JP5255513B2 - Composite optical signal multiplexer / demultiplexer and passive optical subscriber system - Google Patents

Description

  The present invention relates to a composite optical signal multiplexer / demultiplexer having a plurality of optical multiplexing / demultiplexing circuits and a passive optical subscriber system including the same.

  FIG. 5 is a block diagram illustrating a configuration of an optical passive network (Passive Optical Network, hereinafter referred to as PON) 150 whose standard specifications are recommended by the International Telecommunications Union (ITU) as an optical subscriber network. The PON 150 includes a central optical transmission / reception device 151, a trunk transmission line 152, an optical signal branching unit 153, branch transmission lines (161, 162,..., 16n), and terminal optical transmission / reception devices (171, 172,..., 17n). Including. The central optical transmission / reception device 151 is connected to an external network (not shown) via a transmission path 155. The external network is, for example, a city network or a wide area network. The terminal optical transmission / reception devices (171, 172,..., 17n) are connected to terminal devices and the like not shown through terminal transmission paths (181, 182,..., 18n). Here, the total number of terminal optical transceivers (171, 172,..., 17n) is generally from about 32 to about 64.

  The optical signal input / output terminal of the central optical transceiver 151 and the optical signal splitter 153 are connected by the trunk transmission line 152, and the optical signal splitter 153 and the terminal optical transceivers (171, 172,..., 17n) are connected. Each is connected by a branch line transmission path (161, 162,..., 16n).

  The central optical transceiver 151 time-divides the downstream optical signal with the wavelength λd, assigns it to the time slot assigned to each of the terminal optical transceivers (171, 172,..., 17n), and transmits it to the trunk transmission line 152. . The transmitted downstream optical signal having the wavelength λd is branched by the optical signal branching unit 153 and transmitted through the branch transmission lines (161, 162,..., 16n), and the terminal optical transmission / reception devices (171, 172,... • Received at 17n). On the other hand, the terminal optical transmission / reception devices (171, 172,..., 17n) transmit an upstream optical signal having a wavelength λu in each assigned time slot. The optical signal branching unit 153 combines the upstream optical signals of these wavelengths λu that have passed through the branch transmission lines (161, 162,..., 16n), and sends them to the central optical signal transmission / reception device 151 through the trunk transmission line 152. .

  As described above, since the downstream signal transmitted to a plurality of terminal devices is branched by the optical signal branching unit 153, the optical power of the downstream signal is reduced and the transmission distance is limited. Further, since the optical signal branching unit 153 sends the branched downlink signal to all the terminal optical transmission / reception devices (171, 172,..., 17n), the PON is encrypted to prevent information leakage between the terminal devices. There was also a problem that it was necessary to make it.

  A wavelength division multiplexing passive optical network (WDM-PON) is known as a communication system that solves this PON problem (see, for example, Patent Document 1). FIG. 6 is a block diagram illustrating the configuration of the WDM-PON. 6 includes a central optical transceiver 251, a trunk transmission line 152, an optical signal multiplexer / demultiplexer 203, branch transmission lines (161, 162,..., 16 n), terminal optical transceivers (271, 272, ..., 27n). The central optical transmission / reception device 251 is connected to an external network (not shown) via a transmission path 155. The terminal optical transmission / reception devices (271, 272,..., 27n) are connected to terminal devices and the like not shown through terminal transmission paths (181, 182,..., 18n). The optical signal input / output terminal of the central optical transceiver 251 and the optical signal multiplexer / demultiplexer 203 are connected to the main transmission line 152, and the optical signal multiplexer / demultiplexer 203 and the terminal optical transceiver (271, 272, ...). , 27n) are connected by branch line transmission lines (161, 162,..., 16n), respectively.

  The difference between the WDM-PON 200 and the PON 150 of FIG. 5 is that the central optical transceiver 251 combines and outputs optical signals of a plurality of wavelengths (λd1, λd2,... Λdn) and a plurality of wavelengths (λu1). , Λu 2,..., Λun) and a wavelength (λd 1, λd 2,..., 27 n) assigned to each of the terminal optical transceivers (271, 272,..., 27 n). It has a function of receiving an optical signal of λdn) and transmitting an upstream signal of a wavelength (λu1, λu2,... λun) assigned to each.

