KR100704400B1 - Coarse Wavelength Division Multiplexing Diplexer - Google Patents

Abstract

The present invention relates to a low density wavelength division multiplexing diplexer in which a light emitting element and a light receiving element are integrated. The diplexer according to the present invention is a connection member connected to the optical cable, a light emitting element for converting the electrical signal corresponding to the information to the optical signal to emit to the connection member, and converts the optical signal introduced through the connection member into an electrical signal An optical splitter disposed between the light receiving element, the connecting member, the light emitting element, and the light receiving element and transmitting a part of the optical signal and reflecting the rest, and a light beam installed between the light emitting element and the optical splitter and drawn through the connecting member. And an isolator for blocking the arc from entering the light emitting element, and a housing for fixing the connection member, the light emitting element, the light receiving element, the optical splitter, and the isolator.

Optical communication, diplexer, light emitting device, light receiving device, splitter, low density wavelength division multiplexing

Description

Coarse Wavelength Division Multiplexing Diplexer

1 is a block diagram showing a low density wavelength division multiplexing passive optical network according to the prior art;

FIG. 2 is a view showing a pigtail type light emitting device used in the low density wavelength division multiplexing passive optical network of FIG. 1; FIG.

3 is a view illustrating a receptacle type light emitting device used in the low density wavelength division multiplexing passive optical network of FIG. 1;

4 is a view showing an embodiment of a low density wavelength division multiplexing diplexer according to the present invention;

5 is a view showing another embodiment of a low density wavelength division multiplexing diplexer according to the present invention;

Figure 6 is a block diagram showing a low density wavelength division multiplexing passive optical network using a low density wavelength division multiplexing diplexer according to the present invention.

* Explanation of symbols for main parts of drawings *

1,2,3; Optical cable 10; OLT

14,21; Mux / demux 16,17,18,23,24,35; connector

20; RN 100,100 '; Diplexer

101,101 '; Light emitting elements 102, 102 '; Light receiving element

103; Connecting member, pigtail 106; Optical splitter

107; Isolator 109; Receptacle

110,120; MCU

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to optical communication using a wavelength division multiplexing method, and more particularly, to a diplexer for low density wavelength division multiplexing.

In today's advanced information society, the demand for high-speed Internet, high-capacity data services, and multimedia communications is exploding. Therefore, in order to realize such a high-speed information and communication network, continuous research is being conducted in order to increase national competitiveness as well as major enterprises and research institutes. In order to implement such a high speed information communication network, an ultra high speed optical communication network based on optical communication using light has been developed. Examples of such high-speed optical communication networks include Fiber-To-The-Curb (FTTC), Fiber-To-The-Pole (FTTP), and Fiber-To-The-Home (FTTH).

As one of techniques for achieving such FTTx, a wavelength division multiplexing method is used.

The wavelength division multiplexing method is a multiplexing method using multiple communication channels with one transmission line. That is, the wavelength division multiplexing method transmits signals having different wavelengths through one transmission line, and the receiving side separates the transmitted signals into signals according to respective wavelengths. Such wavelength division multiplexing is largely divided into Dense Wavelength Division Multiplexing and Coarse Wavelength Division Multiplexing.

At present, a low density wavelength division multiplexing method having low power consumption, small size, and low cost is widely used. Such a low density wavelength division multiplexing method can multiplex and transmit 16 individual optical signals on a single optical cable by wavelength division multiplexing. In general, low-density wavelength division multiplexing uses 16 channels of 18 channels spaced at 20nm intervals from 1270nm to 1610nm using the communication field of the optical field.

An example of a passive optical network using a low density wavelength division multiplexing scheme is shown in FIG. 1.

Referring to FIG. 1, a low density wavelength division multiplexing passive optical network (CWDM-PON) includes an optical line termination (OLT), a remote node (RN), and an optical network unit (ONU).

The OLT 10 is installed in a communication company and connected to an external Internet. The OLT 10 includes a plurality of MCUs (media converters) connected to one channel of the first mux / demux 14 and the channel 15 of the first mux / demux 14 having a plurality of channels. Unit). Each MCU 8 converts the received optical signal into an electrical signal and converts an electrical signal to be transmitted into an optical signal, which corresponds to each ONU 30 to be described later one to one. In general, since the first mux / demux 14 includes 16 channels 15, 16 MCUs 8 are connected to the first mux / demux 14. In addition, each channel 15 of the first mux / demux 14 and each MCU 8 are connected to the connectors 16 and 18 and the first optical cable 1.

