JP2814987B2 - Semiconductor laser module - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a semiconductor laser module, and more particularly to a structure of a semiconductor laser module having a semiconductor laser element and an optical fiber.

[0002]

2. Description of the Related Art A conventional semiconductor laser module of this type will be described below with reference to FIG. FIG. 3 is a longitudinal section showing an example of a conventional semiconductor laser module.

Referring to FIG. 3, laser light from semiconductor laser device 1 is optically coupled to optical fiber pigtail 9 via lens 6. The thermoelectric cooling element (referred to as “Peltier cooler”) includes a Peltier cooler upper substrate 5a, a Peltier cooler 5c, and a Peltier cooler lower substrate 5b,
It is manufactured as a pre-assembled single part.

The Peltier cooler is mounted on the inner wall of the package bottom plate 10 by a Peltier cooler lower substrate 5b. On the Peltier cooler upper substrate 5a, a laser element 1, a lens 6, a holder 7, a slide ring 8 whose optical axis is adjusted. , And an optical coupling system including a fiber pigtail 9 is mounted.

A thermistor 4 for temperature monitoring is mounted on a carrier 3 on which the laser element 1 is mounted via a heat sink 2. Further, the fiber pigtail 9 is sealed by a solder seal 12 at an introduction portion into the package.

Next, the operation principle of the conventional semiconductor module shown in FIG. 3 will be described. The laser beam emitted from the semiconductor laser device 1 is introduced into the optical fiber and extracted as a signal outside the package by the above-described configuration.

The semiconductor laser module having the above-described configuration is widely used in the field of optical fiber communication and the like, but a signal output in order to ensure communication transmission quality must be sufficiently stable. On the other hand, semiconductor laser devices have temperature characteristics, and the characteristics of laser light vary greatly with temperature.

Accordingly, this type of semiconductor laser module has a thermistor and a Peltier cooler inside. During operation, the temperature near the laser element is constantly monitored by the thermistor, and the input of the Peltier cooler is fed back to operate the semiconductor laser module. The structure is such that the temperature of the laser chip can be kept constant even if the temperature of the atmosphere of the module changes.

Generally, temperature control is performed so that the laser chip temperature T _LD = 25 ° C. with respect to the operation guarantee temperature range T = −40 to 65 ° C. of the laser module.

Strictly speaking, the laser element is a heat source, and when the laser element is energized at an ambient temperature T = 25 ° C., the laser chip temperature T _LD rises by a few degrees from 25 ° C. Neglecting the heat generated by
If it is lower than 5 ° C., the Peltier cooler is operated as a heating device to control T _LD = 25 ° C. On the other hand, when the ambient temperature is higher than 25 ° C., the current flowing through the Peltier cooler is reversed to operate as a cooling device.

[0011]

In this conventional semiconductor laser module, as described above, an optical coupling system, that is, a laser element, a lens, a holder,
Due to the configuration of the fiber pigtail and the like, there are the following problems.

(1) The first problem is that the height of the package is high.

(2) The second problem is that the resistance to mechanical shock is low.

Regarding the first problem, the height of the package in the prior art semiconductor laser module shown in FIG. 3 is limited by the restrictions on the physical dimensions of the optical coupling system and the Peltier cooler due to its configuration. About 10mm
Degree.

[0015] Regarding the second problem, although the Peltier cooler has a mechanical shock resistance of 1500 G or more, an optical coupling system having a considerable weight is mounted on the Peltier cooler. As a result, the load applied to the Peltier cooler when an impact is applied increases,
The application of a mechanical shock of about 0 G causes the Peltier cooler to break.

Next, as a prior art for reducing the package height of a semiconductor laser module, for example, Japanese Patent Application Laid-Open No. 5-226779 proposes a structure of a semiconductor laser module as shown in FIG. Have been.

Referring to FIG.
In the semiconductor laser module described in JP-A-79-79, the substrate below the Peltier cooler is eliminated and
The Peltier element 5c is mounted directly on the inner wall of the Peltier 0. However, in this case, there is only an effect of reducing the thickness of the package for one Peltier cooler lower substrate (approximately 0.5 mm), and there is no effect in improving the resistance to mechanical shock.

