JPH0223730A - Light-branching unit - Google Patents

Abstract

PURPOSE:To eliminate the needs for forming a loop for connecting respective stations and attain simple constitution by attaining optical communication in both ways without using an expensive optical transmission prism, passing a signal through the station concerned when a fault occurs in one of the stations so as to attain communication for the adjacent station. CONSTITUTION:A light-leading path for transmission light 16 in which an optical signal pass in both ways plays a role in terms of the bypass of the optical signal, and a light-leading path for reception light 17 receives the signal from an optical fiber 12 in both ways, which can be added and connected. First to third light-receiving ports 17a-17c are given to the light-leading path 17. First to third light-transmitting ports 18a-18c are provided in a light-leading path for transmission light 18 which transmits optical signals to two ways and optical fiber 12, and the branching light-leading path part B of a communication node 22 is composed of the light-leading path 16 and the light-leading paths for reception and transmission 17 and 18. The light-leading path part B and an optical fiber 11 are connected by connection end parts 13 and 14, and the both end connection parts are in a ternary state by the fiber 11 and the light-leading path part B.

Description

[Detailed description of the invention] [Industrial application field] This invention relates to an optical splitter, and more particularly.

- This relates to an optical branching device that can transmit and receive optical signals in both directions using a single optical fiber.

[Conventional technology]

FIG. 7 shows 1, for example, "
This is a branching communication device of the conventional optical communication device shown in ``Optical Switch.'' Figure 7(a) shows the state with the transmission prism in the optical path, and Figure 7(1b) shows the state with the transmission prism removed from the optical path. FIG. FIG. 8 is a block diagram showing a conventional optical transmission system.

Hereinafter, the term "communication node" refers to a turnout or turnout station, and is also simply referred to as a station.

In Fig. 7, (1) is an optical switch that switches the optical path, which is the traveling direction of the optical signal, and (2) is an optical transmitter with excellent light transmission that is movably installed in the optical switch (1). It's a prism. This transmission prism (2) is disposed in the optical path so that an optical signal can pass through the station in the event that one of the plurality of stations fails.

(3) and (4) are the upstream and downstream optical input ends of the optical switch (1), (5) and (6) are the optical switch (1)
They are the downstream optical output end and the upstream optical output end of the.

In FIG. 8, (7) to H are communication devices (stations), (7) is B station, (8) is 0 station, (9) is D station, α
1 is station A. αB is an optical fiber that transmits optical signals.

A conventional optical communication device is configured as described above, and uses an optical switch (1) using a transmission prism (2) as a branch communication device of the optical communication device. This operation will be explained below.

The light entering the upper light input end (3) of the optical switch (1) passes through the transmission prism (2) and flows out from the downward light output end (5) (see Figure 7+8). This light passes through, for example, the B station (7) in Figure 8, enters the downstream light input end (4) of the optical switch (1) again, and after passing through the transmission prism (2), the upstream light output end ( 6) to the optical switch (1) of the next station, station 0 (8). In this way, the optical signal from AAc0 passes through the optical fiber +I11, passes through each station in order, and is transmitted to station 9D (9). During normal operation, 3 stations + 71. At each station, 0 station (8) and D station (9), the optical signal is amplified to compensate for attenuation due to light absorption, scattering, etc. in the optical path.

If a failure occurs in any of these stations, move the transmission prism (2) in the optical switch (1) for that station using a drive device (not shown). The light entering the upstream light input end (3) of the optical switch (1) was directly output from the upstream light output end (6) (Fig. 7(b)).
reference). Then, the light was not branched and amplified at the failed station (it was transmitted to the secondary normal station).

In this way, in the conventional device, A station a1 → B station (7) → C
A loop was formed in which optical signals were transmitted in one direction, such as station (8)→D station (9)→AAc1.

[Problem to be solved by the invention]

In the conventional optical communication device as described above, when connecting multiple stations to form one optical transmission system, if one of the stations fails, the optical switch fl) connects the station to pass through (pass-through). ) Let me.

It was transmitting an optical signal to a neighboring station.

However, in this type of conventional device, an optical transmission prism (2), which is expensive and difficult to mass-produce, is used in the optical switch (1), which is a branch communication device of an optical communication device.

Ota. When forming an optical transmission system, it is necessary to connect each station to form a unidirectional loop.

Directionality was required in the transmission direction of optical signals.

Furthermore, if any station fails, the transmission prism (
2) A drive mechanism is required to move the device, making the device itself expensive and large.

