JP2000341219A - Optical transmission reception module and optical transmission reception system using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow a transmission reception module to select a communication system corresponding to an optical fiber in use. SOLUTION: This module is provided with an optical transmission reception section 1 that sends/receives an optical signal to/from an optical fiber, and also with a half duplex communication circuit 4 that controls the optical transmission reception section 1 in a half duplex communication system, a full duplex communication circuit 3 that controls the optical transmission reception section 1 in a full duplex communication system, and a changeover device 2 that selects the half duplex communication system or the full duplex communication system for the communication system controlling the optical transmission reception section 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical transmission / reception module for transmitting and receiving by sharing one optical fiber and a single-core bidirectional optical transmission / reception system using the same. In particular, the present invention relates to a digital communication system capable of high-speed transmission, such as IEEE1394 or USB2.

[0002]

2. Description of the Related Art A conventional example of such an optical transmission / reception system is disclosed in Japanese Patent Application No. 11-5872 previously proposed by the present applicant.
No. (filed on Jan. 12, 1999).

[0003] The optical transmission / reception system can use an optical fiber cable for digital audio which has been widely used, and enables two-way communication with one optical fiber cable.

A conventional optical transmission / reception system will be described below with reference to the drawings.

FIG. 9 is a structural view of a conventional optical transmitting / receiving system, in which (a) is a transverse sectional view and (b) is a longitudinal sectional view. FIG. 10 is a front view of the optical transceiver module in the optical transceiver system shown in FIG. FIG. 11 is a diagram for explaining the optical operation of the conventional optical transmitting and receiving system.
(A) is a cross-sectional view, and (b) is an enlarged view of a portion A of (a).

The conventional optical transmission / reception system includes an optical fiber cable 11 and an optical transmission / reception module 21.

The optical fiber cable 11 has an optical fiber 12 serving as an optical path therein, and a plug 13 at an end.
Is provided.

The light transmitting / receiving module 21 includes a light emitting element 23 for converting an electric signal into an optical signal and a light receiving element 24 for converting an optical signal into an electric signal in a holder 22 having an insertion hole 22a formed therein. A mold package 25 for encapsulating the light emitting element 23 and the light receiving element 24, and lenses 25a and 25b formed integrally with the mold package 25.
And a light splitting element 26.

Then, by inserting the plug 13 of the optical fiber cable 11 into the insertion hole 22a of the optical transceiver module 21, the optical fiber cable 11 and the optical transceiver module 21 are optically coupled.

That is, the transmission signal light emitted from the light emitting element 23 passes through the lens 25a integrally formed with the mold package 25, and is converted into substantially parallel light.
The light is converted into a convergent light beam by a lens 26a formed on the back surface of the optical fiber 12, and then deflected in the optical axis direction of the optical fiber 12 by a microprism 26b formed on the surface of the light splitting element 26, and enters the optical fiber 12.

On the other hand, the received signal light emitted from the optical fiber 12 is deflected by a microprism 26b formed on the front surface of the light branching element 26, and then is collimated by a lens 26a formed on the back surface of the light branching element 26. After that, the lens 2 integrally molded in the mold package 25
5b, and is converted into a substantially condensed light beam to enter the light receiving element 24.

An optical communication system disclosed in Japanese Utility Model Registration No. 2585665 is an indirectly related conventional example.

FIG. 12 is an isolated plan view of the optical communication system.

The optical communication system includes a plug (optical fiber cable) 33 having an insertion direction defining key 31 and an optical fiber 32 protruding from a side surface, and a positioning groove 34 into which the insertion direction defining key 31 is fitted at the time of coupling. (Optical communication module) 35 having the positioning groove 3
4 is provided with a detector 36 for detecting the insertion direction defining key 31 fitted in a predetermined state. With this configuration, the detector 36 can detect that the plug 33 has been removed from the adapter 35. Stop the operation of the laser light source,
This solves the problem of causing the laser beam to fly into space, and prevents damage to the user's eyes.

[0015]

However, the above-mentioned conventional optical transmission / reception system has the following problems.

