JPH07326810A - Semiconductor laser device - Google Patents

Abstract

PURPOSE:To provide a semiconductor laser device capable of monitor operation of high precision. CONSTITUTION:Each of the outputted lights from a multi-beam semiconductor laser chip 13 is converged with a condenser means 12, and introduced into each of the four independent photo detection parts 14a... which are formed in a light receiving element 14 for monitoring use. In the condenser means 12, hologram surfaces 12b... which have converging action are formed on a lateral line on one plane of a rectangular parallelopiped transparent block 12a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor laser device.

[0002]

2. Description of the Related Art Conventionally, in a semiconductor laser device, a laser beam emitted from a semiconductor laser chip is APC.
(Automatic Power Control)
In order to drive, a rear emission light emitted rearward of the semiconductor laser or a part of a laser beam emitted frontward is received by a photodiode and monitored.

Further, as shown in FIG. 11, in a semiconductor laser device having a multi-beam semiconductor laser chip 51, each emitted light is guided to a plurality of photodiodes 53 ... I have to.

[0004]

However, in the above-mentioned conventional semiconductor laser device, since the vertical θ and the horizontal θ of the divergent light vary among the semiconductor laser chips, the amount of light protruding from the light receiving surface of the photodiode also varies. Occurs. Therefore, even if the light intensity is the same, there is a difference in the amount of light received by the monitor due to the above-mentioned amount of protruding light, and
In a multi-beam semiconductor laser, crosstalk occurs even if it has an optical guide for monitoring, and it is difficult to perform highly accurate monitoring operation.

As shown in FIG. 11, the light guide provided for monitoring the light quantity of the multi-beam semiconductor laser chip has grooves 52a ... Formed in a Si plate, and these grooves 52a are formed.
The inner surface of ... Is coated with a high-reflectance material, but if the space between the adjacent grooves 52a, 52a is made too narrow for size reduction, sufficient strength cannot be obtained. In order to obtain sufficient strength, when the grooves are formed in parallel, the wall thickness between the grooves must be several tens of μm or more. Further, in order to maintain the strength, if the formation directions of the grooves 52a are made radial (non-parallel) as shown in the figure to secure the thickness between the grooves, a difference occurs in the length of the grooves, which causes a difference in the optical path length. However, there is a difference in the amount of light loss. Therefore, even if the light intensity of each laser chip is the same, the difference in the amount of light received by the monitor causes a difference in the amount of light received by the monitor, and it is not possible to perform a highly accurate monitor operation, or there are many adjustments for obtaining accuracy. This requires time and increases costs. In the multi-beam semiconductor laser, as the number of beams increases, it becomes more difficult to monitor each beam independently, and the above-mentioned problem becomes more serious.

In view of the above circumstances, it is an object of the present invention to provide a semiconductor laser device capable of highly accurate monitor operation in both the single beam system and the multi beam system.

[0007]

The first structure of the present invention is as follows.
In order to solve the above-mentioned problems, it is characterized in that a condensing means for condensing the emitted light of the semiconductor laser chip and guiding it to the monitor light receiving element is provided.

The second configuration is characterized in that a condensing means for condensing the emitted light from each of the multi-beam semiconductor laser chips and guiding it to each of a plurality of monitor light receiving elements is provided.

In the third configuration, the condensing means may be a hologram element in the first or second configuration.

A fourth configuration is the same as the above second configuration,
The condensing means may be composed of a member in which a plurality of hologram surfaces are formed on the surface of one block.

A fifth configuration is the same as the second configuration,
A plurality of light receiving surfaces of the monitor light receiving element may be arranged and formed in two or more rows.

In the sixth configuration, in any one of the first to fifth configurations, the condensing means may be arranged so as to guide the forward emission light of the semiconductor laser chip to the monitor light receiving element.

In the seventh configuration, in any one of the first to sixth configurations, the monitor light receiving element may be formed on the submount.

[0014]

According to the first structure, the emitted light of the semiconductor laser chip is condensed and guided to the monitor light receiving element, so that the emitted light is prevented from protruding from the monitor light receiving element, and a highly accurate monitor is provided. You can take action. Further, since the irradiation light of the semiconductor laser chip is condensed and guided to the monitor light receiving element, it is also possible to widen the arrangement interval between the semiconductor laser chip and the monitor light receiving element, which increases the design flexibility of the semiconductor laser device. It can also be increased.

According to the second structure, in the multi-beam system, the same operation as described above can be obtained.

According to the third structure, since the light converging means is composed of a hologram, even if the beam interval is narrowed for downsizing, the reduction in intensity and the optical path as in the case of using the conventional light guide consisting of the groove. There is no problem of deterioration of monitor accuracy due to the difference in length. Further, in such a configuration, the position of the monitor light receiving element can be appropriately set because diffraction and focusing can be performed, and the degree of freedom in designing the semiconductor laser device increases.

