JP3096583B2 - Method for manufacturing semiconductor laser module - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor laser module used for an optical communication light source or the like in which a semiconductor light emitting element, a lens and an optical fiber are optically coupled and integrated.

[0002]

2. Description of the Related Art FIG. 1 shows a basic structure of a semiconductor laser module. The light emitting point of the semiconductor light emitting element 14 is the lens 1
Both are fixed to the base 18 so as to coincide with the center of 3,
The base 18 is disposed obliquely in the package 17. The laser light emitted from the semiconductor light emitting element 14 is condensed by the lens 13 and is coupled to the optical fiber 12 whose end face 20 has been polished obliquely. The X direction in the figure is the optical fiber 1
2 is a direction from the top to the bottom of the drawing in a plane perpendicular to the axis 11, the Y direction is a direction from the back of the drawing to the front, and the Z direction is a direction from the left to the right parallel to the axis 11 of the optical fiber 12. , Θ directions are counterclockwise as viewed from the right of the optical fiber 12.

The reason why the end face 20 of the optical fiber 12 is polished obliquely is that when the light reflected at the end face 20 (near-end reflection) is re-injected into the semiconductor light emitting element 14, reflection noise is generated and modulation characteristics are generated. This is because there is a problem in that is deteriorated. Furthermore, in order to maximize the amount of light incident on the optical fiber 12,
By tilting the base 18 with respect to the axis 11 of the optical fiber 12, the optical axis 15 of the laser beam
Is tilted. The inclination angle of the optical axis 15 of the laser beam with respect to the axis 11 of the optical fiber 12, that is, the optical axis inclination angle 19
Are disclosed in JP-A-61-67809 and JP-A-61-13.
No. 8216, the optical axis of the laser light in the optical fiber 12 is
Is determined so that the incident light is refracted at the end face 20 of the optical fiber 12. For example, when the end face 20 of the optical fiber 12 is polished at an angle of 8 ° with respect to the vertical plane of the axis 11, the optical axis tilt angle 19 becomes 3.8 ° in order to obtain the maximum amount of incident light. Must be adjusted as follows.

In the assembling process, a base 18 is fixed by using a jig or the like.
Is fixed to the package 17, but the accuracy of the jig,
Due to the fixing accuracy of the lens 13 and the semiconductor light emitting element 14, it is difficult to accurately set the optical axis tilt angle 19 to 3.8 °. Although the optical axis tilt angle 19 in the figure shows only the tilt in the X direction within the XY plane, the tilt actually occurs in the Y direction. Therefore, after fixing the base 18 to the package 17, the package 17 is rotated in the θ direction with respect to the optical fiber 12 while measuring the light quantity so that the light quantity of the laser light emitted through the optical fiber 12 is maximized. Had been adjusted. This is called θ alignment.

[0005]

According to the above-mentioned conventional method, it is necessary to rotate the package 17 at a small angle with respect to the optical fiber 12 in order to obtain the maximum amount of light incident on the optical fiber 12. A lot of time was required for the core process. For example, in order to set the minute angle of θ alignment to 5 ° and to perform alignment within the range of 60 °, position adjustment in the X and Y directions for up to 12 points of angle is required, which is a great deal of time in the alignment process. It takes a long time. Also, since the inclination direction of the optical axis 15 of the laser light varies from product to product,
The dispersion of the alignment time was large, and the management of the process time was very expensive. As a result, in the production of the semiconductor laser module, the productivity is extremely low, which hinders cost reduction.

An object of the present invention is to shorten the alignment time in the assembly process of a semiconductor laser module, thereby improving the productivity and reducing the cost.

[0007]

In order to achieve the above object, the present invention provides a semiconductor light emitting device and a lens in which the laser light emitted through an optical fiber is positioned in the XY plane of the optical fiber with respect to the semiconductor light emitting element and the lens. A step of obtaining a first optimum position; and moving the optical fiber relative to the first optimum position in the Z direction, and moving the optical fiber with respect to the semiconductor light emitting element and the lens such that the amount of laser light emitted through the optical fiber is maximized. A step of obtaining a second optimum position of the optical fiber in the XY plane, and a step of obtaining a required rotation angle from the relationship between the first and second optimum positions and relatively rotating the optical fiber by the angle in the θ direction And adopted.

[0008]

According to the present invention, when the optical fiber is rotated in the θ direction by the angle determined from the relationship between the first and second optimum positions, the final position of the optical fiber in the conventional θ alignment is determined. Almost obtained. Therefore, θ alignment can be started from a state in which a substantially maximum amount of incident light is obtained on the optical fiber. In addition, the step of obtaining the first and second optimum positions can be easily performed as compared with the θ alignment.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A specific example of a method for manufacturing a semiconductor laser module according to the present invention will be described with reference to FIGS.

