This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2022-094423, filed on Jun. 10, 2022, the disclosure of which is incorporated herein in its entirety by reference.
The present disclosure relates to an optical connection device and the like.
An optical connection device such as an optical connector and an optical adapter is used as an interface between an optical transmission device and an optical fiber. A general optical transmission device includes an optical receptacle on a side surface vertical to a horizontal plane (for example, a front plate of the device). An optical connector attached to a distal end of the optical fiber is connected to the optical receptacle, and thus the optical fiber is connected to the optical transmission device via the optical connector and the optical receptacle.
In relation to the present disclosure, Patent Literature (PTL) 1 describes an optical device including a mirror for changing a direction of light propagated between an optical fiber and a grating (diffraction grating). Further, Patent Literature 2 describes a technique of forming a three-dimensional curved optical waveguide.
In general, an optical fiber including an optical connector attached to one end thereof is also referred to as a pig-tail cord. The pig-tail cord is a type of an optical connection device. The pig-tail cord has a structure in which a core wire of the optical fiber is inserted into a center of a ferrule of the optical connector. Thus, the optical fiber of the pig-tail cord connected to an optical receptacle installed on a vertical surface is oriented in a horizontal direction in the vicinity of the optical connector in a manner similar to the ferrule. Therefore, when the optical fiber of the pig-tail cord into which the optical connector is inserted in the horizontal direction is oriented in a vertical direction (for example, downward toward a horizontal plane), an accommodation space for the optical fiber, which is equivalent to a bending radius of the optical fiber, is required in the horizontal direction. A minimum bending radius allowed in a general quartz optical fiber is approximately 30 mm. The accommodation space for the optical fiber is occupied with the optical fiber, and hence it is required to secure a floor area for the accommodation space for the optical fiber at a time of connecting the general pig-tail cord to an optical transmission device. In other words, the general pig-tail cord has a problem that a space required for handling is large due to a restriction of the bending radius of the optical fiber. Thus, there is a problem that it is difficult to reduce a size of the optical connector that enables input and output of light in a direction different from an optical axis of the ferrule (hereinafter, referred to as an “optical angle connector”).
An exemplary object of the disclosure is to provide a technique for achieving a small-sized optical angle connector.
An optical connection device according to the present disclosure includes:
A manufacturing method of an optical connection device according to the present disclosure includes a procedure of
Exemplary features and advantages of the present disclosure will become apparent from the following detailed description when taken with the accompanying drawings in which:
Next, a detailed explanation will be given for a first example embodiment with reference to the drawings.
In each of the example embodiments, elements that are previously described are denoted with the identical names and the identical reference symbols, and overlapping description therefor is omitted as appropriate. Further, the drawings are schematic diagrams for describing the example embodiments, and description such as a cross-sectional view is simplified.
The optical waveguide module 130 is an optical waveguide element including a silicon substrate, and can be connected optically to another optical component at both the ends of the optical waveguide.
The optical fiber 120 is a general quartz glass optical fiber, and is a single-mode optical fiber (SMF) having a core diameter of approximately 9 to 10 μm or a multi-mode optical fiber (MMF) having a core diameter of approximately 50 to 60 μm, for example.
An end surface of the ferrule 110 to which the optical waveguide module 130 is not connected can be connected optically to a ferrule of another optical connector. In other words, the ferrule 110 and the end surface of the other optical connector abut against each other, and thus the other optical connector and the optical fiber 120 can be connected optically to each other. An optical adapter or a split sleeve may be used for connection between the ferrule 110 and the other optical connector.
For example, the optical waveguide module 130 having a function of bending the light propagation direction at 90 degrees can be achieved by forming the core 131 having an arc portion with a bending radius r of 50 μm or smaller. In this case, the optical waveguide module 130 may be a rectangular parallelepiped shape having a side of 1 mm or smaller. Further, each of the sides a and b and the thickness d of the optical waveguide module 130 described above can sufficiently be reduced to be smaller than a diameter D (for example, 1.25 mm) of a ferrule of an LC connector or an MU connector in general. Thus, the optical waveguide module 130 is used, and thus the light propagation direction can be changed at a curvature much smaller than a bending radius of an optical fiber, which is generally required to be several tens of millimeters or larger. In other words, the optical waveguide module 130 is capable of connecting the ferrule 110 having the first optical axis and the optical fiber 120 having the second optical axis different from the first optical axis, to each other. Therefore, in the optical connection device 100, the optical fiber 120 can be connected from the vicinity of the ferrule 110 to the direction different from the optical axis of the ferrule 110 (downward at the right angles in
The connection portion between the ferrule 110 and the optical waveguide module 130, and the connection portion between the optical fiber 120 and the optical waveguide module 130 may each be fixed after optical axis adjustment therebetween. An adhesive formed of a thermosetting resin or an ultraviolet light curable resin as a material is used for fixation of the connection portions, for example.