The RN 20 is installed near the subscriber and is composed of a second mux / demux 21. The RN 20 is connected to the OLT 10 and the second optical cable 2 of one core. The connection of the second optical cable 2 and the first and second mux / demux 14, 21 uses a connector 17, 24.

The ONU 30 is installed at the subscriber side, and serves to connect the subscriber side and the optical communication network. Each ONU 30 is connected to each channel 22 of the second mux / demux 21 of the RN 20, and the ONU 30 and each channel 22 are connected to a third optical cable (1 core). 3) is connected. The ONU 30 includes an MCU 31 that converts the received optical signal into an electrical signal and converts the electrical signal into an optical signal.

Each MCU 8, 31, which is a component of the OLT 10 and the ONU 30, includes a light emitter 11, a light receiver 12, and an optical splitter 13. The light emitter 11 converts an electrical signal corresponding to information to be transmitted into an optical signal, and a DFB LD (Distributed FeedBack Laser Diode) is commonly used. The light receiver 12 converts an optical signal received from the ONU 30 into an electrical signal, and photodiodes (PDs) are commonly used. The optical splitter 13 transmits the optical signal transmitted from the light emitter 11 to the ONU 30, and the optical signal transmitted from the ONU 30 to the light receiver 12.

The light emitter 11 and the light receiver 12 are configured in a pigtail manner or a receptacle manner.

2 shows a peak tail light emitter 11, and FIG. 3 shows a receptacle light emitter 11 '.

In the pigtail type light emitter 11, LD which is a light emitting element 41 is provided at one end of the housing 45, and a pigtail 42 is provided at the other end. Pigtail 42 is composed of a predetermined length of the optical fiber 43 and the connector 44. Therefore, when the connector 44 of the pigtail 42 is connected to the optical splitter 13, the optical signal of the light emitting element 11 may be transmitted to the first optical cable 1 through the optical splitter 13.

In the light emitting device 11 'of the receptacle type, an LD, which is a light emitting element 41, is installed at one end of the housing 45, and a receptacle 46 is installed at the other end. Therefore, the optical splitter 13 may be connected to the optical splitter 13 by connecting an optical fiber having a separate connector to the receptacle 46 of the light emitter 11 ′.

The light receiver 12 has the same structure as the light emitter 11 described above except that a light receiver (not shown) is provided where the light emitting element 41 of the light emitter 11 is installed. Therefore, the description of the light receiver 12 is omitted.

In the MCUs 8 and 31 which use the light emitter 11 and the light receiver 12 as described above, the light emitter 11, the light receiver 12, and the optical splitter 13 are separately provided, and each of them is an optical fiber. It is connected with the connector. Therefore, the conventional MCUs 8 and 31 have a problem that the structure is complicated and it is difficult to downsize. In addition, there is a problem that it is difficult to lower the price because a large number of parts must be used.

The present invention has been made in view of the above problems, and an object thereof is to provide a diplexer for low density wavelength division multiplexing that can be miniaturized, simplified, and inexpensive.

An object of the present invention as described above, the connection member is connected to the optical cable; A light emitting device converting an electrical signal corresponding to information into an optical signal and emitting the same to the connection member; A light receiving element for converting an optical signal introduced through the connection member into an electrical signal; An optical splitter disposed between the connection member, the light emitting device, and the light receiving device, the optical splitter transmitting a part of the optical signal and reflecting the other part; An isolator disposed between the light emitting element and the optical splitter, the isolator blocking the light signal introduced through the connection member from being introduced into the light emitting element; And a housing for fixing the connection member, the light emitting element, the light receiving element, the optical splitter, and the isolator.

In this case, the light emitting device is installed at a position where the emitted optical signal penetrates the optical splitter and enters the connection member, and the light receiving element can receive the optical signal that is introduced from the connection member and reflected on the optical splitter. Is installed in position.

As another example, the light emitting device is installed at a position where the emitted optical signal is reflected from the optical splitter and drawn into the connecting member, and the light receiving element receives the optical signal that is introduced from the connecting member and passes through the optical splitter. Can be installed wherever possible.

The optical splitter may use any one of a filter having a ratio of 50:50, 70:30, and 30:70 between the transmitted optical signal and the reflected optical signal.