According to the fourth structure, since the condensing means is composed of a member in which a plurality of hologram surfaces are formed on the surface of one block, the number of parts is smaller than that in the structure in which the hologram element is individually provided for each of the multi-beams. Can be reduced.

According to the fifth structure, since the plurality of light-receiving surfaces of the monitor light-receiving element are arranged and formed in two or more rows, many light-receiving surfaces are arranged and formed in one horizontal row, so that the light-receiving area becomes small. Due to this, deviation of the beam spot is unlikely to occur, and ease of assembly can be achieved by relaxing the accuracy of component placement.

According to the sixth structure, since the front emission light is received and monitored, the accuracy of the intensity detection of each beam can be improved as compared with the case where the rear emission light is monitored.

According to the seventh structure, since the monitor light-receiving element is formed on the submount, the semiconductor laser chip and the monitor light-receiving element can be arranged on substantially the same surface, and the wire bonding can be led out. Etc. can be easily manufactured and the cost can be reduced.

[0021]

【Example】

(Embodiment 1) The present invention will be described below with reference to the drawings showing the embodiment.

FIG. 1 is a perspective view showing the semiconductor laser device with the cap removed. The submount 2 is arranged on the first stem 1 (block for mounting chips and the like). The semiconductor laser chip 3 and the condensing means 4 are placed and fixed on the submount 2. The semiconductor laser chip 3 has a light-collecting means 4 on the rear light emitting surface side.
Will be placed towards.

The condensing means 4 has a hologram surface 4b formed on one plane of a transparent block 4a having a rectangular parallelepiped shape, and is arranged with the hologram surface 4b facing the above-mentioned rear light emitting surface. The hologram surface 4b has a hologram pattern that collects incident light.

The monitor light-receiving element 5 is arranged and fixed on the first stem 1 so that the light-receiving surface 5a thereof faces the position where the beam condensed by the action of the hologram surface 4b of the light-collecting means 4 is received. ing.

The first stem 1 is arranged and fixed to the second stem 6 (support base). A lead member 7 ... For making an electrical connection to the outside is inserted and fixed to the second stem 6, and a protruding tip portion thereof is a wire (not shown) for the monitor light receiving element 5 or the semiconductor laser chip 3. Connected by bonding.

FIG. 2 (a) shows that in the semiconductor laser device having the above structure, the backward emission light of the semiconductor laser 5 is condensed by the hologram surface 4b of the condensing means 4 and is incident on the light receiving surface 5a of the monitor light receiving element 5. It is a plan view showing how light enters, and FIG. 7B is a side view showing a similar state.

According to the above configuration, the emitted light of the semiconductor laser chip 3 is collected and guided to the monitor light receiving element 5, so that the emitted light is prevented from protruding from the monitor light receiving element 5 and is highly accurate. A monitor operation can be performed. Further, since the irradiation light of the semiconductor laser chip is condensed and guided to the monitor light-receiving element 5, it is possible to widen the arrangement interval between the semiconductor laser chip 3 and the monitor light-receiving element 5, and it is possible to freely design the semiconductor laser device. You can also increase the degree.

(Embodiment 2) Another embodiment of the present invention will be described below with reference to FIG.

The semiconductor laser device of this embodiment is shown in FIG.
As shown in (a) and (b), the condensing means 11 in which the hologram surface 11b is formed on one plane of the transparent block 11a is
The rear emission light of the semiconductor laser chip 3 is transmitted to the submount 2
The monitor light receiving element 5 formed above is configured to diffract and focus light.

According to this structure, the monitor light receiving element 5
Are formed on the submount 2, the semiconductor laser chip 3 and the monitor light-receiving element 5 can be arranged on substantially the same plane, and the semiconductor laser chip 3 and the monitor light-receiving element 5 can be pulled out by wire bonding. Manufacturing is facilitated and cost can be reduced.

Although the transmissive hologram is used as the light collecting means 11, a reflective hologram may be used. For example, by arranging the reflection hologram surface so as to be inclined with respect to the light receiving surface 5a of the monitor light receiving element 5 formed on the submount 2 and the rear light emitting surface of the semiconductor laser chip 3, the semiconductor laser is provided. The backward emission light of the chip 3 can be reflected, diffracted, and guided to the monitor light-receiving element 5 formed on the submount 2.

(Embodiment 3) Another embodiment of the present invention will be described below with reference to FIGS.

In the multi-beam semiconductor laser device of the present embodiment, which has four beams and can be independently driven, as shown in FIG. 4, light emitted from each of the multi-beam semiconductor laser chips 13 is condensed by the condensing means 12. Each of them is condensed and guided to each of the four independent light receiving portions 14a of the monitor light receiving element 14 formed. The light collecting means 12
Is a rectangular parallelepiped transparent block 12a in which one surface has hologram surfaces 12b, ...