The end face of the optical fiber 12 is cut vertically, and the optical fiber cable 11 is not subjected to anti-reflection treatment.
Is used, reflected light of its own transmission signal light from both end faces of the optical fiber 12 is incident on its own light receiving element 24, crosstalk increases, and the full-duplex communication method cannot be adopted. In particular, since reflection at the far end of the optical fiber 11 (far-end reflection) cannot be prevented, the half-duplex communication method is adopted, but there is a problem that the transmission speed is reduced by half.

In order to solve the above-mentioned problems, an optical fiber cable in which the end face of the optical fiber 12 is obliquely cut, an optical fiber cable in which an end face of the optical fiber 12 is provided with an antireflection film, and the length of the optical fiber 12 are very small. A long optical fiber cable may be used. However, since the optical fiber cable in which the end face of the optical fiber 12 is cut vertically is already commercially available and owned by the user, the optical fiber cable in which the end face of the optical fiber 12 is cut obliquely,
If a system that can use only an optical fiber cable having an anti-reflection coating on the end face of the optical fiber 2 and an optical fiber cable having an extremely long optical fiber 12 is used, a problem arises that user assets are cut off.

Further, an optical fiber cable in which the end face of the optical fiber 12 is obliquely cut, an optical fiber cable in which an end face of the optical fiber 12 is provided with an antireflection film, and an optical fiber 12
When a fiber optic cable having a very long cable length is put on the market, a problem arises that a digital audio system cannot be established. Specifically, these optical fiber cables have a problem that communication is impossible due to excessive light quantity or insufficient light quantity.

In view of the above problems, an object of the present invention is to provide an optical transmitting / receiving module that can selectively switch to a communication method according to an optical fiber to be used, and an optical transmitting / receiving system using the same.

[0020]

To achieve the above object, an optical transceiver module according to the first invention of the present invention comprises:
An optical transmitting and receiving module including an optical transmitting and receiving unit for transmitting and receiving light to and from a single optical fiber, comprising: a half-duplex communication control unit that controls the optical transmitting and receiving unit by a half-duplex communication method; A full-duplex communication control unit for controlling by a full-duplex communication method, and a switching unit for selectively switching a communication method for controlling the optical transmission / reception unit to one of the half-duplex communication method and the full-duplex communication method It is characterized by having.

Further, in the optical transceiver module according to the second invention of the present invention, in the optical transceiver module according to the first invention, the switching unit selects a half-duplex communication system when the length of the optical fiber is short. When the length of the optical fiber is long, a full-duplex communication system is selected.

Further, in the optical transceiver module according to the third invention of the present invention, in the optical transceiver module according to the second invention, when the length of the optical fiber is short, the drive current of the light emitting element of the optical transceiver is reduced. When the length of the optical fiber is long, the drive current of the light emitting element is increased.

Still further, in the optical transceiver module according to the fourth invention of the present invention, in the optical transceiver module according to the first invention, when the switching unit performs an antireflection process on an end face of the optical fiber, It is characterized in that a duplex communication method is selected, and otherwise, a half-duplex communication method is selected.

In addition, the optical transmission / reception system according to the fifth invention of the present invention is any one of the first invention to the fourth invention for transmitting and receiving light between an optical fiber cable having an optical fiber and the optical fiber. An optical transmission / reception system having an optical transmission / reception module according to one aspect of the present invention, wherein the optical fiber cable is provided with information means for indicating length information of the optical fiber or non-reflection processing information of an end face, and Detecting means for detecting length information of the optical fiber or non-reflection processing information of the end face from the information means is provided, and the switching unit performs switching based on a detection result from the detecting means.

In addition, in the optical transmission / reception system according to the sixth invention of the present invention, in the optical transmission / reception system according to the fifth invention, the information means is a projection provided on a plug inserted into a connector of the optical transmission / reception module. It is characterized by consisting of.

According to the above configuration, the optical transmission / reception system according to the first invention of the present invention is a half-duplex communication control unit for controlling the optical transmission / reception unit by a half-duplex communication method, and a full-duplex communication between the optical transmission / reception unit. A full-duplex communication control unit that controls the communication method, and a switching unit that selectively switches the communication method that controls the optical transmitting and receiving unit to one of the half-duplex communication method and the full-duplex communication method. The communication method according to the optical fiber used can be selected. Therefore, for example, a half-duplex communication method can be adopted for an optical fiber cable already owned by a user whose optical fiber end face is not subjected to anti-reflection treatment, and an optical fiber cable having a long optical fiber length. A full-duplex communication system can be adopted for an optical fiber cable whose end face is subjected to anti-reflection processing.

