JPS6373572A - Edge-emitting light-emitting diode - Google Patents

Abstract

PURPOSE:To inhibit laser oscillation by forming an edge-face emitting output beams in a slant face having a fixed angle to a luminous axis. CONSTITUTION:An N-type InP clad layer 12, an N-type InGaAsP active layer 13, a F-type InP clad layer 14 and an N-type InGaAsP contact layer 15 are laminated and shaped onto an N-typo InP semiconductor substrate 11 in succession. Zn is diffused selectively in a striped manner from the surface of the contact layer 15 and a current injection section 16 is formed, and a striped light-emitting region is shaped. A P-type electrode 17 consisting of an AuZn film is formed onto the surface of the contact layer 15 and an N-type electrode 18 composed of an AuGeNi film is shaped onto the surface of the bottom of the semiconductor substrate 11. A slant face having a fixed angle to a luminous axis 21 is formed through etching, and an end face 19 on the side emitting output beams is shaped. A nonreflective film 20 made up of an silicon nitride film is formed onto the end face 19 on the main luminous radiation section side. Accordingly, laser oscillation is inhibited, and a high optical output can easily by acquired stably within a wide temperature range.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to an edge light emitting diode, and particularly relates to an edge light emitting diode applied to optical fiber communication, etc. 3. [Prior Art] A light emitting diode intended for optical fiber communication , it is important to have high brightness and large optical power to couple with the optical fiber.

Conventionally, light emitting diodes with high optical output have been developed using striped light emitting areas, as described on pages 128 to 134 of the book "Optical Communication Device Engineering" published by Kogaku Tosho Co., Ltd. (first edition published in 1982). Edge light emitting diodes and the like have been developed that emit light from the end face of a double-hetero laminated structure.

Conventionally, in this type of edge-emitting diode, the light-emitting region has a striped shape, as described above, and the end face is usually a flat surface perpendicular to the light-emitting region, so the gain region length is long. The stimulated emission light component became large, making it easy to increase the output.

However, although this edge-emitting diode can easily provide a high optical output, it has a large stimulated emission component, which makes it prone to laser oscillation at low temperatures, making it difficult to operate stably over a wide temperature range.

Therefore, in order to suppress laser oscillation, a method is generally used in which a non-reflective film is formed on the end face from which light is extracted.

[Problem that the invention seeks to solve]

The conventional edge-emitting diode described above has a stripe-shaped light-emitting region and an anti-reflection film that is perpendicular to the light-emitting region and provided on the flat end face, so it is difficult to sufficiently suppress laser oscillation. The reflectance of the non-reflective film is 0.1%.
The problem is that it is difficult to stably obtain high optical output because it is difficult to achieve such a low reflectance with high reproducibility. was there.

An object of the present invention is to provide an edge-emitting diode that can suppress laser oscillation and stably obtain high optical output over a wide temperature range.

[Means for solving problems]

The edge light emitting diode of the present invention is a double heterostructure having an active layer on a semiconductor substrate, cladding layers sandwiching the active layer from above and below, and a stripe-shaped current injection part for forming a stripe-shaped light emitting region. In an edge light emitting diode that has a laminated structure and emits output light from an end face of the double-hetero laminated structure, the end face that emits the output light is formed as a slope having a predetermined angle with respect to the light emitting axis.

[Effect]

A conventional edge-emitting diode has a striped light-emitting region and a flat end face perpendicular to the light-emitting region, so that a stimulated emission light component is large and a high light output can be obtained.

This is because both the end face with the main light emitting part that emits the output light and the opposite end face have a light emitting region, that is, a plane perpendicular to the light emitting axis. The light travels to the end face while being amplified within the region, is reflected from this end face, and travels within the light emitting region again to the end face on the main light emitting portion side, where it is further amplified.

As a result, high light intensity can be obtained at the end face on the main light emitting part side.

However, the end face on the main light emitting part side is also perpendicular to the substrate,
Although a non-reflective film is provided, it is difficult to reduce the reflectance to less than 0.1%, which suppresses laser oscillation, so light is reflected at this end face and fed back, making it easy to cause laser oscillation.

Therefore, in the present invention, the end face on the side of the main light emitting part is sloped, and the end face has a surface oblique to the light emitting axis and a non-reflection film to reduce the amount of light returning into the light emitting area and prevent laser oscillation. This makes it easy to obtain stable operation even at high optical output.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

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

On an n-type TnP semiconductor substrate 11, an n-type InP cladding layer 12, an n-type InGaAsP active layer 13, and a p-type 1n
P cladding layer 14. Contact I of n-type 1nGaAsP
- The layers 15 are sequentially stacked and formed by, for example, a liquid phase epitaxial method.

Next, from the surface of the contact layer 15, Z
A current injection portion 16 is provided by selectively diffusing n, and a strip-like light emitting region is formed.

Subsequently, the surface of the contact layer 15 is coated with an AuZn film.
Type electrode 17. AuGeNi is deposited on the bottom surface of the semiconductor substrate 11.
N-type electricity 8i by membrane! form 18.

Next, etching and sowing are performed using an ion beam etching method, a chemical etching method, etc. to form a slope with a predetermined angle with respect to the light emitting axis 21, and the end surface 19 on the side that emits the output light, that is, the end surface 19 on the side of the main light emitting part, is Form.

Then, a non-reflective film 20 made of a silicon nitride film is formed on the end face 19 on the side of the main light emitting part, thereby constructing the end face light emitting diode of this embodiment.

In this embodiment, since the end surface 19 on the side of the main light emitting section is sloped, the amount of light reflected and fed back from this end surface 19 to the light emitting region is one-tenth that of the vertical end surface.
Therefore, even if the reflectance of the non-reflective film 20 is about 1%, which can be obtained with good practical reproducibility, the effective reflectance of the light emitting part side end surface 19 is It can be suppressed to less than 0.1%.

As a result, laser oscillation is significantly less likely to occur than in the past, and it is possible to obtain an edge-emitting diode with high output and stable operation that suppresses laser oscillation even at low temperatures.

Note that even higher output can be obtained by providing a highly reflective coating on the surface of the opposite end face 22. Even in this case, laser oscillation is suppressed, and an edge-emitting diode that does not oscillate even at -30° C. can be easily obtained.

〔Effect of the invention〕

As described above, the present invention has the effect of suppressing laser oscillation and stably and easily obtaining high optical output over a wide temperature range by making the end face on the side that emits the output light oblique.

[Brief explanation of the drawing]

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

Claims (1)

[Claims] This double-hetero laminated structure includes an active layer on a semiconductor substrate, a cladding layer that sandwiches the active layer from above and below, and a striped current injection part for forming a striped light-emitting region. 1. An edge light emitting diode that emits output light from an end face thereof, wherein the end face that emits the output light is an inclined surface having a predetermined angle with respect to a light emitting axis.