A lens may be included in at least one of a first position and a second position, where the first position is between the ferrule 110 and the optical waveguide module 130, and the second position is between the optical fiber 120 and the optical waveguide module 130. Even when a numerical aperture (NA) of the ferrule 110 or the optical fiber 120 and a numerical aperture of the core 131 are different from each other, for example, an increase of a connection loss therebetween can be suppressed by using the lens.
The optical connection device described in
With the optical connection device 100 thus configured, a small-sized optical angle connector can be achieved. The reason for this is because the bending portion of light can be reduced in size by using the silicon optical waveguide for the bending portion of the optical transmission path.
Further, in the silicon optical waveguide module (130), one end of the silicon optical waveguide and the first optical axis may be fixed to each other under an optically coupled state. Further, the other end of the silicon optical waveguide and the second optical axis may be fixed to each other under an optically coupled state.
A part of the core 231 is formed to contact with a silicon substrate 233. Further, the core 231 is curved with the radius r in a direction vertical to the silicon substrate 233 from the middle of the core 231 in the longitudinal direction. A manufacturing method of the curved core described above is described in PTL 2. The clad 232 may be formed in such a way to cover the core 231, including a part thereof away from the silicon substrate 233. The core 231 thus formed is also capable of bending a propagation direction of light with a relatively low loss even when the radius r has a curvature of several tens of micrometers.
In
In the following example embodiments and modification examples thereof, description is made on optical connection devices in which the optical waveguide module 130 exemplified in
Further, the means for changing the propagation direction of the incident light is not limited to the curved core. As a technique of changing a light propagation direction by using a small-sized silicon optical waveguide, there has been known a technique in which a coupler using a grating (grating coupler) or a mirror is used. An optical function module using such techniques may be used in place of the optical waveguide modules 130 and 230.
The optical waveguide module 130 is formed of silicon as a material, and hence one side thereof may be smaller than the diameter D of the ferrule 110. Thus, the outer shape dimension of the casing 140 is sufficient enough to cover the ferrule 110. For example, when the diameter of the ferrule 110 is 2 mm, the casing 140 may be formed into a cube having a side of 3 mm. In other words, with the optical connection device 100A, a small-sized optical angle connector can also be achieved.
With this structure, the optical connection device 100A can reduce a risk of damage or optical axis deviation due to an external force because the ferrule 110, the optical fiber 120, and the optical waveguide module 130 can firmly be integrated. As a result, with the optical connection device 100A, a small-sized optical angle connector can be achieved, and reliability of the optical connection device 100 can be improved at the same time.
The optical connection device 100B further includes a knob 150. A screw 151 is provided at the distal end of the knob 150. The screw 151 is engaged with a screw of an optical device (for example, an optical receptor) connected to the optical connection device 100B. The structure for connecting the optical connection device 100B to another optical device is not limited to a screw. For example, the optical connection device 100B may have a connecting structure provided to a general snap-on optical connector.
With this structure, the optical connection device 100B can firmly be connected to another optical device, and hence occurrence of a connection failure due to an external force after connection can be suppressed. As a result, with the optical connection device 100B, a small-sized optical angle connector having high connection reliability can be achieved.
With this structure, in the optical connection device 100C, for example, the two optical receptacles and the two optical fibers 120 that are arranged at a small interval can be connected to each other, and the optical fibers 120 can be arranged in the direction at the right angles with respect to the ferrules 110. In other words, in the optical connection device 100C, small-sized optical angle connectors can be arranged at high density.
The optical waveguide module 130A is modification example of the optical waveguide module 130. Similarly to the optical waveguide module 130, the optical waveguide module 130A is an optical waveguide element formed of silicon as a material, and can optically be connected to another optical component at both the ends of the optical waveguide. The optical waveguide module 130A includes a core 131A having two ends. The core 131A has a structure for bending the light propagation direction by 45 degrees by the curved line of the radius r (0=45 degrees in
Similarly to the optical connection device 100, the connection portion between the ferrule 110 and the optical waveguide module 130A and the connection portion between the optical fiber 120 and the optical waveguide module 130A are both fixed after optical axis adjustment. An adhesive formed of, for example, a thermosetting resin or an ultraviolet light curable resin as a material is used for such fixing.