  The optical signal multiplexer / demultiplexer 203 is, for example, an arrayed optical waveguide diffraction grating (AWG (Arrayed-Waveguide Grating)) type optical multiplexer / demultiplexer circuit. FIG. 7 is a configuration diagram of the AWG. 101 is a substrate, and silicon or quartz is used. An optical waveguide can be formed on the substrate 101 to form an AWG. The AWG 100 in FIG. 7 includes a plurality of input / output waveguides 102, a slab waveguide 103, an arrayed waveguide 104, a slab waveguide 105, and an input / output waveguide 106. The arrayed waveguide 104 is a plurality of waveguide groups having different lengths, and the input / output waveguide 102 and the input / output waveguide 106 are a plurality of waveguide groups. In general, the AWG 100 is configured symmetrically as viewed from the central portion of the arrayed waveguide 104.

  FIG. 8 is a functional configuration diagram of the AWG. In FIG. 8, one of the input / output waveguides of the AWG 100 shown in FIG. 7 is shown as a multiplexing terminal group 110 through which a plurality of optical signals are input and output, and the other of the input / output waveguides of the AWG 100 is input with a plurality of optical signals. This is shown as the output demultiplexing terminal group 120. In addition, two of the terminals constituting the multiplexing terminal group 110 are shown as a multiplexing terminal 111 and a multiplexing terminal 112, respectively, and each of the demultiplexing terminal group 120 is shown as a demultiplexing terminal (121, 122,...). 12n).

  FIG. 9 shows the demultiplexing operation of the AWG 100. When an optical signal having a different wavelength (λ11, λ12,..., Λ1n) is input to the multiplexing terminal 111, the AWG 100 demultiplexes the optical signal, and the demultiplexing terminals (121, 122,..., 12n). Output to each. On the other hand, when optical signals having different wavelengths (λ11, λ12,... Λ1n) are input to the demultiplexing terminals (121, 122,..., 12n), the AWG 100 multiplexes these optical signals. And output from the multiplexing terminal 111. Thus, the AWG 100 has a bidirectional optical signal transmission characteristic.

  FIG. 10 shows the multiplexing operation of the AWG 100. In FIG. 10, optical signals (λ21, λ22,... Λ2n) having different wavelengths are input to the demultiplexing terminals (121, 122,..., 12n) of the AWG 100, respectively. The AWG 100 multiplexes the optical signals (λ21, λ22,... Λ2n) and outputs them from the multiplexing terminal 112. In this case as well, the AWG 100 has bidirectional optical signal transmission characteristics as in FIG.

  FIG. 11 shows an example of optical transmission characteristics between the multiplexing terminal group 110 and the demultiplexing terminal group 120 of the AWG 100. In FIG. 11, the vertical axis indicates optical loss, and the horizontal axis indicates the wavelength of the optical signal. In FIG. 11, the optical transmission characteristic (I) is the light between the multiplexing terminal 111 in the multiplexing terminal group 110 and the demultiplexing terminals (121, 122,..., 12n) in the demultiplexing terminal group 120. The loss characteristic is shown. Here, the optical loss is small at the wavelengths (λ1a, λ1b,..., Λ1n), indicating that the optical signal passes through the AWG 100. Further, the optical transmission characteristic (II) is also an optical loss characteristic between the multiplexing terminal 111 and the demultiplexing terminals (121, 122,..., 12n) in the demultiplexing terminal group 120, and the wavelength ( .lambda.2a, .lambda.2b,..., .lambda.2n) also indicate that the optical signal passband of the AWG 100 is obtained. Here, the wavelengths λ1a and λa2, the wavelengths λ1b and λb2,..., The wavelengths λ1n and the wavelengths λn2 have a constant wavelength interval called a free spectral range (hereinafter referred to as FSR). Further, the wavelengths (λ3a, λ3b,..., Λ3n) shown in the optical transmission characteristic (III) are also passbands of the optical signals of the AWG 100. Wavelength λ1a and wavelength λa3, wavelength λ1b and λb3,..., Wavelength λ1n and wavelength λn3 have a wavelength interval twice that of FSR.

  As shown by the optical transmission characteristics (I), optical transmission characteristics (II), and optical transmission characteristics (III) in FIG. 11, one terminal in the multiplexing terminal group 110 and one terminal in the demultiplexing terminal group 120. As for the optical transmission characteristics between the two, there is a pass band in which an optical signal having a wavelength for each FSR inherent in the AWG 100 can be transmitted with low loss. For example, in the case of the AWG 100 in FIG. 11, optical signals having wavelengths (λ1a, λ2a,..., Λna) can pass bidirectionally between the multiplexing terminal 111 and the demultiplexing terminal 121.

