JP2522805Y2 - Optical communication device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention relates to an optical communication device installed in an optical communication system or the like.

Optical communication devices installed in optical communication systems are usually
A semiconductor laser device is used as a transmission electric / optical converter, while being housed in a metal hermetic housing to remove the influence of external electromagnetic waves. This semiconductor laser device is liable to generate a large amount of heat, thereby increasing the operating temperature, deteriorating oscillation characteristics, and shortening the life of the semiconductor laser device. Therefore, various ideas have been devised for the heat radiation characteristics of the semiconductor laser device.

In a conventional optical communication device, as shown in a cross-sectional view in FIG. 3, a semiconductor laser element 12 is fixed to a bottom surface of a metal package 11 via a metal block and an electronic cooling element 13 by soldering or the like. And this metal package
The bottom surface of 11 is fixed to the bottom surface of metal housing 17 by soldering or the like. A heat radiation fin 19 is attached to a side wall of the housing 17, and an electronic circuit including a voltage / current converter for driving a laser is formed on a printed board 16 housed in the housing 17.

(Problem to be Solved by the Invention) In the conventional optical communication device shown in FIG. 3, the semiconductor laser device is fixed to the bottom surface of the package via the electronic cooling device. For this reason, the capacitance associated with the electronic cooling element has a bad influence on the modulation characteristics of the semiconductor element. Typically, there is a problem that resonance due to the capacitance and the inductance of the lead wire occurs at a frequency around 1.5 GHz, and the modulation characteristics are significantly impaired.

(Means for Solving the Problems) An optical communication device according to the present invention includes: a semiconductor laser module including an optical element including a semiconductor laser element and a package containing the optical element; a printed circuit board on which an electronic circuit is formed; A housing that houses the semiconductor laser module and the printed circuit board and has a radiation fin directly connected to the outside and is maintained at a ground potential, and the semiconductor laser module is coupled at one end side inside the housing and is connected to the outside of the housing. A heat plate or a heat pipe that is coupled to the radiation fin via an electronic cooling element on the other end side and is kept at a ground potential by contact with a side wall of the housing;
It is configured so as to realize efficient heat radiation characteristics without any adverse effect on the modulation characteristics of the semiconductor laser device.

 Hereinafter, the operation of the present invention will be described in detail with examples.

(Embodiment) FIG. 1 is a perspective view showing the configuration of the optical communication device of the present invention, and FIG. 2 is a sectional view taken along the line AA 'of FIG.

The semiconductor laser module is a metal package 1
A metal block 3 fixed to the bottom surface of the package 1 by soldering; and a semiconductor laser element 2 fixed to the block 3 by soldering. The bottom surface 1a of the package 1 is fixed to the upper surface of one end of the hollow plate-shaped heat plate 4 by soldering. The other end of the heat plate 4 penetrates through the side wall of the housing 8 and is exposed to the outside, and is mechanically connected to the radiating fins 9 attached to the side wall of the housing 8 via the electronic cooling element 10. , Thermal and electrical coupling. An electronic circuit including a voltage / current converter for driving a semiconductor laser device is formed on the printed circuit board 7 housed in the housing 8.

The heat plate 4 has a hollow plate shape made of a metal such as copper or an aluminum alloy, and a wick 4a made of a metal mesh or a glass fiber layer is formed on the inner wall surface as is well known. At the same time, a working fluid such as ammonia or water is sealed inside. Semiconductor laser device 2
When the temperature of the heat plate 4 on the semiconductor laser module side rises due to the heat generated, the temperature of the working fluid seeping into the wick 4a rises and evaporates, thereby taking away latent heat of vaporization. The vaporized working fluid vapor moves to the low-temperature / low-pressure side electronic cooling element 10 due to the pressure difference. On the electronic cooling element 10 side,
The steam moving from the high temperature / high pressure side is cooled and condensed. The condensed working fluid returns to the semiconductor laser module due to the capillary action of the wick 4a. By repeating the vaporization, the movement by the pressure difference, the condensation, and the reflux in a cyclic manner, a large amount of heat accompanying the vaporization and the condensation is transmitted from the high temperature side to the low temperature side with extremely high efficiency.

That is, heat generated by the semiconductor laser element 2 is passed through the ground side electrode formed on the bottom surface of the metal block 3.
Is transmitted to one end of the metal heat plate 4 through the bottom surface 1a of the metal package 1, and further transmitted to the radiation fins 9 through the electronic cooling element 10 at the other end of the heat plate 4. Dissipated inside. As is well known, the thermal resistance along the longitudinal direction of the heat plate 4 is an extremely small value of several hundredths of that of a copper plate having the same cross-sectional area. Efficient heat radiation characteristics equivalent to those directly attached to the radiation fins 9 via the cooling element 10 are realized.

The ground side electrode formed on the bottom surface of the conductive laser element 2 is made up of a metal block 3 and a metal heat plate 4.
And is directly connected to the side wall of the housing 8 which determines the ground potential. Therefore, the electronic cooling element 10 fixed between the radiation fin 9 attached to the housing 8 and maintained at the ground potential and the heat plate 4 also maintained at the ground potential by contact with the side wall of the housing 8. Has no adverse effect on the operating characteristics of the semiconductor laser device. As a result, good modulation characteristics are realized up to a high frequency region.

The emitted light of the semiconductor laser element 2 is guided to the connector 6 through the coupling lens in the package 1 arranged in front and the optical fiber held by the optical fiber ferrule 5 attached to the side wall of the package 1, The light is output to an optical transmission line such as an optical fiber cable connected to the optical connector 6.

The configuration using the heat plate having a hollow plate shape as the heat transfer mechanism between the semiconductor laser module and the electronic cooling element has been described above. However, as the heat transfer mechanism, a structure in which one or more cylindrical heat pipes are embedded in a metal plate such as copper may be used.

Further, the optical communication device of the above embodiment may be configured as an optical transmission device including a semiconductor laser module,
Alternatively, it may be configured as an optical transmitting and receiving device including an optical receiving unit in addition to the optical transmitting unit including the semiconductor laser module.

(Effects of the Invention) As described in detail above, the optical communication device of the present invention is:
Since the semiconductor laser module is coupled to one end inside the housing and the heat plate is coupled to the radiation fin via the electronic cooling element at the other end outside the housing, the electric characteristics of the semiconductor laser element are increased. Efficient heat radiation characteristics can be realized without any adverse effect on the device.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the structure of an optical communication device according to an embodiment of the present invention, FIG. 2 is a sectional view taken along the line AA 'of FIG. 1, and FIG. 3 is the structure of the optical communication device according to the prior art. FIG. DESCRIPTION OF SYMBOLS 1 ... Package which accommodates laser element of semiconductor laser module, 1a ... Bottom of package 1, 2 ... Semiconductor laser element, 3 ... Metal block, 4 ... Heat plate, 4a ... Wick, 7 ... ... a printed circuit board on which an electronic circuit is formed, 8 ... a housing for accommodating the semiconductor laser module and the printed circuit board, 9 ... heat radiation fins, 10 ... electronic cooling elements.

Claims (1)

(57) [Scope of request for utility model registration] 1. A semiconductor laser module comprising an optical element including a semiconductor laser element and a package accommodating the optical element, a printed circuit board on which an electronic circuit is formed, and an external device accommodating the semiconductor laser module and the printed circuit board A radiation fin is directly connected to the casing, and the semiconductor laser module is coupled to one end of the casing inside the casing, and an electronic cooling element is attached to the radiation fin at the other end outside the casing. An optical communication device, comprising: a heat plate or a heat pipe that is connected to the housing and is kept at a ground potential by contact with a side wall of the housing.