Optical connectors, optical modules, and optical connector evaluation methods

Abstract

To provide an optical connector that can be evaluated easily regarding whether the same is manufactured as designed.SOLUTION: An optical connector includes: a light transmission wall including a first surface, and a second surface disposed in a back side of the first surface; and a holding part for holding an optical transmission body such that an end face of the optical transmission body faces the second surface. The optical connector includes first multiple optical surfaces disposed on the first surface along the X direction, multiple grooves that extend in a direction opposite to the first surface so as to be separated from the second surface and are disposed in the holding part, and multiple X-direction reference marks. Each of the multiple X-direction reference marks includes a bottom line of a groove of the multiple grooves and is disposed on a first virtual plane vertical to the X direction.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to an optical connector, an optical module, and an evaluation method for an optical connector. [Background technology]

[0002] Optical connectors are known that accommodate optical transmission bodies (e.g., optical fibers or optical waveguides) and receive light from the optical transmission bodies. The optical connectors are configured so that the ends of the optical transmission bodies can be positioned at appropriate positions.

[0003] For example, Patent Document 1 discloses an optical connector having a cladding portion in which an optical waveguide is formed, and a lens provided at a position facing the end face of the optical waveguide. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-168850 Summary of the Invention [Problem to be solved by the invention]

[0005] In an optical connector such as that shown in Patent Document 1, it is important to accurately align the end face of the optical transmission body with respect to the optical connector. Typically, an optical connector is designed so that the optical transmission body is positioned correctly when it is held in the optical transmission body holding portion.

[0006] However, such alignment requires high positional accuracy. Therefore, if the optical connector is not manufactured with high precision according to the design, such as if there is a slight distortion in the optical connector, the optical transmission body may not be aligned accurately. For this reason, it is necessary to evaluate whether the optical connector is manufactured with high precision according to the design.

[0007] One possible evaluation method is as follows: The V-groove in which the optical transmission element is placed is measured with a coordinate measuring machine, the center of an imaginary circle inscribed in the V-groove is calculated, and the positional relationship between the center of the circle and the center of the lens surface of the optical connector is evaluated to determine whether the optical connector has been manufactured as designed. However, this method involves variations in the calculation of the center of the inscribed imaginary circle, which may prevent an appropriate evaluation.

[0008] An object of the present invention is to provide an optical connector that can easily be evaluated for whether it has been manufactured as designed. Another object of the present invention is to provide an optical module that includes the optical connector. Another object of the present invention is to provide a method for evaluating the optical connector. [Means for solving the problem]

[0009] An optical connector according to one embodiment of the present invention is an optical connector having a light-transmitting wall including a first surface and a second surface arranged on the back side of the first surface, and a holding portion for holding the optical transmission body so that the end face of the optical transmission body faces the second surface, and the optical connector has a plurality of first optical surfaces arranged along the X direction on the first surface, a plurality of grooves arranged on the holding portion and extending in the direction opposite to the first surface so as to move away from the second surface, and a plurality of X-direction reference marks, each of the plurality of X-direction reference marks including a valley line of one of the plurality of grooves and arranged on a first imaginary plane perpendicular to the X direction.

[0010] An optical module according to one embodiment of the present invention includes the optical connector described above and an optical transmission element held by the holding portion of the optical connector.

[0011] The optical connector evaluation method according to one embodiment of the present invention evaluates the optical connector based on the positional relationship between each of the plurality of X-direction reference marks and each of the centers of the plurality of first optical surfaces.

[0012] The method for evaluating an optical connector according to one embodiment of the present invention evaluates the optical connector based on the positional relationship between the Y-direction reference mark and each of the centers of the plurality of first optical surfaces. [Effects of the Invention]