  Next, the operation of the WDM-PON 200 in FIG. 6 will be described. The central optical transmission / reception device 251 is a wavelength multiplexed signal obtained by combining downstream optical signals of wavelengths (λd1, λd2,... Λdn) assigned to the terminal optical transmission / reception devices (271, 272,..., 27n). Is transmitted to the main transmission line 152. As described with reference to FIGS. 7 to 11, the optical signal multiplexer / demultiplexer 203 demultiplexes the wavelength-multiplexed signal and outputs the demultiplexed signal to the branch transmission lines (161, 162,..., 16n). The terminal optical transmission / reception devices (271, 272,..., 27n) receive the optical signals transmitted via the branch transmission lines (161, 162,..., 16n). On the other hand, the terminal optical transmission / reception devices (271, 272,..., 27n) send uplink signals of wavelengths (λu1, λu2,..., Λun) assigned to the branch transmission lines (161, 162,. , 16n). As described with reference to FIGS. 7 to 11, the optical signal multiplexer / demultiplexer 203 multiplexes these uplink signals and outputs them as a wavelength multiplexed signal to the trunk transmission line 152. The central optical transceiver 251 receives this wavelength multiplexed signal. The downstream signal and upstream signal have the following wavelength relationship. The wavelength relationship is a relationship in which the wavelength λu1 and the wavelength λd1, the wavelength λu2 and the wavelength λd2, and the wavelength λun and the wavelength λdn have a wavelength interval that is an integral multiple of the FSR of the optical signal multiplexer / demultiplexer 203.

  As described above, the WDM-PON 200 can demultiplex a downstream optical signal having a wavelength (λd1, λd2,... Λdn) with very little loss by the optical signal multiplexer / demultiplexer 203. Can be avoided, and the transmission distance between the central optical transceiver 251 and the terminal optical transceivers (271, 272,..., 27n) can be greatly increased compared to the PON 150. Further, since the optical signal multiplexer / demultiplexer 203 can transmit the downstream signal to the terminal optical transceivers (271, 272,..., 27n) for each wavelength (λd1, λd2,. No encryption is required to prevent information leakage between the two.

JP 2006-166446 A

  However, the WDM-PON 200 in FIG. 6 has a restriction that the upstream signal and the downstream signal must have the following wavelength relationship. The wavelength relationship is a relationship in which the wavelength λu1 and the wavelength λd1, the wavelength λu2 and the wavelength λd2, and the wavelength λun and the wavelength λdn must be a wavelength interval that is an integral multiple of the FSR of the optical signal multiplexer / demultiplexer 203.

  In addition, when the wavelength of the upstream signal and the wavelength of the downstream signal are set regardless of the above wavelength relationship, the optical signal multiplexer / demultiplexer 203 and each terminal device must be connected by two optical fibers. There were restrictions. This is due to the following reason. A case where the optical signal multiplexer / demultiplexer 203 includes the AWG 100 will be described. When the optical signal multiplexer / demultiplexer 203 and each terminal device are connected by a single optical fiber, the AWG 100 transmits and receives an upstream signal and a downstream signal at the same branching terminal. For example, the downlink signal λd1 and the uplink signal λu1 are exchanged at the demultiplexing terminal 121. In this case, the upstream signals (λu1, λu2,..., Λun) are multiplexed at a multiplexing terminal different from the multiplexing terminal 111 to which the downstream wavelength multiplexed signal is input, for example, at the multiplexing terminal 112. For this reason, in order to multiplex the upstream signal at the multiplexing terminal to which the downstream wavelength division multiplexed signal is input in the optical signal multiplexer / demultiplexer 203, the upstream signal from the terminal apparatus is sent to a branching terminal different from the downstream signal. This is because it was necessary to connect. Due to these limitations, there is a problem that a system must be constructed separately from the existing PON in order to introduce the WDM-PON.

  Therefore, an object of the present invention is to provide a composite optical signal multiplexer / demultiplexer and a passive optical subscriber system that can construct a WDM-PON using an existing PON.

  In order to achieve the above object, the composite optical signal multiplexer / demultiplexer according to the present invention combines a plurality of optical multiplexing / demultiplexing circuits.

