JP4965699B2 - Optical connection structure, optoelectric module using the same, and optical waveguide unit - Google Patents

Description

The present invention relates to an optical connection structure such as an optical connector, the optical electric module relates optical waveguide unit, to a technique for connecting an optical waveguide and an optical fiber.

  The spread of broadband is remarkable, and the capacity of routers that handle increasing data is increasing. In current device mounting using electrical transmission, optical mounting is indispensable for realizing a large-capacity router due to the number of connector terminals on the switch board where signals from line cards are concentrated and the limit of transmission speed in the backboard. ing. Under such circumstances, optical mounting such as optical modules that transmit and receive optical signals, optical wiring boards that transmit optical signals, optical connectors that connect optical modules and optical wiring boards, and optical wiring boards electrically and mechanically Development of parts is underway (see, for example, Patent Document 1).

  An optical connector of an optical mounting component generally includes an optical fiber having a core layer and a cladding layer covering the core layer, and an optical waveguide having a core layer and a cladding layer covering the core layer. The end portions of both core layers are connected to each other. Of these, the optical fiber generally has a circular cross section. The core layer of the optical waveguide is generally formed in a rectangular cross section.

JP 2004-62064 A

  As described above, the core layer of the optical fiber constituting the optical connector has a circular shape, and the core layer of the optical waveguide has a rectangular shape. When connected, light coupling loss occurs at the connection. Therefore, there is a demand for an optical connector that can suppress the coupling loss of light at such a connection portion.

An object of the present invention, the optical connection structure can suppress the coupling loss of the optical contact and opto-electric module is to provide an optical waveguide unit.

The present invention includes a plurality of first optical fibers;
A first optical waveguide having a plurality of core layers connected to each of the plurality of first optical fibers, into which light transmitted from the first optical fiber is incident;
A plurality of second optical fibers;
A plurality of core layers connected to each of the plurality of second optical fibers, and a second optical waveguide for transmitting light emitted to the second optical fiber,
In the connecting portion between the first optical fiber and the first optical waveguide, the core layer of the first optical fiber has an outer edge of the cross section disposed inside the outer edge of the cross section of the core layer of the first optical waveguide. ,
In the connection portion between the second optical fiber and the second optical waveguide, the core layer of the second optical waveguide has an outer edge of the cross section disposed inside the outer edge of the cross section of the core layer of the second optical fiber. ,
The cross-sectional areas of the core layers of the first optical fiber and the second optical fiber are substantially equal,
The core layer of the first optical waveguide has a larger cross-sectional area than the core layer of the second optical waveguide,
The distance between centroids of adjacent core layers of the first optical waveguide, the distance between centroids of adjacent core layers of the second optical waveguide, and the core layer and the second of adjacent first optical waveguides centroid distance between the core layer of the optical waveguide substantially V equal is,
The first optical fiber and the second optical fiber are accommodated in the same optical fiber connector;
The optical connection structure is characterized in that the first optical waveguide and the second optical waveguide are accommodated in the same optical waveguide connector .

Further, the present invention provides the above optical connection structure,
The optical connection structure is characterized in that the first optical waveguide and the second optical waveguide are integrated.

Further, the present invention provides the above optical connection structure,
An optical connection structure characterized in that the centroids of the core layers of the first and second optical fibers and the centroids of the core layers of the first and second optical waveguides are positioned substantially in a straight line. is there.

Further, the present invention provides the above optical connection structure,
An outer edge of the core layer of the first optical fiber at a connection portion between the first optical fiber and the first optical waveguide is inscribed with respect to an outer edge of the core layer of the first optical waveguide. It is an optical connection structure.

Further, the present invention provides the above optical connection structure,
The outer edge of the core layer of the second optical fiber at the connection portion between the second optical fiber and the second optical waveguide is circumscribed with respect to the outer edge of the core layer of the second optical waveguide. It is an optical connection structure.

The present invention also provides an optical fiber,
An optical waveguide connected to the optical fiber for transmitting the light emitted to the optical fiber, and
In the connecting portion between the optical fiber and the optical waveguide, the core layer of the optical waveguide has an outer edge of the cross section disposed inside the outer edge of the cross section of the core layer of the optical fiber. Connection structure.

Further, the present invention has a plurality of core layers connected to the plurality of first optical fibers and connected to each of the plurality of first optical fibers, and light transmitted from the first optical fibers is incident thereon. A plurality of first optical waveguides connected to a plurality of second optical fibers each having a core layer having a cross-sectional area substantially equal to the core layer of the first optical fiber, and connected to each of the plurality of second optical fibers; In an optical waveguide unit having a core layer and having a second optical waveguide for transmitting light emitted to the second optical fiber,
The first optical waveguide has a circular shape in which the outer edge is located inside the outer edge in the cross section of the core layer of the first optical waveguide and outside the outer edge in the cross section of the core layer of the second optical waveguide. A cross section of the core layer is made larger than a cross section of the core layer of the second optical waveguide;
The distance between centroids of adjacent core layers of the first optical waveguide, the distance between centroids of adjacent core layers of the second optical waveguide, and the core layer and the second of adjacent first optical waveguides centroid distance between the core layer of the optical waveguide substantially V equal is,
In the optical waveguide unit, the first optical waveguide and the second optical waveguide are accommodated in the same optical waveguide connector .

Further, the present invention provides the optical waveguide unit,
An optical waveguide unit in which the first optical waveguide and the second optical waveguide are integrated.