[0013] According to the present invention, an optical connector that can easily be evaluated for whether it has been manufactured as designed can be provided. Also, according to the present invention, an optical module having the optical connector can be provided. Also, according to the present invention, a method for evaluating the optical connector can be provided. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a cross-sectional view of an optical module according to an embodiment. [Figure 2] FIG. 2 is a perspective view of the optical connector according to the embodiment. [Figure 3] FIG. 3A is a plan view of the optical connector according to the embodiment, and FIG. 3B is a bottom view. [Figure 4] FIG. 4A is a front view of the optical connector according to the embodiment, FIG. 4B is a rear view, FIG. 4C is a left side view, and FIG. 4D is a right side view. [Figure 5] 5A is a cross-sectional view taken along line AA in FIG. 4B, FIG. 5B is a partially enlarged view of FIG. 4B, and FIG. 5C is a partially enlarged view of FIG. 4B. DETAILED DESCRIPTION OF THE INVENTION

[0015] (Optical module configuration) FIG. 1 is a cross-sectional view showing the configuration of an optical module 100 according to an embodiment of the present invention.

[0016] 1, an optical module 100 according to this embodiment includes a plurality of optical transmission elements 110 and an optical connector 120. The optical module 100 is used in a state in which the plurality of optical transmission elements 110 are connected to the optical connector 120.

[0017] The type of optical transmission element 110 is not particularly limited. Examples of the type of optical transmission element 110 include optical fiber and optical waveguide. The number of optical transmission elements 110 is not limited as long as there is more than one. The optical transmission element 110 is placed in the holding portion 130 of the optical connector 120. The optical transmission element 110 is held so that its end face faces the second surface 127. In this embodiment, the optical transmission element 110 is an optical fiber. The optical fiber may be a single-mode type or a multi-mode type.

[0018] (Optical connector configuration) Fig. 2 is a perspective view of optical connector 120 according to an embodiment of the present invention. Fig. 3A is a plan view of optical connector 120 according to an embodiment of the present invention, and Fig. 3B is a bottom view. Fig. 4A is a front view of optical connector 120 according to an embodiment of the present invention, Fig. 4B is a rear view, Fig. 4C is a left side view, and Fig. 4D is a right side view. Fig. 5A is a cross-sectional view taken along line AA in Fig. 4B, Fig. 5B is a partially enlarged view of Fig. 4B, and Fig. 5C is a partially enlarged view of Fig. 4B.

[0019] In the following description, the direction in which the first optical surfaces 121 are arranged as shown in FIG. 4A is referred to as the "X direction." The "X direction" is the direction along the bottom surface of the optical connector 120 when viewed from the front and rear (see FIGS. 4A and 4B). The direction perpendicular to the X direction is referred to as the "Y direction." The "Y direction" is the direction along the side surface (height direction) when viewed from the front and rear. The "Z direction" is the direction perpendicular to the "X direction" and "Y direction." The "Z direction" is the direction along the bottom surface of the optical connector 120 when viewed from the side.

[0020] 1 to 5C, the optical connector 120 is a substantially rectangular parallelepiped member. The optical connector 120 has a light-transmitting wall 122, a holding portion 130, a plurality of first optical surfaces 121, a plurality of X-direction reference marks 128, and a Y-direction reference mark 129.

[0021] 5A, the light-transmitting wall 122 includes a first surface 126 and a second surface 127 disposed on the rear side of the first surface 126. The light-transmitting wall 122 is a wall through which light from the optical transmission element 110 passes or through which light to the optical transmission element 110 passes (see FIG. 1). Specifically, in the light-transmitting wall 122, the light from the optical transmission element 110 passes through the second surface 127 and then the first surface 126, and the light to the optical transmission element 110 passes through the first surface 126 and then the second surface 127 (see FIG. 1).

[0022] 5A, first surface 126 is a surface of light-transmitting wall 122 that is located on the back side of second surface 127. For example, first surface 126 is a surface that faces a device such as another optical connector or an external device when optical connector 120 is connected to the device. First surface 126 preferably has first optical surface 121 for controlling the distribution of light that passes through.

[0023] First optical surface 121 can control light from or to optical transmission element 110. In this embodiment, first optical surface 121 is arranged along the X direction, as shown in Fig. 4A.

[0024] The first optical surface may be, for example, a curved surface that can refract light, and more specifically, may be, for example, a convex lens. The shape of the first optical surface is not particularly limited, but examples thereof include a circle and an ellipse.