  The composite optical signal multiplexer / demultiplexer according to the present invention includes m first (m is a natural number) first multiplexing terminals, one second multiplexing terminal, and n (n is a natural number) first demultiplexing terminals. A first optical multiplexing / demultiplexing circuit having m and n second demultiplexing terminals, a first multiplexing terminal and an n demultiplexing terminal, each of the m number of groups corresponding to the group. Two first optical multiplexing / demultiplexing circuits, m first multiplexing terminals of the first optical multiplexing / demultiplexing circuit, and m first coupling terminals of the m second optical multiplexing / demultiplexing circuits are connected in a one-to-one relationship. For each group of waveguides and first demultiplexing terminals of the first optical multiplexing / demultiplexing circuit, n first demultiplexing terminals in the group and n of the second optical multiplexing / demultiplexing circuit corresponding to the group And n number of second waveguides that connect the number of demultiplexing terminals on a one-to-one basis.

  Another composite optical signal multiplexer / demultiplexer according to the present invention includes m (m is a natural number) first multiplexing terminals, one second multiplexing terminal, and n (n is a natural number) first demultiplexing terminals. A first optical multiplexing / demultiplexing circuit having m and n second demultiplexing terminals, a group of terminals, m multiplexing terminals, and m × n demultiplexing terminals; Are divided into m groups corresponding to the groups of the first demultiplexing terminals of the first optical multiplexing / demultiplexing circuit, and m firsts of the first optical multiplexing / demultiplexing circuit. M first waveguides that connect the multiplexing terminals and the m multiplexing terminals of the second optical multiplexing / demultiplexing circuit on a one-to-one basis, and for each group, n first branching terminals and the first And n second waveguides that connect n demultiplexing terminals of the two-optical multiplexing / demultiplexing circuit on a one-to-one basis.

  The composite optical signal multiplexer / demultiplexer will be described in detail below when m = 1. A composite optical signal multiplexer / demultiplexer according to the present invention includes a first optical multiplexer / demultiplexer having at least two multiplexing terminals, n (n is a natural number) first demultiplexing terminals, and n second demultiplexing terminals. A circuit, a second optical multiplexing / demultiplexing circuit having at least one multiplexing terminal and n demultiplexing terminals, one multiplexing terminal of the first optical multiplexing / demultiplexing circuit, and one of the second optical multiplexing / demultiplexing circuit One-to-one connection between the first waveguide connecting the multiplexing terminal, the n first demultiplexing terminals of the first optical multiplexing / demultiplexing circuit, and the n demultiplexing terminals of the second optical multiplexing / demultiplexing circuit. N second waveguides.

  The first optical multiplexing / demultiplexing circuit outputs the wavelength multiplexed signal obtained by multiplexing the upstream signal to a multiplexing terminal different from the multiplexing terminal to which the downstream wavelength multiplexed signal is input. This wavelength division multiplexed signal is input to the multiplexing terminal of the second optical multiplexing / demultiplexing circuit and is demultiplexed again for each upstream signal. Further, the demultiplexed upstream signal is coupled again to the demultiplexing terminal of the first optical multiplexing / demultiplexing circuit. Here, the demultiplexed upstream signals are coupled to the demultiplexing terminal where they are combined at the multiplexing terminal to which the downstream wavelength division multiplexed signal is input in the first optical multiplexing / demultiplexing circuit.

  Therefore, by setting the composite optical signal demultiplexer as an alternative to the PON optical signal branching unit, the upstream signal wavelength and the downstream signal wavelength can be set regardless of the FSR of the first optical multiplexing / demultiplexing circuit. Therefore, a single optical fiber can be provided between the composite optical signal multiplexer / demultiplexer and the terminal device. Therefore, the present invention can provide a composite optical signal multiplexer / demultiplexer that can construct a WDM-PON using an existing PON.

  It is preferable to further include a substrate on which both the first optical multiplexing / demultiplexing circuit and the second optical multiplexing / demultiplexing circuit of the composite optical signal demultiplexer according to the present invention are mounted. Furthermore, the first waveguide and the second waveguide may also be mounted on the substrate of the composite optical signal branching filter according to the present invention. By integrating the first optical multiplexing / demultiplexing circuit, the second optical multiplexing / demultiplexing circuit, and the first to fourth waveguides on the same substrate, a composite optical signal multiplexer / demultiplexer is realized in a very compact and economical manner. can do.