In addition, it is preferable that the connecting member is formed of either a pigtail or a receptacle.

In addition, the low density wavelength division multiplexing diplexer according to the present invention is installed inside the housing, and further comprises a light absorbing unit for absorbing the optical signal that is not incident to the connection member of the optical signal emitted from the light emitting element; It is preferable.

In addition, one end of the connecting member is preferably anti-reflective treatment.

Hereinafter, an embodiment of a low density wavelength division multiplexing diplexer 100 according to the present invention will be described with reference to the accompanying drawings. However, in the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description and specific illustration thereof will be omitted. In addition, in the following description, the connector means either a female connector or a male connector, or a state in which a female and a male connector are connected.

Referring to FIG. 4, the low density wavelength division multiplexing diplexer according to the present invention 100, the connection member 103, the light emitting element 101, the light receiving element 102, the optical splitter 106, and the isolator 107. ), And housing 108.

The connecting member 103 may connect the optical cable 1 (see FIG. 6) and the diplexer 100, and may be configured as a pigtail or a receptacle. In this embodiment, the connecting member 103 is composed of a pigtail.

The pigtail 103 is composed of an optical fiber 104 and a connector 105 of a predetermined length, and one end of which the connector 105 is not installed is fixed to the housing 108 by the ferrule 104a. Accordingly, the connector 105 of the pigtail 103 is connected to the mux / demux channel by an optical cable of one core. At this time, it is preferable that one end 104b of the optical fiber 104 into which the light emitted from the light emitting device 101 is incident is subjected to anti-reflective treatment so as to minimize the amount of incident light reflected. The anti-reflective treatment method includes an anti-reflective coating directly on the surface of the optical fiber 104 and the ferrule 104a fixing the optical fiber 104, and after the anti-reflective coating on a thin glass plate similar to the refractive index of the optical fiber 104, and then adhesive There is a method of adhering to one surface 104b of the ferrule 104a.

FIG. 5 shows a reflector 100 'in which the connecting member is a receptacle as another embodiment of the diplexer for low density wavelength division multiplexing according to the present invention. The diplexer 100 ′ of FIG. 5 is the same as the diplexer 100 of the above-described embodiment except that the receptacle 109 is formed at one end of the housing 108. The receptacle 109 is a kind of female connector to which the male connector is inserted and fixed. Therefore, when the connector with a one-core optical cable is connected to the receptacle 109 of the low density wavelength division multiplexer 100 'according to another embodiment of the present invention, the diplexer 100' is connected to a mux / demux. Can be connected to the channel.

The light emitting device 101 converts an electric signal corresponding to the information into an optical signal and emits the light to the connection member 103. In the light emitting device 101, DFB LD (Distributed FeedBack Laser Diode) for low density wavelength division multiplexing is commonly used. A plurality of pins 101a are provided at a lower end of the light emitting device 101 and are connected to a light emitting substrate (not shown) for generating an electric signal corresponding to the information. The condenser lens 101b for condensing is provided at the upper end of the light emitting element 101. This can be used for any element having a function of condensing light, such as a ball lens, a spherical lens, an aspherical lens.

The light receiving element 102 converts an optical signal drawn through the connection member 103 into an electric signal, and a low density wavelength division multiplexing PD (Photo Diode) is commonly used. A plurality of pins 102a are provided at a lower end of the light receiving element 102, and are connected to a light receiving substrate (not shown) for processing an electrical signal output from the light receiving element 102. A light collecting lens 102b for condensing is installed at the upper end of the light receiving element 102. This can be used for any element having a function of condensing light, such as a ball lens, a spherical lens, an aspherical lens.

The optical splitter 106 is installed in the housing 108 between the connecting member 103, the light emitting element 101, and the light receiving element 102, and transmits a part of the incident optical signal, and reflects the remaining optical signal. Filter. In this case, the optical splitter 106 uses a semi-transmissive filter that transmits half of the incident optical signals and reflects half of them, that is, a filter having a ratio of 50:50 between the transmitted optical signals and the reflected optical signals. It is preferable. However, according to the purpose, various filters may be used in which the amount of the optical signal transmitted to the optical splitter 106 and the amount of the reflected optical signal are different. For example, when the user wants a strong output value, an optical splitter having a ratio of 70:30 between the transmitted optical signal and the reflected optical signal is used.If the user wants a strong input value, the transmitted optical signal is transmitted. An optical splitter in which the ratio of the optical signal to the reflected optical signal is 30:70 is used. Herein, the ratio between the incident optical signal and the transmitted optical signal is only one example, and it is natural that the ratio may be appropriately determined according to the use.

