JPH0627977Y2 - Semiconductor laser device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a semiconductor laser device most suitable as a light source for an optical disk reader or the like.

(B) Conventional technology At present, as a light source for reading an optical disk, three independent resonators are arranged in parallel at intervals of about 100 μm so that each beam for erasing, reading, and writing can be individually output. The following three-beam type semiconductor laser device has been proposed (Japanese Patent Application No. 61-40952).

(C) Problems to be solved by the invention To independently monitor the laser beams emitted from the resonators close to each other in this way, Japanese Patent Laid-Open No. 102902/1983 has been proposed.
As disclosed in Japanese Unexamined Patent Application Publication No. JP-A-2003-264, there may be considered a method of disposing a light receiving element for monitoring in the vicinity of the resonator in correspondence with each resonator.

However, since the beam divergence θ ₁₁ of the laser light output from the semiconductor laser chip (resonator) is at least about 10 °, the distance between the chip and the light receiving element is 500 μm.
It cannot be accurately monitored unless it is less than m.

That is, as shown in FIG. 3, each of the semiconductor laser chips (1) to (3) arranged in parallel at 100 μm intervals (specifically, the distance between the optical axes (4) of the laser beams output from the respective chips). A light-receiving element having a plurality of light-receiving regions (5) to (7) is arranged so as to face the emitting surface, and further laser light (1
Each spread angle of a) to (3a) is 10 ° and each chip
When the distance between (1) to (3) and the light receiving elements (5) to (7) is 500 μm or more, the laser beams are superposed on the light receiving element side. Therefore, each of the light receiving regions (5) to (7) also receives the laser light output from the chips other than the laser chips facing each other, and it becomes impossible to monitor each laser chip.

In addition, the distance between each chip (1) to (3) and the light receiving area (5) to (7) is 5
Although the above problem can be determined with a thickness of 00 μm or less, such a close proximity is not practical because the alignment of the optical axis between the laser chip and the light receiving element and wiring by wire bonding are complicated.

Therefore, the applicant of the present application, in Japanese Utility Model Application No. 61-185273, arranges a waveguide member in which a plurality of waveguide grooves having the same groove width are formed in a divergent shape on a silicon substrate between each laser chip and a light receiving element. , A structure has been proposed in which the laser light output from each laser chip is completely separated by the waveguide groove.

FIG. 4 shows the device proposed in Japanese Utility Model Application No. 61-185273 (8) is a waveguide member, and (9) to (11) are waveguide grooves formed in the waveguide member. In FIG. 4, the same parts as those in FIG. 3 are designated by the same reference numerals, and the description thereof will be omitted.

However, in such a configuration, since there is a gap between the waveguide member (8) and the light receiving element, the return light reflected by the disk or the like is transmitted through the gap to the light receiving regions (5) to (7). There was a problem of reducing the S / N ratio of the incident light and the output of the light receiving element.

It should be noted that although the above-mentioned gap disappears if the waveguide member (8) and the light receiving element are closely arranged, it cannot be closely arranged because the gold wire connected to the light receiving element is actually present in the gap. .

(D) Means for Solving the Problems The present invention has been made in view of the above points, and its structural feature is that a plurality of semiconductor laser resonators each emitting a laser beam in two directions are arranged in an array. A configured semiconductor laser array, a light receiving element in which a plurality of light receiving regions for individually detecting each laser beam emitted from each resonator of the semiconductor laser array and traveling in the same direction are arranged; A waveguide member that is disposed between the light receiving element and has a plurality of waveguide grooves for guiding the laser beams to the regions, and a transparent member filled between the light receiving element and the waveguide member. It consists of a light-transmitting resin and a light-shielding member that covers the exposed surface of the light-transmitting resin.

(E) Action According to this configuration, the laser light output from the semiconductor laser chip reaches the light receiving area through the waveguide groove and the light-transmitting resin, but the return light is shielded by the light-shielding resin and is thus received. It does not enter the area.

