of the third embodiment is applied to an excitation light source of an optical fiber amplifier.

FIG. 8 is a top view showing a configuration of a component assembly mounted in the case of FIG. 9;

FIG. 9 is a side view showing a case mounting example of the fourth embodiment.

FIG. 10 is a top view showing a case mounting example of the fifth embodiment.

FIG. 11 is a side view showing a case mounting example of the fifth embodiment.

FIG. 12 is an overall configuration diagram when the wavelength multiplexing LD module of the fifth embodiment is applied to an excitation light source of an optical fiber amplifier.

FIG. 13 is a top view showing a configuration of a component assembly mounted in the case of FIG. 14;

FIG. 14 is a side view showing a case mounting example of the sixth embodiment.

FIG. 15 is a diagram showing a configuration of a spherical lens array used as a condenser lens array.

FIG. 16 is a diagram showing a configuration of a Fresnel lens array.

FIG. 17 is a diagram showing a configuration of a CGH lens array.

[Explanation of symbols]

 10, 10a, 10b, 30a, 30b LD 11, 11a, 11b Condenser lens 13, 13a, 13b, 38a, 38b Monitor PD 15, 15a, 15b, 37 Thermistor resistor 21 Electronic cooling element 31 Excitation LD array 32a, 32b Collection Optical lens 33 Condensing lens array 39 Monitor PD array 41 Polarization plane conversion element 42 Polarization plane synthesis element 43 Magnet 44 Reflection mirror 45 Band pass filter

Continued on the front page F term (reference) 2H037 BA03 BA11 DA03 DA04 DA06 DA35 DA38 5F072 AK06 HH02 KK05 KK24 KK30 MM07 MM08 PP07 TT03 TT15 TT27 5F073 AB27 AB28 BA01 FA01 FA06 FA11 FA25 GA23

Claims (9)

[Claims] An electronic cooling element; a plurality of LD elements mounted on the electronic cooling element; a condenser lens mounted on the electronic cooling element; and a monitor serving as a light receiving element for monitoring an output light of the LD. An LD module having a PD and a thermistor resistor. 2. An electronic cooling element, a first LD element mounted on the electronic cooling element, a second LD element mounted on the electronic cooling element, and an electronic cooling element mounted on the electronic cooling element. The first LD element and the second LD element
And a polarization combining element that performs polarization combining of output light of the LD element. 3. The LD module according to claim 2, wherein the condenser lens array is mounted on the thermoelectric cooler, a fiber array is mounted on the thermoelectric cooler, and the light modulator is mounted on the thermoelectric cooler. In addition, there is provided an LD array in which the first LD element and the second LD element are formed at the same pitch, and an optical system is constituted by the LD array, the condenser lens array, and the fiber array. LD module. 4. The LD module according to claim 2, wherein the polarization combining element uses a birefringent crystal. 5. An electronic cooling element, a first LD element mounted on the electronic cooling element, a second LD element mounted on the electronic cooling element, and mounted on the electronic cooling element The first LD element and the second LD element
And a wavelength synthesizing element for performing wavelength synthesis of output light from the LD element. 6. The LD module according to claim 5, wherein a condenser lens array mounted on the thermoelectric cooler, a fiber array mounted on the thermoelectric cooler, and a fiber array mounted on the thermoelectric cooler. In addition, there is provided an LD array in which the first LD element and the second LD element are formed at the same pitch, and an optical system is constituted by the LD array, the condenser lens array, and the fiber array. LD module. 7. The LD module according to claim 1, wherein the LD module is used as an excitation light source for an optical fiber amplifier. 8. The LD module according to claim 3, wherein a Fresnel lens array is used as the light-collecting lens array. 9. The LD module according to claim 3, wherein a CGH lens array is used as the light-collecting lens array.