[0025] In this embodiment, the multiple first optical surfaces 121 are arranged in a line along the X direction so as to correspond to the multiple optical transmission bodies 110, respectively. In this embodiment, the multiple first optical surfaces 121 are arranged so that no gap is formed between two adjacent first optical surfaces 121. However, the multiple first optical surfaces 121 may also be arranged spaced apart from one another.

[0026] The number of first optical surfaces 121 is not particularly limited as long as it is plural. In this embodiment, the number of first optical surfaces 121 is 16.

[0027] 5A, second surface 127 is a surface of light transmitting wall 122 that is located on the back side of first surface 126 and that directly faces the end face of optical transmission element 110 (see FIG. 1). In this embodiment, second surface 127 is in contact with the end face of optical transmission element 110. In this embodiment, second surface 127 is a flat surface that is parallel to the plane formed by the X direction and the Y direction and is longer in the X direction (see FIG. 4B).

[0028] 1, holding portion 130 is a portion that holds optical transmission element 110 so as to face second surface 127. In this embodiment, as shown in FIG. 3A, holding portion 130 has a plurality of grooves 131 for positioning optical transmission element 110, and optical transmission element 110 is arranged along grooves 131.

[0029] 3A, groove 131 is arranged to extend linearly in the direction opposite to first surface 126 and away from second surface 127. Specifically, in this embodiment, groove 131 is arranged to extend perpendicular to second surface 127 when optical connector 120 is viewed in plan.

[0030] The shape of groove 131 is not particularly limited as long as it can hold optical transmission element 110. Examples of groove 131 include a V-groove and a U-groove. Here, a "V-groove" refers to a groove formed by two flat surfaces, with a V-shaped cross section perpendicular to the direction in which the groove extends. The connection between the two flat surfaces may be chamfered (processed to round the corners). A "U-groove" refers to a groove formed by a single curved surface, with a circular arc-shaped cross section perpendicular to the direction in which the groove extends.

[0031] The number of grooves 131 is not particularly limited as long as it is plural, and may be, for example, the same as the number of first optical surfaces 121. In this embodiment, the number of grooves 131 is 16.

[0032] The multiple X-direction reference marks 128 are arranged corresponding to the multiple first optical surfaces 121 and the multiple grooves 131. The X-direction reference marks 128 are marks that serve as a reference when evaluating whether the corresponding grooves 131 have been manufactured so that the center of the optical transmission body 110 can be aligned with the corresponding first optical surfaces 121 as desired. As shown in FIGS. 5B and 5C , the X-direction reference marks 128 are each arranged on a first imaginary plane P1 that includes the valley lines of the grooves 131 and is perpendicular to the X direction. Note that the "valley lines" are lines that extend in the Z direction, connecting the deepest points of the grooves 131. Note that if the deepest points cannot be uniquely determined, the intersection of the line of symmetry (axis of symmetry) when the grooves 131 are viewed in cross section with the bottom of the grooves 131 is taken as the deepest point, and the "valley lines" are lines that extend in the Z direction, connecting the intersection points.

[0033] In the optical module 100, the center of the optical transmission body 110 placed in the groove 131 is expected to be on the first imaginary plane P1, and the center of the first optical surface 121 is also expected to be on the first imaginary plane P1 (see FIG. 1). In other words, one condition for ideally achieving optical coupling is that the two coincide in the X direction. Therefore, by evaluating the positional relationship between the X-direction reference mark 128, which is formed so as to be placed on the first imaginary plane P1, and the center of the first optical surface 121, it is possible to evaluate whether the optical connector 120 has been manufactured as desired.

[0034] The position of the X-direction reference mark 128 is not particularly limited as long as it is on the first imaginary plane P1. The X-direction reference mark 128 may be located, for example, on the first surface 126 or the second surface 127 on the first imaginary plane P1. In this embodiment, the X-direction reference mark 128 is located on the second surface 127 (see FIG. 5A ). When the optical connector of this embodiment is obtained by injection molding, by providing the X-direction reference mark 128 on the second surface 127, it is possible to process both the groove 131 and the X-direction reference mark 128 on a single piece for forming the groove 131. In other words, since both the groove 131 and the X-direction reference mark 128 can be formed without removing the piece attached to the processing stage, it is possible to provide the reference mark with high accuracy. If the X-direction reference mark 128 were formed on the first surface 126, the reference mark would be machined on a separate piece in a separate process from the groove machining. This would result in accumulated processing errors, mold assembly errors, and other factors, making it impossible to achieve the accuracy of this embodiment.

