JPH0933761A - Optical module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adjust the position with high size precision and lower the manufacture cost by providing a wedgelike pedestal which adjusts position relation so that the optical axes of an optical element and a lens are aligned with each other between a lens holder and a base member. SOLUTION: The lens 16 is held by the lens holder 18, whose bottom surface is slanted. The wedgelike pedestal 20 is interposed between the lens holder 18 and base member 10 and arranged so as to adjust the position relation so that the optical axes of the optical element 12 and lens 16 are aligned with each other. The use of the wedgelike pedestrial 20 enables the positioning of the lens 16 in any direction (all of five directions required for positioning) so that the optical axis is aligned with the optical element 12, and optimum joint efficiency is obtained. Further, the respective members are in simple shapes and abut against each other merely on their surfaces, so they can stably be positioned, so that the position adjustment can be performed with high size precision.

Description

Detailed Description of the Invention

[0001]

[0001] The present invention relates to an optical module. In a device such as optical communication and optical measurement using an optical fiber, an optical fiber terminal is fixed to an optical module having an optical element, and the optical fiber and the optical element are optically coupled. The optical module is provided by fixing the optical element and the lens to the base member so as to optically couple the optical element and the optical fiber. In this optical module, it is necessary that the optical element and the lens are accurately fixed to the base member so that the optical axes of the optical element and the lens coincide with each other. In order to fix the lens with such accuracy and obtain a highly efficient coupling of light, the lens must be movable and adjustable in any direction with respect to the optical element. Further, after the lens and the optical element have been adjusted to the optimal coupling state, the position must be fixed without changing. In addition, in order to optically couple the optical module provided as described above with the optical axis aligned with the optical axis, the end of the optical fiber must be fixed to the optical module with high dimensional accuracy. is there.

[0002]

2. Description of the Related Art FIG. 5 shows a conventional optical module. 10
Is a base member and is formed in a plate shape. A rectangular parallelepiped carrier 14 is fixed on the base member 10, and an optical element 12 is fixed on the carrier 14. 30
Is a lens holder, which is a rectangular parallelepiped frame member that holds the lens 16. Reference numeral 32 denotes a U-shaped support member, which is provided as an intermediary member for fixing the lens holder 30 at a predetermined position on the base member 10. When the lower surface of the support member 32 contacts the surface of the base member 10 and both side wall portions of the support member 32 stand upright on the base member 10,
The support member 32 is mounted on the base member 10. The lens holder 30 is fitted and inserted between both side wall portions of the U-shaped support member 32.

According to the optical module having such a structure, the lens 16 is moved in the two-dimensional directions of XY and the base by moving the support member 32 back and forth and left and right on the surface of the base member 10. The angle can be adjusted with respect to the rotation direction θ1 parallel to the surface of the member 10. Further, by sliding the lens holder 30 with respect to the support member 32 and moving the lens holder 30 in the vertical direction, the position of the lens 16 can be adjusted in the Z direction. Further, the lens holder 30 can be rotated in the rotation direction θ2 parallel to the surface orthogonal to the surface of the base member 10, and the position can be adjusted also in that direction. That is, the position and angle of the lens 16 can be adjusted in all five directions required for the position adjustment.

However, in the above-mentioned conventional optical module, the fitting relationship between the U-shaped support member 32 and the lens holder 30 is so loose that it can be freely inserted and removed for position adjustment, and laser welding is performed when fixing. Must be tight enough to be suitable. The optical module is a precision product, and in order to make the fitting relationship of the lens holder 30 to the U-shaped support member 32 suitable, it is necessary to make the dimensional accuracy extremely severe. Therefore, the processing unit cost of the lens holder 30 and the U-shaped support member 32 becomes high, and it is difficult to reduce the cost of the product. In addition, the lens holder 30 has to be adjusted in position while being floated from the inner bottom surface of the U-shaped support member 32, and there is a problem that it is difficult to improve the positional accuracy due to lack of stability.