Further, the present invention provides the optical waveguide unit,
The cross section of the core layer of the first optical waveguide and the second optical waveguide has a rectangular shape,
About the core layer of the first optical waveguide, the length of the side parallel to the first direction is Lw1, the length of the side parallel to the second direction orthogonal to the first direction is Lh1,
For the core layer of the second optical waveguide, the length of the side parallel to the first direction is Lw2, the length of the side parallel to the second direction is Lh2,
For the circle, if the diameter is defined as φ,
Lw1 ≧ φ, Lh1 ≧ φ, Lw2 ≦ φ / √2, Lh2 ≦ φ / √2
An optical waveguide unit characterized by satisfying all of the following relational expressions.

Further, the present invention provides the optical waveguide unit,
The cross sections of the core layers of the first optical waveguide and the second optical waveguide are square,
When the length of the side of the core layer of the first optical waveguide is defined as Lw1, and the length of the side of the core layer of the second optical waveguide is defined as Lw2,
Lw1 / Lw2 ≧ √2
An optical waveguide unit that satisfies the following relational expression:

Further, the present invention provides the optical waveguide unit,
The optical waveguide unit is characterized in that the centroid of the core layer of the first optical waveguide and the centroid of the core layer of the second optical waveguide are positioned substantially in a straight line.

The present invention includes: the optical connection structure,
A first photoelectric conversion member for converting the light transmitted by the optical connection structure to an electrical input signal,
An electric circuit for performing processing based on the converted electric input signal;
Converts the electrical output signal outputted by the processing of the electrical circuit into light, a photoelectric module including a second photoelectric conversion member for transmitting light said converted into the optical connection structure, a.

  According to the present invention, in the connection portion between the first optical fiber and the first optical waveguide into which the light transmitted from the first optical fiber is incident, the core layer of the first optical fiber has an outer edge of its cross section. Is disposed inside the outer edge of the cross section of the core layer of the first optical waveguide, so that most of the light propagating through the first optical fiber is good for the first optical waveguide without leaking from the connection portion. Will be transmitted. Therefore, the coupling loss of light at the connection portion between the first optical fiber and the first optical waveguide is satisfactorily prevented.

Further , in the connecting portion between the second optical fiber and the second optical waveguide for transmitting the light emitted to the second optical fiber, the core layer of the second optical waveguide has an outer edge in a cross section thereof. Since it is disposed inside the outer edge of the cross section of the core layer of the two optical fibers, most of the light propagating through the second optical waveguide is satisfactorily transmitted to the second optical fiber without leaking from the connecting portion. The Rukoto. Therefore, the coupling loss of light at the connecting portion between the second optical fiber and the second optical waveguide is satisfactorily prevented.

As a result, by realizing an optical connection structure combining the first optical fiber and the first optical waveguide, and the second optical fiber and the second optical waveguide, the first optical fiber → the first optical waveguide, In addition, there is a synergistic effect that bidirectional optical communication between the second optical waveguide and the second optical fiber can be performed in a state where the coupling loss of light is extremely small.
In addition, about the magnitude relationship of the cross-sectional area of each core layer of a 1st optical fiber and a 2nd optical fiber, and a 1st optical waveguide and a 2nd optical waveguide, about the core layer of the said 1st and said 2nd optical fiber If the cross-sectional areas are substantially equal and the cross-sectional area of the core layer of the first optical waveguide is larger than the cross-sectional area of the core layer of the second optical waveguide, it is not necessary to prepare a plurality of types of optical fibers. Productivity of the optical connector having the above-described optical connection structure is further improved.
When the cross-sectional areas of the core layers of the first and second optical fibers are substantially aligned, the core layer of the first optical waveguide is such that a circle with the outer edge located outside the outer edge of the cross-section of the core layer of the optical waveguide exists. The cross section of the core layer of the second optical waveguide may be made larger than the cross section of the core layer of the second optical waveguide, so that the outer edge of the cross section of the core layer of the first optical fiber is the core layer of the first optical waveguide. The core layer of the second optical waveguide is disposed inside the outer edge of the second optical fiber, and the outer edge of the cross section is disposed inside the outer edge of the core layer of the second optical fiber. It is easy to understand if the above circle is replaced with a cross section of the core layer of the optical fiber.
Also, the centroid spacing between adjacent core layers of the first optical waveguide, the centroid spacing between adjacent core layers of the second optical waveguide, and the core layer and second optical waveguide of the adjacent first optical waveguide. The distance between the centroids and the core layer is substantially equal.

Furthermore, the pre-Symbol first and second optical fiber in the same optical fiber connector, said first and second optical waveguides of the same optical waveguide connector, by accommodating each a single optical connection structure as described above This can be realized with an optical connector, and the number of parts can be reduced. Further, by integrating the first and second optical waveguides, the configuration of the optical connection structure can be further simplified.

  In addition, if the centroids of the core layers of the first and second optical fibers and the centroids of the core layers of the first and second optical waveguides are positioned on a substantially straight line, the first and second The height position of the optical fiber and the height positions of the first and second optical waveguides can be substantially aligned. As a result, the connection between the first optical fiber and the first optical waveguide and the connection between the second optical fiber and the second optical waveguide are facilitated, and the productivity of the optical connector having the optical connection structure of the present invention is improved. .