For this reason, in this type of optical communication device, there has been a demand for optical branching communication that is simple and allows bidirectional transmission and reception of optical signals (without using expensive optical transmission prisms).

Therefore, this invention enables bidirectional optical communication.

Moreover, even if one of the stations breaks down, it is possible to pass through all stations and transmit optical signals to neighboring stations, and it is also necessary to form a loop between each station when configuring the system. The objective is to provide an optical splitter that does not require

[Means for Solving the Problems] The optical branching device according to the present invention has three connecting ends α41, α41, . (1!
9, 2 connection ends (I3. (14) are 2 e.g.
The remaining one connection end (l!9) is branched into two systems.One of the three systems connects the two connection points !+1.t14 from both directions. A light guide path 0e for passing light through which an optical signal can pass, and another one of the three systems mentioned above.
One of the two systems is branched into the two connection end α grooves, the first light receiving port (17a) and the second light receiving port (17b) that receive optical signals from the α destination direction, and one of the two systems branched out. The system is the one connection end a! A receiving light guide path 11η having a third light receiving port (17) for receiving optical signals from nine directions, and the remaining one of the three systems connect to the two connecting ends α, and transmit light toward the α center. The first light transmitting port (
18a) and the second light transmission port (18b), and the other system branched into the two systems connects to the first connection end (the third light transmission port (18c) that transmits the optical signal in the L jet direction). a transmission light light guide path α ladder having the above-mentioned light guide path α for receiving light;
The first light receiving port (17a) and the second light receiving port (17t+
) and a light receiving element U that receives an optical signal from the third light receiving port (17c) and converts it into an electrical signal.

an amplifier circuit for amplifying the electric signal from the light receiving element αl;
and converts the electric signal into an optical signal and transmits the light guide path for the transmitted light (
The first light transmitting port (18a) and the second light transmitting port (18b)
) and a light emitting element QB that emits an optical signal at the third light transmitting port (18c).

[Effect]

In the optical branching device of the present invention, two connecting ends α3, . (14 is the 2 connection end am, (1 The first light receiving port (17a) and the second light receiving port (17a)
a receiving light guide path (1rI) having a light receiving port (17b), and a first connecting end 0.a for transmitting optical signals in the 4 direction, respectively.
The light guide path 6s for transmission light has a light transmission port (18a) and a second light transmission port (18111), and is branched into three systems, and
The remaining one connection end al is connected to the one connection end a! A receiving light light guide path (I?) having a third light receiving port (17c) that receives optical signals from 9 directions, and a third light transmitting port (1?) that transmits the optical signal toward the 1 connection end 05 direction. 18c), and the energy conversion section (A).
The optical signals from the first light receiving port (17a), the second light receiving port (17b), and the third light receiving port (17c) of the received light guide path αη are converted into electrical signals by the light receiving element. The electric signal is amplified by the amplifier circuit -, and the electric signal is converted into an optical signal by the two light emitting elements 211, and the light guide path for transmitting light + the ISO first light transmitting port (18a), the second light transmitting port (tab), and Since the light is emitted from the third light transmitting port (18c), the optical signal transmitted through the single-wire optical fiber aυ can be received in both directions, and the optical signal can be photoelectrically converted into an electric signal. Various electrical signals can be converted into electrical signals and transmitted bidirectionally as optical signals. Moreover, a part of the optical signal can pass through the light guide path ae for transmitted light and be transmitted to a neighboring station or the like. Also,
Similarly K.

If it is possible to receive an optical signal transmitted through the optical fiber 12 made of a single wire, it is possible to convert various electrical signals into electro-optical signals and transmit them as optical signals.

〔Example〕

FIG. 1 is a circuit diagram showing a communication node of an optical branching device according to an embodiment of the present invention, and FIG. 2 is a sectional view showing the vicinity of a connection end of a branch optical path section of the communication node in FIG.