[0035] Furthermore, the X-direction reference mark 128 is preferably disposed on the first surface 126 or the second surface 127 so as not to interfere with light transmitted through the light-transmitting wall 122. In this embodiment, the X-direction reference mark 128 is disposed in a location other than the portion where the optical transmission body 110 is disposed. Furthermore, the X-direction reference mark 128 is preferably disposed on the first surface 126 or the second surface 127 so that the X-direction reference mark 128 and the corresponding first optical surface 121 can be seen at the same time when the optical connector 120 is viewed in the Z direction. More specifically, in this embodiment, as shown in FIG. 5B , the X-direction reference mark 128 is disposed on the second surface 127 above the position where the optical transmission body 110 is disposed.

[0036] The shape of the X-direction reference mark 128 is not particularly limited as long as the position of the first imaginary plane P1 is known. Examples of the shape of the X-direction reference mark 128 include a convex portion, a concave portion, a groove, etc. In this embodiment, as shown in Figures 5B and 5C, the X-direction reference mark 128 is a convex portion arranged on the second surface 127, has a tapered shape, and its tip coincides with the first imaginary plane P1.

[0037] The number of X-direction reference marks 128 is not particularly limited, but is usually the same as the number of first optical surfaces 121 or grooves 131. In this embodiment, the number of X-direction reference marks 128 is 16.

[0038] The Y-direction reference mark 129 is located on a second imaginary plane P2 that includes the center of the first optical surface 121 and is perpendicular to the second surface 127, in a portion other than the area in which the plurality of grooves 131 are arranged in the holding portion 130 when the second imaginary plane P2 is viewed in plan and perspective views (see FIGS. 5A and 5C). The Y-direction reference mark 129 is a mark that serves as a reference when evaluating whether the optical connector 120 has been manufactured as desired so that the optical transmission body 110 can be appropriately positioned in the Y direction.

[0039] Specifically, the center of the optical transmission body 110 placed in the groove 131 is expected to be on the second imaginary plane P2. That is, it is considered that one condition for ideally achieving optical coupling is that the center of the first optical surface 121 and the center of the optical transmission body 110 coincide in the Y direction. Therefore, the Y-direction reference mark 129 can be used to evaluate whether the optical connector 120 has been manufactured as desired.

[0040] The position and configuration of the Y-direction reference mark 129 are not particularly limited as long as it is disposed on the second imaginary plane P2 and serves as a reference in the Y direction. For example, the Y-direction reference mark 129 may be a convex portion, a concave portion, a groove, or the like disposed on the first surface 126 or the second surface 127. Alternatively, the Y-direction reference mark 129 may be a flat surface disposed on the holder 130, as shown in FIG. 5C . The Y-direction reference mark 129 is preferably disposed on the first surface 126, the second surface 127, or the holder 130 so that the Y-direction reference mark 129 and the corresponding first optical surface 121 are simultaneously visible when the optical connector 120 is viewed in the Z direction. In this embodiment, the Y-direction reference mark 129 is a flat surface disposed on the second imaginary plane P2 and is disposed in a portion of the holder 130 other than the area where the multiple grooves 131 are disposed. More specifically, the Y-direction reference mark 129 is disposed outside the area where the multiple grooves 131 are disposed on the holder 130. Even if the Y-direction reference mark 129 is flat as shown in FIG. 5C, the reference in the Y direction can be seen when viewed from the Z direction, and therefore it functions as a Y-direction reference mark.

[0041] The optical connector 120 according to this embodiment has the above-mentioned multiple X-direction reference marks 128, and may further optionally have the above-mentioned Y-direction reference mark 129.

[0042] (Evaluation method) A method for evaluating an optical connector having an X-direction reference mark 128 will be described below.