  In addition, according to the present invention, the size of the first optical waveguide is adjusted more than necessary so that the outer edge of the core layer of the first optical fiber is inscribed with the outer edge of the core layer of the first optical waveguide. In addition, it is not necessary to enlarge the first optical waveguide. As a result, there is an advantage that the productivity of the first optical waveguide can be improved.

  Further, according to the present invention, the outer edge of the core layer of the second optical fiber is circumscribed with respect to the outer edge of the core layer of the second optical waveguide, so that it is not necessary to make the second optical waveguide smaller than necessary. Positioning of the core layer of the two optical fibers and the core layer of the second optical waveguide is facilitated.

Here, regarding the cross-sectional shape (rectangular shape) of the core layer of the first optical waveguide, the lengths of two orthogonal sides are defined as Lw1 and Lh1, respectively, and the cross-sectional shape (rectangular shape) of the core layer of the second optical waveguide is defined. , Defining the length of two orthogonal sides as Lw2 and Lh2, respectively, and defining the diameter of the circle as φ,
Lw1 ≧ φ, Lh1 ≧ φ, Lw2 ≦ φ / √2, Lh2 ≦ φ / √2
If the first and second optical waveguides satisfying all the relational expressions are prepared, an optical connection structure with a small coupling loss of light when connected to an optical fiber can be realized.

When the cross-sectional shape of the core layer of the first and second optical waveguides is square, the length of the side of the core layer of the first optical waveguide is Lw1, and the length of the side of the core of the second optical waveguide is If we define Lw2,
Lw1 / Lw2 ≧ √2
If the first and second optical waveguides satisfying the above relational expression are prepared, an optical connection structure with less optical coupling loss can be realized by appropriately adjusting the cross-sectional area of the core layer of the optical fiber.

By configuring the photoelectric module incorporates fewer optical connection structure of the optical coupling loss as described above, by precise information than ever is input by the optical connector, the electrical circuit such as a driver IC More accurate processing than before is performed, and the processed information is transmitted to the outside more accurately than before by the optical connector. Therefore, for example, by incorporating a photoelectric module into a device that requires high precision and accurate processing (for example, a computer device such as a super computer, a workstation, or a server, or a communication connection device such as a router) The performance can be greatly improved.

It is a perspective view of the optical connector 1 with which the 1st ferrule (optical waveguide connector) was connected to the 2nd ferrule (fiber connector). It is a top view of the optical connector 1 of FIG. It is a side view (III-III line end view of FIG. 2) showing the principal part of a 1st ferrule (optical waveguide connector). FIG. 4A is an exploded side view of a first ferrule (optical waveguide connector), FIG. 4A is a side view of the fixing member 7, and FIG. 4B is a side view of the first and second optical waveguides 6a and 6b. FIG. 4C is a side view of the ferrule body 5. It is an end view (VV line end view of Drawing 2) showing the important section of the 2nd ferrule (optical fiber connector). FIG. 6A is a perspective view showing the optical connector according to the first embodiment of the present invention, FIG. 6A is a perspective view showing the relationship between the first optical waveguide and the core layer of the first optical fiber, and FIG. It is a perspective view showing the relationship between a 2nd optical waveguide and the core layer of a 2nd optical fiber. 4 is a flowchart showing a manufacturing method of the optical connector 1 in stages. It is a flowchart showing the manufacturing method of a 1st ferrule (optical waveguide connector) in steps. It is sectional drawing showing the optoelectric module which mounts the optical connector 1 shown in FIG. It is a perspective view which shows a pair of optical connector 1a, 1b which concerns on the reference example of this invention. It is a top view which shows the optoelectric module which mounts the optical connectors 1a and 1b of FIG. It is sectional drawing of the optoelectric module of FIG.

(First embodiment)
In this embodiment, the optical connection structure according to the present invention is realized by a single optical connector.

<Overall structure of optical connector 1>
FIG. 1 is a perspective view showing a state in which an optical waveguide connector is connected to an optical fiber connector.

  The optical connector 1 according to the present embodiment is generally inserted into both the first ferrule 2 as an optical waveguide connector, the second ferrule 3 as an optical fiber connector, and both the first ferrule 2 and the second ferrule 3. The first and second ferrules 2 and 3 are detachably connected to each other at their end faces.

  The longitudinal direction of the guide pins is defined as the x direction, the guide pin arrangement direction is defined as the y direction, and the direction perpendicular to the x and y directions (ferrule thickness direction) is defined as the z direction.

<Structure of the first and second ferrules>
<< Structure of the first ferrule >>
2 is a plan view of the optical connector 1. FIG. 2A is a plan view showing a state in which the optical waveguide connector (first ferrule) is connected to the optical fiber connector (second ferrule). FIG. ) Is a plan view showing a state in which the optical waveguide connector (first ferrule) is detached from the optical fiber connector (second ferrule). FIG. 3 is an end view (end view taken along line III-III in FIG. 2) showing a main part of the optical waveguide connector (first ferrule). 4 is an exploded end view of the optical waveguide connector. FIG. 4A is an end view of the fixing member 7, FIG. 4B is an end view of the optical waveguide body 6, and FIG. 3 is an end view of the ferrule body 5. FIG.

  The first ferrule 2 includes a ferrule body 5 having a recess 12 and a pair of guide holes 5a and 5b, first and second optical waveguides 6a and 6b fitted in the recess 12 of the ferrule body 5, and the first and second A fixing member 7 for fixing the second optical waveguides 6a and 6b to the ferrule body 5 is provided.

