JPH1168250A - Semiconductor laser device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To emit near-infrared laser beams and visible laser beams onto the same optical axis by a simple, small-sized and inexpensive constitution. SOLUTION: A light-emitting laser chip 10 for emitting a visible laser beam 19 to an upper side and a surface light-emitting laser chip 20 for emitting the near-infrared laser beam 29 to the upper side are laminated on the base 50 of a stem, so as to position the chip 10 on the chip 20 while matching the emitting light axes and the near-infrared laser beam 29 is transmitted, without being adsorbed inside the chip 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a semiconductor laser device suitable for a medical laser treatment device or the like.

[0002]

2. Description of the Related Art Semiconductor laser devices are used for optical communication, optical measurement,
It is used in various fields such as the field of medical treatment as well as the field of optical information systems. In the field of medicine,
2. Description of the Related Art A laser treatment device or the like that irradiates an affected part with a laser beam to perform treatment therefor is used. The laser treatment device uses a semiconductor laser device that generates laser light in a near-infrared region that is a wavelength effective for treatment. However, since light in this wavelength range is invisible to human eyes, it is difficult to properly irradiate the treatment site. Therefore, conventionally, a semiconductor laser device that generates visible laser light for positioning is separately used, and this visible laser light is made the same as the near-infrared laser light for treatment by an optical system that combines a lens, a mirror, and a beam splitter. Irradiation is performed so as to overlap on the optical axis.

[0003]

However, conventionally, there have been problems such as a complicated structure and a large scale. That is, first, two separately packaged semiconductor laser devices must be used, second, a complicated and large-scale optical system using a large number of optical components is required, and There has been a problem that it is necessary to perform an operation that is difficult to align the axes, and it is difficult to reduce the manufacturing cost, and it is not possible to reduce the size.

[0004] In view of the above, the present invention provides a semiconductor that emits near-infrared laser light and visible laser light on the same optical axis, which can be formed in one package, can be easily miniaturized, and can be manufactured at low cost. It is an object to provide a laser device.

[0005]

In order to achieve the above object, a semiconductor laser device according to the present invention comprises a near-infrared semiconductor laser chip and a visible semiconductor laser chip.
Both emission sides are oriented in the same direction, the visible semiconductor laser chip is positioned on the emission side of the near-infrared semiconductor laser chip, and the respective optical resonators are arranged on the same optical axis. It is characterized by being arranged.

Near-infrared laser light emitted from the near-infrared semiconductor laser chip passes through the active layer and the optical resonator of the visible semiconductor laser chip and is emitted to the outside. Is larger than the energy gap of the material of the near-infrared semiconductor laser chip, the near-infrared laser light emitted from the near-infrared semiconductor laser chip is not absorbed by the visible semiconductor laser chip. Since the near-infrared laser light passes through the visible semiconductor laser chip and emits, the emitted near-infrared laser light overlaps with the visible laser light emitted from the visible semiconductor laser chip, The irradiation position of the near-infrared laser light can be easily confirmed by the visible laser light. In order to make the optical axes of these two emitted lights coincide, it is only necessary to perform the alignment of the two semiconductor laser chips, so that the adjustment is easy. It is sufficient to simply position and arrange the two chips, and it is not necessary to use an optical system including various optical components. Therefore, the structure is simple, the structure can be extremely compact, and the manufacturing cost can be reduced.

[0007]

Next, embodiments of the present invention will be described in detail with reference to the drawings. In FIG. 1, a visible surface emitting laser chip 10 and a near-infrared surface emitting laser chip 20 are stacked on a stem base 50. These chips 10 and 20 are arranged in the optical axis direction such that the emission optical axes match. The order of the arrangement is such that the chip 20 and the chip 10 are arranged from bottom to top so that the visible surface emission laser chip 10 is located on the emission side (upper side in the figure) of the near-infrared surface emission laser chip 20. ing. Specifically, the electrodes are fixed by joining them with metal bumps (solder). After the two chips 10 and 20 are assembled on the base 50, they are hermetically sealed with resin or the like to form one package.

More specifically, referring to FIGS. 2 to 5, an upper surface electrode 11 having an emission window 13 is provided on the upper surface of the visible surface emitting laser chip 10 as shown in FIG. As shown in FIG. 3, a lower surface electrode 12 is provided. An electrode pad 14 is further provided on the lower surface, and is electrically connected to the upper electrode 11 by a wiring pattern 15 provided on a side surface of the chip 10.

