JPH03196006A - Semiconductor laser module - Google Patents

Abstract

PURPOSE:To enable coupling without aligning optical axes by forming a hole or groove acting as a light emitting end at one side of a light emission region in a semiconductor substrate, putting an optical fiber with an obliquely polished end in the hole or groove and fixing the fiber so that light from the light emitting end enters into the fiber. CONSTITUTION:A hole 10 having a slightly larger diameter than an optical fiber 8, coming in contact with a striped active layer 3 and having the center on an extension line of stripes is formed in the semiconductor substrate 1 of laser assembled in a junction-down state. The thickness of the layer and that of an electrode are set so that emitted light enters into the central part of the optical fiber 8 put in the hole 10. The optical fiber 8 can be coupled with the semiconductor laser only by putting in the hole 10 and fixing with resin 11.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor laser module in which a semiconductor laser and an optical fiber are coupled.

[Conventional technology]

FIGS. 3 and 4 show an example of a conventional method of coupling a fiber with an obliquely polished tip and a semiconductor optical device.

In FIGS. 3 and 4, 1 is a semiconductor substrate, 2 is a lower cladding layer, 3 is an active layer, 4 is an upper cladding layer, 5 is a contact layer, 6 and 7 are electrodes, and 8 is a tip into which light output is incident. An obliquely polished fiber (hereinafter simply referred to as an optical fiber) 9 is an optical output.

Next, the combining method will be explained.

FIG. 3 shows the coupling between the surface emitting LED and the optical fiber 8,
FIG. 4 shows the coupling between the edge-emitting LED and the optical fiber 8.

In these coupled states, the light output 9 emitted from the light emitting region enters the optical fiber 8 from the side surface, is reflected by the end face polished to about 45°, and enters the core of the optical fiber 8.

[Problem to be solved by the invention]

The conventional coupling between the semiconductor laser and the optical fiber 8 is such that the optical output 9 is input into the core of the optical fiber 8.
It was necessary to monitor the light while inputting it into the optical fiber 8, align the optical axis, and then fix the optical fiber 8 to a package or the like. Not limited to optical fiber 8, but also other fibers (loose 1, coupling.

A similar process was used for couplings using spherical fibers, etc.).

The above process is complicated and time-consuming, and has many problems such as the possibility of variations in coupling characteristics, and is particularly unsuitable for coupling optical elements arranged in an array.

The present invention was made in order to solve the above-mentioned problems, and an object of the present invention is to obtain a semiconductor laser module that can be coupled without the need for optical axis alignment.

[Means to solve the problem]

In the semiconductor laser module according to the present invention, a hole or a groove serving as a light emitting end face on one side of a light emitting region is formed in a semiconductor substrate, a beveled tip polished fiber is inserted into the hole or groove, and an output from the light emitting end face is formed. The fiber is fixed so that light enters the fiber with an obliquely polished tip.

[Effect]

The semiconductor laser module of the present invention has an obliquely polished fiber tip inserted directly into the hole or groove in contact with the light emitting end surface of the laser, so that the optical output from the light emitting end surface is transmitted through the obliquely polished fiber tip without optical axis alignment. Be injected into.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of the present invention. In this figure, the same reference numerals as those in FIG. 3, FIG. 4, and FIG. The semiconductor light emitting element is inserted and fixed at an optimum position where output light from the light emitting end face of the semiconductor light emitting element is incident. 11 is a resin for that purpose. Further, 12 indicates a heat sink.

Next, the operation will be explained.

The semiconductor substrate 1 of the laser assembled in a junkyard has a diameter slightly larger than the fiber diameter (several microns).
A hole 10 is formed in contact with the striped active layer 3 and whose center is on an extension of the stripe. In this hole 10, an optical fiber 8 is placed with a resin 1, with the side surface opposite to the obliquely polished tip surface facing the light emitting end surface of the laser.
It is fixed at 1. The light output emitted from the active layer 3 is output from the light emitting end face, enters the optical fiber 8 from the side surface of the optical fiber 8, is reflected by the slope polished to about 45 degrees, and is parallel to the axis of the optical fiber 8. The light propagates within the optical fiber 8 in a certain direction. In the above modularization process, the layer thickness and electrode thickness are set in advance so that the light output is incident on the center part of the optical fiber 8, and the optical fiber 8 is inserted into the hole 10 and fixed with the resin 11. It becomes possible to couple the optical fiber 8 and the semiconductor laser with only a few steps.

In the above embodiment, the distance from the surface of the electrode 6 of the semiconductor laser to the active layer 3 is generally about 8 μm. On the other hand, the diameter of the optical fiber currently used for boat fishing is 125 μm. For B, when using an optical fiber 8 with a diameter of 125 μm, the distance from the active layer 3 to the surface of the electrode 6 must be as large as 62.5 μm in order to make the laser beam enter the center of the optical fiber. layer 5 or electrode 6 (extremely thick contact layer 5 or electrode 6).

FIG. 2 is a sectional view showing another embodiment of the present invention, in which the tip of the optical fiber 8 is polished and flattened in a direction perpendicular to the core. In addition, the second
The same reference numerals in the figure as in FIG. 1 indicate the same components.

Also, a hole 10 is formed in the heat sink 12, and the tip of the optical fiber 8 is passed through the semiconductor substrate 1 into the heat sink 12.
The positioning may be performed by inserting it into the hole 10 of.

According to the above method, bonding is possible without the need to thicken the contact layer or the like.

In the above embodiment, a case has been described in which the semiconductor laser is assembled in a junction-down manner, but it goes without saying that the same application is possible even if the semiconductor laser is assembled in a junction-up manner and the optical fiber 8 is inserted from the surface. In this case, the hole 10 does not have to be a through hole. Further, in the above embodiment, the optical fibers 8 are coupled by forming the holes 10, but grooves may be formed and the optical fibers are coupled.

〔Effect of the invention〕

As explained above, the invention of B forms a hole or a groove in a semiconductor substrate to serve as a light emitting end face on one side of a light emitting region, inserts an obliquely polished fiber into the hole or groove,
Since the output light from the light emitting end face is fixed so as to enter into the obliquely polished fiber, there is no need to align the optical axis of the obliquely polished fiber, making it possible to couple the semiconductor laser and the obliquely polished fiber in a simple manner. It can be performed.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a semiconductor laser module showing one embodiment of the present invention, FIG. 2 is a sectional view showing another embodiment of the invention, and FIGS. FIG. 3 is a cross-sectional view showing the connection with a polished fiber. In the figure, 1 is a semiconductor substrate, 2 is a lower crystal layer, and 3 is a semiconductor substrate.
is an active layer, 4 is an upper cladding layer, 5 is a contact layer, 6 and 7 are electrodes, 8 is an obliquely polished tip fiber, 9 is an optical output,
10 is a hole, 11 is a tree II, and 12 is a heat hole. Note that the same reference numerals in each figure indicate the same or corresponding parts. Diagram] 1 fat 12 rate] cut

Claims (1)

[Claims] In a semiconductor laser having a striped light emitting region, a hole or a groove serving as a light emitting end face on one side of the light emitting region is formed in the semiconductor substrate, a beveled tip polished fiber is inserted into the hole or groove, and the light emitting end face is formed on one side of the light emitting region. 1. A semiconductor laser module, wherein the semiconductor laser module is fixed so that output light from the end face is input into the obliquely polished fiber.