The ferrule body 5 is made of, for example, epoxy resin, PPS (PPS: Polyphenylene
It is made of a material in which inorganic particles such as silica particles are contained in a synthetic resin such as a sulfied resin.

  As shown in FIG. 4 (c), the ferrule body 5 is formed to be concave in the yz cross section, and first and second optical waveguides 6a of the first ferrule 2 to be described later are formed at both ends in the y direction. 6b and the first and second optical fibers 8 and 9 of the second ferrule 3 are formed with guide holes 5a and 5b into which a pair of guide pins 4a and 4b are inserted. Each guide hole 5a, 5b is provided along the x direction. The guide holes 5a and 5b may be formed so as to penetrate the ferrule body 5. In this case, there is an effect that the processing accuracy is improved when the ferrule body 5 is formed by the injection molding method.

  Further, the first and second optical waveguides 6a and 6b fitted into the recesses 12 of the ferrule body 5 have a large number of core layers 10a and 10b, and a plurality of core layers 10a and 10a, respectively, as shown in FIG. A first optical waveguide 6a having clad layers 11a and 11b covering 10b, and metal layers 14a and 14b made of copper foil which are deposited on the principal surfaces of the clad layers 11a and 11b and function as reinforcing materials. In addition, the end faces of the second optical waveguide 6b are provided in close contact with each other. The clad layers 11a and 11b have a multilayer structure (not shown).

  The core layers 10a and 10b are made of a material having a smaller refractive index than the cladding layers 11a and 11b. For example, as the core layers 10a and 10b, materials such as epoxy resin, acrylic resin, silicon resin, and quartz are usually used. On the other hand, as the cladding layers 11a and 11b, a material that is the same kind of material as the core layer 10a and whose refractive index is changed by changing the mixing ratio of a plurality of components constituting the raw material is used.

  Light transmitted from the first optical fiber 8 of the second ferrule 3 enters the core layer 10a of the first optical waveguide 6a. Light transmitted to the second optical fiber 9 of the second ferrule 3 is incident on the core layer 10b of the second optical waveguide 6b.

  Although the core layer 10a of the first optical waveguide 6a will be described in detail later, the cross-sectional area is set larger than that of the core layer 10b of the second optical waveguide 6b.

  The core layers 10a of the first optical waveguide 6a are arranged at a substantially constant pitch δ1 (the centroid interval between adjacent core layers 10a). The core layers 10b of the second optical waveguide 6b are arranged at a substantially constant pitch δ2 (the centroid interval between adjacent core layers 10b). The pitch δ1 of the core layer 10a and the pitch δ2 of the core layer 10b are preferably set to be approximately equal (for example, it is preferable to satisfy | δ1-δ2 | ≦ 1 μm). By setting in this way, the pitch of the first and second optical fibers arranged in the second ferrule, which will be described later, can be made substantially constant, and the productivity of the second ferrule, and hence the productivity of the optical connector can be improved. improves. The core layer 10a and the core layer 10b are adjacent to each other at the boundary portion between the first optical waveguide 6a and the second optical waveguide 6b, but the pitch δ3 between the core layer 10a and the core layer 10b is set to δ1 and It is preferable to set it approximately equal to δ2 (preferably satisfying | δ3-δ1 | ≦ 1 μm and | δ3-δ2 | ≦ 1 μm at the same time).

  On the other hand, as shown in FIG. 4A, the fixing member 7 holds the fitted state of the first and second optical waveguides 6 a and 6 b fitted in the recess 12 of the ferrule body 5. It is made of a material in which silica particles are filled in a synthetic resin such as epoxy resin and PPS resin similar to the main body 5. The fixing member 7 is formed in a rectangular shape in plan view, and is formed in a convex shape when viewed in the x direction.

<< Second Ferrule Structure >>
FIG. 5 is an end view (end view taken along the line V-V in FIG. 2) showing the main part of the optical fiber connector (second ferrule).

  The second ferrule 3 is formed in a rectangular parallelepiped shape with a material in which inorganic particles such as silica particles are contained in a synthetic resin such as an epoxy resin or a PPS resin, and the first and second optical fibers 8 and 9 are inserted therein. A large number of fiber holes and guide holes 3a and 3b into which a pair of guide pins 4a and 4b are inserted are provided.

  The first and second optical fibers 8 and 9 inserted into the fiber holes are arranged such that their longitudinal directions are parallel to the x direction. Specifically, the first optical fibers 8 corresponding to the first optical waveguide 6a are arranged adjacent to each other, and the second optical fibers 9 corresponding to the second optical waveguide 6b are arranged adjacent to each other. The first optical fiber 8 has a function of propagating light transmitted to the first optical waveguide 6a. The second optical fiber 9 has a function of propagating light incident from the second optical waveguide 6b.

  The first optical fibers 8 are arranged at a pitch of δ1 in the y direction so as to correspond to the core layer 10a of the first optical waveguide 6a. The second optical fibers 9 are arranged at a pitch of δ2 in the y direction so as to correspond to the core layer 10b of the second optical waveguide 6b. Further, at the boundary between the arrangement of the first optical fibers 8 and the arrangement of the second optical fibers 9, the first optical fibers 8 and the second optical fibers 9 are arranged at a pitch of δ3.

  The first and second optical fibers 8 and 9 have a configuration in which core layers 8a and 9a having a circular cross section are covered with cladding layers 8b and 9b made of a material having a smaller refractive index than the core layers 8a and 9a. The principle of total reflection prevents light from leaking outside as much as possible.