  The passive optical subscriber system according to the present invention includes a central optical transmission / reception device that transmits / receives wavelength multiplexed signals to / from an external network, and the central optical transmission / reception device and the wavelength through another multiplexing terminal of the first optical multiplexing / demultiplexing circuit. The composite optical signal multiplexer / demultiplexer for transmitting / receiving multiplexed signals, and n terminal optical transceivers connected in a one-to-one relationship with the n second demultiplexing terminals of the first optical multiplexing / demultiplexing circuit.

  If this composite optical signal demultiplexer is used as an alternative to an optical signal splitter, a passive optical subscriber system that can construct a WDM-PON using an existing PON can be provided. Further, the upstream signal wavelength and the downstream signal wavelength can be set regardless of the FSR of the first optical multiplexing / demultiplexing circuit, and the network configuration is very advantageous.

  The present invention can provide a composite optical signal multiplexer / demultiplexer and a passive optical subscriber system that can construct a WDM-PON using an existing PON.

It is the schematic explaining the composite-type optical signal multiplexer / demultiplexer based on this invention. It is the schematic explaining the demultiplexing operation | movement of the composite-type optical signal multiplexer / demultiplexer based on this invention. It is the schematic explaining the multiplexing operation | movement of the composite-type optical signal multiplexer / demultiplexer which concerns on this invention. It is a block diagram explaining the structure of a passive optical subscriber system in this invention. It is a block diagram explaining the structure of the conventional PON. It is a block diagram explaining the structure of the conventional WDM-PON. It is a block diagram of AWG. It is a functional block diagram of AWG. It is a functional block diagram of AWG. It is a functional block diagram of AWG. It is a figure explaining the optical transmission characteristic of AWG. It is the schematic explaining the composite-type optical signal multiplexer / demultiplexer based on this invention. It is the schematic explaining the composite-type optical signal multiplexer / demultiplexer based on this invention.

  Hereinafter, the present invention will be described in detail with specific embodiments, but the present invention is not construed as being limited to the following description. In the present specification and drawings, the same reference numerals denote the same components.

  FIG. 1 is a configuration diagram illustrating a composite optical signal multiplexer / demultiplexer 303 according to this embodiment. The composite optical signal multiplexer / demultiplexer 303 includes a first multiplexing terminal (11, 12), an n number of first demultiplexing terminals 13 (n is a natural number) 13 and an n number of second demultiplexing terminals 14. Optical multiplexing / demultiplexing circuit 10, second optical multiplexing / demultiplexing circuit 20 having one multiplexing terminal 21 and n demultiplexing terminals 23, multiplexing terminal 11 of first optical multiplexing / demultiplexing circuit 10, and second optical multiplexing / demultiplexing The first waveguide 30 that connects the multiplexing terminal 21 of the circuit 20, the n first demultiplexing terminals 13 of the first optical multiplexing / demultiplexing circuit 10, and the n demultiplexing terminals of the second optical multiplexing / demultiplexing circuit 20 And n second waveguides 40 that are connected in a one-to-one relationship.

  The first optical multiplexing / demultiplexing circuit 10 and the second optical multiplexing / demultiplexing circuit 20 may be, for example, the AWG 100 described with reference to FIGS. The multiplexing terminals (11, 12) of the first optical multiplexing / demultiplexing circuit 10 are multiplexing terminals (111, 112) of the AWG 100, respectively, and the first demultiplexing terminal 13 and the second demultiplexing of the first optical multiplexing / demultiplexing circuit 10 are provided. The demultiplexing terminals (121, 122,..., 12n) of the AWG 100 are configured with the terminal 14. Similarly, the multiplexing terminal 21 of the second optical multiplexing / demultiplexing circuit 20 is the multiplexing terminal 111 of the AWG 100, and the demultiplexing terminal 23 of the second optical multiplexing / demultiplexing circuit 20 is respectively the demultiplexing terminal (121, 122,. .., 12n). The multiplexing terminal 12 is connected to an input / output terminal 51 that transmits and receives wavelength multiplexed signals to the outside. The second demultiplexing terminal 14 is connected to terminal terminals (52-1, 52-2,..., 52-n) that exchange optical signals with the outside.

