JPH06103779B2 - Semiconductor laser device - Google Patents

Description

The present invention relates to a semiconductor laser device for forming a module by combining with an optical element or the like.

(Prior Art) A semiconductor laser device is used in combination with an optical device such as a collimator lens or an optical fiber to form a semiconductor laser module. In such a module, it is important to efficiently capture the beam emitted from the semiconductor laser device into the optical fiber. Conventionally, the coupling between the semiconductor laser device and the optical fiber is performed as follows. First, the semiconductor laser element is fixed to the heat sink by soldering, and the heat sink is further fixed to the support. Next, the semiconductor laser device is oscillated to emit a beam, which is taken into the optical fiber. The position of the optical fiber is determined so that the intensity of the light is maximized while monitoring the intensity of the taken-in light, and the optical fiber is fixed.

(Problems to be Solved by the Invention) The position of the optical fiber must be determined while actually oscillating the semiconductor laser device and monitoring the light incident on the optical fiber. This is because the semiconductor laser device itself does not have a reference for determining the emitting position. For example, as in the semiconductor laser device having a buried hetero structure shown in FIG. 5, when both the substrate-side surface and the growth-layer-side surface of the device are flat, whichever surface is in contact with the heat sink. Even if the module is manufactured by using the above method, the upper surface is flat and there is no reference for positioning.

In this semiconductor laser device, the n-InP clad layer 2, the InGaAsP active layer 3, and the p-In formed on the n-InP substrate 1 are used.
The P-clad layer 4 is embedded in the Fe-doped InP current blocking layer 5, and the p-InGaAsP cap layer 6 is further formed thereon. As described above, the method performed while monitoring the incident light is inefficient in manufacturing the module, and improvement has been desired.

Therefore, an object of the present invention is to provide a semiconductor laser device having a structure in which the position of the waveguide of the semiconductor laser element can be easily known.

(Means for Solving the Problems) In the semiconductor laser device of the present invention, a waveguide indicating section serving as a reference for determining the emission position of light from the semiconductor laser element section is integrated with the semiconductor laser element section. A semiconductor laser device having a structure, wherein the waveguide directing section is arranged in proximity to a side surface of the conductor laser element section other than a laser light emitting end surface, and the waveguide directing section is provided in the semiconductor laser element section. It has the same laminated structure as a part of the laminated structure, and thereby the above object is constituted.

(Examples) The present invention will be described below with reference to Examples.

FIG. 1 shows a first embodiment of the semiconductor laser device of the present invention. This semiconductor laser device has a semiconductor laser element section 8 and a waveguide directing section 9. The structure of the semiconductor laser device 8 is the same as that of the semiconductor laser device having a normal buried hetero structure shown in FIG.
Are laterally extended from the semiconductor laser element portion 8. The laterally extending cap layer 6 is provided with a waveguide collecting and supporting portion 9. The waveguide directing section 9 includes the semiconductor laser element section 8
It has the same structure as the laminated structure from the cap layer 6 to the active layer 3a having a buried hetero structure.

A method of manufacturing the semiconductor laser device of FIG. 1 will be described with reference to FIG. As shown in FIG. 2A, an n-InP clad layer 2, an InGaAsP active layer 3, and a p-InP clad layer 4 are sequentially formed on the n-InP substrate 1 by epitaxial growth. in addition
The SiO ₂ film 7 is deposited. Next, by leaving a stripe region that contributes to laser oscillation and a region that will later become the waveguide indicating portion 9 in a mesa shape, by photolithography and etching,
The portion reaching the substrate 1 from the clad layer 4 is removed (FIG. 2 (b)). Next, using the remaining SiO ₂ films 7a and 7b as a mask, Fe is selectively removed at the portions removed by etching.
The doped InP electrode blocking layer 5 is formed by epitaxial growth. (FIG. 2 (c)). As the current blocking layer 5, p
A pn junction obtained by continuously growing -InP and n-InP may be used, and in this case, reverse bias is used.
Next, after the SiO ₂ films 7a and 7b are removed, the p-InGaAsP cap layer 6 is formed by epitaxial growth over the p-InP cladding layers 4a and 4b and the current blocking layer 5 (second layer). Figure (d)). Next, in order to expose the waveguide indicating portion, the portion where the n-InP layer 2b, the InGaAsP layer 3b, and the p-InP layer 4b exist is etched by etching only InP, for example, HC.
It is selectively etched by 1 / H ₃ PO ₄ . By this etching, the n-InP substrate 1, the n-InP layer 2b, and the Fe-doped InP current blocking layer 5 are removed, and the mesa-shaped waveguide directing portion 9 is exposed (FIG. 1).