The isolator 107 is installed between the light emitting element 101 and the optical splitter 106, and an optical signal transmitted through the optical splitter 106 among the optical signals introduced through the connecting member 103 is transferred to the light emitting element 101. Block incoming.

The housing 108 fixes the aforementioned connection member 103, the light emitting device 101, the light receiving device 102, the light splitter 106, and the isolator 107 so that the space between them is maintained. Inside the housing 108 is provided a light absorbing portion 108a for absorbing an optical signal emitted from the light emitting element 101 and reflected from the optical splitter 106. The light absorbing portion 108a is formed of a hole, and the inside of the hole has a structure that reflects the incident light several times. At this time, the inner surface of the hole of the light absorbing portion 108a is preferably painted to minimize the reflection of light.

Hereinafter, the operation of the low density wavelength division multiplexing diplexer 100 according to the present invention as described above will be described with reference to FIG. 4.

When an electric signal corresponding to information is input from a light emitting substrate (not shown), the light emitting element 101 emits an optical signal corresponding to the input electric signal. The optical signal emitted from the light emitting element 101 passes through the isolator 107 and is incident to the optical splitter 106. Part of the optical signal incident on the optical splitter 106 passes through the optical splitter 106, and the other optical signal is reflected. If the optical splitter 106 is a transflective filter, half of the optical signal passes through the optical splitter 106 and the other half is reflected by the optical splitter 106. The reflected optical signal is introduced into the light absorbing unit 108a and extinguished. The optical signal transmitted through the optical splitter 106 is transmitted to the optical cable to which the pigtail is connected through the connecting member 103, that is, the pigtail.

On the contrary, when the optical signal is transmitted through the pigtail that is the connecting member 103, the transmitted optical signal is incident to the optical splitter 106. Half of the optical signal incident on the optical splitter 106 passes through the optical splitter 106 and the other half is reflected by the optical splitter 106. The optical signal transmitted through the optical splitter 106 does not enter the light emitting element 101 by the isolator 107 and disappears. In addition, the optical signal reflected by the optical splitter 106 is led to the light receiving element (102). The light receiving element 102 outputs an electric signal corresponding to the incoming optical signal to a light receiving substrate (not shown).

In the above description, the light emitting device 101 is installed at a position where the emitted optical signal penetrates the optical splitter 106 and enters the connection member 103, and the light receiving element 102 is drawn from the connection member 103 and is an optical splitter. Although the diplexer 100 provided at the position capable of receiving the optical signal reflected by the 106 has been described, the diplexer for low density wavelength division multiplexing according to the present invention is not limited thereto.

That is, although not shown, the light emitting element 101 is installed at a position where the emitted optical signal is reflected by the optical splitter 106 and drawn into the connecting member 103, and the light receiving element 102 is drawn from the connecting member 103. It is also possible to configure a low-density wavelength division multiplexing diplexer installed at a position capable of receiving an optical signal transmitted through the optical splitter 106.

Hereinafter, in another aspect of the present invention, a low density wavelength division multiplexing passive optical network (CWDM-PON) using the low density wavelength division multiplexing diplexers 100 and 100 'according to the present invention will be described with reference to the accompanying drawings. It demonstrates.

Referring to FIG. 6, a low density wavelength division multiplexing passive optical network includes an optical line termination (OLT) 10, a remote node (RN) 20, and an optical network unit (ONU) 30.

The OLT 10 is installed in a telecommunication company or a telephone station, and is connected to an external Internet or the like that provides an additional service. The OLT 10 includes a plurality of agents connected to each of the first mux / demux 14 and the channel 15 of the first mux / demux 14 having a plurality of channels 15. It consists of 1 Media Converter Unit (MCU) 110. Each of the first MCU 110 converts the received optical signal into an electrical signal and converts the electrical signal into an optical signal. In general, since the first mux / demux 14 includes 16 channels 15, 16 first MCUs 110 are connected to the first mux / demux 14. In addition, each channel 15 of the first mux / demux 14 and each of the first MCUs 110 are connected to the first optical cable 1 and the connectors 16 and 18.

