Optical module

Abstract

To obtain an optical module in which cracking and chipping of a lens is prevented.SOLUTION: An optical module comprises: a package; a pipe component provided on the package; and a lens which is fixed on the pipe component with solder and in which penetration slits are formed at an outer peripheral part thereof. The lens is configured such that the penetration slits are formed in such a manner as that. The lens configured as such relaxes strain of the lens caused by heat given at the time of fixing of the lens. Relaxation of the strain enables occurrence of cracking and chipping of the lens to be prevented.SELECTED DRAWING: Figure 1

Description

Technical Field

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[0001] The present disclosure relates to an optical module in which a lens is fixed to a pipe component provided in a package by soldering.

Background Art

[0002] An optical module is provided with a lens for the purpose of condensing light or converting it into collimated light. Some optical modules have a lens fixed to a pipe component provided in a package. Patent Document 1 discloses an optical module in which a lens is fixed to a pipe component provided in a package. <ooo0010>

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the optical module disclosed in Patent Document 1, when attempting to fix a lens to a pipe component using solder, there is a risk that the lens may crack or chip due to distortion caused by the heat applied to melt the solder.

[0005] The present disclosure has been made to solve the above problems, and an object thereof is to obtain an optical module that prevents cracking and chipping of the lens.

Means for Solving the Problems

[0006] The optical module according to the present disclosure includes a package, a pipe component provided in the package, and a lens that is fixed to the pipe component by solder on a fixing surface provided on the outer peripheral portion, and a through slit is formed on the outer peripheral portion that is cut from the outermost periphery toward the inside. The fixed surface is the surface of the outer periphery that intersects the optical axis of the lens. . [Effects of the Invention]

[0007] According to this disclosure, by providing a through-slit in the lens, it is possible to obtain an optical module that prevents cracking and chipping of the lens. [Brief explanation of the drawing]

[0008] [Figure 1] This is a cross-sectional view showing an optical module according to Embodiment 1. [Figure 2] This is a diagram showing the lens according to Embodiment 1. [Figure 3] This is a diagram showing the lens according to Embodiment 1. [Figure 4] This figure shows a modified example of the lens according to Embodiment 1. [Figure 5] This is a cross-sectional view showing an optical module according to Embodiment 2. [Figure 6] This is a diagram showing the lens according to Embodiment 2. [Figure 7] This figure shows a modified example of the lens according to Embodiment 2. [Figure 8] This figure shows the pipe component according to Embodiment 3. [Modes for carrying out the invention]

[0009] Embodiment 1. Figure 1 shows a cross-sectional view of an optical module 10 according to Embodiment 1. The optical module 10 comprises a package 12 having an opening at the top. A carrier 14 is provided on the bottom plate of the package 12. A semiconductor laser 16 is provided on the carrier 14. An element-side lens 18 is fixed on the carrier 14 in front of the semiconductor laser 16. A lid 20 is provided to close the opening of the package 12.

[0010] The optical module 10 includes a pipe component 22. The pipe component 22 is provided on the side plate of the package 12. A hole is made in this side plate, and the pipe component 22 is fitted into this hole.

[0011] The optical module 10 includes a lens 26. The lens 26 is fixed to a pipe component 22. A recess is formed in the pipe component 22, and the lens 26 is housed in this recess.

[0012] Figures 2 and 3 show the lens 26 viewed perpendicular to the optical axis and from the direction of the optical axis, respectively. The lens 26 includes a lens portion 28. The lens portion 28 is the part that refracts light and focuses the light from the semiconductor laser 16. The lens 26 also includes an outer peripheral portion 30. Here, the outer peripheral portion is the part around the lens portion 28 and includes the outermost periphery of the lens 26. The lens 26 is fixed to the pipe component 22 with solder on a fixing surface 32 provided on the outer peripheral portion 30. The type of solder is, for example, gold tin. Since the optical properties deteriorate if the solder reaches the lens portion 28, the soldering is done between the fixing surface 32 and the pipe component 22, avoiding the lens portion 28.

[0013] The lens 26 has a through-slit 36 ​​formed in its outer peripheral portion 30. The through-slit 36 ​​penetrates the lens 26 when viewed from the optical axis direction and is cut inward from the outermost edge of the lens 26. Since the through-slit 36 ​​is formed in the outer peripheral portion 30 and does not reach the lens portion 28, it does not cause any problems with the optical performance of the lens 26.