  The first waveguide 30 and the second waveguide 40 can be, for example, optical fibers or optical waveguides. The first waveguide 30 connects the multiplexing terminal 11 of the first optical multiplexing / demultiplexing circuit 10 and the multiplexing terminal 21 of the second optical multiplexing / demultiplexing circuit 20. The second waveguide 40 connects the n first demultiplexing terminals 13 of the first optical multiplexing / demultiplexing circuit 10 and the n demultiplexing terminals 23 of the second optical multiplexing / demultiplexing circuit 20 on a one-to-one basis.

  The composite optical fiber multiplexer / demultiplexer 303 further includes a substrate 50 on which both the first optical multiplexer / demultiplexer circuit 10 and the second optical multiplexer / demultiplexer circuit 20 are mounted. The substrate 50 is, for example, silicon or quartz. Input / output terminals 51 and terminal terminals (52-1, 52-2,..., 52-n) are also mounted on the substrate 50. By integrating these on the same substrate 50, it can be realized very small and economically.

  The substrate 50 also mounts the first waveguide 30 and the second waveguide 40. If either one or both of the first waveguide 30 and the second waveguide 40 are integrated on the substrate 50, the composite optical fiber multiplexer / demultiplexer 303 can be realized even more compactly and economically.

  FIG. 2 is a schematic diagram for explaining the demultiplexing operation of the composite optical fiber multiplexer / demultiplexer 303. When the wavelength division multiplexed signal (λ11, λ12,... Λ1n) is input to the multiplexing terminal 12, the first optical multiplexing / demultiplexing circuit 10 receives the wavelength (λ11, λ12,... ... Λ1n) optical signal is demultiplexed. That is, the composite optical fiber multiplexer / demultiplexer 303 demultiplexes the wavelength division multiplexed signals (λ11, λ12,... Λ1n), which are downstream signals, for each wavelength, and transmits the terminal terminals (52-1, 52-2,... -Output to 52-n).

  FIG. 3 is a schematic diagram for explaining the multiplexing operation of the composite optical fiber multiplexer / demultiplexer 303. The first optical multiplexing / demultiplexing circuit 10 multiplexes optical signals (λ21, λ22,..., Λ2n) having different wavelengths, respectively, when they are input to the second demultiplexing terminal 14, and outputs them from the multiplexing terminal 11. Wavelength multiplexed signals (λ21, λ22,..., Λ2n) are output. The first waveguide 30 couples the wavelength multiplexed signal (λ21, λ22,... Λ2n) to the multiplexing terminal 21 of the second optical multiplexing / demultiplexing circuit 20. The second optical multiplexing / demultiplexing circuit 20 demultiplexes the wavelength multiplexed signals (λ21, λ22,... Λ2n) to the respective demultiplexing terminals 23. The n second waveguides 40 couple the optical signals (λ21, λ22,... λ2n) output from the demultiplexing terminal 23 to the first demultiplexing terminal 13 of the first optical multiplexing / demultiplexing circuit 10, respectively. . The first optical multiplexing / demultiplexing circuit 10 multiplexes these optical signals (λ21, λ22,... Λ2n) and outputs them from the multiplexing terminal 12. That is, the composite optical fiber multiplexer / demultiplexer 303 multiplexes optical signals (λ21, λ22,..., Λ2n) having different wavelengths, which are upstream signals, and outputs a wavelength multiplexed signal to the input / output terminal 51.

  As described above, the composite optical fiber multiplexer / demultiplexer 303 demultiplexes and responds to each of the downstream wavelength multiplexed signals (λ11, λ12,... Λ1n) input to the input / output terminal 51. Terminal terminals (52-1, 52-2,..., 52-n), and the terminal terminals (52-1, 52-2,. When optical signals (λ21, λ22,..., Λ2n) are input, a wavelength multiplexed signal obtained by combining them is output from the input / output terminal 51.

  Since the first optical multiplexing / demultiplexing circuit 10 is the AWG 100, the multiplexing terminal of the AWG 100 to which the optical signals (λ 21, λ 22,..., Λ 2 n) from the second demultiplexing terminal 14 are multiplexed is defined as the multiplexing terminal 11. A demultiplexing terminal of the AWG 100 that can multiplex optical signals (λ21, λ22,..., Λ2n) to the multiplexing terminal 12 is used as the first demultiplexing terminal 13. Thus, the upstream signal wavelength and the downstream signal wavelength can be set regardless of the FSR of the first optical multiplexing / demultiplexing circuit 10, and each terminal terminal (52-1, 52-2,..., 52-n) and each terminal device can be a single optical fiber. Therefore, the composite optical signal demultiplexer 303 can be substituted for the PON optical signal branching unit.