The RN 20 is installed near the subscriber and is composed of a second mux / demux 21. The second mux / demux 21 of the RN 20 and the first mux / demux 14 of the OLT 10 are connected to the second optical cable 2. The connection of the second optical cable 2 and the first and second mux / demux 14, 21 uses a connector 17, 24.

The ONU 30 is installed at the subscriber side, and serves to connect the communication device and the optical communication network at the subscriber side. Each ONU 30 is connected one-to-one to each channel 22 of the second mux / demux 21 of the RN 20, and the ONU 30 and each channel 22 are connected to the third optical cable 3. ). The ONU 30 includes a second MCU 120 that converts the received optical signal into an electrical signal and converts the electrical signal into an optical signal.

In the above, the first, second, and third optical cables 1, 2, and 3 use one core optical cable having one core.

Each of the first and second MCUs 110 and 120, which are components of the OLT 10 and the ONU 20, has a low density according to the present invention in which the light emitting device 101, the light receiving device 102, and the optical splitter 106 are integrated. And a diplexer (100, 100 ') for wavelength division multiplexing. Since the configuration of the low density wavelength division multiplexing diplexers 100 and 100 'is the same as described above, a detailed description thereof will be omitted.

Hereinafter, the operation of the low density wavelength division multiplexing passive optical network configured as described above will be described with reference to FIGS. 4 to 6.

First, a case in which information is sent from the subscriber to the user side toward the OLT 10 will be described. When the user sends information, an electrical signal corresponding to the information that the user wants to send is introduced into the second MCU 120 of the ONU 30. The electrical signal introduced into the second MCU 120 is introduced into the second light emitting device 101 'of the second diplexer 100' through a second light emitting substrate (not shown). Then, the second light emitting element 101 'emits an optical signal corresponding to the electric signal. The optical signal emitted from the second light emitting element 101 'passes through the second isolator 107' and enters the second optical splitter 106 '. Half of the optical signal introduced into the second optical splitter 106 'passes through the second optical splitter 106' and enters the optical fiber of the receptacle 109 fixed by the ferrule 104'a. At this time, since one end 104'b of the ferrule 104'a is subjected to anti-reflection processing, the amount of reflection of the incident optical signal is minimized. Therefore, the light emitted from the second light emitting element 101 'is minimized to act as noise of the second light receiving element 102'. The optical signal introduced into the receptacle 109 is introduced into the second mux / demux 21 of the RN 20 through the male connector 35 of the third optical cable 3 inserted into the receptacle 109. In addition, the optical signal reflected by the second light splitter 106 'is introduced into the second light absorbing unit 108'a and extinguished.

The optical signal introduced into one channel 22 of the second mux / demux 21 is multiplexed with the optical signal introduced into the other channel of the second mux / demux 21 to be OLT through the second optical cable 2. Transmitted to the first mux / demux 14 of (10). The optical signal transmitted to the first mux / demux 14 is divided into 16 channels 15 and introduced into the first MCU 110 connected to each channel 15 through the first optical cable 1.

The optical signal introduced into the first MCU 110 is incident to the first optical splitter 106 through the pigtail 103. Half of the optical signal incident on the first optical splitter 106 is transmitted through the first optical splitter 106 to the first isolator 107, and the other half of the optical signal is reflected on the first optical splitter 106. And incident toward the first light receiving element 102. The optical signal incident on the first light receiving element 102 is converted into an electrical signal by the first light receiving element 102 and output to the first light receiving substrate (not shown). Then, the first light receiving substrate performs an operation according to the electrical signal corresponding to the information sent by the user. The optical signal transmitted through the first optical splitter 106 is extinguished without being transmitted to the first light emitting device 101 by the first isolator 107.

Next, the case where information is sent from the OLT 10 side to the user side will be described. An electrical signal corresponding to the information is introduced into the first MCU 110. The electrical signal introduced into the first MCU 110 is introduced into the first light emitting device 101 of the first diplexer 100 through a first light emitting substrate (not shown). Then, the first light emitting device 101 emits an optical signal corresponding to the electric signal. The optical signal emitted from the first light emitting element 101 passes through the first isolator 107 and enters the first optical splitter 106. Half of the optical signal introduced into the first optical splitter 106 passes through the first optical splitter 106 and enters the optical fiber 104 of the pigtail 103 fixed by the ferrule 104a. At this time, since one end 104b of the ferrule 104a is anti-reflective, the amount of reflection of the incident optical signal is minimized. Therefore, the light emitted from the first light emitting device 101 is minimized to act as noise of the first light receiving device 102. The optical signal introduced into the pigtail 103 is introduced into the channel 15 of the first mux / demux 14 through the first optical cable 1 connected to the connector 105. In addition, the optical signal reflected by the first optical splitter 106 is introduced into the first light absorbing unit 108a and extinguished.

