JP2002368345A - Semiconductor laser module and optical pickup module - Google Patents

Abstract

(57) [Summary] [Problem] It is not possible to reduce cost, ease mounting accuracy, and mass productivity. SOLUTION: Two semiconductor lasers 1 arranged in parallel,
2 and an optical element 3 having a plurality of reflection surfaces corresponding to the respective semiconductor lasers 1 and 2, wherein the optical element 3 is not perpendicular or parallel to the optical axis of the semiconductor laser 1, but is parallel to each other and faces each other. It has a pair of reflecting surfaces 31a and 31b and a pair of reflecting surfaces 32a and 32b that are parallel to each other and are not perpendicular or parallel to the optical axis of the semiconductor laser 2 and are opposed to each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor laser module and an optical pickup module.

[0002]

2. Description of the Related Art CD-R, DVD, S
-Various optical disks such as DVDs have begun to spread, but ideally, it is preferable that a single recording and reproducing device can record and reproduce a plurality of types of disks.

However, in the case of a laser beam having a wavelength of 780 nm used in CDs and CD-Rs, the light spot is D
It is not possible to narrow down to the size of a pit on a VD disk. On the other hand, dyes used for CD-R discs are not reflected by laser light having a wavelength of 650 nm used in DVDs, and are not readable.

Therefore, for example, one CD-R and one DVD
In order to enable recording and reproduction by one recording and reproducing apparatus, two semiconductor laser devices having a wavelength of 780 nm and a wavelength of 650 nm must be used.

Therefore, a semiconductor laser device has been proposed in which a semiconductor laser chip having a wavelength of 650 nm and a semiconductor laser chip having a wavelength of 780 nm are mounted in parallel on a single package. , The distance between the light emitting points of the two laser chips becomes as large as 300 to 400 μm.
It becomes very difficult to design the optical system of the pickup.

For this reason, a method has been proposed in which a light emitting point is pseudo-closed using a reflection surface. For example, JP
Japanese Patent Application Publication No. 1-39684 discloses a method in which light emitting points are brought close to each other by using a submount having a triangular cross section. Referring to FIG. 6, the outputs B1 and B2 from the semiconductor lasers 102 and 103 are bent by the adjacent reflecting surfaces 104 and 105 by the submount 101 having a triangular cross section. Close to each other.

[0007]

However, in order to realize the structure as shown in FIG. 6, it is necessary to manufacture a structure having a triangular cross section. In particular, it is not easy to make an inclined surface having a triangular cross section having an angle of 45 degrees, and although some manufacturing methods have been proposed so far, it cannot be manufactured so stably that it can be actually applied to mass production. Did not. It is also possible to add a triangular cross section using a microprism, but mounting becomes very difficult, and it becomes very expensive in terms of cost, making mounting on an optical pickup impractical. .

As described above, the conventional method of making the light emitting points pseudo close to each other by using the reflecting surface is not a simple method suitable for mass production and has a problem that it cannot be realized at low cost. is there.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has been made to reduce the mass productivity and cost of a semiconductor laser module in which the intervals between the light emitting points of a plurality of semiconductor lasers are pseudo-closed using a reflecting surface. The purpose is to aim.

[0010]

According to a first aspect of the present invention, there is provided a semiconductor laser module having a plurality of reflecting surfaces respectively corresponding to two semiconductor lasers arranged in parallel. The optical element has two sets of a pair of reflecting surfaces which are not perpendicular or parallel to the optical axis of the semiconductor laser but are parallel to each other and opposed to each other.

According to a second aspect of the present invention, there is provided the semiconductor laser module according to the first aspect, wherein the optical axes of the light beams emitted from the two semiconductor lasers arranged in parallel are different from each other at the first reflection surface of the optical element. It is bent toward the semiconductor laser.

According to a third aspect of the present invention, in the semiconductor laser module according to the second aspect, the arrangement of the semiconductor laser and the reflection surface of the optical element arranged in parallel are symmetrical.