Further, in the optical transceiver module according to the second invention of the present invention, the switching section selects the half-duplex communication method when the length of the optical fiber is short, and selects the half-duplex communication method when the length of the optical fiber is long. Since the full-duplex communication method is selected, it is possible to prevent a state in which communication is impossible due to the influence of the far-end reflected light of the optical fiber when using an optical fiber having a short length, and to use the optical fiber when using a long optical fiber. Since there is no influence of the far-end reflected light, the transmission speed can be improved.

Further, in the optical transceiver module according to the third invention of the present invention, when the length of the optical fiber is short, the drive current of the light emitting element of the optical transceiver is reduced, and when the length of the optical fiber is long. Since the driving current of the light emitting element is increased, power consumption can be reduced when the length of the optical fiber is short.

Further, in the optical transceiver module according to the fourth invention of the present invention, the switching unit selects a full-duplex communication system when the end face of the optical fiber is subjected to the anti-reflection processing, and does not perform this operation. When a half-duplex communication method is selected, the transmission speed can be improved because there is no influence of the far-end reflection light of the optical fiber when using an optical fiber with anti-reflection treatment on the end face, and the anti-reflection treatment is applied to the end face. When an optical fiber that is not used is used, it is possible to prevent a state in which communication is impossible due to the influence of the far-end reflected light of the optical fiber.

In addition, the optical transmission / reception system according to the fifth invention of the present invention transmits and receives light between an optical fiber cable having an optical fiber and the optical fiber.
An optical transmission / reception system comprising: the optical transmission / reception module according to any one of claims 1 to 3, wherein the optical fiber cable is provided with information means for indicating length information of the optical fiber or non-reflection processing information of an end face, the optical transmission / reception The module is provided with detection means for detecting the length information of the optical fiber or the non-reflection processing information of the end face from the information means, and the switching unit performs switching based on the detection result from the detection means, so that the optical fiber used , The optimum communication method can be automatically determined.

In addition, in the optical transmission / reception system according to the sixth aspect of the present invention, the information means comprises a projection provided on a plug inserted into a connector of the optical transmission / reception module. A long-length optical fiber and an optical fiber whose end face has been subjected to non-reflection treatment are connected to another optical transmitting / receiving module to prevent erroneous insertion of the other optical transmitting / receiving module used in the system. Can be prevented from being unable to communicate due to excessive light quantity or insufficient light quantity.

[0032]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An optical transmission / reception module according to an embodiment of the present invention and an optical transmission / reception system using the same will be described with reference to the drawings.

The optical transmission / reception module according to the present embodiment is obtained by adding the following configuration to the conventional optical transmission / reception system. Only the added configuration will be described, and the same components as those of the conventional configuration will be described. Is omitted.

FIGS. 1A and 1B are structural views showing a first state of the optical transmission / reception system according to the embodiment of the present invention, wherein FIG. 1A is a transverse sectional view and FIG. 1B is a longitudinal sectional view. FIG. 2 is a block diagram showing a first state of the optical transceiver module used in the optical transceiver system according to the embodiment of the present invention. FIGS. 3A and 3B are structural diagrams showing a second state of the optical transmitting and receiving system according to the embodiment of the present invention, wherein FIG. 3A is a cross-sectional view and FIG. FIG. 4 is a block diagram showing a second state of the optical transceiver module used in the optical transceiver system according to the embodiment of the present invention. FIG.
1 is a front view of an optical transceiver module used in an optical transceiver system according to an embodiment of the present invention.

In FIG. 1, reference numeral 14 denotes an erroneous insertion prevention key formed of a projection provided on the surface of the plug 13 of the optical fiber cable 11, and reference numeral 22 b denotes an insertion hole provided in an insertion hole 22 a serving as a connector of the optical transceiver module 21. Hole 2
A groove into which the erroneous insertion preventing key 14 is inserted when the erroneous insertion preventing key 14 is inserted into the groove 2a is a switch serving as a detecting means for detecting the presence or absence of the erroneous insertion preventing key 14. The switch 27 includes a fixed terminal 27a and a movable terminal 27b which is provided in a non-contact state with the fixed terminal 27a and which comes into contact with the fixed terminal 27a when pressed by the erroneous insertion prevention key 14. Without the prevention key 14, an erroneous insertion prevention key 14 is detected by contact.

