JP2011033900A - Optical component holding holder and optical structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical component holding holder capable of miniaturizing an optical module, while keeping the dimension of an optical component. <P>SOLUTION: The optical component holding holder is made of a material having a thermal expansion coefficient which is the same as that of the optical component, has a U-shape and holds the optical component with two supporting parts. The optical component holding holder is formed of a material having a thermal expansion coefficient which is the same as that of the optical component, thereby the optical component and the optical component holding holder are not out of alignment even when temperature changes. Consequently, the optical component is directly held by the optical component holding holder when the optical component is held by the optical component holding holder. Thereby, the dimension of an optical structure composed of the optical component and the optical component holding holder are reduced. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an optical component holding holder for holding an optical component on an optical module and an optical structure using the same.

  Conventionally, in order to fix an optical component such as a lens on an optical module, the lens is held by a lens holder or the like, and the lens holder and the lens holder are fixed on the optical module by a U-shaped support member (for example, (See Patent Document 1). FIG. 1 is a view for explaining a conventional optical component holding holder.

  In a conventional optical module, a rectangular parallelepiped carrier 14 is fixed on a base portion 10 formed in a plate shape, and an optical element 12 is fixed on the carrier 14. The lens 16 is held by a lens holder 30 that is a rectangular frame material that holds the lens 16. The U-shaped support component 32 is arranged as a member that mediates in order to fix the lens holder 30 at a predetermined position on the base portion 10. In this optical module, it is necessary that the optical element 12 and the lens 16 are fixed to the base portion 10 with high precision so that the optical axes of the optical element 12 and the lens 16 coincide. The lens 16 must be movable and adjustable in an arbitrary direction in order to obtain high light coupling efficiency with respect to the optical element 12. In addition, after the lens 16 and the optical element 12 are adjusted to the optimum coupling state, the lens 16 and the optical element 12 must be able to be fixed without changing the position. A fixing method of fixing the U-shaped support component 32 onto the base portion 10 and fixing the lens holder 30 and the U-shaped support component 32 is performed by laser welding.

JP 09-33760 A

  However, since the lens 16 is held by the lens holder 30 that is a rectangular frame material that holds the lens 16, it is difficult to reduce the size of the optical module while maintaining the effective diameter of the lens 16. However, there has been a problem that it is difficult to realize further downsizing of optical modules that have been required in recent years.

  Accordingly, an object of the present invention is to provide an optical component holding holder and an optical structure that can reduce the size of the optical module while maintaining the size of the optical component.

  In order to achieve the above object, the optical component holding holder according to the present invention directly holds the optical component.

  Specifically, the optical component holding holder according to the present invention is a U-shaped optical component holding holder formed by two support portions and a bottom portion, and the bottom portion includes the two support portions. The surface opposite to the optical component sandwiched between the two is a flat surface, and the support portion and the bottom portion are made of a material having the same thermal expansion coefficient as that of the optical component.

  Conventionally, a component such as the lens holder 30 in FIG. 1 absorbs the difference in expansion coefficient depending on the temperature of the optical component and the optical component holding holder. The optical component holding holder of the present invention is made of a material having the same thermal expansion coefficient as that of the optical component. For this reason, even if temperature changes, an optical component and an optical component holding holder do not shift. For this reason, when holding an optical component with this optical component holding holder, a component like the lens holder 30 of FIG. 1 is unnecessary, and an optical component can be directly held with this optical component holding holder. Therefore, the size of the optical structure constituted by the optical component and the optical component holding holder can be reduced. In addition, since the surface opposite to the optical component at the bottom is a flat surface, the optical structure using the optical component holding holder can be easily translated on the base portion of the optical module.

  Therefore, the present invention can provide an optical component holding holder that enables downsizing of the optical module while maintaining the size of the optical component.

  It is desirable that the material of the optical component holding holder according to the present invention transmits light. By using a material that transmits ultraviolet rays, a UV curable adhesive can be used for the optical component and the optical component holding holder. A UV curable adhesive does not require a temperature raising device like a temperature curable adhesive. Further, unlike laser welding, it is not necessary to increase the dimensional accuracy of the optical component and the dimensional accuracy of the optical component holding holder to eliminate the gap between them. Therefore, it is possible to reduce costs in the process of manufacturing the optical component holding holder and fixing the optical component.