  In the case of a multimode optical fiber mainly used for short-distance communication, the diameter of a clad layer is 125 μm and the diameter of an inner core layer covered with the clad layer is currently 50 μm to 62.5 μm. It has become. In the case of a single mode used for long-distance communication, the diameter of the cladding layer is standardized to 125 μm, and the diameter of the inner core layer covered with the cladding layer is standardized to 10 μm.

  In the present embodiment, the first optical fiber 8 and the second optical fiber 9 have the same diameter. As a result, the productivity of the second ferrule 3 is well prevented from becoming complicated. The first optical fiber 8 and the second optical fiber 9 may have different diameters, but in this case, the second ferrule 3 is divided into a plurality (for example, two), and the first optical fiber is divided into the first divided body. It is preferable that the second optical fiber is arranged in the second divided body, and the second ferrule 3 is configured by arranging each divided body.

<< Details of connection part of first ferrule and second ferrule >>
6 is a perspective view showing an optical connector according to an embodiment of the present invention. FIG. 6A is a perspective view showing a relationship between the first optical waveguide and the core layer of the optical fiber, and FIG. It is a perspective view showing the relationship between a 2nd optical waveguide and the core layer of an optical fiber.

  The core layer 10a of the first optical waveguide 6a is connected to the core layer 8a of the first optical fiber 8, as shown in FIG. On the other hand, the core layer 10b of the second optical waveguide 6b is connected to the core layer 9a of the second optical fiber 9, as shown in FIG.

  In the connection portion between the first optical fiber 8 and the first optical waveguide 6a, the outer edge of the cross section of the core layer 8a of the first optical fiber 8 is disposed inside the outer edge of the cross section of the core layer 10a of the first optical waveguide 6a. As described above, in the connection portion between the second optical fiber 9 and the second optical waveguide 6b, the outer edge in the cross section of the core layer 10b of the second optical waveguide 6b is the outer edge in the cross section of the core layer 9a of the second optical fiber 9b. The size of the cross-sectional area of the core layers 10a and 10b of the first and second optical waveguides 6a and 6b is set so as to be disposed inside the first and second optical waveguides 6a and 6b.

  Specifically, when the cross-sectional shape of the core layers 10a and 10b is substantially rectangular, the length in the y direction is Lw1 and the length in the z direction is Lh1 for the core layer 10a of the first optical waveguide 6a. For the core layer 10b of the second optical waveguide 6b, the length in the y direction is Lw2, the length in the z direction is Lh2, and the diameters of the core layers 8a, 9a of the first and second optical fibers 8, 9 are φ, Define each. At this time, in this embodiment, the expressions Lw1 ≧ φ, Lh1 ≧ φ, Lw2 ≦ φ / √2, and Lh2 ≦ φ / √2 are satisfied at the same time.

  Therefore, most of the light propagating through the first optical fiber 8 is in the connecting portion between the first optical fiber 8 and the first optical waveguide 6a through which light is transmitted in the order of the first optical fiber 8 → the first optical waveguide 6a. It will be transmitted well to the first optical waveguide 6a without leaking from the connecting portion. Therefore, the coupling loss of light at the connecting portion is well prevented.

  Further, in the connecting portion between the second optical fiber 9 and the second optical waveguide 6b through which light is transmitted in the order of the second optical waveguide 6b → the second optical fiber 9, most of the light propagating through the second optical waveguide 6b is It will be transmitted well to the second optical fiber 9 without leaking from the connecting portion. Therefore, the coupling loss of light at the connecting portion is well prevented.

  As a result of the above, by realizing an optical connector by combining the first optical fiber 8 and the first optical waveguide 6a, and the second optical fiber 9 and the second optical waveguide 6b, bidirectional optical communication in the optical connector is achieved. It has a synergistic effect that it can be carried out in a state where the coupling loss of light is extremely small.

  In addition, when the cross-sectional shape of the core layers 10a and 10b of the first and second optical waveguides 6a and 6b is square, the length of the side of the core layer 10a of the first optical waveguide 6a is Lw1, and the length of the second optical waveguide 6b is When the side length of the core layer 10b is defined as Lw2, if the first and second optical waveguides 6a and 6b satisfying the relational expression of Lw1 / Lw2 ≧ √2 are prepared, the first and second optical fibers 8 are prepared. By adjusting the diameter φ of the core layers 8a, 9a to 9 to some value, an optical connector with a small optical coupling loss can be realized.

  In the present embodiment, the first and second optical fibers 8 and 9 are accommodated in the second ferrule 3 and the first and second optical waveguides 6a and 6b are accommodated in the first ferrule 2, respectively. The optical communication can be realized with a single optical connector, and the number of parts can be reduced.

  The centroids of the core layers of the first optical fiber 8 and the second optical fiber 9 and the centroids of the core layer 10a of the first optical waveguide 6a and the core layer 10b of the second optical waveguide 6b are substantially in a straight line. If they are positioned, the height positions of the first and second optical fibers 8 and 9 and the height positions of the core layers 10a and 10b of the first and second optical waveguides 6a and 6b can be substantially aligned. As a result, the connection between the first optical fiber 8 and the first optical waveguide 6a and the connection between the second optical fiber 9 and the second optical waveguide 6b are facilitated, and the productivity is improved. Since the core layers 10a and 10b of the first and second optical waveguides 6a and 6b have different cross-sectional areas, the first and second optical waveguides 6a and 6b have the same cross-sectional area. This is done by adjusting the thickness of the cladding layers 11a and 11b and the thickness of the metal layers 14a and 14b.