  FIG. 4 is a block diagram illustrating the configuration of the passive optical subscriber system 300. The passive optical subscriber system 300 includes a central optical transmission / reception device 351 that transmits / receives wavelength multiplexed signals to / from an external network (not shown), and a composite of FIG. 1 that transmits / receives wavelength multiplexed signals to / from the central optical transmission / reception device 351 through input / output terminals 51. Type optical signal multiplexer / demultiplexer 303 and n terminal optical transceivers (371, 372,...) Connected one-to-one with terminal terminals (52-1, 52-2,..., 52-n). 37n).

  In the passive optical subscriber system 300, the composite optical signal demultiplexer 303 of FIG. 1 can be substituted for the optical signal splitter 153 of the PON 150 of FIG. In the passive optical subscriber system 300, the central optical transceiver 351 and the terminal optical transceivers (371, 372, ..., 37n) in FIG. 4 are respectively the central optical transceiver 151 and the terminal optical transceiver in FIG. It may be the same as the devices (171, 172,..., 17n), or may be a central optical transceiver and a terminal optical transceiver according to the characteristics of this system. Since the passive optical subscriber system 300 includes the composite optical signal demultiplexer 303, the wavelength selection of the upstream signal and downstream signal is limited by the FSR of the optical multiplexing / demultiplexing circuit such as the WDM-PON 200 of FIG. There is no. Specifically, the passive optical subscriber system 300 includes each wavelength (λd1, λd2,..., Λdn) of the downstream wavelength multiplexed signal transmitted by the central optical transceiver 351 and the terminal optical transceiver (371, 371). 372,..., 37n) can independently select each wavelength (λu1, λu2,... Λun) of the upstream optical signal transmitted.

(Other embodiments)
There are a plurality of forms constituting the second optical multiplexing / demultiplexing circuit. 12 and 13 are diagrams for explaining a composite optical signal multiplexer / demultiplexer having a plurality of second optical multiplexer / demultiplexers. FIGS. 12 and 13 are examples, and the number and connection method of the second optical multiplexing / demultiplexing circuits can be set according to mounting conditions.

  The composite optical signal multiplexer / demultiplexer 304 in FIG. 12 includes a first optical multiplexer / demultiplexer circuit 10, a second optical multiplexer / demultiplexer circuit (20-1, 20-2), and a first waveguide (30-1, 30). -2) and second waveguides (40-1, 40-2). More second optical multiplexing / demultiplexing circuits may be provided under mounting conditions.

  The first optical multiplexing / demultiplexing circuit 10 includes two first multiplexing terminals (11-1, 11-2), one second multiplexing terminal 12, and n (n is a natural number) first dividing terminals 13. −1, a group formed by n first branching terminals 13-2, and n second branching terminals 14.

  The second optical multiplexing / demultiplexing circuit 20-1 has one multiplexing terminal 21-1 and n demultiplexing terminals 23-1. The second optical multiplexing / demultiplexing circuit 20-1 corresponds to the group of the first demultiplexing terminals 13-1 of the first optical multiplexing / demultiplexing circuit 10. The second optical multiplexing / demultiplexing circuit 20-2 has one multiplexing terminal 21-2 and n demultiplexing terminals 23-2. The second optical multiplexing / demultiplexing circuit 20-2 corresponds to the group of the first demultiplexing terminals 13-2 of the first optical multiplexing / demultiplexing circuit 10.

  The first waveguide 30-1 is connected to the first multiplexing terminal 11-1 of the first optical multiplexing / demultiplexing circuit 10 and the multiplexing terminal 21-1 of the second optical multiplexing / demultiplexing circuit 20-1. The first waveguide 30-2 is connected to the first multiplexing terminal 11-2 of the first optical multiplexing / demultiplexing circuit 10 and the multiplexing terminal 21-2 of the second optical multiplexing / demultiplexing circuit 20-2.

  The second waveguide 40-1 includes n first demultiplexing terminals 13-1 of the first optical multiplexing / demultiplexing circuit 10 and n demultiplexing terminals 23-1 of the second optical multiplexing / demultiplexing circuit 20-1. N waveguides connected one-on-one. The second waveguide 40-2 includes n first demultiplexing terminals 13-2 of the first optical multiplexing / demultiplexing circuit 10 and n demultiplexing terminals 23-2 of the second optical multiplexing / demultiplexing circuit 20-2. N waveguides connected one-on-one.