In the figure, fill is an optical fiber that transmits optical signals similar to conventional ones, a2 is an optical fiber that can be additionally connected even if it is continuously connected by optical fiber αD, (
C) is a communication node which is a branch in this embodiment. This communication node frame consists of a branch light guide section (B) and an energy conversion section (A). (I9 is a light-receiving element such as a photodiode that converts an optical signal into an electrical signal, the handle is a light-receiving element (19 is an amplifier circuit that amplifies the electrical signal photoelectrically converted, 6!l is a constant voltage power supply, and c!41 is an amplification Circuit (a)
This is an output transistor that is activated by a signal from the Qll is a light emitting element such as a light emitting diode (LED) that converts various electrical signals into optical signals, and the handle is a light emitting element 91.
) is a resistor that limits the current to the The energy conversion section (A) of the communication node performs both the operations of photoelectrically converting and amplifying the optical signal into an electric signal and the operation of electro-optically converting the electric signal into an optical signal. αe is a light guide path for passing light through which an optical signal can pass in both directions, and serves as a bypass for the optical signal. αη is a received light guide path that receives optical signals from the optical fiber σa, which can be bidirectionally connected and additionally connected, and includes a first light receiving port (17a) and a second light receiving port (17'b).
), and has a third light receiving port (17c). +111 is a light guide path for transmitting light that sends light signals to optical fiber circles that can be bidirectionally connected and additionally connected, and the first light sending port (18a
), second light transmitting port (18'b), third light transmitting port (18'c)
). Communication node (A) with the above-mentioned light guide path 11e for passing light, light guide path aη for receiving light, and light guide path +11 for transmitting light.
This constitutes a branch light guide path section (B).

Q3 and a4 are optical fiber αB and branch light guide section (B)
This is the connecting end. The relationship between this optical fiber +I11 and the branch light guide section (B) is as shown in FIG.

Both connection ends are in a three-branch state of a light guide path t1G for passing light, a light guide path αη for receiving light, and a light guide path fil for transmitting light. Also, tL! Reference numeral 9 denotes a connecting end between the optical fiber na that can be additionally connected and the branch light guide section (B), and the relationship between this connectable optical fiber a'tr and the branch light guide section (Bl) is as shown in FIG. Now, this connection end a
! 9 is in a bifurcated state of a light guide path (I?) for receiving light and a light guide path α barrel for transmitting light.

The optical splitter of this embodiment is configured as described above,
It is connected to each communication node station (not shown) located on both the left and right sides by an optical fiber ttn consisting of a single line, and is also connected to a third communication node station (not shown) located on both the left and right sides by a single line. It is connected by optical fiber 〇.

Here, the operation of the communication node (2), which is the optical branching device of this embodiment, will be explained below.

For example, a case will be described in which an optical signal is transmitted from a station located on the left side in FIG. A portion of the envelope signal transmitted within the optical fiber fill passes through the light guide path ae for passing light, and is transmitted as it is to the station located on the right side via the optical fiber I on the opposite side. Further, a part of the received light passes through the received light guide path (Iη) and is transmitted from the first light receiving port (17a) to the light receiving element a9.

This light-receiving element performs photoelectric conversion and becomes an electrical signal.

The signal is amplified by an amplifier circuit (Incorporated) and transmitted to the received signal input terminal RD as a collector signal via a transistor (Incorporated) for the l:E1 driver.

On the other hand, in the case of light transmission and transmission, the light emitting element QD emits light in response to an electric signal from the transmission signal terminal TD. The optical signal converted into electrical light by this light emitting element e9 is as follows.

Both connection ends Ql, 114 from the first light transmission port (18a) and the second light transmission port (18'b) of the light guide path a for transmission light.
The light is transmitted through the left and right optical fibers +111, and from the third light transmitting port (18c) to the optical fiber α2 connected to a third communication node station (not shown). and.

The signal is transmitted to the neighboring stations on the left and right and to the third station.

In the above case, the case where an optical signal is transmitted from a station located on the left side is described, but the same operation is performed when an optical signal is transmitted from a station located on two opposite sides.

Next, a case will be described in which an optical signal is transmitted from a third station connected to an additionally connectable optical fiber σ2.

The optical signal transmitted through the optical fiber nz passes through the received light guide path αη, and is transmitted from the third light receiving port (17c) to the received signal input terminal RD via the light receiving element αY.

On the other hand, in the case of light transmission transmission, as described above, the light is transmitted to the left and right adjacent stations and the third station, respectively.

As described above, the optical branching device of this embodiment can receive optical signals in both left and right directions and from the third station, and can also transmit optical signals in both directions and to the third station. I can do it.

Therefore, in this embodiment, even in optical fiber communication consisting of a single wire, there is no need to form a loop for optical communication, and bidirectional optical communication is possible.

Multi-drop bus communication becomes possible.

Furthermore, since it is possible to connect to a third station using an additionally connectable optical fiber, bidirectional communication in a tree-like system is also possible.