Therefore, an object of the present invention is to provide an optical module capable of performing position adjustment with high dimensional accuracy and reducing manufacturing cost.

[0006]

To achieve the above object, the present invention has the following arrangement. That is, the present invention
In an optical module in which an optical element and a lens are optically coupled and provided on a base member, a lens holder for holding the lens and the optical element and the lens interposed between the lens holder and the base member. And a wedge-shaped pedestal whose positional relationship is adjusted so as to match the optical axes of and.

Further, since the base member and the pedestal, and the pedestal and the lens holder are fixed by laser welding, they can be fixed without changing the position of which the position is adjusted, and a highly accurate optical module can be obtained. Can be formed.

Further, the upper surface of the lens holder and the upper surface of the base member can be made substantially parallel to each other by forming the inclined surface of the lens holder in contact with the wedge-shaped pedestal.

[0009]

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a perspective view showing an example of an optical module according to the present invention. FIG. 2 is an exploded view showing a state before the lens holder 18 in which the lens 16 is fitted and held and the wedge-shaped pedestal 20 are fixed to the base member 10. The base member 10 is formed in a plate shape. Reference numeral 12 is an optical element, which is the base member 1.
It is fixed on a rectangular parallelepiped carrier 14 which is fixed on one side on the upper side of 0. The optical element 12 is a laser diode that emits light or a photodiode that receives light and outputs a signal.

The lens 16 is held by a lens holder 18 which is a frame material. This lens holder 18
The bottom surface of is formed as a slope. Wedge-shaped pedestal 20
Is interposed between the lens holder 18 and the base member 10 and is arranged to adjust the positional relationship so that the optical axes of the optical element 12 and the lens 16 coincide with each other. The lower surface of the wedge-shaped pedestal 20 is formed into a flat surface, and contacts the upper surface of the base member 10. In addition, the upper surface of the wedge-shaped pedestal 20 is formed as an inclined surface, and the bottom surface of the lens holder 18 formed on the inclined surface corresponding to the surface is in contact. As a result, the base member 10, the wedge-shaped pedestal 20, and the lens holder 18 are arranged in this order in a three-tiered stack. In the stacked state as shown in FIG. 1, the surface of the base member 10 and the upper surface of the lens holder 18 are substantially parallel to each other.

The above-mentioned base member 10 and lens holder 1
As the pedestal 8 and the wedge-shaped pedestal 20, stainless steel or the like, which is a metal material resistant to corrosion and having good laser weldability, may be used. Further, in order to fix the above configurations with each other with high accuracy, the base member 10 and the wedge-shaped pedestal 20,
The wedge-shaped base 20 and the lens holder 18 may be fixed by laser welding. According to the laser welding, the metal members can be locally heated and melted, and the members can be fixed to each other without heating other portions. Therefore, thermal deformation of the entire metal member can be prevented, and each component can be fixed with high accuracy. Laser welding includes YAG welding.

Next, the operation of the wedge-shaped pedestal 20 when adjusting the positional relationship so that the optical axes of the optical element 12 and the lens 16 coincide will be described in detail. First, the wedge-shaped pedestal 20 on which the lens holder 18 is mounted is moved forward and backward (Y direction) left and right (X direction) on the surface of the base member 10 and is rotated, whereby the lens 16 is moved in the XY direction.
The position adjustment (angle adjustment) can be performed in the two-dimensional direction and the rotation direction θ1 parallel to the surface (horizontal surface) of the base member 10. Further, by sliding the lens holder 18 along the slope of the wedge-shaped base 20, the lens holder 18 can be moved in the vertical direction with respect to the wedge-shaped base 20. This allows the lens 16 to be adjusted in position in the Z direction. Further, as shown in FIG. 3, by rotating the wedge-shaped pedestal 20 on the surface of the base member 10 and rotating the lens holder 18 on the wedge-shaped pedestal 20, a surface orthogonal to the surface of the base member 10 ( The lens holder 18 can be rotated in a rotation direction θ2 parallel to the vertical plane, and the position adjustment (angle adjustment) of the lens 16 can also be performed in that direction.

