JPS63262886A - Semiconductor laser device - Google Patents

Abstract

PURPOSE:To reduce reactive currents, and to improve characteristics at the time of operation at high speed by forming one of p side or n side electrode for injecting carriers into a light-emitting region into the upper or lower region of the light-emitting region and near it. CONSTITUTION:An n side electrode 5a is shaped onto a main surface between two mesa grooves 6 in and near a region on a light-emitting region 1, and connected to a contact section 5b.When a p side electrode 3 is supplied with positive forward currents and the n side electrode 5a with negative ones, currents are constricted and flow through an active layer, and beams equal to the band gap of the active layer are generated in the light-emitting region 1, and projected as laser beams from an edge face. Since conductors are hardly shaped onto insulating films 4 on the outsides of the mesa grooves 6, however, capacitance between the electrodes 3, 4 is reduced, thus approximately diminishing reactive currents, which do not flow through the active layer, even when a device is operated at high speed, then stably working the device.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor laser device capable of high-speed operation.

[Conventional technology]

Figure 2 shows, for example, JOtlRNAL OF LIGHT
W^VE TIC [1-NOLOGY, VOL, LT-
3,NO,5,0CTOBER19855AKAKIB
ARAet, al,: InGaAsP P-S
1 is a perspective view showing the structure of a conventional semiconductor laser device shown in UBS'l'RATE LASER3.

In this figure, 1 is a light emitting region, 2 is a semiconductor crystal layer, and 3 is a light emitting region.
4 is a p6III electrode, 4 is an insulating film, 5 is an n-side electrode, and 6 is a mesa groove, which are formed on both sides of the light emitting region 1 of the semiconductor crystal layer 2 along the cavity direction.

In this configuration, when a positive p r>@negative forward bias voltage is applied to the p-side electrode 3, the current is constricted by the insulating film 4, and the current flows through the active H (not shown). Light equal to the energy bandgap is generated in the light emitting region 1, and is emitted from the end face as a laser beam.

[Problem that the invention seeks to solve]

In the conventional semiconductor laser device as described above, since there is a parallel capacitance between the n-side electrode 5 outside the mesa groove 6 and the p611 electrode 3, when operated at high speed.

There is a problem in that the reactive current flowing between the n-side electrode 5 and the p-side electrode 3 outside the mesa groove 6 increases, and the characteristics deteriorate as the frequency increases.

This invention was made to solve this problem, and aims to provide a semiconductor laser device that can reduce the reactive current that does not flow through the active layer and improve the characteristics during high-speed operation. Zuro.

[Means for solving problems]

In the semiconductor laser device according to the present invention, one of the p@ electrode and the n-side electrode for injecting carriers into the light emitting region is
It is formed only in the region above or below the light emitting region and in the vicinity thereof.

[Effect]

In this invention, the capacitance between the p-side electrode and the n-side electrode is reduced.

[Embodiment] FIG. 1 is a perspective view showing the structure of an embodiment of a semiconductor laser device of the present invention.

In this figure, the same reference numerals as in FIG. is formed. Reference numeral 5b denotes a contact portion of a wiring formed in a region other than the region above the light emitting region 1, and is connected to the n#J electrode 5a.

The semiconductor laser device of this invention also has p
When a positive forward bias voltage is applied to the side electrode 3 and a negative forward bias voltage is applied to the n-side electrode 5a, electric light is constricted and flows through the active layer (not shown), and light equal to the energy band gap is generated in the light emitting region 1. , which is emitted from the end face as a laser beam.
.

However, in the semiconductor laser device of the present invention, since almost no conductor is formed on the insulating film 4 outside the mesa groove 6,
The capacitance between the p-side electrode 3 and the n-side electrode 5a is smaller than that of the conventional structure.

Therefore, even when operating at high speed, there is almost no generation of reactive current that does not flow through the active layer, and the device operates stably.

In the above embodiment, a semiconductor laser device constructed using a p-type substrate was described, but the same effect can be obtained even if the present invention is constructed using an n-type substrate and the conductivity types of each semiconductor layer are reversed. Let it go.

Further, in the above embodiment, a semiconductor laser device having a structure in which the current to the active layer is constricted from the mesa groove 6 by the insulating film 4 formed on the outside thereof has been described; however, other structures may be used.
For example, the present invention may be applied to a semiconductor laser device having a structure in which current is constricted by reverse bias of a pn junction.

〔Effect of the invention〕

As explained above, in this invention, either the p-side electrode or the n-side electrode for injecting carriers into the light-emitting region is formed only on the light-emitting region or in the region below the light-emitting region and in the vicinity thereof. The capacitance between the n-side electrodes is reduced, and the reactive current that does not flow through the active layer is reduced even during high-speed operation, allowing current to flow effectively through the active layer, resulting in stable operation.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the structure of an embodiment of the semiconductor laser device of the invention, and FIG. 2 is a perspective view showing an example of the structure of a conventional semiconductor laser device. In the figure, 1 is a light emitting region, 2 is a semiconductor crystal layer, and 3 is a p
#I electrode, 4 is an insulating film, 5a is an n-side electrode, 5b is a wiring contact portion, and 6 is a mesa groove. Note that the same reference numerals in each figure indicate the same or corresponding parts. Agent: Masuo Oiwa (2 others) Diagram 2 procedural amendment (voluntary) Showa year/month Date of the Office of the Director-General's Palace 1, Indication of case: Patent Application No. 1982-99008 2, Title of invention: Semiconductor laser device 3 , Relationship to the case of the person making the amendment Patent Applicant Address 2-2-3 Marunouchi, Chiyoda-ku, Tokyo Name (601) Mitsubishi Electric Corporation Representative Moriya Shiki 4, Agent Address Marunouchi, Chiyoda-ku, Tokyo 2-2-3-5
3, :)-゛3 5. Detailed Description of the Invention Column 1 of the Specification Subject to Amendment 1 Brief Description of the Drawing Column and Drawing 6 Contents of the Amendment (1) Page 2 of the Specification, Line 3, Line 5 "1 is the light-emitting region" on page 17 line is corrected to "1 is the active layer (light-emitting region)". (2) Similarly, "active layer (not shown)" in line 9 of page 2 and lines 3 to 4 of page 4 are corrected to "active layer 1". (3) Similarly, on page 2, lines 15 and 16, the term ``capacitance in parallel with the rp-side electrode 3'' was changed to ``the active layer 1 is connected to the p-side electrode 3''.
The capacitance is corrected in parallel to . (4) In the drawings, Figure 1 should be amended as shown in the attached sheet. Above is Figure 1 “4: Yoshikoshi

Claims (2)

[Claims] (1) A semiconductor laser device characterized in that one of a p-side electrode and an n-side electrode for injecting carriers into a light-emitting region is formed only on the light-emitting region or in a region below the light-emitting region and in the vicinity thereof. (2) The semiconductor laser device according to claim (1), wherein the electrode is connected to a contact portion of a wiring formed in a region other than above or below the light emitting region.