(F) Embodiment FIG. 1 and FIG. 2 show an embodiment of the present invention, and (21) is a heat sink, which is made of a semiconductor such as silicon or a good heat radiator such as metal. (22) is an In layer laminated on one main surface of the heat sink (21), and (23) is a laser including first to third semiconductor laser chips (24) to (26) having a pair of laser light emitting surfaces. The array is an array, and the array is provided on the left end side of the main surface of the heat sink (21) with the optical axes (24b) to (2) of laser beams (24a) to (26a) output from the chips (24) to (26).
6b) are aligned so that they are parallel. (27) is a light receiving element made of silicon, (28) to (30) are first to third light receiving regions formed on one main surface of the light receiving element, and the light receiving element (27) is one main surface thereof. Is arranged on the right side of the heat sink (21) so as to face the laser light emitting surface of one of the laser chips (24) to (26). The distance between the regions (28) to (30) is larger than the distance between the optical axes (24b) to (26b). (31)
Is a waveguide means made of silicon, which is fixed on the heat sink (21) adjacent to the laser chips (24)-(26). (32) to (34) are first to first formed by dicing or etching on the fixed surface side of the waveguide means (31).
A third waveguide groove, which extends from the laser array (23) side to the light receiving element (27) side, and the opening thereof is the laser array (23).
On the side, the intervals between the optical axes (24b) to (26b) and on the side of the light receiving element (23) are the same as the intervals between the light receiving regions (28) to (30). Therefore, as shown in FIG. 2, the laser light emitting surface of the second laser chip (25) and the second light receiving area
When facing (29), the second waveguide groove (33) is connected to the optical axis (24
b) to (26b), the first and third waveguide grooves (3
2) (34) does not extend parallel to the optical axes (24b) to (26b). The groove width of the first and third waveguide grooves (32) and (34) is about twice that of the first waveguide groove (33), and each groove (3
2) to (34) are vapor-deposited with gold or the like on the inner surface to enhance light reflectivity.

Further, a transparent resin filled between the wave guide means (31) and the light receiving element (27) of (41), (42) is a light-shielding resin that covers the surface of the transparent resin, Light-transmitting resin (41) and light-shielding resin
For example, transparent silicone resin and black epoxy resin are most suitable as (42).

In such a device, the laser beams (24a) to (26a) emitted from the first to third laser chips (24) to (26) are respectively emitted from the first to third laser chips.
-The light is transmitted through the third waveguide grooves (32)-(34) and the light-transmissive resin (41) and is incident on the first-third light receiving regions (28)-(30).

Further, since the surface of the light-transmissive resin (41) is covered with the light-shielding resin (42), a light receiving area (gap) between the waveguide means (31) for returning light or the like and the light receiving element (27) ( 28) to (30) can be prevented.

(G) Effect of the Invention According to the present invention, since it is possible to prevent the returning light or the like from entering the light receiving area, the S / S of the light receiving element output by the returning light as in the conventional case is reduced.
N ratio reduction can be suppressed.

[Brief description of drawings]

1 and 2 show an embodiment of the present invention. FIG. 1 is a sectional view taken along the line BB ′ in FIG. 2, FIG. 2 is a sectional view taken along the line AA ′ in FIG. 1, and FIG. FIG. 4 and FIG. 4 are a schematic view and a cross-sectional view for explaining a conventional example, respectively. (23) …… laser array, (24) to (26) …… first to third semiconductor laser chips, (27) …… light receiving element, (28) to (30) …… first to third light receiving areas, (31) …… Waveguide member, (32) to (34) ……
First to third waveguide grooves, (41) ... translucent resin, (42) ... shielding resin

Claims (1)

[Scope of utility model registration request] 1. A semiconductor laser array in which a plurality of semiconductor laser resonators each emitting a laser beam in two directions are arranged in an array, and each laser beam emitted from each resonator of the semiconductor laser array and traveling in the same direction. A light receiving element formed by arranging a plurality of light receiving regions for individually detecting, respectively, and arranged between the semiconductor laser array and the light receiving element,
A waveguide member having a plurality of waveguide grooves for guiding the laser beams to the regions, a translucent resin filled between the light receiving element and the waveguide member, and the translucent resin. And a light-shielding member for covering the exposed surface of the semiconductor laser device.