In FIG. 2, reference numeral 1 denotes an optical transmission / reception unit having a light emitting element and a light receiving element, 2 denotes a switch as a switching unit, and 3 denotes half-duplex communication for controlling the optical transmission / reception unit 1 by a half-duplex communication method. A half-duplex communication circuit, which is a control unit, 4 is a full-duplex communication circuit, which is a full-duplex communication control unit that controls the optical transmission / reception unit 1 in a full-duplex communication system, 5 is an external connection terminal, The communication unit 2 selectively switches the communication system for controlling the optical transmission / reception unit 1 to one of the half-duplex communication system and the full-duplex communication system.

First, conditions for establishing the full-duplex communication system will be described.

The full-duplex communication system is a system capable of receiving while transmitting, similarly to a telephone.
If the reflected light of the own transmission signal light is established, communication by the full-duplex communication method is possible.

In the optical transmission / reception system, the reflected light of the transmission signal light from its own light emitting element 23 is reflected by its own light receiving element 24.
The amount of light incident on the substrate was analyzed by optical simulation. The results are shown in Tables 1 and 2. FIG. 6 is a vertical cross-sectional view for explaining the reflection portion in Table 1.

[0040]

[Table 1]

[0041]

[Table 2] Assuming that the minimum receiving sensitivity of the receiving device including the optical system of the mold package 25 and the optical splitting element 26, which is the receiving side of the optical transmitting and receiving module, and the light receiving element 24 is -21 dB, the light splitting element 26 reduces the light amount by half (− 3 dB), the setting is made such that a reception signal light of at least −25 dB is incident on the light receiving element 24 in consideration of manufacturing variations.

Therefore, when the total sum of the reflected light of the own transmission signal light is -25 dB or less, communication by the full-duplex communication system becomes possible. That is, as can be seen from Tables 1 and 2, if there is no reflected light from the end face of the optical fiber (hereinafter referred to as “POF”) 12, communication by the full-duplex communication method is possible.

Therefore, the end face of the POF 12 is subjected to non-reflection processing, specifically, it is cut obliquely to deflect reflected light,
If an anti-reflection film made of magnesium oxide or the like is provided on the end face of the OF 12, the reflected light from the end face of the POF 12 is eliminated, so that communication using the full-duplex communication method is possible.

In Table 2, since the attenuation of the POF 12 is not taken into consideration, the amount of attenuation of the POF per unit length is -0.2 dB / m.
If the length is 3 m (optical fiber cable length), it is understood that communication by the full-duplex communication method is possible.

Next, the switching operation between the full-duplex communication system and the half-duplex communication system will be described.

The optical fiber cable 11 capable of performing communication by the full-duplex communication system is all provided with an erroneous insertion prevention key 14 having a projection on the surface of the plug 13.

As shown in FIG. 1, the plug 13 with the erroneous insertion prevention key 14
When the key is inserted into the key a, the switch 27 for detecting the presence or absence of the erroneous insertion prevention key 14 is turned on (ON). In this case, as shown in FIG. 2, the optical transceiver 1 and the full-duplex communication circuit 3 are electrically connected by the switch 2, and the output from the optical transceiver 1 is input to the full-duplex communication circuit 3. , Communication is performed by the full-duplex communication method.

On the other hand, the conventional optical fiber cable 1
In FIG. 1, since the plug 13 is not provided with the erroneous insertion prevention key 14, when the plug 13 is inserted into the insertion hole 22a of the optical transceiver module 21, as shown in FIG. Switch 4 is turned off (OF)
F). In this case, as shown in FIG. 4, the optical transmitter / receiver 1 and the half-duplex communication circuit 4 are electrically connected by the switch 2, and the output from the optical transmitter / receiver 1 is
, And communication by the half-duplex communication method is performed.