According to a fourth aspect of the present invention, there is provided a semiconductor module.
In any one of the semiconductor laser modules of (1) to (3),
The material of the optical element is single crystal silicon.

According to a fifth aspect of the present invention, there is provided a semiconductor module.
In any one of the semiconductor laser modules of (1) to (4),
The emission wavelengths of the semiconductor lasers arranged in parallel are different from each other.

According to a sixth aspect of the present invention, in the semiconductor laser module according to any one of the first to fifth aspects, the light emitting points of the semiconductor lasers arranged in parallel are biased toward the adjacent semiconductor laser.

According to a seventh aspect of the present invention, there is provided an integrated type optical pickup module comprising the semiconductor laser module according to any one of the first to sixth aspects.

[0017]

Embodiments of the present invention will be described below with reference to the accompanying drawings. First, the principle of the present invention will be described with reference to FIG. In the case of using a method in which a pseudo light emitting point interval is reduced by using a reflecting surface, the most important point is that the optical axes of the two semiconductor lasers after reflection must be aligned. The reason why the reflecting surface having an angle of 45 degrees is required is because the optical axes of the semiconductor lasers arranged opposite to each other are aligned in the same direction after reflection. As described above, since the direction of the optical axis after the reflection changes in the single reflecting surface, only the reflecting surface having a specific angle such as 45 degrees can be used.

On the other hand, the present invention eliminates such a limitation by utilizing two parallel and opposed reflecting surfaces. That is, the optical axis that has entered the two parallel and opposite reflecting surfaces becomes completely parallel again to the first optical axis after the second reflection. By using this principle, even if a reflecting surface having an arbitrary angle is used, if the optical axes of the two semiconductor lasers before entering the reflecting surface are made parallel, the optical axis after reflection is also made parallel be able to.

That is, as shown in FIG. 1, two semiconductor lasers 1 and 2 arranged in parallel, and reflection surfaces 31a and 31b and a reflection surface 32 corresponding to the semiconductor lasers 1 and 2, respectively.
a, 32b, and the optical element 3 having the reflection surfaces 31a, 31b of the optical element 3.
, And the light emitted from the semiconductor laser 2 is sequentially reflected by the reflection surfaces 32 a and 32 b of the optical element 3.

Here, since the semiconductor lasers 1 and 2 are arranged in parallel, the optical axes 1a and 2a of the laser light before being incident on the reflection surfaces 31a and 32a of the optical element 3 are parallel. Thereafter, the parallel reflecting surfaces 31a, 31b of the optical element 3
Since the optical axes 1a and 2a of the laser light reflected twice by the optical elements 3a and 32b are parallel to those before entering the optical element 3, the optical axes 1a and 2a of the laser light reflected by the optical element 3 Be parallel. Here, the reflection surfaces 31a, 3a of the optical element 3
The angle between 1b and 32a, 32b is arbitrary, and the optical element 3
Even if the relative position of the semiconductor lasers with respect to the semiconductor lasers 1 and 2 is slightly shifted, the light emitting point interval after passing through the optical element 3 is not affected.

According to the first aspect of the present invention, there is provided a semiconductor laser module including two semiconductor lasers arranged in parallel and an optical element having a plurality of reflecting surfaces corresponding to the respective semiconductor lasers. The device has a configuration in which two pairs of a pair of reflecting surfaces which are parallel and opposed to each other and which are not perpendicular or parallel to the optical axis of the corresponding semiconductor laser.

Thus, the angle of the reflecting surface can be set at an arbitrary angle, so that the cost of the optical element can be reduced. In addition, since the mounting accuracy of the optical element can be reduced, a simple mounting method suitable for mass production can be adopted.