  Conventionally, the fitting relationship between the support component 32 and the lens holder 30 is such that when laser welding is performed, the support component 32 is loose enough to be freely inserted and removed for position adjustment, and has no gap so that laser welding can be performed satisfactorily. It was necessary. In order to improve the fitting relationship, it is necessary to make the dimensional accuracy of the support component 32 very strict. For this reason, the subject that the processing unit price of the support component 32 became high occurred.

  It is desirable that the material of the optical component holding holder according to the present invention is glass or plastic. The optical component holding holder according to the present invention is smaller than the conventional optical component holding holder, and if it is processed with metal, the processing unit cost is further increased. On the other hand, glass and plastic can be processed with high accuracy. For this reason, a manufacturing unit price can be lowered | hung by using glass or a plastic for the material of an optical component holding holder.

  The bottom portion of the optical component holding holder according to the present invention has a protrusion that contacts a part of the optical component. The grounding property of the optical component holding holder to the base surface of the optical module is improved. Further, it is easy to adjust the forward or backward tilt with respect to the optical axis about the contact point between the optical component and the protrusion.

  The optical structure according to the present invention includes a lens that is the optical component, the optical component holding holder that sandwiches an end of the lens between the two supporting portions, and the support portion of the lens and the optical component holding holder. A UV curable adhesive for fixing the two.

  By using the UV curable adhesive, the processing accuracy as much as laser welding is not required for the lens and the optical component holding holder, and the processing unit cost can be reduced. Further, when fixing the lens and the optical component holding holder, a large-scale temperature raising device such as a thermosetting adhesive is not required.

  The present invention can provide an optical component holding holder that enables downsizing of an optical module while maintaining the size of the optical component.

It is a figure explaining the conventional optical component holding holder. It is a figure which compares the magnitude | size of the optical component holding holder which concerns on this invention, and the conventional optical component holding holder. It is a figure which compares laser welding and fixation with an adhesive agent. It is a figure which compares the deformation | transformation of the optical component holding holder which concerns on this invention, and the conventional optical component holding holder when stress is given to an optical component. It is a front view of the optical component holding holder which concerns on this invention. It is a perspective view of the optical component holding holder which concerns on this invention. It is a perspective view of the optical component holding holder which concerns on this invention. It is a perspective view of the optical component holding holder which concerns on this invention. It is a perspective view of the optical component holding holder which concerns on this invention. It is sectional drawing of the optical component holding holder which concerns on this invention. It is an example of the optical module using the optical component holding holder which concerns on this invention.

  Hereinafter, the present invention will be described in detail with specific embodiments, but the present invention is not construed as being limited to the following description. In the present specification and drawings, the same reference numerals denote the same components.

  The optical component holding holder of the present embodiment is made of a material having the same thermal expansion coefficient as that of the optical component, and has a U-shape that sandwiches the optical component with two support portions. In the present embodiment, the optical component is described as the lens 116. FIG. 2 is a diagram comparing external sizes including a lens when a lens having the same effective diameter is held by an optical component holding holder. In this specification, a structure in which an optical component is supported by an optical component holding holder or a support component is referred to as an optical structure. FIG. 2A shows a conventional optical structure, and FIG. 2B shows the optical structure of this embodiment. In the conventional optical structure, the lens 16 is held by the lens holder 30. In order to secure the effective diameter of the lens 16, the lens holder 30 has a certain size so that the laser welding process can be satisfactorily fixed by laser welding when the lens holder 30 and the U-shaped support component 32 are fixed. Is required.

  On the other hand, the optical structure of this embodiment has no lens holder, and has a structure in which the lens 116 is directly fixed by the U-shaped optical component holding holder 132. With this structure, the optical component holding holder 132 can be downsized without changing the effective diameter of the lens 116. For example, in a conventional optical structure, a lens holder 30 having a width of 3.5 mm holding a lens 16 having a lens effective diameter of φ1.5 mm and a lens outer diameter of φ2 mm is supported by a U-shaped support component 32 having a width of 4.5 mm. is doing. At this time, the height from the bottom surface of the U-shaped support component 32 to the top surface of the lens holder 30 when the lens holder 30 is adjusted is 3.95 mm. On the other hand, in the optical structure of the present embodiment, the lens 116 having an effective lens diameter of 1.5 mm and a lens outer shape of 2 mm is held by the optical component holding holder 132 having a width of 3 mm, and the optical component holding holder when the lens 116 is adjusted. The height from the bottom surface 132 to the upper portion of the lens 16 is 2.75 mm. The width of the optical component holding holder 132 is about 34% smaller than that of the conventional support component 32. With respect to the height of the entire structure after adjustment, if the optical component holding holder 132 is used, the conventional support component 32 is used. Compared to the case, the size can be reduced by about 30%.