With the above-described structure, as shown in FIGS. 5A and 5B, the emitted light of the multi-beam semiconductor laser chip 13 is condensed and the independent light receiving portion 14 of the monitor light receiving element 14 is collected.
Since the light is guided to each of the a ...
4a ... Can be prevented from protruding and a highly accurate monitor operation can be performed. Further, since the arrangement interval between the multi-beam semiconductor laser chip 13 and the monitor light receiving element 14 can be widened, the degree of freedom in design is increased.

Further, since the light condensing means 12 is composed of a hologram, even if the beam interval is narrowed for downsizing, the monitor is caused by a decrease in intensity and a difference in optical path length as in the case of using a conventional optical guide consisting of a groove. The problems of reduced accuracy and crosstalk between beams do not occur. Further, since the light condensing means 12 has a plurality of hologram surfaces 12b ... Formed on the plane of one block 12a, the number of parts is reduced as compared with the configuration in which the hologram element is individually provided for each of the multi-beams. be able to.

(Embodiment 4) Another embodiment of the present invention will be described below with reference to FIGS. 6 and 7.

In the semiconductor laser device of this embodiment, as in the case of the above-mentioned third embodiment, the emitted light from each of the multi-beam semiconductor laser chips is collected by the light collecting means, and a plurality of independent light receiving portions of the light receiving element for monitoring are provided. In common with the point that the light collecting means 15 is configured so as to lead to each of the above, as shown in FIG. 6, the condensing means 15 condense diffraction (first-order diffraction) on one plane of the transparent block 15a having a rectangular parallelepiped shape. It is configured to have a plurality of hologram surfaces 15a having an action. Further, on the back side of the transparent block 15a, a black light shielding portion 15c for shielding the transmitted light from the hologram surface 15a is formed.

According to the above configuration, as shown in FIG.
The backward emission light of each of the multi-beam semiconductor laser chips 13 is diffracted and condensed by the condensing means 15, is guided to each of the plurality of independent light receiving portions 14a of the monitor light receiving element 14, and is the same as in the third embodiment. The action will be obtained.

(Embodiment 5) Another embodiment of the present invention will be described below with reference to FIG.

In this embodiment, the structure of the third embodiment is adapted for multi-beam. That is, FIG. 8 (a)
As shown in (b), four independent light receiving portions 14a ... Are formed on the submount 2, and the backward emission light of the multi-beam semiconductor laser chip 13 is directed to each independent light receiving portion 14a. Each is diffracted and condensed and guided.

(Embodiment 6) Another embodiment of the present invention will be described below with reference to FIG.

In this embodiment, the multi-beam semiconductor laser chip 20 which has eight beams and can be independently driven in the structure of the third embodiment is used.
The monitor light receiving element 21 includes eight independent light receiving portions 21a ...
Are arranged and formed in two rows of four in the lateral direction. Also,
The light converging means 22 is formed by forming eight hologram surfaces 22b ... On one plane of a rectangular parallelepiped transparent block 22a, and eight independent hologram surfaces 22b ... Are formed in the above two rows. Eight beams of the multi-beam semiconductor laser chip 20 are diffracted and condensed and guided to each of the light receiving portions 21a.

As described above, since the eight independent light receiving portions 21a are arranged and formed in two rows, four in the horizontal direction, the width of each independent light receiving portion 21a is 4 when the number of beams is four. The same width as the lateral width is maintained, the deviation of the beam spot due to the reduction of the light receiving area of the independent light receiving portion 21a is less likely to occur, and the assembly accuracy can be facilitated by relaxing the component placement accuracy.

It should be noted that eight independent light receiving portions 21a ... Are arranged on the submount 2 in four rows in the lateral direction in two rows, and backward emission light is emitted to each independent light receiving portion 21a using the configuration of the fifth embodiment. Alternatively, the light may be diffracted and condensed and guided. Also in a multi-beam semiconductor laser device having more than eight beams, a plurality of rows of light receiving portions and a hologram element having a hologram surface corresponding to each beam are used similarly to the present embodiment, and there is no problem such as crosstalk. The monitor can be operated.

(Embodiment 7) Another embodiment of the present invention will be described below with reference to FIG.

In the semiconductor laser device of this embodiment, a condenser means 26 having a plurality of hologram surfaces 26b ... Formed on one plane of a transparent block 26a having a rectangular parallelepiped shape, and a monitor having a plurality of light receiving surfaces 27a ... The light receiving element 27 is provided on the front side of the multi-beam semiconductor laser chip 25.
It is arranged on the first stem 1. The light collecting means 26
Are arranged so that their hologram surfaces 26b ... Are directed toward the front light emission surface side of the multi-beam semiconductor laser chip 25, and the front emission light is diffracted and condensed respectively, and the light receiving surface 2
It is designed to lead to 7a.