Moreover, in the case of multi-drop bus communication using the optical branching device according to the second embodiment of the present invention, a part of the optical signal passes through the light guide path ae for passing light as it is (pass-through) to the station located on the opposite side. Since optical signals can be transmitted to each other, even if the station in question breaks down or loses power, optical signals can be transmitted to the neighboring station. Therefore, even if one of the stations is out of order, the station will be allowed to pass through.

Optical signals can be reliably transmitted between neighbors.

Therefore, even if a communication system is configured with a large number of communication nodes, and even if this passing light can only pass through one station due to optical loss, etc., three consecutive circuits will fail. Unless otherwise specified, the entire communication system can be controlled.

If the distance between the two communication nodes is long and the optical loss of the passing light is large, as shown in FIG.

The connection end between the optical fiber αD and the branch light guide section (B) is branched into four systems, and two of these systems are connected to the light guide path a for passing light.
S, and the other system is called the receiving light guide path αη.

By using the remaining one line as a transmitting light guide path (one piece), the optical power of the passing light increases, and optical signals can be reliably transmitted between adjacent channels.

In particular, the probability that two consecutive stations will fail at the same time is theoretically extremely small compared to the probability that only one station will fail. Therefore, if the optical branching device of this embodiment is adopted, two System reliability can be dramatically improved.

Furthermore, since the optical branching device of this embodiment is capable of two-way communication, it can communicate with conventional electrical signal multi-drop bus communication using, for example, electrical coaxial cables.

The same communication protocol can be used.

That is, by attaching two communication nodes to each station of an electrical signal communication system such as a coaxial cable system, bidirectional optical communication can be easily performed.

Yet again. In this embodiment, each of the above-mentioned operations such as optical signal branching, signal extraction, and light transmission can be configured by the two-branch light guide section (B) without using the expensive transmission prism (2). Since this branching light guide path section (B) can be formed of an optical fiber or the like, the device becomes a very inexpensive device and can also be miniaturized.

Next, an example of use of the communication system using the optical branching device of this embodiment will be described. FIG. 5 is a circuit diagram showing a control system for an air conditioner which is an example of the use of the optical splitter of the present invention. This means that the communication node (to) explained in FIG.
A third optical fiber (12a) is connected to a communication system (X) configured by connecting multiple optical fibers I of this book.
It is a communication system configured in a tree shape by connecting several stations.

In the figure, (to) is communication node A (hereinafter referred to as A station)
This is an indoor unit for air conditioning (air conditioner) connected to the The left neighbor of this A station is B station, the right neighbor of A station is [0 station, D station,
Station E constitutes two communication systems (X). Also,
Similarly, the F station and G station constitute a communication system (Y). In the 2 communication systems (X) and (Y), the F station is additionally connected to the A station and the 19 F stations are additionally connected to the 0 station, resulting in a communication system configured in a tree shape as a whole. c3
B and D connected respectively.

For example, it is a remote control (hereinafter referred to as a remote control) of an air conditioning temperature controller. 03 is a commercial power source that is a power source for driving each air conditioning indoor unit (to), and @ is an air conditioning outdoor unit that is differentially paired with each air conditioning indoor unit (to). [Yes] is a microcomputer built into the remote control C11l, and @ is a microcomputer built into the air conditioning indoor unit (to).

The control system for this air conditioner is 9. For example, in a large room
, B, C! A system (X) in which air conditioning indoor units (to) connected to stations , D, and E are arranged in four units and their operation is controlled according to temperature, etc. with one remote control I3n.
A system consisting of air conditioning indoor units (to) connected to station F and station G (power is additionally connected and operation is controlled by one remote control C1l+.The control signal in remote control C is D). A and B are converted into optical signals at the station and sent in both left and right directions.

It is transmitted to stations 0 and E and additionally connected stations F and G.

Communication operations in the control system configured as described above will be described below.

First, a temperature signal set by the clII using the remote controller is outputted as an electrical signal from the microcomputer (Incorporated) to the transmission signal output terminal TD.

This signal is subjected to electro-optical conversion by the light emitting element Q11 in the communication node, as described in the explanation of FIG. 1 above.

Then, as an optical signal, the first light transmitting port (18a), the second light transmitting port (18b), and the light transmitting port (18c) in FIG.
(not used) is optically transmitted to stations 0 and E, which are located on both the left and right sides of station D, via optical fiber a9.

The communication node of station 0 receives this optical signal.

A part of the optical signal passes through the transport light guide path (1e) and is directly transmitted to the adjacent station A.