  In addition, the optical component holding holder 132 of the present embodiment is formed of a material having the same thermal expansion coefficient as that of the optical component. Even if there is a temperature change, the lens 116 and the optical component holding holder 132 expand and contract at the same ratio, so that no distortion or breakage occurs.

  In general, glass parts and plastic materials are often used for the optical parts such as the lens 16, and in order to use the metal U-shaped support part 32, it is necessary to use a thermosetting adhesive. It was. A thermosetting adhesive requires time for curing, and requires major changes such as adding a temperature raising function to the mounting apparatus. On the other hand, the optical component holding holder 132 of the present embodiment is made of a material that transmits the same light as the lens 116. For example, the optical component holding holder 132 is made of the same glass material as the lens 116. By using a material that transmits ultraviolet light as the material of the optical component holding holder 132, it is possible to use a UV curable adhesive that cures in a short time. Mounting device structure with UV curable adhesive can be relatively simple device change such as addition of UV light source. For example, the type of UV curable adhesive should be fixed without changing the position after curing the UV curable adhesive by selecting an epoxy system that has a low cure shrinkage and is strong in heat resistance and chemical resistance. Can do. The same applies to the lens 116 made of plastic. In this case, the optical component holding holder 132 is also made of plastic.

  FIG. 3 shows the present embodiment in which (a) a conventional optical structure for laser welding the lens holder 30 and the support component 32, and (b) the lens 116 and the optical component holding holder 132 are fixed with a UV curable adhesive. It is the figure which compared these optical structures. In laser welding (for example, YAG welding) which is a conventional fixing method, high accuracy is required for processing the lens holder 30 and the support component 32 so as not to cause a gap between the components in order to perform stable welding. On the other hand, the fixing of the UV curable adhesive employed in the present embodiment requires an adhesive layer between the lens 116 and the optical component holding holder 132, so that laser welding is performed on the lens 116 and the optical component holding holder 132. No machining accuracy is required and the machining unit cost can be reduced.

  A large optical component can be held by making the optical component holding holder 132 of the present embodiment from glass. The same applies to the case where the lens 116 is made of plastic and the optical component holding holder 132 is made of plastic. For example, compared to optical components used in DIP type with multiple terminals projecting downward, or butterfly type with multiple terminals projecting from both side walls, optics used in wavelength selective switches, optical multiplex guns, etc. The parts are large. For this reason, when the conventional support component 32 made of metal is enlarged to correspond to a large optical component, it is very difficult to process with the same processing accuracy as a small optical component. The unit price becomes high. On the other hand, the optical component holding holder 132 for holding a large optical component is made of glass. It is known that processing of glass parts can be performed with very high accuracy. By making the optical component holding holder 132 for holding a large optical component with glass, the accuracy can be made equivalent to that of the small bracket-made support component 32.

  FIG. 4 shows the maximum stress when the same area is pressed with a force of 500 N / m 2 from the direction of the arrow in the figure for (a) a conventional optical structure and (b) the optical structure of this embodiment. It is a figure explaining the shape which analyzed by stress analysis.

  In the conventional optical structure of FIG. 4A, the maximum stress is 0.562 Kpa at the maximum stress generation point A, and the deformation of the lens 16 near the pressurization point is particularly large, and the maximum stress generation point A is also pressed. The result occurred near the point. The maximum stress in the optical structure of this embodiment shown in FIG. 4B is 0.564 Kpa at the maximum stress generation point A, the deformation of the lens 116 near the pressing point is large, and the maximum stress generation point is also The result was generated near the pressure point. From this analysis result, the stress generated in both the glass optical component holding holder 132 and the metal support component 32 is equal. That is, there is little influence by having used the conventional metal support components as glass optical component holding holders.