With this structure, the same operation as that of the third embodiment can be obtained. Further, since the front emission light is received and monitored, the accuracy of intensity detection of each beam can be improved as compared with the case where the rear emission light is monitored.

It should be noted that, in the above-described embodiments, the monitor light-receiving element is arranged on the first stem 2 in a structure other than the structure in which the monitor light-receiving element is formed on the submount 2. It may be arranged on the second stem 6, or may be arranged on another place such as the second stem 6. In this case, even if the monitor light receiving element is arranged at a position relatively distant from the semiconductor laser chip, the irradiation light of the semiconductor laser chip is condensed and guided to the monitor light receiving element. It does not protrude from the light receiving surface.

Although an optical member other than the hologram can be used as the light converging means, the hologram can condense light in a relatively arbitrary direction by setting the pattern, and the above-mentioned embodiment 6 is used. It is possible to easily deal with the case where the independent light receiving portions 21a ... Of the monitor light receiving element 21 shown by are formed in two or more rows. Further, it is possible to make the intensities of the respective monitor lights uniform by setting the hologram pattern, or vice versa. Further, the light condensing member formed by forming the hologram surface on the transparent block can be easily obtained by, for example, simply forming a plurality of hologram surfaces on a glass substrate in a predetermined pattern and appropriately cutting the hologram surface, and thus can be manufactured at low cost. .

[0050]

As described above, according to the present invention, it is possible to improve the accuracy of the monitor, increase the degree of freedom of design, reduce the number of parts, facilitate the assembly, and reduce the cost. .

[Brief description of drawings]

FIG. 1 is a perspective view of a semiconductor laser device of the present invention.

2 (a) is a plan view of a main part of the semiconductor laser device of FIG. 1, and FIG. 2 (b) is a side view thereof.

3A is a side view of a main part of a semiconductor laser device according to another embodiment of the present invention, and FIG. 3B is a plan view thereof.

FIG. 4 is a perspective view of a semiconductor laser device according to another embodiment of the present invention.

5A is a plan view of a main part of the semiconductor laser device of FIG. 4, and FIG. 5B is a side view thereof.

FIG. 6 is a perspective view of a condensing unit used in a semiconductor laser device according to another embodiment of the present invention.

FIG. 7 is a side view of a main part of a semiconductor laser device using the condensing unit of FIG.

8A is a side view of a main part of a semiconductor laser device according to another embodiment of the present invention, and FIG. 8B is a plan view thereof.

FIG. 9 is a perspective view of a main part of a semiconductor laser device according to another embodiment of the present invention.

FIG. 10A is a perspective view of a focusing means used in a semiconductor laser device of another embodiment of the present invention, and FIG.
FIG. 4 is a side view of a main part of a semiconductor laser device using the above-mentioned condensing means.

FIG. 11 is a plan view of a main part of a semiconductor laser device using a conventional light guide.

[Explanation of symbols]

 1 1st stem 2 Submount 3 Semiconductor laser chip 4 Condensing means 4b Hologram surface 5 Monitor light-receiving element 11 Condensing means 12 Condensing means 13 Multi-beam semiconductor laser chip 14 Monitoring light-receiving element 15 Condensing means 16 Condensing Means 20 Multi-beam semiconductor laser chip 21 Light receiving element for monitor 22 Condensing means

Front page continuation (72) Inventor Takao Yamaguchi 2-5-5 Keihan Hondori, Moriguchi City, Osaka Sanyo Electric Co., Ltd.

Claims (7)

[Claims] 1. A semiconductor laser device comprising: a condensing unit that condenses light emitted from a semiconductor laser chip and guides it to a light receiving element for monitoring. 2. A semiconductor laser device comprising a condensing means for condensing emitted light from each of the multi-beam semiconductor laser chips and guiding it to each of a plurality of monitor light receiving elements. 3. The semiconductor laser device according to claim 1, wherein the condensing means is a hologram element. 4. The semiconductor laser device according to claim 2, wherein the light converging means comprises a member having a plurality of hologram surfaces formed on the plane of one block. 5. The semiconductor laser device according to claim 2, wherein a plurality of light receiving surfaces of the monitor light receiving element are arranged and formed in two or more rows. 6. The semiconductor laser device according to claim 1, wherein the condensing means is arranged so as to guide the front emission light of the semiconductor laser chip to the monitor light receiving element. 7. The semiconductor laser device according to claim 1, wherein the monitor light-receiving element is formed on the submount.