FIG. 7 shows the types of optical fiber cables that can be used in the optical transmission / reception system.

(A) is an optical fiber cable which is already commercially available, for example, a cable having a length of 1 m and the POF end face not subjected to an anti-reflection treatment. This fiber optic cable is
Digital audio optical signals can be transmitted by one-way optical communication, and IEEE 1394 optical signals can be transmitted by half-duplex communication. In this case, there is no erroneous insertion prevention key. The same applies to other optical fiber cables already on the market.

(B) shows that the cable length is 3 m or more (for example, 2 m).
0m) is an optical fiber cable whose end face is not subjected to non-reflection treatment. With this optical fiber cable, transmission of digital audio optical signals is impossible due to insufficient light quantity,
The transmission of the IEEE 1394 optical signal enables bidirectional optical communication by a full-duplex communication system. Therefore, the erroneous insertion prevention key 14 is an information unit that indicates length information that the POF length is long.
have.

(C) is an optical fiber cable in which the POF end face is obliquely cut. This fiber optic cable is
Although transmission of digital audio optical signals is impossible due to insufficient light quantity, transmission of IEEE 1394 optical signals allows bidirectional optical communication by full-duplex communication. Therefore, PO
It has an erroneous insertion prevention key 14 which is information means for indicating that the F end face has been subjected to anti-reflection processing.

(D) is an optical fiber cable whose POF end face has been subjected to antireflection processing. In this optical fiber cable, transmission of digital audio optical signals is impossible when a particularly short optical fiber is used due to excessive light quantity.
The transmission of the EEE1394 optical signal enables bidirectional optical communication by a full-duplex communication system. Therefore, it has an erroneous insertion prevention key 14 which is information means for indicating that the POF end face has been subjected to non-reflection processing.

In the present embodiment, the plug 13 is provided with the erroneous insertion prevention key 14, but for example, Japanese Patent Application No. 9-283516.
The plug 13 may be provided with a pattern as proposed in (1), and the switching unit 2 may be operated by recognizing the pattern by another detecting means of the optical transmission / reception module 21.

When the length of the optical fiber cable 11 is long (in other words, when the length of the POF 12 is long), only one key 14 for preventing the plug 13 from being erroneously inserted is used. Are set so that they can be distinguished by using two wrong insertion prevention keys 14, for example.
If the length of the optical fiber cable 11 is long, the current to the light emitting element 23 is increased, and if the length of the optical fiber cable 11 is short, the current to the light emitting element 23 is reduced, so that the power consumption can be reduced.

Further, if the number of erroneous insertion prevention keys 14 is increased or decreased stepwise according to the length of the optical fiber cable 11 and the drive current of the light emitting element 23 is increased or decreased stepwise, power consumption is further increased. Can be reduced.

FIG. 8 is a perspective view showing an example of an optical fiber cable provided with different numbers of erroneous insertion prevention keys. (A)
Shows the case where there is one erroneous insertion prevention key 14, and FIG.
Two cases where the erroneous insertion prevention key 14 is provided every 80 degrees are shown, and (c) shows three cases where the erroneous insertion prevention key 14 is provided every 120 degrees.

[0058]

As described above, according to the optical transmission / reception system according to the first aspect of the present invention, a half of an optical fiber which has not been subjected to anti-reflection processing on an end face already possessed by a user. In addition to enabling communication using the duplex communication method, communication can be performed using the full-duplex communication method with respect to an optical fiber having a long length or an optical fiber having an end face subjected to anti-reflection processing.
Therefore, the communication method can be selectively switched to the communication method according to the optical fiber used, and it is possible to prevent the user assets from being truncated and to enable high-speed transmission.

Further, according to the optical transceiver module of the second aspect of the present invention, it is possible to prevent a state in which communication cannot be performed when an optical fiber having a short length is used, and to transmit a signal when an optical fiber having a long length is used. Increase speed and enable high-speed transmission.

Further, according to the optical transceiver module according to the third aspect of the present invention, it is possible to reduce power consumption when using an optical fiber having a short length.

Furthermore, according to the optical transceiver module of the fourth aspect of the present invention, when an optical fiber having an end face subjected to anti-reflection processing is used, the transmission speed is improved to enable high-speed transmission. It is possible to prevent a state in which communication is not possible when using an optical fiber that has not been subjected to anti-reflection processing.