Accordingly, the present invention has been made in view of the above circumstances, and an object of the present invention is to reduce the thickness of a package in a semiconductor laser module having a Peltier cooler and to reduce the resistance to mechanical shock. An object of the present invention is to provide an improved semiconductor laser module.

[0019]

In order to achieve the above object, the present invention provides a semiconductor laser module having a semiconductor laser element and an optical fiber, wherein a temperature adjusting element is provided on a top plate and a bottom plate of a package of the semiconductor laser module. An optical coupling system is provided on the inner wall surface side of one of the top plate and the bottom plate of the package which is to be subjected to temperature adjustment, between the top plate and the bottom plate of the package.

In the present invention, the carrier on which the semiconductor laser device is mounted and an optical system for optically coupling the semiconductor laser device and the optical fiber are both provided on the top plate and the bottom plate of the package. It is arranged on the inner wall surface of one plate to be adjusted.

Further, in the present invention, the carrier on which the semiconductor laser device is mounted is mounted on the inner wall of the substrate to be temperature-controlled by the temperature control device.

The outline of the present invention will be described below. In recent years, the required standard for this type of semiconductor laser module has become strict.
m or less, and a resistance to mechanical shock of 1500 G or more is required.

In the semiconductor laser module according to the present invention, the Peltier element as the temperature adjusting element is sandwiched between the top plate and the bottom plate of the package, and all or a part of the optical coupling system is subjected to temperature adjustment. A semiconductor laser module that satisfies the above-mentioned required standard is provided by forming the inner wall of a package plate or the inner wall of a Peltier cooler substrate. Here, for the Peltier element which is a temperature adjusting element, for example, when performing a heat absorbing operation from the upper substrate and a heat releasing operation from the lower substrate during cooling, the entire optical coupling system is provided on the inner wall side of the package top plate to be cooled. Alternatively, a configuration in which a part is provided is adopted. Then, when the Peltier element is used as a heating element, heat is radiated from the upper substrate of the Peltier element by reversing the direction of the current flowing through the Peltier element. The package top plate side that is in contact is heated.

[0024]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view for explaining the configuration of the first embodiment of the present invention.

Referring to FIG. 1, Peltier cooler upper substrate 5
a, a Peltier cooler composed of a Peltier element 5c and a Peltier cooler lower substrate 5b is mounted so as to be sandwiched between a package top plate 11 and a package bottom plate 10. An optical coupling system in which a semiconductor laser chip 1 is mounted on a carrier 3 via a thermistor 4 and a heat sink 2 and a holder 7 to which a carrier 3, a lens 6, a slide ring 8 and a fiber pigtail 9 are fixed is provided. , On the inner wall of the package top plate 11. In this case, the Peltier cooler upper substrate 5a is a substrate whose temperature is to be adjusted by the Peltier element.

As described above, in the first embodiment of the present invention, the Peltier cooler is sandwiched between the package top plate and the package bottom plate, and the optical coupling system is formed on the package top plate. Is, for example, 10 mm
It is possible to reduce the thickness to about 6 mm, that is, about half. The resistance to mechanical shock can be increased to 1500 G or more, which is the mechanical shock resistance of the Peltier cooler alone.

FIG. 2 is a longitudinal sectional view for explaining a second embodiment of the present invention. Referring to FIG. 2, in the second embodiment of the present invention, unlike the first embodiment, the carrier 3 on which the semiconductor laser chip 1 is mounted via the thermistor 4 and the heat sink 2 is a Peltier cooler. It is characterized in that it is mounted on the inner wall of the upper substrate 5a.

The operating principle of the semiconductor laser modules of the first and second embodiments will be described together.