The optical signal introduced into one channel 15 of the sixteen channels of the first mux / demux 14 is multiplexed with the optical signal introduced into the other channel of the first mux / demux 14 so that the second optical cable 2 Is transmitted to the second mux / demux 21 of the RN 20. The optical signal transmitted to the second mux / demux 21 is divided into 16 channels 22 and introduced into the second MCU 120 connected to each channel 22 through the third optical cable 3.

The optical signal introduced into the second MCU 120 is incident to the second optical splitter 106 ′ through the receptacle 109. Half of the optical signal incident on the second optical splitter 106 'is transmitted through the second optical splitter 106' to the second isolator 107 ', and the other half of the optical signal is transmitted to the second optical splitter 106'. ') Is reflected toward the second light receiving element 102'. The optical signal incident on the second light receiving element 102 'is converted into an electrical signal by the second light receiving element 102' and output to the second light receiving substrate (not shown). Then, the second light receiving substrate transmits an electric signal corresponding to the information transmitted from the OLT 10 to the communication device of the user. The optical signal transmitted through the second optical splitter 106 'is not transmitted to the second light emitting element 101' by the second isolator 107 'and is destroyed.

As described above, the low density wavelength division multiplexing diplexer according to the present invention is integrated with a light emitting element, a light receiving element, and an optical splitter, so that the system can be miniaturized and simplified.

In addition, the manufacturing cost can be lowered compared to the diplexer in which the light emitting element, the light receiving element, and the optical splitter are separated.

Therefore, when the low density wavelength division multiplexing diplexer according to the present invention is used, the MCU can be miniaturized and simplified, and the manufacturing cost thereof can be reduced.

The present invention is not limited to the specific embodiments described above, but can be performed by a person skilled in the art to which the present invention pertains without departing from the spirit of the present invention described in the claims below. Substitutions, additions, deletions, and alterations fall within the scope of the claims.

Claims (9)

A connection member connected to the optical cable; A light emitting device converting an electrical signal corresponding to information into an optical signal and emitting the same to the connection member; A light receiving element for converting an optical signal introduced through the connection member into an electrical signal; An optical splitter disposed between the connection member, the light emitting device, and the light receiving device, the optical splitter transmitting a part of the optical signal and reflecting the other part; An isolator disposed between the light emitting element and the optical splitter, the isolator blocking the light signal introduced through the connection member from being introduced into the light emitting element; A housing fixing the connection member, the light emitting element, the light receiving element, the optical splitter, and the isolator; And And a light absorbing part installed inside the housing and absorbing an optical signal that is not incident to the connection member among the optical signals emitted from the light emitting device. The light emitting device of claim 1, wherein the light emitting device is installed at a position where the emitted optical signal passes through the optical splitter and enters the connection member, and the light receiving element receives the optical signal reflected from the connection member and reflected on the optical splitter. A low density wavelength division multiplexing diplexer, which is installed at a position where it can be received. The light emitting device of claim 1, wherein the light emitting device is installed at a position where the emitted optical signal is reflected from the optical splitter and drawn into the connecting member, and the light receiving element receives the optical signal that is introduced from the connecting member and transmitted through the optical splitter. A low density wavelength division multiplexing diplexer, which is installed at a position where it can be received. The optical splitter according to any one of claims 1 to 3, wherein A diplexer for low density wavelength division multiplexing, characterized in that the ratio of the transmitted optical signal and the reflected optical signal among the incident optical signals is 50:50. The optical splitter according to any one of claims 1 to 3, wherein A diplexer for low density wavelength division multiplexing, wherein the ratio of the transmitted optical signal and the reflected optical signal among the incident optical signals is 70:30 or 30:70. The method of claim 1, wherein the connecting member, A low density wavelength division multiplexing diplexer comprising a pigtail. The method of claim 1, wherein the connecting member, A low density wavelength division multiplexing diplexer comprising a receptacle. delete The method of claim 1, One end of the connection member is an anti-reflective multiplexing multiplexing diplexer, characterized in that the.

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