In
With this structure, the optical connection device 101A can reduce a risk of damage or optical axis deviation due to an external force because the ferrule 110, the optical fiber 120, and the optical waveguide module 130A can firmly be integrated. As a result, the optical connection device 101A can improve reliability of the optical connection device 101. Further, with the optical connection device IOTA, a small-sized optical angle connector can also be achieved.
Further, similarly to the optical connection device 100B in the second modification example of the first example embodiment, the optical connection device IOTA may also has a configuration for engagement with another optical device (for example, an optical receptacle).
In the optical connection device 101, the ferrule 111 can be connected in the direction at the angle of 90 degrees with respect to the optical axis of the ferrule 110. The sizes of the two sides a and b of the optical waveguide module 130B may be larger than those of the optical waveguide module 130 for direct connection of the adjacent ferrules 110 and 111. In
The connection portion between the ferrule 110 and the optical waveguide module 130B and the connection portion between the ferrule 111 and the optical waveguide module 130B are both fixed after optical axis adjustment. An adhesive formed of a thermosetting resin or an ultraviolet light curable resin as a material is used for such fixation, for example. With the optical connection device 102 thus configured, a small-sized optical angle connector can also be achieved.
Similarly to the example embodiments described above, the inside of the casing 140B is filled with the filler 141. The materials of the casing 140B and the filler 141 are not particularly limited. For example, the casing 140B is formed of metal or plastic. The filler 141 is, for example, a thermosetting resin or an ultraviolet light curable resin. The casing 140B may be attached in such a way to cover the optical waveguide module 130B after optical axis adjustment between the optical waveguide module 130B and the ferrules 110 and 111, and the inside of the casing 140B may be filled with the adhesive as the filler 141.
With this structure, the optical connection device 102A can reduce a risk of damage or optical axis deviation due to an external force because the ferrules 110 and 111 and the optical waveguide module 130B can firmly be integrated. As a result, the optical connection device 102A can improve reliability of the optical connection device 102. Further, in the optical connection device 102A, the split sleeve 114 facilitates connection to the ferrule of the other optical connector. Further, with the optical connection device 102A, a small-sized optical angle connector can also be achieved.
The optical connection device 102A-1 and the optical connection device 102A-2 are rotatable about the center axis of the split sleeve 114. Therefore, in the optical connection device 102B, the angle formed between the ferrule 111 of the optical connection device 102A-1 and the ferrule 110 of the optical connection device 102A-2 can be changed.
Alternatively, the optical axis of the ferrule 111 of the optical connection device 102A-1 and the optical axis of the ferrule 110 of the optical connection device 102A-2 may not be on the same linear line, and may be parallel to each other. With the optical connection device 102B thus configured, a small-sized optical angle connector capable of changing an optical axis on a plane to an optical axis on a different plane (in other words, capable of performing three-dimensional change) can be achieved. Further, the optical connection devices 102A-1 and 102A-2 are connected to each other, and thus the optical connection device 102B may be referred to as a composite optical connection device. Here, the optical connection device 102A-1 may be referred to as a first optical connection device, and the optical connection device 102A-2 may be referred to as a second optical connection device.
In the optical connection device 103 thus configured, the two ferrules 110 are connected by the optical fiber 120 having flexibility. Similarly to the optical connection device 102B, with the optical connection device 103, a small-sized optical angle connector capable of changing an optical axis on a plane to an optical axis on a different plane can be achieved. Further, as compared to the optical connection device 102B according to the third example embodiment, the optical connection device 103 exerts an effect that the angle and the positional relationship between the two ferrules 110 can be set freely within a range of the bending amount allowed for the optical fiber 120.
The communication device 600 includes optical interfaces 611, 612, 621, 622, 631, and 632 as interfaces to the outside. Those interfaces are optical receptacles included on a front surface or a rear surface of the communication device 600.