  Further, the size of the core layer 10a of the first optical waveguide 6a is adjusted so that the outer edge of the core layer 8a of the first optical fiber 8 is inscribed with the outer edge of the core layer 10a of the first optical waveguide 6a (Lw1 = (φ, Lh1 = φ), it becomes unnecessary to make the core layer 10a of the first optical waveguide 6a larger than necessary. As a result, there is an advantage that the productivity of the first optical waveguide 6a can be improved.

  The size of the core layer 10b of the second optical waveguide 6b is adjusted so that the outer edge of the core layer 9a of the second optical fiber 9 is circumscribed with respect to the outer edge of the core layer 10a of the second optical waveguide 6a (Lw2 = φ , Lh2 = φ), it is not necessary to make the core layer 10b of the second optical waveguide 6a smaller than necessary, and the alignment between the core layer 9a of the second optical fiber 9 and the core layer 10b of the second optical waveguide 6b is achieved. Becomes easy.

<Optical connector manufacturing method>
FIG. 7 is a flowchart showing the manufacturing method of the optical connector 1 step by step. The manufacturing method of the optical connector of the present embodiment is roughly the step (A) for manufacturing the first ferrule 2, the step (B) for manufacturing the second ferrule 3, the first ferrule 2 and the second ferrule 3. And the step (C) of connecting the two. Needless to say, the order of the step (A) and the step (B) may be changed.

(A) First Ferrule Manufacturing Process FIG. 8 is a flowchart showing the first ferrule manufacturing method step by step.

  (Step a1) First, the ferrule body 5, the first and second optical waveguides 6a and 6b, and the fixing member 7 are formed.

  The ferrule body 5 and the fixing member 7 are formed by a conventionally known injection molding method. On the other hand, in the first and second optical waveguides 6a and 6b, when the cross-sectional areas of the core layers 10a and 10b are different as in the present embodiment, the thickness of the core layers 10a and 10b and the thickness of the cladding layers 11a and 11b are respectively different. Because it is different, some ingenuity is necessary for production. When the first and second optical waveguides 6a and 6b are manufactured by using the printing method, first, the core layer 10a and the clad layer 11a are formed on a part of the metal layer 14 made of copper foil by a well-known photolithography technique and etching. After forming a portion corresponding to the first optical waveguide 6a using the technique, the core layer 10b and the clad layer 11b are formed on the remaining portion of the metal layer 14 using the well-known photolithography technique and etching technique. By forming a portion corresponding to 6b, the metal layer 14 is made common to manufacture the first and second optical waveguides 6a and 6b. Alternatively, when the metal layer 14 is formed by a printing method without using it in common, the first and second optical waveguides 6a and 6b are separate metal layers 14a and 14b, and the optical waveguides 6a and 6b are conventionally known. It may be formed by using a photolithographic technique or an etching technique, and both end faces may be formed by bonding with an adhesive such as an epoxy resin or an acrylic resin. Moreover, when forming so that 1st and 2nd optical waveguide 6a, 6b may be integrated, it forms by the method using a conventionally well-known metal mold | die.

  (Step a2) Subsequently, the first and second optical waveguides 6a and 6b are fitted to the concave portion 12 of the ferrule body 5 manufactured in Step a1 via an adhesive, and the convex portion of the fixing member 7 is fitted to the concave portion 12. The first ferrule 2 is completed by pressing the first and second optical waveguides 6a and 6b with the fixing member 7 and fixing the positions of the first and second optical waveguides 6a and 6b by fitting the 7a. To do.

(B) Second Ferrule Manufacturing Process Since the second ferrule 3 in the present embodiment uses the first and second optical fibers 8 and 9 having the same diameter, a conventionally known photolithography method, mold or It is manufactured using a stamp method using a rubber mold. When the diameters of the first and second optical fibers 8 and 9 are different, the second ferrule 3 includes a first divided body that accommodates the first optical fiber 8 and a second divided portion that accommodates the second optical fiber 9. Each body is formed by using a conventionally known stamp method or the like, and both the divided bodies are fixed with an adhesive.

(C) Connection process of 1st ferrule and 2nd ferrule About the 1st, 2nd ferrule 2, 3 each manufactured in the said process, the end surface corresponding to a connection part is previously used using processing machines, such as a grinder. Surface smoothening to increase smoothness and cleaning. Then, an optical connector is completed by connecting between the connection parts of the 1st ferrule 2 and the 2nd ferrule 3 via a refractive index matching material, for example. The refractive index matching material includes substantially the same refractive index as the core layers 8a and 9a of the first and second optical fibers 8 and 9 and the core layers 10a and 10b of the first and second optical waveguides 6a and 6b. Or a translucent matching material having a refractive index between the core layers 8a and 9a and the core layers 10a and 10b), and by interposing the refractive index matching material between the connection end portions, Light reflection at the end faces of the second optical fibers 8 and 9 and the end faces of the first and second optical waveguides 6a and 6b can be further reduced.

<Photoelectric module structure>
FIG. 9 is a cross-sectional view schematically illustrating an optoelectric module configured using the optical connector 1 described above.

  The optical module shown in FIG. 9 includes a substrate 19, an optical connector 1 on which an optical waveguide is placed on the substrate 19, mirror means 15 connected to the optical waveguide of the optical connector 1 and reflecting light, and mirror means 15. The light receiving element 16 (corresponding to the first photoelectric conversion member) that receives the light reflected by the light receiving element and converts the received light into an electric signal, and the electric signal converted by the light receiving element 16 are input. A driver IC 22 (corresponding to an electric circuit) that performs processing based on the signal and an electric signal output by the processing of the driver IC 22 are input, and the light emitting element 17 that converts electricity into light based on the input electric signal And a configuration provided with.

  The mirror means 15 is provided with an inclined surface in the vicinity of the ends of the first and second optical waveguides 6a and 6b, and a metal material that reflects light such as gold, aluminum, titanium, and chromium is attached to the inclined surface. Configured. In addition, as a method of inclining the end surfaces of the first and second optical waveguides 6a and 6b, there are a method of forming with a mold and a method of processing with a diamond tool. The metal material is deposited by vapor deposition or the like. In order to transmit the light reflected by the mirror means 15 to the light receiving element 16 or to transmit the light from the light emitting element 17 to the mirror means 15, the metal layers 14 of the first and second optical waveguides 6a and 6b are In the vicinity of the area where the mirror means 15 is formed (light passage area), the mirror means 15 is removed.

  For example, a photodiode is used as the light receiving element 16 and receives light transmitted through the first optical waveguide 6a. As the light emitting element 17, a VCSEL or other surface emitting semiconductor laser, an edge emitting laser diode or the like is used, and emits light toward the second optical waveguide 6b. The light receiving element 16 and the light emitting element 17 are linearly arranged so as to correspond to the positions of the first and second optical waveguides 6a and 6b.

  By configuring the opto-electric module having such a configuration, more accurate information than before is input by the optical connector, so that the electrical circuit such as the driver IC 22 performs more accurate processing than before, and the processed information Is transmitted to the outside more accurately than before by the optical connector. Therefore, for example, by incorporating a photoelectric module into a device that requires high precision and accurate processing (for example, a computer device such as a super computer, a workstation, or a server, or a communication connection device such as a router) The performance can be greatly improved.

  In the present embodiment, a receiver for amplifying the electric signal converted by the light receiving element 16 may be mounted on the substrate 19. Further, an arithmetic processing unit such as a CPU that performs processing based on an electric signal may be mounted on the substrate 19 as an electric circuit. A capacitor may be provided to stabilize the power supply voltage supplied to the driver IC 22 and the receiver.

( Reference example )
<Description of optical connector>
FIG. 10 is a perspective view showing a pair of optical connectors 1a and 1b according to a reference example of the present invention.

In the first embodiment, the first optical waveguide 6a and the second optical waveguide 6b are accommodated in the same ferrule. However, in this reference example , the optical waveguides 6a and 6b are respectively provided as separate ferrules 2a and 2b. Accommodate. As a result, the second ferrule 3 is also a separate ferrule 3a, 3b, and the optical connection structure for performing bidirectional optical communication is realized by the pair of optical connectors 1a, 1b. Other basic configurations are substantially the same as those in the first embodiment.

Although this reference example has a larger number of parts than the first embodiment, it is advantageous in that it can be easily manufactured by a conventionally known method when manufacturing a ferrule that accommodates the optical waveguides 6a and 6b. Basically, however, the pair of optical connectors according to the present reference example has the same effects as those of the first embodiment.

<Description of photoelectric module>
FIG. 11 is a plan view showing an optoelectric module on which the optical connectors 1a and 1b of FIG. 10 are mounted. FIG. 12 is a cross-sectional view of the photoelectric module of FIG. The photoelectric module according to the present reference example includes a substrate 19, a driver IC 22 and a capacitor 20 mounted on the substrate 19, a light emitting element 17, an optical connector 1b, a receiver 21 mounted on the substrate 19, and a light receiving function. It has the structure provided with the element 18 and the optical connector 1a. In FIG. 12, the ratio of the first and second optical waveguides 6a and 6b and the optical fiber to the ferrule is shown enlarged from the actual one.

In the present reference example , the first optical waveguide 6a and the second optical waveguide 6b are accommodated in separate ferrules 2a and 2b, so that unlike the first embodiment, a pair of optical connectors 1a on the substrate 19 is provided. 1b are arranged at intervals, the mirror means 15a and the light receiving element 18 are located at a position corresponding to the optical connector 1a, and the mirror means 15b and the light emitting element 17 are located at a position corresponding to the optical connector 1b. The mirror means 15 a reflects the light from the first optical waveguide 6 a toward the light receiving element 18. The mirror means 15b reflects the light from the light emitting element 17 toward the second optical waveguide 6b. Other components are basically the same as those of the photoelectric module of the first embodiment. The photoelectric module having such a configuration also has the advantage of being superior to the first embodiment from the viewpoint of productivity, in addition to the same effects as the first embodiment.

DESCRIPTION OF SYMBOLS 1 Optical connector 2 1st ferrule 3 2nd ferrule 5 Ferrule main body 6a 1st optical waveguide 6b 2nd optical waveguide 7 Fixing member 8 1st optical fiber 8a Core layer (1st optical fiber)
8b Clad layer (first optical fiber)
9 Second optical fiber 9a Core layer (second optical fiber)
9b Clad layer (second optical fiber)
10a Core layer (first optical waveguide)
10b Core layer (second optical waveguide)
14, 14a, 14b Metal layer 15 Mirror means 16, 18 Light receiving element 17 Light emitting element 19 Substrate 20 Capacitor 21 Receiver 22 Driver IC

Claims (11)

A plurality of first optical fibers;
A first optical waveguide having a plurality of core layers connected to each of the plurality of first optical fibers, into which light transmitted from the first optical fiber is incident;
A plurality of second optical fibers;
A plurality of core layers connected to each of the plurality of second optical fibers, and a second optical waveguide for transmitting light emitted to the second optical fiber,
In the connecting portion between the first optical fiber and the first optical waveguide, the core layer of the first optical fiber has an outer edge of the cross section disposed inside the outer edge of the cross section of the core layer of the first optical waveguide. ,
In the connection portion between the second optical fiber and the second optical waveguide, the core layer of the second optical waveguide has an outer edge of the cross section disposed inside the outer edge of the cross section of the core layer of the second optical fiber. ,
The cross-sectional areas of the core layers of the first optical fiber and the second optical fiber are substantially equal,
The core layer of the first optical waveguide has a larger cross-sectional area than the core layer of the second optical waveguide,
The distance between centroids of adjacent core layers of the first optical waveguide, the distance between centroids of adjacent core layers of the second optical waveguide, and the core layer and the second of adjacent first optical waveguides centroid distance between the core layer of the optical waveguide substantially V equal is,
The first optical fiber and the second optical fiber are accommodated in the same optical fiber connector;
An optical connection structure, wherein the first optical waveguide and the second optical waveguide are accommodated in the same optical waveguide connector . The optical connection structure according to claim 1 ,
An optical connection structure, wherein the first optical waveguide and the second optical waveguide are integrated. The optical connection structure according to claim 1 or 2 ,
An optical connection structure characterized in that the centroids of the core layers of the first and second optical fibers and the centroids of the core layers of the first and second optical waveguides are positioned substantially in a straight line. . The optical connection structure according to any one of claims 1 to 3 ,
An outer edge of the core layer of the first optical fiber at a connection portion between the first optical fiber and the first optical waveguide is inscribed with respect to an outer edge of the core layer of the first optical waveguide. Optical connection structure. The optical connection structure according to any one of claims 1 to 4 ,
The outer edge of the core layer of the second optical fiber at the connection portion between the second optical fiber and the second optical waveguide is circumscribed with respect to the outer edge of the core layer of the second optical waveguide. Optical connection structure. A first optical waveguide connected to a plurality of first optical fibers, having a plurality of core layers connected to each of the plurality of first optical fibers, into which light transmitted from the first optical fibers is incident; , Connected to a plurality of second optical fibers each having a core layer having a cross-sectional area substantially equal to the core layer of the first optical fiber, and having a plurality of core layers connected to each of the plurality of second optical fibers. In an optical waveguide unit having a second optical waveguide for transmitting light emitted to the second optical fiber,
The first optical waveguide has a circular shape in which the outer edge is located inside the outer edge in the cross section of the core layer of the first optical waveguide and outside the outer edge in the cross section of the core layer of the second optical waveguide. A cross section of the core layer is made larger than a cross section of the core layer of the second optical waveguide;
The distance between centroids of adjacent core layers of the first optical waveguide, the distance between centroids of adjacent core layers of the second optical waveguide, and the core layer and the second of adjacent first optical waveguides centroid distance between the core layer of the optical waveguide substantially V equal is,
The optical waveguide unit, wherein the first optical waveguide and the second optical waveguide are accommodated in the same optical waveguide connector . In the optical waveguide unit according to claim 6 ,
An optical waveguide unit, wherein the first optical waveguide and the second optical waveguide are integrated. In the optical waveguide unit according to claim 6 or 7 ,
The cross section of the core layer of the first optical waveguide and the second optical waveguide has a rectangular shape,
About the core layer of the first optical waveguide, the length of the side parallel to the first direction is Lw1, the length of the side parallel to the second direction orthogonal to the first direction is Lh1,
For the core layer of the second optical waveguide, the length of the side parallel to the first direction is Lw2, the length of the side parallel to the second direction is Lh2,
For the circle, if the diameter is defined as φ,
Lw1 ≧ φ, Lh1 ≧ φ, Lw2 ≦ φ / √2, Lh2 ≦ φ / √2
An optical waveguide unit characterized by satisfying all the relational expressions of In the optical waveguide unit according to claim 6 or 7 ,
The cross sections of the core layers of the first optical waveguide and the second optical waveguide are square,
When the length of the side of the core layer of the first optical waveguide is defined as Lw1, and the length of the side of the core layer of the second optical waveguide is defined as Lw2,
Lw1 / Lw2 ≧ √2
An optical waveguide unit characterized by satisfying the relational expression: The optical waveguide unit according to any one of claims 6 to 9 ,
An optical waveguide unit, wherein the centroid of the core layer of the first optical waveguide and the centroid of the core layer of the second optical waveguide are positioned substantially in a straight line. An optical connection structure according to any one of claims 1 to 5 ,
A first photoelectric conversion member that converts light transmitted by the optical connection structure into an electrical input signal;
An electric circuit for performing processing based on the converted electric input signal;
A photoelectric module comprising: a second photoelectric conversion member that converts an electrical output signal output by the processing of the electrical circuit into light, and transmits the converted light to the optical connection structure.

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