A part of the received light passes through the light guide path (Iη) and is transmitted from the light receiving port to the light receiving element H9.Then, it is converted into an electrical signal by the light receiving element member, and further amplified by the amplifier circuit (A). , is input to the reception signal input terminal RD.This input signal is input to the microcomputer (to) in the air conditioning indoor unit (a).
is received. The microcomputer (to) generates a signal with a predetermined communication speed and a predetermined constant pulse width in synchronization with this received signal. Then, the transmission signal is output to the transmission signal output terminal TD of each communication node (to). After that, the transmitted signal is converted into electrical light, and the optical signal is optically transmitted through optical fiber 09 to stations A and D, which are located on both the left and right sides of station 0.

The signal is optically transmitted to station F through an optical fiber (12b) for additional connection.

Therefore, the temperature setting signal from the remote controller 01 is transmitted to the A station as well as to the 0 station. Furthermore, the signal is energized and transmitted at station 0. Therefore, even if several stations are connected to the left side of station A, the same communication information can be sequentially transmitted in the same way.Also.

The same applies to the remote control (station D) on the right side.

Moreover, since each of these stations has 9 light guide paths αG for passing light, for example, if 0 stations are out of order or the commercial power supply (c)
Even if station D is not supplied, the communication signal from station D is transmitted to the neighboring station.

On the other hand, the F station, which is optically transmitted from the C station through the optical fiber (12b) for additional connection, can also sequentially transmit the same communication information to the 0th station and its right neighbors in the same manner as described above.

Here, for transmission from station 0 to station F, an additional connection end (I5
However, if station 0 becomes unable to transmit light due to a failure or the like because it does not have a light guide path Oe for passing light for the signal from station D (or station A).

Information will no longer be transmitted to station F. Therefore, by connecting stations 2 other than station 0, for example, station A and station F, communication information can be transmitted to station F even if station 0 has a failure or the like. This means that, in the same way that two consecutive stations can communicate via the light guide path σ0 for passing light as long as there is no failure, station 0 (!:C For example, station 2 other than the station.

Communication information can be transmitted to station F except when both stations of A station cannot transmit light at the same time due to a failure or the like.

As mentioned above, the communication node (a) of this embodiment is.

Even if a station is unable to transmit light due to a failure of a certain station, the entire tree-like communication system other than the failed station can be controlled as long as the failure does not occur three consecutive times. Furthermore, even if it is desired to add a remote control (not shown) to stations other than the D station, it can be easily added by, for example, connecting an optical fiber to the additional connection end aS of the E station.

By the way, in each of the above embodiments, the use of the optical splitter in an air conditioner control system was omitted, but there are two cases in which the present invention is implemented.

It is not limited to this system. for example.

Due to the characteristics of optical communication, which is not affected by electromagnetic noise, it can be widely used in information equipment such as personal computers, factory communication systems such as NO machines, home automation communication systems, etc. It can be used in industry.

FIG. 6 is a block diagram of an embodiment of a control system for information equipment such as a personal computer, which is another example of the use of the present invention. In addition, in Figure 2.

The same reference numerals and symbols as in FIGS. 1 to 5 indicate constituent parts that are the same as or correspond to the constituent parts of the previous embodiment, and repeated explanation will be omitted here.

In particular, only the differences from the embodiment shown in FIG. 5 will be explained.

This control system can be used for example in Building B, where a network of information devices such as personal computers is set up.
and Building T are connected by optical communication.

It constitutes one system. In each building S and building TF1'3, an information device 14G such as a personal computer is connected to the communication node (a) of this embodiment, forming two communication systems. Additional connection end a! 9, there is no need to connect from the ends of Building S and Building T (,
By connecting an arbitrary communication node (a) that is the shortest distance and easiest to connect between Building Day and Building T, Shiwapiru S and Building T can be configured as one communication system.

For example, the communication system inside the L-shaped pill S and the L-shaped building S
When connecting the communication system in building T adjacent to the L-shaped bend, connect any communication node in building T to the communication node station near the L-shaped bend in building S. Optical fiber (12a) that can be connected and additionally connected
), by bypass-connecting any two stations in buildings S and T, even if the communication node station (c) that directly connects buildings S and T is unable to transmit information due to a failure etc. Building S and building T, ! by the optical light guide path 0e that can pass through (bus-through) and the bypassed additional connecting optical fiber (12b)! A communication system that integrates : can communicate information except for the failed station.

Further, by combining the optical branching devices according to this embodiment, optical connection communication using an infinite tree-like multi-drop bus system is possible.