In this case, the light emitted from the semiconductor lasers 1 and 2 spreads around the optical axes 1a and 2a, so that the longer the distance from the light emitting point to the reflecting surfaces 31a and 32a, the more the light is required on the reflecting surfaces. Is increased. Since the size of the reflecting surface cannot be smaller than the light emitting point interval, it is necessary to make the distance between the light emitting point and the reflecting surface as short as possible in order to make the light emitting point interval close. In the above-described configuration of claim 1, in order to bring all the reflecting surfaces as close as possible to the light emitting point, the first reflecting surface 31 of the optical element 3 is required.
The optical axes 1a and 2a may be bent toward the other (the other) semiconductor laser at the points a and 32a, and the optical axes 1a and 2a may be directed toward the front again at the second reflecting surfaces 31b and 32b.

According to a second aspect of the present invention, in the semiconductor laser module according to the first aspect, the optical axis of the light emitted from the two semiconductor lasers arranged in parallel is the first reflection surface of the optical element. To be bent toward another semiconductor laser. This makes it possible to realize a semiconductor laser module capable of further reducing the light emitting point interval.

The distance between the light emitting point and the reflecting surface can be minimized in the configuration of the second aspect of the invention because the reflecting surfaces 31a and 31a of the optical elements 3 and the semiconductor lasers 1 and 2 arranged in parallel.
This is the case where the arrangement of b and 32a, 32b is symmetrical.

Therefore, according to a third aspect of the present invention, in the semiconductor laser module according to the second aspect, the arrangement of the semiconductor lasers arranged in parallel and the reflection surface of the optical element is symmetrical. . As a result, a semiconductor laser module that can minimize the light emitting point interval can be realized.

The optical elements according to the first to third aspects of the invention are required to have the parallelism between the reflecting surfaces facing each other,
The point is that it can be manufactured at low cost. The material most suitable for such applications is single crystal silicon. Single crystal
Since the (111) plane of Si is hardly etched by an etching solution such as a KOH aqueous solution as compared with other crystal planes, a crystal plane usable as a reflection plane can be selectively obtained. Therefore, opposed reflecting surfaces having high parallelism can be easily manufactured, and the manufacturing cost can be reduced by a semiconductor process.

Therefore, according to a fourth aspect of the present invention, in the semiconductor laser module according to the first to third aspects, the material of the optical element is single crystal silicon. Thus, an optical element having a highly accurate parallel reflection surface can be easily manufactured at low cost.

As described above, two semiconductor laser devices having a wavelength of 780 nm and a wavelength of 650 nm must be used so that, for example, a CD-R and a DVD can be recorded and reproduced by one recording and reproducing device. Claim 1
In the semiconductor laser module according to the fourth aspect, the wavelength 78
With a configuration using two semiconductor lasers having a wavelength of 0 nm and a wavelength of 650 nm, a two-wavelength light source having a very small light emitting point interval can be obtained even when a normal individual semiconductor laser is used.

Therefore, according to a fifth aspect of the present invention, in the semiconductor laser module according to the first to fourth aspects, the semiconductor lasers arranged in parallel have different emission wavelengths. This makes it possible to easily obtain a two-wavelength light source having a very small light emitting point interval even when using a normal individual semiconductor laser.

Further, as described in detail in the description of the second aspect of the present invention, the size of the reflecting surface cannot be smaller than the interval between the light emitting points. The distance must be as close as possible. here,
As is clear from FIG. 1, the distance between the light emitting point and the reflecting surface depends on the distance from the light emitting point to the end of the semiconductor laser chip. By reducing the distance, the distance between the light emitting point and the reflecting surface can be reduced.

According to a sixth aspect of the present invention, in the semiconductor laser module according to the first to fifth aspects, the light emitting points of the semiconductor lasers arranged in parallel are biased toward the adjacent semiconductor laser. I have. As a result, a semiconductor laser module having a small light emitting point interval can be realized, which cannot be realized by using a semiconductor laser having a normal light emitting point at the center.

Further, by combining the semiconductor laser module according to the first to sixth aspects with a hologram element, a PD chip or the like, a module for an integrated optical pickup having a small light emitting point interval can be easily realized at low cost. it can.

Therefore, in the invention of claim 7, a module for an integrated optical pickup is constituted by using the semiconductor laser module according to claims 1 to 6.
As a result, an integrated optical pickup module having a small light emitting point interval can be easily realized at low cost.

