JPS61108189A - Semiconductor laser device - Google Patents

Abstract

PURPOSE:To enable a lens and a semiconductor chip to be aligned with high accuracy, by providing a cap having side walls which have flexibility and contraction/expansion properties such that it can be deformed only under power exceeding a predetermined value. CONSTITUTION:Side walls 3a of a cap 3' for airtightly sealing a laser chip 2 mounted on a stem 1 is composed of metallic bellows 7. The metallic bellows 7 having flexibility and contraction and expansion properties enables the relative position between a lens 6 and the laser chip 2 to be adjusted in a certain extent even after the cap 3' is welded to the steam 1. Consequently, the bulk productivity is improved. Further, the side walls composed of metallic bellows ensure the good hermetic properties and resistance to environment.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a semiconductor laser device, and particularly to a hermetically sealed structure for a semiconductor laser chip.

[Conventional technology]

FIG. 2 is a sectional view showing a semiconductor laser device that has been in practical use. In Figure 1, 1 is the stem;
2 is a semiconductor laser chip mounted on the stem 1, 3 is a cap welded and fixed on the stem 1, 3a is a side wall thereof, and 4 is a blank sealed to the side wall 3a of the cap 3. Optical windows 5a and 5b are electrode terminals of the semiconductor laser chip 2, and the semiconductor laser chip 2 is hermetically sealed with a stem 1 and a cap 3 with an optical window 4. It has a highly reliable structure.

Next, the operation of this semiconductor laser device will be explained.

In FIG. 1, an electrode terminal 5 provided on the stem 1
When current is passed through the semiconductor laser chip 2 through a and 5b, laser oscillation occurs, and light is emitted from the end face of the semiconductor laser chip 2. This light passes through the optical window 4 as shown in the direction of the arrow in FIG. It is taken out and used outside.

However, the light emitted from the optical window 4 generally has extremely poor directivity, and the full width at half maximum is 3 on one side.
It reaches 0 to 40 degrees. Therefore, in most applied fields, a separate lens (not shown) is placed on the optical window 4 with high precision to condense or collimate the emitted light.

In addition, as a method to improve such problems, Figure 1
Instead of the glass plate optical window 4 shown in this figure, a structure can be considered in which a lens 6 with a non-reflection coating is provided as shown in FIG. According to , the optical window 4 with an expensive anti-reflection coating (see FIG. 2) can be omitted, and the lens 6 necessary for the application is also integrated, resulting in an extremely advantageous structure.

[Problem that the invention seeks to solve]

However, with such a configuration, extremely difficult alignment is required between the lens 6 and the tiny light-emitting portion from which the emitted light of the semiconductor laser chip 2 is output. Ordinary welding equipment for caps 3, such as the one shown in Figure 3, cannot be used, and a welding equipment that requires some kind of special high-precision positioning mechanism is required. will be damaged. In addition, even if highly accurate positioning is possible before welding, during welding, there will always be slight sinking of the welded part, so some misalignment is unavoidable. It was a problem.

Therefore, the present invention has been made in view of the above-mentioned conventional problems, and its purpose is to improve mass productivity and manufacturing yield without using an expensive optical window made of a glass plate with an anti-reflection coating. An object of the present invention is to provide a lens-embedded semiconductor laser device that can be realized at low cost.

[Failure to solve the problem]

In order to achieve such an object, the present invention provides a cylindrical body that deforms only when a predetermined force or more is applied to the side wall of the cap, making it flexible and stretchable. .

[Effect]

According to such a configuration, the relative positioning of the lens and the semiconductor laser chip can be variably adjusted, so that highly accurate positioning of the lens and the light emitting portion of the semiconductor laser chip is possible.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of a semiconductor laser device according to the present invention, and the same parts as those in the previous figures are given the same reference numerals. In the figure, a cap 3' that hermetically seals the semiconductor laser chip 2 mounted on the stem 1# has a metal bellows as a cylindrical body that deforms only when a predetermined force or more is applied to the cap side wall 321. 7 are integrally provided.

According to such a configuration, the side wall portion 3a of the cap 3'
The metal bellows 6 is flexible and stretchable, so even after the cap 3' is fixed to the stem 1 by welding, the lens 6 and the semiconductor laser chip 2 remain connected. The relative positions of can be adjusted within a certain range. Therefore, as explained in FIG. 3, there is no need for extremely high-precision positioning during cap welding between the lens 6 and the semiconductor laser chip 2, which was required in the conventional semiconductor laser device. Not only is it possible to use a superior conventional cap welding device, it is also possible to avoid a decrease in manufacturing yield due to slight positional deviation during welding. Further, since the side wall portion 3a of the cap 3' is formed of the metal bellows 7, airtightness and environmental resistance are improved, and relative positioning with high reliability and high accuracy is possible.

In the above-described first embodiment, a case was explained in which a metal peg was provided as a cylindrical body that deformed only when a predetermined force or more was applied to the side wall of the cap, but the present invention It goes without saying that the bellows is not limited to this, and the same effect as described above can be obtained even if the bellows is made of various rubber or plastic materials.

〔Effect of the invention〕

As explained above, according to the present invention, the side wall portion of the cap has a cylindrical structure that deforms only when a force exceeding a predetermined value is applied, so that an optical window made of an expensive anti-reflection coated glass plate can be used. The present invention has an extremely excellent effect in that a lens-embedded semiconductor laser device omitting the above can be obtained at a low cost without impairing mass productivity or manufacturing yield.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of a semiconductor laser device according to the present invention, and FIGS. 2 and 3 are sectional views showing an example of a conventional semiconductor laser device. 1... Stem, 2... Semiconductor laser chip, 3
'...Cap, 3a...Side wall part, 5a, 5
bφ...electrode terminal, 6...lens, 7...metal bellows.

Claims (2)

[Claims] (1) The semiconductor laser chip mounted on the stem is hermetically sealed with a cap that has a cylindrical body on the side wall that deforms only when a predetermined force or more is applied, and has a lens as an optical window. Semiconductor laser device. (2) The semiconductor laser device according to claim 1, wherein the cylindrical body is a metal bellows.