[0014] When solder is used to fix the lens 26 and the pipe component 22, heat is applied to melt the solder during the process of fixing the lens 26. This heat causes stress, which leads to distortion in the lens 26. However, in this embodiment, a through-slit 36 ​​is formed, so the stress is released at the through-slit 36. Therefore, the stress is reduced, and the distortion of the lens 26 is alleviated.

[0015] Also, for stress relaxation, it is important that the through slit 36 is cut from the outermost periphery of the lens 26 towards the inside. If the through slit does not reach the outermost periphery of the lens 26, the portion of the lens 26 outside this through slit cannot release stress, so the distortion is not relaxed. However, in this embodiment, since the through slit 36 reaches the outermost periphery of the lens 26, there is no such concern.

[0016] In addition, as shown in FIG. 3, the through slit 36 is preferably a cut from the outermost periphery of the lens 26 towards the center. By forming the through slit 36 in this way, the vicinity of the through slit 36 at the outermost periphery of the lens 26 does not become an acute angle, so cracks and chips at this location can be prevented. Also, the formation of the slit is easy. However, this is not essential. For example, as shown in FIG. 4, if the through slit 36 is cut from the outermost periphery of the lens 26 towards the inside, the effect of stress relaxation can be obtained.

[0017] Also, for stress relaxation, it is important that the slit penetrates the lens 26. If the slit does not penetrate the lens 26, the thickness of the lens 26 at the location of the slit will become thinner. The lens 26 is usually made of glass, and the thinner portion is more vulnerable to distortion. Also, stress relaxation cannot be achieved. However, in this embodiment, since the slit penetrates, there is no such concern.

[0018] Also, since the through slit 36 is formed in the outer peripheral portion 30, excess solder among the solder used for fixing the lens 26 accumulates in the through slit 36.

[0019] Also, if there are multiple through slits 36, the effect of stress relaxation is enhanced and the storage capacity of excess solder can be increased. It is desirable that the multiple through slits 36 are arranged at equal distances from the center of the lens 26. With this arrangement, stress concentration can be avoided, so the distortion is more effectively relaxed and excess solder can be stored in a balanced manner.

[0020] Returning to Figure 1, the receptacle 38 is fixed to the pipe component 22.

[0021] The inside of package 12, surrounded by package 12, lid 20, pipe component 22, and lens 26, is hermetically sealed.

[0022] Light emitted from the semiconductor laser 16 (dashed line in Figure 1) passes through the element-side lens 18 and becomes collimated light. The collimated light is focused by lens 26 and emitted to the outside through a stub ferrule (not shown) of the receptacle 38.

[0023] As described above, according to this embodiment, since a through slit 36 ​​is formed in the lens 26, distortion of the lens 26 due to the heat applied when the lens 26 is fixed is mitigated. Therefore, cracking and chipping of the lens 26 can be prevented.

[0024] Furthermore, excess solder accumulates in the through-slit 36, preventing contamination of the lens 26 due to solder leakage.

[0025] Embodiment 2. Figure 5 shows a cross-sectional view of the optical module 40 according to Embodiment 2. The optical module 40 is similar to the optical module 10 according to Embodiment 1, but there is a difference in the lens 56. Figure 6 shows the lens 56 as viewed from a direction perpendicular to the optical axis. In Figure 6, although not shown, the pipe component 52 is located to the right of the lens 56. As shown in this figure, when viewed from a direction perpendicular to the optical axis of the lens 56, the outermost circumference of the lens 56 has a tapered shape that widens as it moves away from the pipe component 52. The recess in the pipe component 52 also has a shape that follows the taper of the lens 56.

[0026] Because the outermost circumference of the lens 56 is tapered, the lens 56 can be smoothly inserted when fixing it to the pipe component 52, preventing cracking or chipping of the lens 56. Alternatively, as shown in Figure 7, only the outermost circumference on the pipe component 52 side may be tapered.

[0027] Embodiment 3. The optical module according to Embodiment 3 is similar to the optical module 10 according to Embodiment 1, but there is a difference in the pipe component 82. Figure 8 shows the pipe component 82 as seen from the semiconductor laser side. As shown in this figure, the pipe component 82 has a recess 84 formed at the location where the lens is fixed with solder.