Hereinafter, a specific embodiment of the present invention will be described with reference to FIGS. First, a first embodiment of the present invention will be described with reference to FIGS. FIG. 2 is a top view showing the operation of the semiconductor laser module to which the present invention is applied, and FIG. 3 is a perspective explanatory view of the module.

This semiconductor laser module comprises two semiconductor lasers 11 arranged in parallel to emit a laser beam having a wavelength of 650 nm and a semiconductor laser 12 emitting a laser beam having a wavelength of 780 nm.
An optical element 13 having a plurality of reflecting surfaces corresponding to the optical element 11, wherein the optical element 13 is not perpendicular or parallel to the optical axis 11 a of the semiconductor laser 11, 131b and a pair of reflecting surfaces 132a and 132b that are perpendicular and not parallel to the optical axis 12a of the semiconductor laser 12 and that are parallel and opposed to each other, and these semiconductor lasers 11 and 12 and the optical element 13 It is mounted on the submount 14.

Each light emitting point 11 of the semiconductor lasers 11 and 12
The laser beams emitted from 1, 121 have their optical axes 11a, 12a.
The beam spreads 11b and 12b occur with respect to a, and the reflecting surfaces 131a and 131b of the optical element 13 which are parallel and opposed to each other are formed.
After being reflected twice at 132a and 132b, the optical axes 11a and 12a are turned back, and then emitted upward in FIG.

The optical element 13 is formed of single crystal silicon (Si), and the reflecting surfaces 131a, 132b and 132
a and 132b are crystal planes of the (111) plane and are formed symmetrically to the left and right.

Here, the light emitting point 1 of the semiconductor lasers 11 and 12
The pseudo light emitting point interval after passing through the optical element 13 is significantly smaller than the interval between 11 and 121.

Next, a second embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. FIG. 2 is a top view showing the operation of the semiconductor laser module to which the present invention is applied, and FIG. 3 is a perspective explanatory view of the module.

This semiconductor laser module comprises two parallel arranged semiconductor lasers 21 and 22 which emit laser light having a wavelength of 650 nm and 780 nm, respectively.
An optical element 23 having a plurality of reflective surfaces corresponding to the optical element 2, wherein the optical element 23 is not perpendicular or parallel to the optical axis 21 a of the semiconductor laser 21, 231b and a pair of reflecting surfaces 232a and 232b that are perpendicular and not parallel to the optical axis 22a of the semiconductor laser 22 and that are parallel and opposed to each other, and these semiconductor lasers 21 and 22 and the optical element 23 It is mounted on the submount 24.

Here, the light emitting points 211 and 221 of the semiconductor lasers 21 and 22 are respectively connected to the other semiconductor laser 2.
It is arranged so as to be biased toward the side 2 and 21. The laser light emitted from each of the light emitting points 211 and 221 of the semiconductor lasers 21 and 22 has its optical axis 21a and 22a with a beam spread 2
1b and 22b are generated, and after being reflected twice by the reflecting surfaces 231a and 231b and 232a and 232b of the optical element 23, which are parallel and opposed to each other, the optical axes 21a and 22a are turned back, and then, the upward direction in FIG. Are emitted.

The optical element 23 is made of single-crystal silicon (Si), and has reflection surfaces 231a, 232b and 232.
a and 232b are crystal planes of the (111) plane and are symmetrically formed.

Here, the light emitting point 2 of the semiconductor lasers 21 and 22
The pseudo light emitting point interval after passing through the optical element 13 is significantly smaller than the interval of 11 and 221.

The present invention is not limited to the requirements shown here, such as the shapes described in the above embodiments and combinations with other elements.

[0046]

As described above, according to the semiconductor laser module of the first aspect, the optical element having a plurality of reflection surfaces corresponding to each of the two semiconductor lasers arranged in parallel is provided by the light of the semiconductor laser. Since there are two pairs of a pair of reflecting surfaces that are parallel to each other and are not perpendicular and parallel to the axis, the angles of the reflecting surfaces can be any angle,
The cost of the optical element can be reduced, and the mounting accuracy of the optical element can be reduced, so that a simple mounting method suitable for mass production can be adopted.