  The shape of the portion of the conventional support component 32 that holds the lens holder 30 is fixed by laser welding, so that the focus position variation of laser welding is eliminated in order to perform stable laser welding, that is, the shape of a rectangular parallelepiped. Was common. However, since the optical component holding holder 132 fixes the lens 116 with a UV curable adhesive, there is no restriction on the shape of the portion that holds the lens 116. FIG. 5 is a front view of the optical component holding holder 132, and FIGS. 6 to 8 are perspective views of the optical component holding holder 132. A portion sandwiching the lens 116 is described as a support portion 111. As described above, the shape of the support portion 111 can be arbitrarily changed to a rectangular parallelepiped (FIG. 6), a semi-cylindrical body (FIG. 7), and a triangular prism (FIG. 8) in accordance with the mounting space.

  FIG. 9 is a perspective view of the optical component holding holder 132. FIG. 10 is a cross-sectional view of the optical component holding holder 132. The optical component holding holder 132 has a protrusion 113 with which a part of the lens 116 comes into contact with the bottom 112. By providing the protrusion 113 on the bottom 112 and bringing the lens 116 into contact with the protrusion 113 and applying pressure, the grounding property when the optical component holding holder 132 is disposed on the base surface of the optical module or the like can be improved. Furthermore, as shown in FIG. 10, the α axis of the lens 116 can be adjusted with the protrusion 113 as a fulcrum. FIG. 10 is a diagram for explaining the adjustment of the α axis of the lens 116. In addition, in FIG. 9, although the support part 111 is a semi-cylinder, a triangular prism and a rectangular parallelepiped shape may be sufficient.

  As described above, the optical component holding holder 132 is made of a material having the same thermal expansion coefficient as that of the lens 116, so that the optical component holding holder 132 can directly hold the lens 116 and change the effective diameter of the lens. Therefore, the optical module can be downsized. Further, by fixing the optical component holding holder 132 and the lens 116 with an adhesive, it is possible to make the shapes of the two support portions 111 that are impossible with conventional laser welding, and freedom in structural design. The degree is improved. Therefore, the optical component holding holder 132 is very advantageous for downsizing the optical structure for downsizing the optical module, which has been difficult with the conventional shape. In addition, since the optical component holding holder 132 is made of glass, it is possible to reduce the price while ensuring the member processing accuracy.

  In the above description, the optical component is described as a lens. However, the optical component is not limited to this, and may be, for example, a mirror used in a wavelength selection switch or the like, or a sub-assembly product on which the optical component is mounted. FIG. 11 is a diagram for explaining the wavelength selective switch 301. The wavelength selection switch 301 includes a Littrow lens 181, a mirror 184, a plate 187 on which a focusing lens 185 and a microlens array 188 are mounted, a grating 182, and a MEMS (Micro Electro Mechanical Systems) module 183 on the base unit 10. The wavelength selection switch 301 holds the Littrow lens 181, the mirror 184, and the plate 187 with the optical component holding holder 132. Since the side of the bottom 112 of the optical component holding holder 132 opposite to the optical component is a flat surface, the optical structure can be easily translated when positioning on the base 10.

10: Base part 12: Optical element 14: Carrier 16: Lens 30: Lens holder 32: Supporting part 111: Supporting part 112: Bottom part 113: Protruding part 116: Lens 121: Adhesive 132: Optical part holding holder 181: Littrow lens 182 : Grating 183: MEMS module 184: Mirror 185: Focusing lens 186: Fiber array 187: Plate 188: Microlens array 301: Optical module

Claims (5)

A U-shaped optical component holding holder formed by two support portions and a bottom portion,
The bottom portion has a flat surface opposite to the optical component sandwiched by the two support portions,
The optical part holding holder, wherein the support part and the bottom part are made of a material having the same thermal expansion coefficient as that of the optical part.   The optical component holding holder according to claim 1, wherein the material transmits light.   The optical component holding holder according to claim 1, wherein the material is glass or plastic.   The optical part holding holder according to any one of claims 1 to 3, wherein the bottom part has a protruding part with which a part of the optical part comes into contact. A lens that is the optical component;
The optical component holding holder according to any one of claims 1 to 4, wherein an end of the lens is sandwiched between the two support portions.
A UV curable adhesive for fixing the lens and the support part of the optical component holding holder;
An optical structure comprising

Images