JPH01165181A - Optical semiconductor device - Google Patents

Abstract

PURPOSE:To obtain a high light output by a method wherein at least two optical waveguides which have light emitting parts are respectively jointed with each other to form a single optical waveguide and a light is emitted from one end of the single optical waveguide. CONSTITUTION:The respective one ends of optical waveguides 16-18 are coupled with one end of an optical waveguide 19 and a light is emitted from the other end of the optical waveguide 19. The other ends of the optical waveguides 16-18 reach the end surface of a wafer. An electrode 20 is formed above the left parts of the optical waveguides 16-18 and above the optical waveguide 19 to leave the right parts of the optical waveguides 16-18 as non-excited regions. It is to be noted that the electrode 20 is practically formed over the whole surface of the wafer and a window with a pattern shown by the figure is formed in an insulating film such as an SiO2 film.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to optical semiconductor devices such as light emitting diodes and semiconductor lasers, and particularly relates to optical semiconductor devices used in optical communications and the like.

"Prior Art" There are two types of light emitting diodes: surface emitting type and edge emitting type. The surface-emitting type is mainly used for displays, and may also be used for optical communication, and has the drawback of low coupling efficiency with optical fibers. On the other hand, edge-emitting type devices have strong optical output directionality and can be coupled with optical fibers with high efficiency, so they are often used for optical communications.

FIGS. 5A and 5A are plan views showing the concept of a conventional edge-emitting type light emitting diode. In order to suppress the laser operation (oscillation operation), the one shown in FIG. It is embedded with substance 3 to form a window structure, and the one shown in Figure 5 (b) is
A non-excitation region 4 is provided in the optical waveguide 1 to increase the loss in the region where no current is injected. In addition, in FIG. 1(b), the reference numeral 5 indicates an electrode.

"Problems to be Solved by the Invention" By the way, all of the conventional edge-emitting type light emitting diodes described above have a drawback of weak light output.

Accordingly, an object of the present invention is to provide an optical semiconductor device with enhanced optical output.

``Means for Solving the Problems J'' This invention comprises at least two or more optical waveguides each having a light emitting portion, and a single optical waveguide to which each of the optical waveguides is connected, It is characterized in that light is emitted from the end face of the wave path.

"Operation" According to the present invention, light is emitted in each of two or more optical waveguides each having a light emitting section, and these lights are combined in a single optical waveguide and radiated to the outside. The output can be increased.

"Embodiment" Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a plan view showing the concept of a light emitting diode according to a first embodiment of the present invention.

In this figure, reference numerals 11 to 14 are optical waveguides (active waveguides) that emit light, and one end of each of the optical waveguides 11 to 13 is coupled to one end of an optical waveguide 14, and the optical waveguide Light is emitted from the other end 14a of I4, and the other end of each of the optical waveguides 11 to 13 is embedded with a low refractive index material to form a window structure. In addition, each optical waveguide 11 to 1
Electrodes are formed corresponding to each of 4. That is,
Light is emitted in each of the optical waveguides If-14.

Here, the configuration of the optical waveguide 11-14 is as shown in FIG.
structure) may be used, and the B C (B
uried Crecent) structure may be used, and
In addition, DC-PBH (Double
Channel-P Ianer Buried
Heterostructure) structure may also be used.

In these structures, 3 at Kl- is a light emitting region. Note that all of these structures are conventionally well-known structures of refractive index waveguide stripe lasers. Also, (b)
In the structure (c) and (c), electrodes are formed on the entire upper surface.

However, according to the above configuration, an optical waveguide! Light is emitted in each of I to 14, and the light is collectively radiated in the optical waveguide I4.

This concentration makes it possible to obtain a large light output.

FIG. 3 is a plan view showing the concept of a light emitting diode according to a second embodiment of the invention. In this figure, one end of each of optical waveguides 16 to 18 is coupled to one end of optical waveguide 19,
Light is emitted from the other end of the optical waveguide 19. Further, the other ends of the optical waveguides 16 to 18 reach the end surface of the wafer. 20
is an electrode, and this electrode 20 is formed above the left part of the optical waveguides 16 to 18 and above the optical waveguide 19, and is not formed above the right part of the optical waveguides 16 to I8. Therefore, the right portions of the optical waveguides 16 to 18 are non-excited regions. Although the electrode 20 is actually formed on the entire surface of the wafer, a window of an insulating film made of 5iOy or the like is formed in the shape shown in FIG. 3.

However, even in the above configuration, the optical waveguides 16 to 19
The light emitted from each is collected in the optical waveguide 19 and radiated to the outside.

FIG. 4(A) is a plan view showing the concept of a light emitting diode according to a fourth embodiment of the present invention, and FIG. 4(B) is a sectional view taken along the line B--B of FIG. 4(A). In these figures, optical waveguides 22-2
4 is coupled to one end of the optical waveguide 25, and light is emitted from the other end of the optical waveguide 25. The other ends of the optical waveguides 22 to 24 reach the end surface of the wafer, and electrodes 26 to 28 are formed above the optical waveguides 22 to 24, respectively.

As shown in FIG. 4(b), the optical waveguide 23 includes an active waveguide layer 23a, a cladding layer 23b, and a low-loss waveguide layer 23.
It is composed of c. The configurations of the optical waveguides 22 and 24 are also similar. Further, the optical waveguide 25 is composed of a low-loss waveguide layer.

According to the above configuration, light is emitted in the active waveguide layer below the electrodes 26 to 28, and the light is combined in the optical waveguide 25 and radiated to the outside.

"Effects of the Invention" As explained above, according to the present invention, the invention includes at least two or more optical waveguides each having a light emitting section, and a single optical waveguide to which each of the optical waveguides is connected, Since light is emitted from the end face of one optical waveguide, the light emitted from the plurality of light emitting sections is collectively emitted, and therefore, a larger light output than the conventional one can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the concept of the first embodiment of the present invention;
FIG. 2 is a diagram showing an example of the configuration of the Al-A2 line cross section in FIG. 1, FIG. 3 is a plan view showing the concept of the second embodiment of the present invention, and FIG. 5. (B) is a sectional view taken along the line B-B shown in (A). FIGS. It is. 11-14.16-19.22-25... Optical waveguide.

Claims (1)

[Claims] It is characterized by comprising at least two or more optical waveguides each having a light emitting part and a single optical waveguide to which each of the leading waveguides is connected, and that light is emitted from an end face of the single optical waveguide. Optical semiconductor device.