Since the growth layer side of the semiconductor laser device manufactured as described above is flat, the cap layer 6 and the heat sink can be fixed with solder so that the heat dissipation effect can be improved. When the cap layer 6 is fixed as described above, the waveguide directing portion 9 faces upward, and the position of the optical element can be easily determined with this as a reference.

FIG. 3 is a diagram showing a second embodiment of the present invention in which the waveguide indicating portion 9 is formed on the substrate 1. In the semiconductor laser device of FIG. 3, since the substrate 1 side is in contact with the heat sink and is fixed with solder, the waveguide indicating portion 9 is directed upward,
The position of the optical element can be easily determined based on this.

FIG. 4 is a diagram showing a third embodiment of the present invention.

In this embodiment, the semiconductor laser element is a VSIS (V-Channel
d Substrate Inner Stripe) structure. p-GaAs
An n-GaAs current blocking layer 12 is formed on the substrate 11 by epitaxial growth, and V-shaped grooves 17a and 17b are formed by photolithography and etching. 17a is a stripe for constricting the current in the semiconductor laser element portion 8
Reference numeral 7b is a portion that will be exposed later as the waveguide guide portion 9.
Next, p-GaAlAs clad layer 13, n-GaAlAs active layer 14, n-GaAlA
The s, the cladding layer 15, and the n-GaAs cap layer 16 are sequentially formed by epitaxial growth. Then, in order to expose the waveguide directing portion 9, the portion where the V-shaped groove 17b exists is Ga
Etchant for etching As only, eg NH ₃ / H ₂ O ₂
/ H ₂ O selectively etches. By this etching, the p-GaAs substrate 11 and the n-GaAs layer 12 are removed and the V-shaped groove is formed.
17b serves as a mountain-shaped protrusion to expose the waveguide indicating portion 9.

(Effects of the Invention) As described above, according to the semiconductor laser device of the present invention, the waveguide indicating section serving as a reference for determining the emission position of the light from the semiconductor laser element section is provided with the laser beam of the element section. Since it is arranged close to a side surface other than the emission end face, and the waveguide indicating portion has the same laminated structure as a part of the laminated structure of the semiconductor laser element portion, not only the layer direction of the laser element, Also in the layer thickness direction, the light emission position can be accurately known with reference to the waveguide indicating portion. Moreover, since the element part having the same layer structure and the waveguide directing part can be manufactured with the same mask, the positional deviation between the two caused by the mask alignment margin during the manufacturing process can be eliminated, and the waveguide directing part can be used. The light emitting position that can be known can be made to have a very small error.

As a result, the proper positions of the optical elements such as the collimator lens and the optical fiber can be accurately and quickly determined, and the semiconductor laser module can be manufactured efficiently.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of a semiconductor laser device of the present invention, FIGS. 2 (a) to (d) are diagrams showing a method of manufacturing the semiconductor laser device of FIG. 1, FIG. 3 and FIG. FIG. 4 is a diagram showing second and third embodiments of the semiconductor laser device of the present invention, and FIG. 5 is a diagram showing an example of a conventional semiconductor laser device. 1a …… n-InP substrate, 3a …… InGaAsP active layer, 5 …… Fe-doped I
nP current blocking layer, 6 …… p-InGaAsP cap layer, 8 …… Semiconductor laser device section, 9 …… Waveguide indicator section, 11 …… P-GaAs substrate, 12
…… n-GaAs electrode blocking layer, 13 …… p-GaAlAs cladding layer, 14…
… N-GaAlAs active layer, 15 …… n-GaAlAs cladding layer, 16 …… n-
GaAs cap layer, 17a ... V-shaped groove, 18 ... Optical fiber support groove.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Haruhisa Takiguchi 22-22 Nagaike-cho, Abeno-ku, Osaka City, Osaka Prefecture Sharp Corporation (56) References JP-A-55-110082 (JP, A) JP-A-61 -269390 (JP, A) Actually opened Sho 61-79556 (JP, U)

Claims (1)

[Claims] 1. A semiconductor laser device having a structure in which a waveguide designating section serving as a reference for determining a light emission position from a semiconductor laser element section is integrated with the semiconductor laser element section. The indicating portion is arranged close to a side surface of the semiconductor laser element portion other than the laser light emitting end face, and the waveguide indicating portion has the same laminated structure as a part of the laminated structure of the semiconductor laser element portion. Semiconductor laser device.