JPS63128783A - Semidonductor laser device - Google Patents

Abstract

PURPOSE:To make the natural light emitted from the side of a semiconductor laser chip useable as the light for monitor use and to output a high-output laser beam from one side of a resonator edge by installing a photodetector which is laminated on the side which crosses the resonator edge of the semiconductor laser chip having a pair of resonator edges. CONSTITUTION:A first to a third light-receiving devices 12-14 are laminated on the right side perpendicular to resonator edges of chips 2-4. After an electric current of bigger than a threshold value of a first semiconductor laser chip 2 has been applied and a laser beam has been output, the output of the laser beam becomes proportional to the output of the photodetector. Accordingly, it is possible to control the output of the laser beam on the basis of the output of the photodetector. As a result, it is not necessary to use the laser beam to be output from the resonator edge as the light for monitor use; it is possible to take out the high-output laser beam in such a way that one side of a pair of resonator edge is made to be highly reflective while the laser beam is output only from the other resonator edge.

Description

[Detailed description of the invention] (b) Industrial application field The present invention relates to a semiconductor laser device.

(b) Prior Art Currently, as a method for monitoring laser light output from a semiconductor laser chip, as disclosed in Japanese Patent Publication No. 5B-46879, laser light is emitted from both of a pair of resonator end faces of a semiconductor laser chip. This was done by outputting light and detecting the laser beam output from one side with a light receiving element.

Vl Problems to be Solved by the Invention Unsurprisingly, in this method, laser light must always be output from the end face of the rain gear resonator, and the reflectance of one resonator end face is set to approximately 100%, while the reflectance of the other resonator end face is set to approximately 100%. By outputting laser light from only one source, it is not possible to create a configuration in which high-output laser light can be extracted.

B) Means for Solving the Problems The present invention has been made in view of the above points, and its structural feature #'i is a semiconductor laser chip having one pair of resonator end faces, and the above-mentioned resonator end faces of the chip. It consists of a light-receiving element laminated on the side surface.

(e) Operation Laser light is output from the resonator end face of the semiconductor laser chip, but natural light is also emitted from other faces in approximately proportion to the laser oscillation.

Therefore, the light receiving element receives the natural light.

(C) Embodiment FIG. 1 shows a first embodiment of the present invention, in which first to third semiconductor laser chips (21 to (4)) are fixed on a heat sink (1) made of Sl. .Such a chip (2
) to (4) are a first cladding layer made of P-type GaO, ss AlO, and 45As on a P-type ()aAs substrate (5) in which a groove extending perpendicular to the plane of the paper is formed approximately at the center of the surface. (6), non-doped Ga (1,,5Aj?o,ts
Active layer (7) made of As, n-type Gao, s6 kl
Second cladding layer (8) made of O,45As and n-type G
This is a refractive index waveguide type semiconductor laser chip in which cap layers (9) made of aAs are sequentially laminated. In each of the chips (2) to (4), when a forward bias is applied between the first and second electrodes 10αυ formed on the other main surface of the substrate (5) and the surface of the cap layer (9), Laser light is emitted from a pair of resonator end faces parallel to the plane in a direction perpendicular to the plane of the paper. Further, first to third light receiving elements 02 to 141 are layered on the right side surface of each of the chips (2) to (4) perpendicular to the resonator end face. Each of the above light receiving elements (
2) ~ αI are 5i02 and S laminated on the right side surface of each chip (2) ~ (4) and a part of the surface of the second electrode 011, respectively.
A 1,000-layer thick transparent insulating film made of iN, ANz 05, etc.; a 2,000-layer-thick transparent electrode made of TO%5n02, etc.; a light-receiving layer made of an amorphous semiconductor material; and a 2,000-layer-thick transparent electrode. are layered one after another. Note that the light receiving layer C171 described above is used. Further, on the back surface of the All electrode, an optical barrier α9 made of a transparent material is laminated to prevent external light from entering the light-receiving layer αη.

FIG. 2 shows, for example, the first semiconductor laser light output (2).
, the laser drive current and the first semiconductor laser chip (2
) and the relationship between this laser light output and the first
The relationship between the output of the light receiving element (1z) and the output of the photodetector (1z) is shown by a solid line and a dashed-dotted line, respectively. In the figure, points A%B indicate the time point when a threshold current is applied to the semiconductor laser chip, respectively. ) has a horizontal width of approximately 100 μm.

As is clear from FIG. 2, the first semiconductor laser chip (
After a current equal to or higher than the threshold value is applied to 2) and the laser light is output, the laser light output and the light receiving element output have a proportional relationship. Therefore, the output of the laser beam can be controlled based on the output of the light receiving element.

Therefore, in this example device, since the laser beam output from the resonator end face is not used as a monitor light and the surface is good, one of the pair of resonators is set to have a high reflectance, and only the other resonator end face is used. By outputting laser light, high-power laser light can be extracted.

Moreover, the first to third semiconductor laser chips (2) to (4)
As shown in FIG. 1, even when the chips are placed close to each other, for example, natural light emitted from the left side of the second semiconductor laser chip (3) is not absorbed by the first semiconductor laser chip (3) due to the presence of the first light-receiving element α2 and the optical barrier Oj. It is possible to prevent the laser beam from entering the laser chip (2). Therefore, the first semiconductor laser chip (2
), it is possible to prevent output fluctuations, decreases in S/N ratio, etc. due to the influence of natural light emitted from the side surface of the second semiconductor laser chip (3).

Furthermore, each of the light receiving elements 02 to α is connected to each chip (2) to (
4) Since it acts as a padding film on the right side, the life of the semiconductor laser chip can be extended.

In addition, in this example, the light receiving element was laminated only on the right side, but
The passivation effect can be further improved by stacking a light receiving element on the left side as well.

FIG. 3 shows a second embodiment of the present invention, and the difference from the first embodiment is that in the first embodiment, the first to third semiconductor lasers are mounted in a hybrid manner on the heat sink (1). While the first to third light receiving elements (1) to (α) were formed on each of the chips (2) to (4), in the second embodiment, one substrate (
5) First to third semiconductor laser chips (2) to (4) on top.
) The first to third light receiving elements 0z to 0 are formed on each chip of the device formed monolithically. In FIG. 3, the same parts as in FIG. 1 are designated by the same reference numerals, and their explanation will be omitted.

Even with this configuration of the second embodiment, similar effects to those of the first embodiment can be obtained.

(G) Effects of the Invention According to the present invention, natural light emitted from the side surface of a semiconductor laser chip can be used as monitor light.
High-power laser light can be output from one of the cavity end faces.

[Brief explanation of the drawing]

1 and 3 are cross-sectional views showing the first and second embodiments of the present invention, respectively, and FIG. 2 is a characteristic diagram showing the relationship between laser light output, drive current, and light-receiving element output. (2) to (4)...first to third semiconductor laser chips,
02~αt...first~third light receiving elements.

Claims (1)

[Claims] (1) A semiconductor laser chip having a pair of cavity end faces;
A semiconductor laser device comprising a light receiving element laminated on a side surface of the chip that intersects with the resonator end surface.