The mechanism by which the laser light of the semiconductor laser chip 1 is extracted out of the package as a signal is described below.
This is the same as the above-mentioned prior art. Further, the temperature of the laser chip 1 is detected by the thermistor 4 mounted in the vicinity of the laser chip 1, and the structure for feeding back the operation of the Peltier cooler 5 c so that the output signal of the thermistor 4 becomes constant is the same as the conventional one. Embodiments of the present invention
The temperature of the package top plate 11 exposed to the package atmosphere or the Peltier cooler upper substrate 5a itself mounted on the inner wall of the package top plate 11 is changed by the Peltier cooler 5c to control the temperature in the vicinity of the laser element 1. Become.

Therefore, in the embodiment of the present invention, the cooling temperature is higher than that of the Peltier cooler used in the conventional semiconductor laser module so that the temperature of the package top plate 11 does not change due to the ambient temperature of the semiconductor laser module. A capable Peltier cooler is required, which can be accommodated by current Peltier cooler technology.

The second embodiment of the present invention is less susceptible to the influence of the ambient temperature than the first embodiment, and requires a lower cooling capacity for the Peltier cooler.

The embodiment of the present invention has been described above.
The present invention is not limited to the above-described embodiments, but includes various embodiments and modifications in accordance with the principles of the present invention.

[0033]

As described above, according to the present invention,
Conventionally, the Peltier cooler is sandwiched between the package top plate and the package bottom plate, and the optical coupling system is configured on the package top plate, or a part is configured on the inner wall of the Peltier cooler. The height of the package, which has been limited to the physical dimensions that can be summed up by the height of the system, can be reduced in thickness, and the mechanical shock resistance can be improved. According to the semiconductor laser module of the present invention, the package height can be reduced from 10 mm to about half, that is, about 6 mm, and its mechanical shock resistance is increased to 1500 G or more, which is the mechanical shock resistance of the Peltier cooler alone. Can be raised.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a first embodiment of the present invention.

FIG. 2 is a diagram for explaining a second embodiment of the present invention.

FIG. 3 is a view for explaining a conventional semiconductor laser module.

FIG. 4 is a view for explaining another conventional semiconductor laser module.

[Description of Signs] 1 Semiconductor laser element 2 Heat sink 3 Carrier 4 Thermistor 5 Peltier cooler 5a Peltier cooler upper substrate 5b Peltier cooler lower substrate 5c Peltier element 6 Lens 7 Holder 8 Slide ring 9 Fiber pigtail 10 Package bottom plate 11 Package top plate 12 Solder 13 Photodiode for monitor

Claims (4)

(57) [Claims] 1. A semiconductor laser module having a semiconductor laser element and an optical fiber, wherein a temperature adjusting element is sandwiched between a top plate and a bottom plate of a package of the semiconductor laser module, and a temperature adjustment element is provided between the top plate and the bottom plate of the package. A semiconductor laser module comprising an optical coupling system disposed on an inner wall surface side of one plate to be adjusted. 2. A carrier on which the semiconductor laser device is mounted, and an optical system for optically coupling the semiconductor laser device and the optical fiber are both a temperature adjustment target of a top plate and a bottom plate of the package. 2. The semiconductor laser module according to claim 1, wherein said semiconductor laser module is disposed on an inner wall surface of said one plate. 3. A semiconductor laser module comprising a semiconductor laser element and an optical fiber, wherein a temperature adjusting element is sandwiched between a top plate and a bottom plate of a package of the semiconductor laser module, and a carrier on which the semiconductor laser element is mounted is: A semiconductor laser module mounted on an inner wall of a substrate whose temperature is to be adjusted by the temperature adjusting element. 4. A semiconductor laser module comprising a semiconductor laser element and an optical fiber, wherein a temperature adjusting element is provided with an upper substrate and a lower substrate in contact with a top plate and a bottom plate of a package of the semiconductor laser module. A carrier on which the semiconductor laser element is mounted is disposed on an inner wall of the package plate in contact with one of the upper substrate and the lower substrate to be subjected to temperature adjustment, or on an inner wall of the substrate to be subjected to temperature adjustment. And an optical coupling system for optically coupling the semiconductor laser element and the optical fiber is disposed on the package plate side in contact with the substrate to be subjected to the temperature adjustment. Semiconductor laser module.