[0043] In the optical connector 120 as described above, the optical connector 120 can be evaluated based on the positional relationship between each of the multiple X-direction reference marks 128 and each of the centers of the multiple first optical surfaces 121.

[0044] Specifically, it is sufficient to evaluate the positional relationship between an extension line (a line coinciding with first imaginary plane P1) derived from X-direction reference mark 128 when viewed from the Z direction and the center of first optical surface 121. Ideally, the center of first optical surface 121 is located on this extension line. By evaluating the deviation from this ideal state, optical connector 120 can be evaluated.

[0045] A method for evaluating the optical connector 120 having the Y-direction reference mark 129 will be described below.

[0046] In the optical connector 120 as described above, the optical connector 120 can be evaluated based on the positional relationship between the Y-direction reference mark 129 and the center of the first optical surface 121.

[0047] Specifically, it is only necessary to evaluate the positional relationship between an extension line (a line coinciding with second imaginary plane P2) derived from Y-direction reference mark 129 when viewed from the Z direction and the center of first optical surface 121. Ideally, the center of first optical surface 121 is located on this extension line. By evaluating the deviation from this ideal state, optical connector 120 can be evaluated.

[0048] It is possible to combine the evaluation method using the X-direction reference mark 128 and the evaluation method using the Y-direction reference mark 129. In this case, the intersection of the extension line derived from the X-direction reference mark 128 and the extension line derived from the Y-direction reference mark 129 ideally coincides with the center of the first optical surface 121. Therefore, the optical connector 120 can be evaluated by evaluating the deviation between the intersection point and the center.

[0049] (effect) According to the optical connector 120 and its evaluation method of this embodiment, since it has multiple X-direction reference marks 128 and optionally Y-direction reference marks 129, it is possible to easily evaluate whether the optical connector 120 has been manufactured as designed. [Industrial Applicability]

[0050] The optical connector according to the present invention can be easily evaluated to determine whether it has been manufactured with high precision, and is therefore useful for carrying out optical communications using an optical transmission medium with high precision. [Explanation of symbols]

[0051] 100 Optical Modules 110 Optical transmission body 120 Optical Connector 121 1st optical surface 122 Light transmission wall 126 Page 1 127 2nd page 128 X-direction fiducial marks 129 Y-direction reference mark 130 Holding part 131 Groove P1 First virtual plane P2 Second virtual plane

Claims

1. a light-transmitting wall including a first surface and a second surface disposed on the rear side of the first surface; a holding portion for holding the optical transmission body so that an end surface of the optical transmission body faces the second surface; An optical connector having a plurality of first optical surfaces arranged along an X direction on the first surface; a plurality of grooves disposed in the retaining portion, the grooves extending in a direction opposite the first surface and away from the second surface; a plurality of X-direction reference marks; and each of the plurality of X-direction reference marks includes a valley line of any one of the plurality of grooves and is disposed on a first imaginary plane perpendicular to the X-direction; the X-direction reference mark is disposed on the second surface; Optical connector.

2. 2. The optical connector of claim 1, wherein a Y-direction reference mark is located on a second imaginary plane that includes the centers of the plurality of first optical surfaces and is perpendicular to the second surface, and when viewed in plan and through the second imaginary plane, is located in a portion of the holding portion other than the area in which the plurality of grooves are located.

3. The optical connector according to claim 1 or 2; an optical transmission element held by the holding portion of the optical connector; An optical module having:

4. 2. The method for evaluating an optical connector according to claim 1, evaluating the optical connector based on a positional relationship between each of the plurality of X-direction reference marks and each of the centers of the plurality of first optical surfaces; Evaluation methods for optical connectors.

5. 3. The optical connector evaluation method according to claim 2, evaluating the optical connector based on a positional relationship between the Y-direction reference mark and each of the centers of the plurality of first optical surfaces; Evaluation methods for optical connectors.

6. 3. The optical connector evaluation method according to claim 2, evaluating the optical connector based on a positional relationship between each of the plurality of X-direction reference marks and the Y-direction reference mark and each of the centers of the plurality of first optical surfaces; Evaluation methods for optical connectors.

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