According to the semiconductor laser module of the second aspect, in the semiconductor laser module of the first aspect, the optical axis of light emitted from the two semiconductor lasers arranged in parallel is equal to the first reflection surface of the optical element. Since it is bent to the other semiconductor laser side, it becomes possible to further reduce the light emitting point interval.

According to the semiconductor laser module of the third aspect, in the semiconductor laser module of the second aspect, the arrangement of the reflecting surfaces of the semiconductor laser and the optical element arranged in parallel is symmetrical, so that the interval between the light emitting points is minimized. Can be smaller.

According to the semiconductor module of the fourth aspect, in the semiconductor laser module of any one of the first to third aspects, since the material of the optical element is single crystal silicon, the optical element having a highly accurate parallel reflection surface can be used. The module can be easily manufactured at low cost, and the cost of the module can be reduced.

According to the semiconductor module of the fifth aspect, in the semiconductor laser module of any one of the first to fourth aspects, the emission wavelengths of the semiconductor lasers arranged in parallel are different from each other. Also, a two-wavelength light source having a very small light-emitting point interval can be easily obtained.

According to the semiconductor laser module of the sixth aspect, in the semiconductor laser module of any one of the first to fifth aspects, the emission points of the semiconductor lasers arranged in parallel are biased toward the adjacent semiconductor laser. The distance between the light emitting points can be made smaller than when a semiconductor laser having a normal light emitting point at the center is used.

According to a module for an integrated optical pickup according to a seventh aspect of the present invention, since the semiconductor laser module according to any one of the first to sixth aspects is provided, the module for the integrated optical pickup having a small issue point interval is provided. Can be obtained at low cost.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram for explaining the principle of the present invention.

FIG. 2 is an explanatory top view illustrating a first embodiment of the present invention.

FIG. 3 is an explanatory perspective view of the embodiment.

FIG. 4 is an explanatory top view illustrating a second embodiment of the present invention.

FIG. 5 is an explanatory perspective view of the embodiment.

FIG. 6 is an explanatory diagram for explaining a conventional module.

[Explanation of symbols]

1, 2, semiconductor laser, 3 optical element, 1a, 2a optical axis, 31a, 31b, 32a, 32b reflective surface, 11,
12, 21, 22 ... semiconductor laser, 13, 23 ... optical element, 14, 24 ... submount, 11a, 12a, 21
a, 22a ... optical axis, 131a, 131b, 132a, 1
32b, 231a, 231b, 232a, 232b ... reflection surface,

Claims (7)

[Claims] 1. A semiconductor laser module comprising: two semiconductor lasers arranged in parallel; and an optical element having a plurality of reflection surfaces corresponding to each of the semiconductor lasers, wherein the optical element is arranged with respect to an optical axis of the semiconductor laser. A semiconductor laser module comprising two sets of a pair of reflecting surfaces which are not perpendicular and not parallel and which are parallel and opposed to each other. 2. The semiconductor laser module according to claim 1, wherein an optical axis of light emitted from the two parallelly arranged semiconductor lasers is closer to the other semiconductor laser at a first reflection surface of the optical element. A semiconductor laser module characterized by being bent. 3. The semiconductor laser module according to claim 2, wherein the arrangement of the semiconductor lasers arranged in parallel and the reflection surface of the optical element are symmetrical. 4. The semiconductor laser module according to claim 1, wherein a material of said optical element is single-crystal silicon. 5. The semiconductor laser module according to claim 1, wherein the emission wavelengths of the semiconductor lasers arranged in parallel are different from each other. 6. The semiconductor laser module according to claim 1, wherein light emitting points of the semiconductor lasers arranged in parallel are biased toward the adjacent semiconductor laser. 7. A module for an integrated optical pickup, comprising the semiconductor laser module according to claim 1. Description: