JP2001242350A - Optical transceiver - Google Patents

Abstract

(57) [Summary] (with correction) [PROBLEMS] To provide an inexpensive miniaturized optical transceiver using a metal-sealed optical element without using any special parts. SOLUTION: Cylindrical ferrules 6 and 7 are attached to tips of two optical fibers 5 extending from a two-core MT ferrule 3 of a fitting pin alignment method. Device holder 1
A metal seal type optical element (light receiving element 8 or light emitting element 9) is accommodated and fixed in 1 and 12, and cylindrical ferrules 6 and 7 are inserted and fixed. This part becomes the transmission / reception optical module. These parts are set on a board connecting the leads of the optical elements 8 and 9, and the mating MT-RJ connected to the MT ferrule 3 is installed.
And a receptacle for coupling the optical connector. The optical elements 8 and 9 of the metal seal type are larger in size than the optical elements of the chip components, and the two optical elements 8 and 9 are larger.
Although the distance between them becomes wide, the MT ferrule 3 having a narrow distance between two optical fibers can be used by interposing the optical fiber 5 to which the cylindrical ferrules 6 and 7 are attached.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical transceiver for transmitting and receiving an optical signal in an optical LAN or the like, and more particularly, to a so-called MT-RJ type optical connector which is miniaturized by using a ferrule of a so-called MT optical connector for a connection portion. The present invention relates to an MT-RJ type optical transceiver in which is connectable.

[0002]

2. Description of the Related Art In short-distance optical communication such as optical LAN, 2
In a system that performs optical transmission and reception using a pair of optical fiber cords, a cylindrical member having a smaller diameter than the SC optical connector is used as the optical connector instead of a double SC optical connector (described later) that has been widely used in the past. MT having a double LC optical connector (described later) or an MT optical connector (described later) type ferrule (MT ferrule) miniaturized by using a cylindrical ferrule.
-The use of RJ-type optical connectors (described later) has been aimed at miniaturization of equipment, and standards for miniaturized optical transceivers have already been established.

[0003] Of the miniaturized optical transceiver standards described above, the optical transceiver used in the MT-RJ interface system also has a connection portion of the MT-RJ.
It is necessary that the receptacle has a receptacle shape to which the optical connector can be connected. In recent years, MT-RJ optical transceivers have been manufactured in response to such market demands. However, MT optical connectors (MT ferrules) are different from conventional dual SC optical connectors and dual LC optical connectors. Compared to,
Since the distance between the two optical fibers is extremely small, a large-sized CAN (metal-sealed) light-receiving element and a light-emitting element are arranged side by side, so that a small-sized light can be connected to the MT-RJ optical connector. Cannot be a transceiver. Therefore, in the MT-RJ type optical transceiver, a light receiving element and a light emitting element formed by chip components are surface-mounted (bare-chip mounting) at a small interval on a substrate, and two optical fiber protrusions (built-in and fixed in the MT ferrule) are used. Pigtails) have been proposed to directly face the light receiving element and the light emitting element, respectively.

[0004] The SC optical connector is a single-core optical connector having a structure in which an optical fiber is fixed to a cylindrical ferrule made of zirconia or the like, and is detachably attached with one touch.
The LC type optical connector uses a smaller ferrule than the SC optical connector and is downsized. In addition, two single SC optical connectors or two LC optical connectors are integrated in parallel in a housing.
An optical connector or a dual LC optical connector. Also,
The MT optical connector is an optical connector of a pin fitting position alignment system, and corresponds to an F12 type multi-core optical fiber connector of JIS C5981. Further, the MT-RJ type optical connector has a structure in which a ferrule (MT ferrule) of the MT optical connector is housed in a plug housing, and is mutually aligned with the MT ferrule on the mating side with a fitting pin. Connected in state.

[0005]

In the above-mentioned optical transceiver having a structure using chip components, it is necessary to newly produce a special component such as a silicon substrate in a bare chip mounting portion. For this reason, the manufacturing method becomes difficult, for example, the parts become expensive, and special equipment for assembling is required, and there has been a problem that the cost is inevitably higher than that of the conventional double type. The present invention has been made in order to solve the above-mentioned conventional disadvantages, and can be reduced in size enough to be able to connect an MT-RJ type optical connector without using any special parts, easily and inexpensively. It is an object to provide an optical transceiver that can be manufactured.

[0006]

An optical transceiver 1 according to the present invention for solving the above-mentioned problems is provided for coupling an even-numbered ferrule of a fitting pin alignment method and a mating optical connector connected to the even-numbered ferrule. A receptacle, and an even-numbered cylindrical ferrule in which the other end of an even-numbered optical fiber having one end fixed to the even-numbered ferrule is inserted and fixed, and a metal-sealed light-receiving element or a light-emitting element is housed and fixed therein, and A light-receiving side device holder and a light-emitting side device holder, each cylindrical ferrule being housed and fixed so as to face the light-receiving element or the light-emitting element, and these members are connected to leads of the light-receiving element and the light-emitting element. It is characterized by being integrated with a substrate.

[0007]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be described with reference to FIGS. FIG. 1 shows an optical transceiver 1 according to an embodiment of the present invention and an MT-RJ connected thereto.
FIG. 2 is a plan view showing the internal structure of the optical connector 2, and FIG. 2 is a front view showing the internal structure of the optical transceiver 1.
The optical transceiver 1 of this embodiment has a two-core MT which is a ferrule of an MT optical connector of a fitting pin alignment method.
A ferrule (even-numbered ferrule) 3 and a mating optical connector connected to the MT ferrule 3, that is, an MT-R
Receptacle 4 for connecting J-type optical connector 2
And two small-diameter cylindrical ferrules 6 and 7 in which the other ends of two optical fibers 5 each having one end fixed to the MT ferrule 3 are inserted and fixed, and a metal-sealed light-receiving element 8 or a light-emitting element therein. A light-receiving device holder 11 and a light-emitting device holder 12 in which the element 9 is accommodated and fixed and each of the cylindrical ferrules 6 is accommodated and fixed so as to face the light-receiving element 8 or the light-emitting element 9. The member is integrated with the substrate 13 to which the leads 8a, 9a of the light receiving element 8 and the light emitting element 9 are connected.

[0008] The MT ferrule 3 is an MT optical connector (F of JIS C5981) of a pin fitting position alignment method.
(Corresponding to a 12-type multi-core optical fiber connector). However, as the even-numbered ferrule used in the present invention, even if it is not the MT ferrule itself,
Any ferrule having an even number of cores in a pin fitting position alignment method may be used. The MT-RJ optical connector 2 has a structure in which a ferrule of the MT optical connector type (MT ferrule 15) is housed in a plug housing 16 as described above. When inserted into the receptacle 4 of the optical transceiver 1, the M
The MT ferrule 15 on the side of the T-RJ type optical connector 2 and the MT ferrule 3 on the side of the optical transceiver 1 are connected in a state where they are aligned with each other by fitting pins 17. MT-RJ
When attaching and detaching the optical connector 2, the claw 18a of the locking lever 18
Is locked in the locking hole 4a of the receptacle 4 or the locking hole 4a
And detachment is performed.

FIG. 3 illustrates the procedure for assembling the optical module portion (electric / optical, optical / electrical conversion portion) of the optical transceiver 1. (A) shows before assembling, and (B) shows after assembling. The cylindrical ferrules 6 and 7 are ferrules used for an LC type optical connector, for example, are made of zirconia and have an outer diameter of 1.25 mm (half of SC ferrule), and the optical fiber 5 is inserted into the optical fiber hole. It is fixed with an adhesive and the end face is polished. Device holder 11, 12
Is made of, for example, a plastic such as polycarbonate, and contains therein a light receiving element 8 such as a photodiode or a light emitting element 9 such as a laser diode and is fixed with an adhesive. Then, the cylindrical ferrules 6 attached to the optical fibers 5 are inserted into the ferrule attachment cylindrical portions 11a and 12a of the device holders 11 and 12, respectively, and fixed with an adhesive. The optical elements 8 and 9 of the metal seal type are larger in size than the optical element of the chip component, and the space between the two optical elements 8 and 9 is wider. However, the optical fiber 5 to which the cylindrical ferrules 6 and 7 are attached is used. By intervening,
It is possible to use the MT ferrule 3 having a narrow interval between two fibers. Regarding the connection between the cylindrical ferrule 3 and the light receiving element 8 or the light emitting element 9, as shown in an enlarged sectional view of the main part in FIG. The lens 20 faces the unit or the light emitting unit (the light emitting element is shown in the figure), but the accuracy of each part of the device holders 11 and 12 and the accuracy of the cylindrical ferrule 3 are determined by simply inserting the cylindrical ferrule 3. Since it is manufactured so that the optical axis is aligned with high accuracy only by itself, the optical axis aligning work at the time of assembling is unnecessary.

Note that the MT ferrule 3 of this embodiment
Is mounted on a stage 21 fixed to the substrate 13 and covered with a cover 22. The light receiving element 8 and the light emitting element 9 are mounted on a device holder support 23 fixed to the substrate 13. Reference numeral 24 denotes a terminal pin of the substrate 13. The components described above are integrated by a synthetic resin mold 25.

In the SFF (Small Form Factor) size already established as a standard for miniaturized optical transceivers, the width W is 13.6 mm and the length L is 49.5 mm. Despite using metal-sealed optical elements 8 and 9 that are larger in size than the chip components, a small-diameter cylindrical ferrule 6 is attached to the other end of the optical fiber 5 having one end attached to the MT ferrule 3. The SFF is attached to the light receiving element 8 or the light emitting element 9 by using the small-diameter cylindrical ferrule 6. In addition,
In order to shorten the length L, the distance between the MT ferrule 3 and the cylindrical ferrule 6 is set to 5 to 10 mm, but the optical fiber 5 to be connected is connected so that the optical fiber 5 can be connected at this short distance. 250μm UV with high flexibility
Insulated wire is used. Note that UV coating is removed from the portions fixed to the MT ferrule 3 and the cylindrical ferrule 6 at both ends of the optical fiber 5. In order to reduce the size of the optical transceiver, it is desirable to use a ferrule of an LC type optical connector having an outer diameter of 1.25 mm.
An SC optical connector ferrule of 5 mm can be used.

FIG. 5 shows another embodiment of the present invention. The optical transceiver 1 'of this embodiment uses a four-core MT ferrule 3', and each of the four cores of the MT ferrule 3 'has two cylindrical optical fibers 5 (two pairs of two MT ferrules). The ferrule 6 is attached, two of the four cylindrical ferrules 6 are attached to the light-receiving device holder 11, and the other two are attached to the light-emitting device holder 12.
This is a two-pair parallel MT type optical transceiver for transmitting and receiving four pairs of optical fibers. Furthermore, optical fiber transmission and reception of four pairs of eight fibers
It is also possible to configure a four-pair parallel MT type optical transceiver performed by a stand. The other parts are basically the same in structure as the two-core optical transceiver 1, and are denoted by the same reference numerals and will not be described again. Although the optical transceiver in this case does not fall into the so-called SFF size category, two or four pairs of transmission and reception can be performed with one MT connector connection.

[0013]

According to the optical transceiver of the present invention, an even-numbered ferrule of a fitting pin alignment method, a receptacle for coupling a mating optical connector connected to the even-numbered ferrule, and an even-numbered ferrule are provided. An even-numbered cylindrical ferrule in which the other end of an even-numbered optical fiber having one end fixed is inserted and fixed, and a metal-sealed light-receiving element or a light-emitting element is housed and fixed therein, and the cylindrical ferrule is connected to the light-receiving element. Or a light receiving side device holder and a light emitting side device holder housed and fixed to face the light emitting element, and these members are integrated with a substrate to which the leads of the light receiving element and the light emitting element are connected. , Without using any special parts like the conventional bare chip mounted optical transceiver,
While using a metal seal type optical element which is inexpensive but larger in size than the chip component, it is possible to realize a sufficiently small size to be able to connect an MT-RJ type optical connector. The cost was reduced, the production was easy without the need for dedicated equipment for assembly, and the cost of the miniaturized optical transceiver could be reduced. Also, if the cylindrical ferrule and device holder are manufactured with high precision, the optical axis is aligned with high accuracy just by inserting the cylindrical ferrule into the device holder, so that the optical axis alignment during assembly is unnecessary. In this respect, also in this point, the production is easy and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a plan view showing an internal structure of an optical transceiver according to an embodiment of the present invention and an MT-RJ type optical connector connected to the optical transceiver.

FIG. 2 is a front view showing an internal structure of the optical transceiver and the MT-RJ type optical connector of FIG. 1;

3A and 3B are diagrams showing a configuration of an optical module portion in the optical transceiver, wherein FIG. 3A shows a state before a cylindrical ferrule is mounted, and FIG. 3B shows a state after the cylindrical ferrule is mounted.

FIG. 4 is an enlarged sectional view of the vicinity of a tip of a cylindrical ferrule in a device holder of the optical transceiver.

FIG. 5 is a plan view showing an internal structure of an optical transceiver according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 1 'Optical transceiver 2 MT-RJ type optical connector 3 Two-core MT ferrule (even number ferrule) 4 Receptacle 5 Optical fiber 6 Cylindrical ferrule 8 Light receiving element 9 Light emitting element 11 Light receiving side device holder 12 Light emitting side device holder 13 Substrate 15 MT ferrule (of MT-RJ type optical connector) 16 Plug housing 17 Mating pin 18 Locking lever

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Takehisa Ide 1440, Murosaki, Sakura-shi, Chiba F-term in Fujikura Sakura Works (reference) 2H036 NA01 QA12 QA44 QA49 QA57 2H037 AA01 BA04 BA13 CA14 DA03 DA04 DA05 DA06 DA15 DA33 5F041 AA41 CB32 DC23 EE01 FF14 5F073 BA01 FA08 FA23 5F088 AA01 BA18 BB01 JA14

Claims (1)

[Claims] 1. An even-numbered ferrule of a fitting pin positioning method, a receptacle for coupling a mating optical connector connected to the even-numbered ferrule, and an even-numbered light having one end fixed to the even-numbered ferrule. An even-numbered cylindrical ferrule into which the other end of the fiber is inserted and fixed, and a metal-sealed light-receiving element or light-emitting element housed and fixed inside, and each of the cylindrical ferrules is housed so as to face the light-receiving element or light-emitting element. An optical transceiver comprising a fixed light-receiving device holder and a light-emitting device holder, and each of these members is integrated with a substrate to which leads of the light-receiving element and the light-emitting element are connected.