[0028] Because a recess 84 is formed, excess solder generated when fixing the lens and the pipe component 82 accumulates in the recess 84, preventing the lens from becoming dirty due to solder leakage.

[0029] Having multiple recesses 84 increases the amount of excess solder that can be stored. It is desirable that the multiple recesses 84 be arranged at equal distances and equal intervals from the center of the pipe component 82. This arrangement allows for balanced storage of the excess solder.

[0030] In Figure 8, the concave area is depicted as a circle, but this is not the only option. For example, it could be a polygon, a straight line, a curved shape, or something similar.

[0031] In addition, in all embodiments, the semiconductor laser may be replaced with a photodetector. For example, if the semiconductor laser 16 in Figure 1 is replaced with a photodetector, light incident from the outside is incident on the photodetector via the lens 26 (and the element-side lens 18).

[0032] Furthermore, the contents of Embodiment 3 may be applied to the optical module according to Embodiment 2.

[0033] Although preferred embodiments have been described in detail above, the invention is not limited to the embodiments described above, and various modifications and substitutions can be made to the embodiments described above without departing from the scope of the claims.

[0034] The various aspects of this disclosure are summarized below as an appendix.

[0035] (Note 1) The package and The pipe component provided in the aforementioned package, A lens is fixed to the pipe component by solder at a fixed surface provided on the outer circumference, and a through slit is formed on the outer circumference, cut from the outermost edge toward the interior. An optical module equipped with this. (Note 2) The aforementioned through-slit is cut from the outermost edge of the lens toward the center. The optical module described in Appendix 1. (Note 3) There are multiple through-slits, The multiple through-slits are arranged at equal distances and equal intervals from the center of the lens. The optical module described in Appendix 1 or 2. (Note 4) When viewed from a direction perpendicular to the optical axis of the lens, at least the outermost edge of the lens on the pipe component side has a tapered shape that widens as it moves away from the pipe component. An optical module as described in any one of the items 1 to 3 of the appendix. (Note 5) The pipe component has a recess formed where the lens is fixed with solder. An optical module as described in any one of the items 1 to 4 of the appendix. (Note 6) There are multiple recesses, The multiple recesses are arranged at equal distances and equidistant intervals from the center of the lens. The optical module described in Appendix 5. (Note 7) The package contains a semiconductor laser, Light emitted from the semiconductor laser is emitted to the outside through the lens. An optical module as described in any one of the items 1 to 6 of the appendix. (Note 8) The package is equipped with a light-receiving element inside, Light incident from the outside is incident on the light-receiving element through the lens. An optical module as described in any one of the items 1 to 6 of the appendix. [Explanation of symbols]

[0036] 10,40 optical modules, 12 packages, 16 semiconductor lasers, 22,52,82 pipe components, 26,56 lenses, 30 outer periphery, 36 through slits, 84 recesses

Claims

1. The package and The pipe component provided in the aforementioned package, A lens is fixed to the pipe component by solder at a fixed surface provided on the outer circumference, and a through slit is formed on the outer circumference, cut from the outermost edge toward the interior. Equipped with, The fixed surface is an optical module, which is a surface of the outer periphery that intersects the optical axis of the lens.

2. The optical module according to claim 1, wherein the through-slit is cut from the outermost periphery of the lens toward the center.

3. There are multiple through-slits, The optical module according to claim 1, wherein the plurality of through slits are arranged at equal distances and at equal intervals from the center of the lens.

4. The optical module according to claim 1, wherein, when viewed from a direction perpendicular to the optical axis of the lens, at least the outermost circumference of the lens on the side of the pipe component has a tapered shape that widens as it moves away from the pipe component.

5. The optical module according to claim 1, wherein the pipe component has a recess formed at the location where the lens is fixed with solder.

6. There are multiple recesses, The optical module according to claim 5, wherein the plurality of recesses are arranged at equal distances and at equal intervals from the center of the lens.

7. The package contains a semiconductor laser, The optical module according to any one of claims 1 to 6, wherein light emitted from the semiconductor laser is emitted to the outside through the lens.

8. The package is equipped with a light-receiving element inside, The optical module according to any one of claims 1 to 6, wherein light incident from an external source is incident on the light-receiving element through the lens.

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