An upper surface electrode 21 having an emission window 23 is provided on the upper surface of the near-infrared surface emitting laser chip 20 as shown in FIG. 4, and a lower electrode 2 as shown in FIG.
2 are provided. This top electrode 21 is
Is connected to an electrode pad 24 (see FIG. 5) provided on the lower surface via a wiring pattern 25 provided on the side surface. Further, the chip 20 has an upper surface electrode pad 31
And a lower electrode pad 32 connected thereto through a wiring pattern 33 on the side surface, and an upper electrode pad 34 and a lower electrode pad 35 connected to the wiring pattern 36 on the side surface are provided.

The lower electrode pad 14 of the visible surface emitting laser chip 10 and the upper electrode pad 31 of the near-infrared surface emitting laser chip 20 are connected by metal bumps 41, and the lower electrode 12 of the chip 10 and the upper electrode pad 34 of the chip 20 are connected.
Are connected by a metal bump 42. The lower electrode 22 of the near-infrared surface emitting laser chip 20 is connected to a wiring pattern 53 provided on the upper surface of the stem base 50 by a metal bump 46. The lower electrode pads 24, 32, 35 of the chip 20 are metal bumps 47,
43, 44, the wiring pattern 5 on the upper surface of the base 50
1, 52, etc.

In this manner, current is supplied from the wiring patterns 51 to 53 of the stem base 50 and the like, and the metal bumps 47, the lower electrode pads 24, the wiring patterns 25, the upper electrodes 21, Chip 2
0, a current flows through the path of the lower surface electrode 22 and the metal bump 46. Thereby, near-infrared laser light 29 is emitted upward from the emission window 23 of the near-infrared surface-emitting laser chip 20.

The visible surface emitting laser chip 10 includes a wiring pattern 51 of a base 50, a metal bump 43, a chip 2
0 lower electrode pad 32, wiring pattern 33, chip 2
0 upper electrode pad 31, metal bump 41, chip 1
0 lower electrode pad 14, wiring pattern 15, chip 1
0, the upper electrode 11, the chip 10, the lower electrode 12, the metal bump 42, the upper electrode pad 34 of the chip 20, the wiring pattern 36, the lower electrode pad 35 of the chip 20, the metal bump 44, and the wiring pattern 52 of the base 50. An electric current flows, whereby the visible laser light 19
Is emitted.

A near-infrared laser beam 29 transmitted from the near-infrared surface emitting laser chip 20 and transmitted through the chip 10 is also emitted from the emission window 13 of the visible surface emitting laser chip 10. The visible surface emitting laser chip 10 and the near-infrared surface emitting laser chip 20 are arranged so that their optical axes coincide with each other, and near-infrared laser light 29 from the chip 20 passes through the active layer and the optical resonator of the chip 10. Although the energy gap of the material forming the visible surface emitting laser chip 10 is larger than the energy gap of the material forming the near infrared surface emitting laser chip 20, the near infrared laser light 29 is generated in the chip 10. The light is emitted without being absorbed. Therefore, the visible laser light 1 is placed on the same optical axis.
9 and the near-infrared laser light 29 are emitted, so that the irradiation position of the near-infrared laser light 29 can be easily confirmed by the visible laser light 19.

The visible surface emitting laser chip 10 and the near-infrared surface emitting laser chip 20 may have a structure as shown in FIG. 6, for example. As shown in FIG. 6, a cylindrical active layer 62 having a size several times the wavelength is grown on a substrate 61, and a current confinement layer 63 such as a pn reverse junction is formed around the active layer. Multi-layer reflecting mirrors 64 and 65 constituting an optical resonator are formed on the upper and lower surfaces, and a current flows between an electrode 68 provided on an insulating layer 66 having a window and an electrode 67 provided on another surface. Then, the active layer 6
The electrons and holes injected into recombination 2 recombine to generate light,
The light is amplified and oscillated while reciprocating in the optical resonator, and light is emitted to the outside (upward).

Since the surface-emitting type laser chip is used as described above, integration is easy by stacking in a three-dimensional direction (height direction) by flip-chip connection as shown in FIG. Other circuits, such as APC
(Automatic output adjustment) Integration with a circuit or the like is also possible. In addition, the surface emitting laser chip has a dynamic single wavelength operation, and has an advantage that a round and sharp light beam can be obtained. Therefore, these two chips 10 and the near-infrared surface emitting laser chip 20 may be connected by metal bumps so that their optical axes are aligned with each other, so that the assembly is easy and the adjustment work of the optical axis alignment is also easy. is there.