As described above, by using the wedge-shaped pedestal 20, the lens 16 can be aligned in any direction (5 necessary for alignment) so that the optical axis is aligned with the optical element 12.
It is possible to align in all directions)
Optimal joining efficiency can be obtained.

FIG. 4 shows an example of the LD module. This LD module is a two-ball lens type L lens in which an optical element 12 and an optical fiber 22 are optically coupled by using two lenses.
It is a D module. The LD module may be of a one-ball lens type using one lens, a DIP type in which a plurality of terminals project downward, or a butterfly type in which a plurality of terminals project from both side walls. This two-ball lens type LD
In the module, an optical module 11 having the above-described configuration and an optical fiber terminal 25 are fixed to a housing 24. The optical fiber terminal 25 has a lens 26
And optical fiber 2 protected by ferrule 27
The end of 2 is fixedly provided by the protective tube 28. A cover 29 covers the housing 24 and protects the optical module 11. Since the optical fiber terminal 25 is fixed to the optical module 11 with high dimensional accuracy, the optical axes of the optical fiber 22 and the optical element 12 are aligned,
Both can be optically coupled.

In the above-described embodiment, laser welding (for example, Y
AG welding) was used. This is for securely forming the optical module without worrying about loosening as compared with fixation by pressure bonding or adhesion, but depending on conditions, it may be fixed by a method other than laser welding. For example, each member can be fixed by brazing such as solder. Further, a function for adjusting the position may be provided on the fixed side of the optical element, and for example, the carrier fixing the optical element may be divided into an upper member and a lower member, and the lower part may be a wedge-shaped pedestal, which is described above. It is possible to accurately match the optical axes of the optical element and the lens, as in the above-described embodiment. As described above, various preferred embodiments of the present invention have been described. However, the present invention is not limited to these embodiments, and it goes without saying that many more modifications can be made without departing from the spirit of the invention. That is.

[0016]

According to the present invention, each member has a simple shape, and the contact relationship between the base member and the wedge-shaped pedestal, and the wedge-shaped pedestal and the lens holder is a simple face-to-face contact. It is in contact with each other and can be positioned stably. Therefore, there is a remarkable effect that the position adjustment can be performed with high dimensional accuracy. In addition, a fitting failure such as a conventional relationship between the insertion object and the insertion object, which occurs when errors of both are integrated (the insertion object cannot be inserted into the insertion object, or the fitting relationship is Too loose) can be prevented. That is, since the shape of each component is simple and its dimensional accuracy can be relaxed, the unit price of each component can be reduced, and consequently the overall manufacturing cost can be reduced.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of an optical module according to the present invention.

FIG. 2 is an exploded view of the optical module of FIG.

FIG. 3 is a perspective view illustrating angle adjustment of the lens holder in FIG.

FIG. 4 is a sectional view showing a state in which an optical fiber terminal is connected to the optical module according to the present invention.

FIG. 5 is a perspective view showing a conventional technique.

[Explanation of symbols]

 10 base member 12 optical element 14 carrier 16 lens 18 lens holder 20 wedge-shaped pedestal

Claims (3)

[Claims] 1. An optical module in which an optical element and a lens are optically coupled to each other and provided on a base member, wherein a lens holder for holding the lens is interposed between the lens holder and the base member, and An optical module, comprising: a wedge-shaped pedestal whose positional relationship is adjusted so that the optical axes of the optical element and the lens coincide with each other. 2. The base member and the wedge-shaped pedestal,
The optical module according to claim 1, wherein the wedge-shaped base and the lens holder are fixed by laser welding. 3. The optical module according to claim 1, wherein a surface of the lens holder that comes into contact with the wedge-shaped pedestal is formed as an inclined surface.