〔Effect of the invention〕

As explained above, the optical splitter of the present invention is as follows.

The branching light guide section that connects to the optical fiber for optical communication includes a light guide path for passing light through which an optical signal can pass, a light guide path for receiving light having a first light receiving port and a second light receiving port, and a first light guide path for receiving light having a first light receiving port and a second light receiving port. It is branched into three systems: a light guide path for transmitting light having a light transmitting port and a second light transmitting port, and an additional connection end is connected to a light guide path for receiving light having a third light receiving port and a light guide path for transmitting light having a third light receiving port. The light guide path for transmitting light has a first light receiving port, and the first light receiving port has a first light receiving port.
The optical signal from the second light receiving port and the third light receiving port is photoelectrically converted by the light receiving element, and the electrical signal is amplified by the amplifier circuit, and the electrical signal is converted into electrical light by the two light emitting elements, and the light signal is converted to the first light receiving port. By emitting light to the second light transmitting port and the third light transmitting port, it is possible to receive the optical signal transmitted within the optical fiber consisting of a single wire in both directions. It is possible to receive optical signals that transmit both signals, convert the optical signals into electrical signals, and convert various electrical signals into optical signals and send them in both directions and to additional connection terminals. When forming a loop, <
, single-wire bidirectional optical communication is possible even in a tree-like communication format. Moreover, in the multi-drop bus configuration, a part of the optical signal passes through the light guide path for passing light and is transmitted to the neighboring residence, etc., and in the tree-like communication configuration, two additional optical fibers are connected. By doing so, even if the station in question is out of order, it is possible to transmit optical signals to the neighboring house, thereby improving the reliability of the two communication systems.

Furthermore, each operation such as branching of optical signals, outputting signals, and transmitting light can be performed without using a transmission prism, making it extremely inexpensive and compact.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing a communication node of an optical branching device according to an embodiment of the present invention, FIG. The figure is also a sectional view showing the vicinity of the additional connection end of the communication node in Figure 1;
FIG. 4 is the same (a sectional view showing the vicinity of the connecting end of the branched light guide when the communication node in FIG. 1 has two light guides for passing light. FIG. FIG. 6 is a block circuit diagram showing a control system for an air conditioner, which is an example of how the distributor is used; FIG. Fig. 7 is a plan view showing a state in which a transmission prism of an optical switch used in a conventional optical communication device is inserted into the optical path and a state in which the transmission prism is removed from the optical path, and Fig. 8 shows a conventional optical transmission system. This is a configuration diagram. In the figure, α] is an optical fiber, f12 is an additional optical fiber that can be connected, α3 is a connection end for three systems, αe is a connection end for two systems, and σe is a light guide path for passing light. ,aη
(17a) is the light guide path for receiving light, (17a) is the first light receiving port,
(17b) is the second light receiving port, (17c) is the third light receiving port, α barrel is the light guide path for transmitting light, (18a) is the first light receiving port.
(18b) is the second light transmission port, (18
c) is the third light transmission port, A is the energy conversion section, and B is the branch light guide path section. In addition, in FIG. 9, the same reference numerals and the same symbols indicate the same or equivalent parts.

Claims (1)

[Scope of Claims] An optical branch comprising three connection ends connected to optical fibers for optical communication, which have two connection ends where a branch light guide path is branched into three systems and one connection end where the branch light guide path is branched into two systems. In the device, there is provided a communication light guide path that allows optical signals to pass from both directions between the two connection ends branched into the three systems, and an optical signal guide path that allows optical signals from both directions to pass between the two connection ends that are branched into the three systems. a received light light guide path having a first light receiving port and a second light receiving port that each receive light, and a third light receiving port that receives an optical signal from the one connection end direction branched into the two systems; a first light transmitting port and a second light transmitting port that respectively transmit optical signals in both directions of the two connection ends that are branched into the two systems; and a third light transmission port that transmits optical signals in the direction of the one connection end that has branched into the two systems.
a light guide for transmitting light having a light transmitting port, and a light receiving element that receives optical signals from the first light receiving port, second light receiving port, and third light receiving port of the light guide for receiving light and converts them into electrical signals. an amplifier circuit that amplifies the electrical signal from the light receiving element; and an amplifier circuit that converts the electrical signal into an optical signal and connects the first light transmitting port, the second light transmitting port, and the third light transmitting port of the light guide path for transmitting light. What is claimed is: 1. An optical splitter comprising: an energy converter having a light emitting element for sending light to a light transmitting port;