FIG. 7 shows a second embodiment, in which an edge-emitting laser chip is used. That is, the visible edge emitting laser chip 70 and the near infrared edge emitting laser chip 80 are arranged on the stem base 50 (that is, on the same plane). These chips 70, 8
In the case of 0, electrodes 71, 72, 81, 82 are provided on the upper and lower surfaces, and the lower electrodes 72, 82 are fixed to the base 50 by being joined to the wiring patterns 52, 51 on the base 50 of the stem. An electrical connection is made. The upper electrodes 71 and 81 are electrically connected by bonding wires 74 and 84. After these two chips 70 and 80 are assembled on the base 50, they are hermetically sealed with a resin or the like and packaged.

In the visible edge emitting laser chip 70 and the near-infrared edge emitting laser chip 80, an optical resonator is formed using two opposing cleavage surfaces as reflecting mirrors, and light is emitted from one of the surfaces 73 and 83. . The visible end face emitting laser chip 70 and the near infrared end emitting laser chip 80 are arranged such that the emission end faces 73 and 83 face the same direction, and their emission optical axes are the same, and the chips 80 and 7 in the emission direction.
They are arranged in the order of 0. for that reason,
Near-infrared laser light 89 emitted from the emission end face 83 of the near-infrared end face emitting laser chip 80 passes through the active layer and the optical resonator of the visible end face emitting laser chip 70, and from the emission end face 73 of the chip 70. The near-infrared laser light 89 is also emitted together with the visible laser light 79, which is the light emitted from the chip 70 itself. At this time, since the energy gap of the material forming the visible end face emitting laser chip 70 is larger than the energy gap of the material forming the near infrared end emitting laser chip 80, the near infrared laser light 89 is absorbed in the chip 70. Never.

Therefore, the visible laser light 79 is placed on the same optical axis.
And the near-infrared laser light 89 are emitted, so that the irradiation position of the near-infrared laser light 89 can be easily confirmed by the visible laser light 79. In addition, even when the edge emitting laser chip is used, the optical axis alignment may be performed only at the stage of assembling the chip, so that the assembling work including the optical axis aligning operation becomes easy. Integration with other circuits, such as an APC circuit, is also easy. By using such an edge-emitting laser chip, monolithic integration becomes possible.

The above description relates to one embodiment, and the specific configuration of the present invention is not limited to these descriptions and can be variously modified. For example, in FIG. 1, electrical connection is made by flip-chip connection, but connection by wire is also possible.

[0020]

As described above, in the semiconductor laser device of the present invention, near-infrared laser light and visible laser light can be emitted on the same optical axis with a configuration that can be enclosed in one package. Therefore, a complicated optical system or the like is not required, and it can be made very small and can be manufactured at low cost. Although the work of optical axis alignment is not eliminated, it is very easy because it is performed when assembling the chip. It is also advantageous for integration with other circuits such as an APC circuit.

[Brief description of the drawings]

FIG. 1 is a schematic side view showing an embodiment of the present invention.

FIG. 2 is a top view of the chip 10 of FIG.

FIG. 3 is a bottom view of the chip 10 of FIG. 1;

FIG. 4 is a top view of the chip 20 of FIG. 1;

FIG. 5 is a bottom view of the chip 20 of FIG. 1;

FIG. 6 is a half sectional perspective view schematically showing an example of a surface emitting laser chip.

FIG. 7 is a schematic side view showing a second embodiment of the present invention.

[Explanation of symbols]

10
Visible surface emitting laser chip 11, 21 Upper surface electrode 12, 22 Lower surface electrode 13, 23 Emission window 14, 31, 32, 34, 35 Electrode pad 15, 33, 36, 51-53 Wiring pattern 19
Visible laser light 20
Near infrared surface emitting laser chip 29
Near infrared laser light 41-44 Metal bump 50
Stem base 61
Substrate 62
Active layer 63
Current confinement layer 64, 65 Multilayer reflector 66
Insulating layer 67, 68 Electrode 70
Visible end surface emitting laser chip 71, 72, 81, 82 Electrode 73, 83 Emitting end surface 74, 84 Connection wire 79
Visible laser light 80
Near infrared edge emitting laser chip 89
Near infrared laser light

Claims (1)

[Claims] 1. A near-infrared semiconductor laser chip and a visible semiconductor laser chip, the emission sides of which are oriented in the same direction, and the visible semiconductor laser chip is positioned on the emission side of the near-infrared semiconductor laser chip. And a semiconductor laser device in which the optical resonators are arranged so as to be aligned on the same optical axis.