The first interface circuit 610 converts an optical signal, which is input from the first network 510 to the optical interface 611, in such a way to be processed in the communication device 600, and outputs the converted optical signal to the optical interface 612. The optical amplification circuit 620 amplifies the light input from the optical interface 621, and outputs the amplified light to the optical interface 622. The second interface circuit 630 converts an optical signal, which is input to the optical interface 631, in such a way to be transmitted via the second network 520, and outputs the converted optical signal to the optical interface 632. The first interface circuit and the second interface circuit adjust intensity or a spectrum of the input light by using an optical attenuator or an optical filter.
According to the specification of the communication system 500, the optical amplification circuit 620 may be used or may not be used in some cases. When the optical amplification circuit 620 is not used, the optical interface 612 is directly connected to the optical interface 631 being the second interface circuit. When the optical amplification circuit 620 is used, the optical amplification circuit 620 amplifies an output of the first interface circuit 610, and outputs the resultant to the second interface circuit 630. In this case, by optically connecting the optical interfaces 612 and 621 to each other and optically connecting the optical interfaces 622 and 631 to each other, the communication device 600 is capable of amplifying the light input from the first network 510 and outputting the amplified light to the second network 520.
In general, an optical fiber (patch cord, patch cable) including optical connectors at both the ends is used for connection between the optical interfaces 612 and 621 and connection between the optical interfaces 622 and 631. The optical interfaces 612, 621, 622, and 631 are optical receptacles installed on the side surface of the communication device 600. Thus, when the general patch cord is connected to those optical receptacles, a restriction of a minimum bending radius of the optical fiber increases a floor area required for installation of the communication device 600. Here, the interval between the ferrules of the optical connection device 104 or 104A can match with the interval between the optical interface 612 and the optical interface 621. With this configuration, the optical connection device 104 or 104A can be inserted into the optical receptacle of the optical interfaces 612 and 621. Similarly, the optical interfaces 622 and 631 can be connected to each other through use of the optical connection device 104 or 104A.
The optical connection device 104 is used for connection between the optical interfaces provided to the communication device 600, and thus the two optical interfaces can be connected to each other in an occupied area smaller than that in a case in which a general optical fiber provided with a connector. In other words, with the optical connection device 104, a small-sized optical angle connector can be achieved, and hence an accommodation efficiency of the communication device 600 in a station building can be improved.
When the interval between the two ferrules and the interval between the two optical receptacles match with each other, the two optical interfaces may be connected to each other by using the optical connection device 102B or the optical connection device 103, in place of the optical connection device 104.
The present disclosure provides an optical connection device, a composite optical connection device, and a manufacturing method of an optical connection device that achieve a small-sized optical angle connector.
The example embodiments of the disclosure of the present application may be described as in the following supplementary notes, but are not limited thereto.
An optical connection device including:
The optical connection device according to Supplementary Note 1, wherein
The optical connection device according to Supplementary Note 2, further including
The optical connection device according to any one of Supplementary Notes 1 to 3, wherein
The optical connection device according to any one of Supplementary Notes 1 to 3, wherein the first optical axis and the second optical axis are not on the same linear line, and are parallel to each other.
The optical connection device according to any one of Supplementary Notes 1 to 3, wherein
The optical connection device according to any one of Supplementary Notes 1 to 3, wherein
A composite optical connection device including a first optical connection device and a second optical connection device each being the optical connection device according to any one of Supplementary Notes 1 to 3, wherein
The composite optical connection device according to Supplementary Note 8, wherein
A manufacturing method of an optical connection device, including connecting, to each one of a first optical component having a first optical axis and a second optical component having a second optical axis different from the first optical axis, a silicon optical waveguide module including a silicon optical waveguide having a bending shape for changing a direction of the first optical axis to a direction of the second optical axis.
The manufacturing method of an optical connection device according to Supplementary Note 10, comprising:
The previous description of embodiments is provided to enable a person skilled in the art to make and use the present disclosure. Moreover, various modifications to these example embodiments will be readily apparent to those skilled in the art, and the generic principles and specific examples defined herein may be applied to other embodiments without the use of inventive faculty. Therefore, the present disclosure is not intended to be limited to the example embodiments described herein but is to be accorded the widest scope as defined by the limitations of the claims and equivalents.
Further, it is noted that the inventor's intent is to retain all equivalents of the claimed disclosure even if the claims are amended during prosecution.
Further, the configurations described in the example embodiments are not necessarily exclusive from one another. The actions and the effects of the present disclosure may be achieved by a configuration acquired by combining all or some of the example embodiments described above.
Number | Date | Country | Kind |
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2022-094423 | Jun 2022 | JP | national |