In FIG. 1, a laser beam emitted from a semiconductor light emitting element 14 is condensed by a lens 13 and then enters an optical fiber 12. The optical axis 15 of the incident laser light is inclined in the X and Y directions with respect to the axis 11 of the optical fiber 12 for the reason described in the conventional example. First, in this state, the alignment in the X, Y, and Z directions is performed by measuring the output of the optical fiber 12, and the position (X ₀ , Y ₀ ) of the optical fiber 12 at which the amount of incident light is maximum is measured.

Next, the optical fiber 12 is moved in the + Z direction by, for example, 100 μm, and the alignment in the X and Y directions is performed, and the position (X ₁ , Y ₁ ) of the optical fiber 12 at which the amount of incident light is maximized.
Is measured. FIG. 2 is an example showing the position of (X ₁ , Y ₁ ) when (X ₀ , Y ₀ ) is the origin. In this example, it can be seen that the optical axis 15 of the laser light is inclined in the + X direction and also inclined in the + Y direction.

The angle θ ₁ in FIG. 2 is given by θ ₁ = tan
^-1 ((Y ₁ -Y ₀ ) / (X ₁ -X ₀ )).
As described above, by determining the X and Y positions at which the maximum amount of light incident on the optical fiber 12 is obtained at two points in the Z direction, the optical axis 1 of the laser light with respect to the axis 11 of the optical fiber 12 is obtained.
5 can be easily known.

Next, the package 17 is rotated in the θ direction by an angle θ _{1 with} respect to the optical fiber 12. At this point, the final position of the optical fiber 12 in the conventional θ alignment is substantially obtained. Therefore, if θ alignment is performed from this state,
Since the θ alignment can be started from a state in which a substantially maximum amount of incident light is obtained on the optical fiber 12, the alignment time can be greatly reduced. Actually, as compared with the conventional method, the alignment time was reduced to about 1/5 on average. In addition, since the alignment in the θ direction can be started from a state where the θ alignment is substantially performed, the variation in the alignment time is very small,
Process control costs can be minimized.

As described above, in the present embodiment, prior to the conventional alignment in the θ direction, the alignment in the X, Y, and Z directions, and the X, Y with the optical fiber 12 slightly moved in the Z direction. Since the three processes of centering in the direction and relative rotation of the optical fiber 12 in the θ direction are adopted, the centering in the θ direction can be started from a state where the θ is centered substantially, and the centering time is greatly reduced. can do.

[0015]

As described above, according to the present invention, the X and Y positions at which the maximum amount of incident light on the optical fiber can be obtained at two points in the Z direction are obtained, and based on the result, only the required angle is obtained. Since the optical fiber is relatively rotated in the θ direction, the alignment time in the assembling process of the semiconductor laser module can be significantly reduced as compared with the related art, and variation in the alignment time can be minimized. Thereby, the productivity of the semiconductor laser module can be improved, and the process management cost can be reduced.
As a result, significant cost reduction can be achieved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a semiconductor laser module to which the present invention is applied.

FIG. 2 is an explanatory diagram of an optical axis tilt angle measuring method according to the present invention.

[Explanation of symbols]

 Reference Signs List 11 optical fiber axis 12 optical fiber 13 lens 14 semiconductor light emitting element 15 laser light optical axis 17 package 18 base 19 optical axis tilt angle 20 end face of optical fiber

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-166906 (JP, A) JP-A-60-191211 (JP, A) JP-A-63-94208 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) G02B 6/24-6/42

Claims (1)

(57) [Claims] An optical fiber having a semiconductor light emitting element, at least one lens, and an optical fiber having an oblique end face, wherein a laser beam emitted from the semiconductor light emitting element passes through the lens and has a required optical axis inclination with respect to the axis of the optical fiber. What is claimed is: 1. A method for manufacturing a semiconductor laser module, wherein an optical fiber is optically coupled so as to be incident on an oblique end face of the optical fiber at an angle, and a Z axis is set in an axial direction of the optical fiber, When taking an XY plane, the semiconductor light emitting element and the lens with respect to the lens so that the amount of laser light incident on the oblique end face of the optical fiber through the lens from the semiconductor light emitting element and emitted through the optical fiber is maximized. Obtaining a first optimum position in the XY plane of the optical fiber; and connecting the optical fiber to the semiconductor light emitting element and the lens. Is moved relative to the Z-axis direction from the optimal position of the optical fiber, and the second optimal position in the XY plane of the optical fiber with respect to the semiconductor light emitting element and the lens is set so that the amount of laser light emitted through the optical fiber is maximized. Determining a position; determining a required rotation angle from a relationship between the first and second optimal positions; and relative to the semiconductor light-emitting element and the lens by the determined angle relative to the semiconductor light-emitting element and the lens about the Z axis. Rotating the semiconductor laser module.