In addition, according to the optical transmission / reception system according to the fifth aspect of the present invention, it is possible to automatically select and switch to an optimum communication method according to the optical fiber used.

In addition, according to the optical transmitting / receiving system according to the sixth aspect of the present invention, an optical fiber having a long length and an optical fiber whose end face is subjected to non-reflection processing are used for other optical transmitting / receiving systems used in a digital audio system, for example. It is possible to prevent the other optical transmission / reception module connected to the module from becoming unable to communicate due to excessive light quantity or insufficient light quantity.

[Brief description of the drawings]

FIG. 1 is a structural diagram showing a first state of an optical transmission / reception system according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a first state of the optical transceiver module used in the optical transceiver system according to the embodiment of the present invention.

FIG. 3 is a structural diagram showing a second state of the optical transmitting and receiving system according to the embodiment of the present invention;

FIG. 4 is a block diagram illustrating a second state of the optical transceiver module used in the optical transceiver system according to the embodiment of the present invention.

FIG. 5 is a front view of an optical transceiver module used in the optical transceiver system according to the embodiment of the present invention.

FIG. 6 is an explanatory diagram of a reflection part.

FIG. 7 is a diagram for explaining types of optical fiber cables.

FIG. 8 is a perspective view showing an optical fiber cable provided with different numbers of erroneous insertion prevention keys.

FIG. 9 is a structural diagram of a conventional optical transmission / reception system.

FIG. 10 is a front view of an optical transceiver module used in a conventional optical transceiver system.

FIG. 11 is a diagram for explaining an optical operation of a conventional optical transmission / reception system.

FIG. 12 is a separated plan view of a conventional optical communication system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical transmission / reception part 2 Switching device 3 Full-duplex communication circuit 4 Half-duplex communication circuit 11 Optical fiber cable 12 Optical fiber 13 Plug 14 Mis-insertion prevention key 21 Optical transmission / reception module 22a Insertion hole 23 Light emitting element 27 Switch

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) H04L 5/16 // H04N 7/22 (72) Inventor Yuji Ichikawa 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka No. Sharp Corporation F-term (reference) 2H037 AA01 BA02 BA11 DA11 DA33 5C064 EA01 5K002 AA05 AA07 BA06 BA32 DA42 FA01 5K018 AA01 BA01 BA03 CA01 DA05 DA12

Claims (6)

[Claims] 1. An optical transmission / reception module including an optical transmission / reception unit for transmitting / receiving light to / from one optical fiber, comprising: a half-duplex communication control unit for controlling the optical transmission / reception unit by a half-duplex communication method; A full-duplex communication control unit that controls the optical transmitting / receiving unit using a full-duplex communication method, and a communication method that controls the optical transmitting / receiving unit is selected from the half-duplex communication method and the full-duplex communication method. An optical transmitting and receiving module, comprising: a switching unit for selectively switching. 2. The switching unit selects a half-duplex communication method when the length of the optical fiber is short, and selects a full-duplex communication method when the length of the optical fiber is long. The optical transceiver module according to claim 1. 3. The driving current of the light emitting element of the optical transmitting / receiving unit is reduced when the length of the optical fiber is short, and the driving current of the light emitting element is increased when the length of the optical fiber is long. The optical transceiver module according to claim 2, wherein 4. The switching unit selects a full-duplex communication system when an anti-reflection process is performed on an end face of the optical fiber, and selects a half-duplex communication system otherwise. The optical transceiver module according to claim 1. 5. An optical fiber cable provided with an optical fiber, and optical transmission and reception between said optical fiber.
An optical transmission / reception system comprising: the optical transmission / reception module according to any one of claims 1 to 3, wherein the optical fiber cable is provided with information means for indicating length information of the optical fiber or non-reflection processing information of an end face, the optical transmission / reception The module is provided with detecting means for detecting optical fiber length information or end face non-reflection processing information from the information means, and the switching unit performs switching based on a detection result from the detecting means. Transmission / reception system. 6. The optical transmission / reception system according to claim 5, wherein said information means comprises a projection provided on a plug inserted into a connector of said optical transmission / reception module.