JPS6234472Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a semiconductor laser device, and more particularly to a structure for integrating a semiconductor laser element and a lens system for focusing its emitted light.

In order to realize highly efficient coupling between the semiconductor laser device and the optical fiber, a microlens such as a cylindrical lens 1 with a minute diameter is arranged horizontally to the output end face 3 of the semiconductor laser device 2, as shown in FIG. ,
There is one in which the emitted light is focused on the light receiving surface of the optical fiber 4.

In the above structure, the semiconductor laser element 2 is bonded to a diamond heat sink 5 with good thermal conductivity in order to improve the dissipation of the heat generated internally, and the diamond heat sink is further made of a support base 6 made of a material with high thermal conductivity such as copper. fixed on top.
On the other hand, the lens 1 is glued onto the holder 7, and the holder 7
is the above-mentioned output end surface 3 of the heat sink 5 and the support base 6
It is fixed by adhesive on the side end surface 8.

The relative positional relationship between the lens 1 and the semiconductor laser element 2 arranged in this manner requires very strict precision. In other words, the coupling efficiency decreases by 1 [dB]
The relative position accuracy is approximately ±0.2 [μ
m] or less. Therefore, when bonding the holder 7, it is necessary to adjust the position of the holder so that the bonding efficiency is maximized, and to maintain this state using a jig or the like until the adhesive is completely cured.

However, since it takes a long time for the adhesive to completely harden, it is not always easy to maintain the above-mentioned positional accuracy during that time.

In order to solve the problems of the prior art described above, the present invention provides a structure of a semiconductor laser device that can fix the holder in a very short time.

The present invention will be explained below with reference to examples.

FIG. 2 is a sectional view of a main part showing an embodiment of the present invention, in which the end of the support plate 6 is made of a material with a thermal conductivity of 1.7 [W/cm/°C] or less, such as iron (Fe). A base 11 is bonded and interposed between the holder 7 and the support base 6. Other than this point, there is no other difference from the conventional example shown in FIG.

In this embodiment, by interposing the base 11 made of a low heat conductive material as described above, it is possible to fix the holder 7 to the base 11 by laser beam irradiation instead of using adhesive. That is, as shown in FIG. 3, the side surface 12 of the holder 7
By irradiating the vicinity of the joining line between the end face 8' of the base 11 and the base 11 with a laser beam 13, the two can be bonded together.

The low thermal conductivity materials used for the base 11 include metals such as iron (Fe), Monel, stainless steel, Invar, and Super Invar, as well as alumina magnetic,
It may also be silicon (Si), quartz, or the like. Among these, metals such as iron (Fe) are plated with nickel (Ni) and gold (Au) on the surface, and in the case of alumina magnetism, the surface is plated with titanium (Ti) - platinum (Pt) - gold (Au). It is used after being metalized by a method such as sequential formation of thin layers by sputtering.

The material of the holder 7 does not need to be particularly limited, but
When both the holder 7 and the base 11 are made of the same metal with a relatively low melting point, such as iron (Fe),
As described above, by irradiating the laser beam 13, both are locally melted and joined. If either or both of the holder 7 and the base 11 are made of a metal with a high melting point, or if they are made of alumina magnetic or quartz, gold-tin (Au-Sn), gold-silicon (Au
-Si), gold-antimony (Au-Sb), gold-germanium (Au-Ge), lead-tin (Pb-Sn), indium-tin (In-Sn) alloys, etc. The brazing material is melted by irradiation and can be bonded through this.

Furthermore, as shown in FIG.
The angle formed by the back surface and the two side surfaces 12, 12' that intersect with both of the back surfaces facing and in contact with the back surface is an acute angle, and the edge portion 14 joined to the base 11 is shaped like a knife edge. In this way, the direction of irradiation of the laser beam to the two edge portions 14 can be made constant. In the example shown in FIG. 3, since the laser beam 13 must be irradiated obliquely, in order to bond both sides 12, 12' of the holder 7,
Compared to having to change and adjust the irradiation direction, the work becomes easier by forming the holder 7 in the shape shown in FIG. 4.

Note that when the holder is directly bonded to the support base 6 made of copper (Cu), which is a highly thermally conductive material, as in the conventional structure, even if it is heated by laser beam irradiation, the heat is quickly dissipated through the support base 6. Therefore, it is not possible to locally raise the temperature to the temperature required for welding. The thermal conductivity of the various materials mentioned above that can be laser beam welded is the highest for silicon (Si), which is 1.7 (W/cm/℃), and the others are smaller. Therefore, the thermal conductivity is 1.7 [W/cm/℃]. cm/℃] A base 11 made of the following materials is attached to a holder 7 and a support base 6.
Laser welding becomes possible by interposing the material between the two. By the way, the thermal conductivity of copper (Cu) is approximately 4.
[W/cm/°C].

As explained above, according to the present invention, the holder can be fixed instantaneously, so it is easy to maintain the relative positional accuracy between the semiconductor laser element and the optical fiber, and work efficiency is improved.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a main part showing a conventional semiconductor laser device, FIGS. 2 and 3 are a cross-sectional view and a perspective view of a main part showing an embodiment of the present invention, and FIG. 4 is a modified example. FIG. 3 is a perspective view of main parts. In the figure, 1 is a microlens, 2 is a semiconductor laser element, 3 is an emission end face, 5 is a heat sink,
6 is a support base, 7 is a holder, 8 and 8' are end faces, 11
12 and 12' are side surfaces, 13 is a laser beam, and 14 is a knife edge portion.

Claims (1)

[Claims for Utility Model Registration] (1) A microlens disposed on the emission end face of the semiconductor laser element to focus the emitted light of the semiconductor laser element supports a heat sink on which the semiconductor laser element is mounted and the heat sink. In the semiconductor laser device supported on a holder fixed to the end face on the emission end side of the support base, the thermal conductivity between the holder and the support base is 1.7 [W/cm/°C] or less. A semiconductor laser device characterized by interposing a base made of a material. (2) The above-mentioned utility model registration request characterized in that the two side surfaces of the holder, which intersect with both the upper surface that supports the microlens and the back surface that contacts the base, form an acute angle with the back surface. The semiconductor laser device according to item 1.