  The composite optical signal multiplexer / demultiplexer 305 of FIG. 13 includes a first optical multiplexer / demultiplexer circuit 10, a second optical multiplexer / demultiplexer circuit 25, a first waveguide (30-1, 30-2), and a second waveguide. And waveguides (40-1, 40-2). The composite optical signal multiplexer / demultiplexer 305 includes a second optical multiplexer / demultiplexer circuit 25 having a plurality of multiplexing terminals. In FIG. 13, the second optical multiplexing / demultiplexing circuit 25 has two multiplexing terminals, but may have more multiplexing terminals under mounting conditions. The composite optical signal multiplexer / demultiplexer 305 may include a plurality of second optical multiplexer / demultiplexers 25 under mounting conditions.

  The first optical multiplexing / demultiplexing circuit 10 is the same as the first optical multiplexing / demultiplexing circuit 10 of FIG.

  The second optical multiplexing / demultiplexing circuit 25 includes two multiplexing terminals (21-1, 21-2), a group composed of n demultiplexing terminals 23-1, and n demultiplexing terminals 23-2. It has a group consisting of The group of the demultiplexing terminal 23-1 corresponds to the group of the first demultiplexing terminal 13-1 of the first optical multiplexing / demultiplexing circuit 10, and the group of the demultiplexing terminal 23-2 is the first of the first optical multiplexing / demultiplexing circuit 10. This corresponds to the group of the demultiplexing terminal 13-2.

  The first waveguide 30-1 is connected to the first multiplexing terminal 11-1 of the first optical multiplexing / demultiplexing circuit 10 and the multiplexing terminal 21-1 of the second optical multiplexing / demultiplexing circuit 25. The first waveguide 30-2 is connected to the first multiplexing terminal 11-2 of the first optical multiplexing / demultiplexing circuit 10 and the multiplexing terminal 21-2 of the second optical multiplexing / demultiplexing circuit 25.

  The second waveguide 40-1 has a one-to-one correspondence between the n first demultiplexing terminals 13-1 of the first optical multiplexing / demultiplexing circuit 10 and the n demultiplexing terminals 23-1 of the second optical multiplexing / demultiplexing circuit 25. N waveguides connected in a line. The second waveguide 40-2 has a one-to-one correspondence between the n first demultiplexing terminals 13-2 of the first optical multiplexing / demultiplexing circuit 10 and the n demultiplexing terminals 23-2 of the second optical multiplexing / demultiplexing circuit 25. N waveguides connected in a line.

  The composite optical signal multiplexer / demultiplexer (304, 305) demultiplexes the wavelength multiplexed signal of the wavelengths (λ1, λ2,..., Λ9) input from the input / output terminal 51 to wavelength (λ1, λ2,. λ3) set of optical signals, wavelengths (λ4, λ5, λ6) sets of optical signals, and wavelengths (λ7, λ8, λ9) sets of optical signals are respectively connected to terminal terminals (52-1, 52-2, 52-3).

  On the other hand, the composite optical signal multiplexer / demultiplexer (304, 305) is an optical signal of a set of wavelengths (λ1, λ2, λ3) input from the terminal terminals (52-1, 52-2, 52-3). , Wavelength (λ4, λ5, λ6) and optical signals of wavelength (λ7, λ8, λ9) are combined and wavelength multiplexed signals of wavelengths (λ1, λ2,..., Λ9) are combined. Is output from the input / output terminal 51.

  The composite optical signal multiplexer / demultiplexer (304, 305) can be incorporated into the passive optical subscriber system of FIG. 4 as an alternative to the composite optical signal multiplexer / demultiplexer 303.

10: First optical multiplexing / demultiplexing circuit 11, 11-1, 11-2: First multiplexing terminal 12: Second multiplexing terminal 13, 13-1, 13-2: First multiplexing terminal 14: Second dividing Wave terminals 20, 20-1, 20-2: second optical multiplexing / demultiplexing circuits 21, 21-1, 21-2: multiplexing terminals 23, 23-1, 23-2: demultiplexing terminals 30, 30-1, 30-2: First waveguides 40, 40-1, 40-2: Second waveguide 50: Substrate 51: Input / output terminals 52-1, 52-2, 52-3, ..., 52-n: Terminal terminal 100: Array optical waveguide diffraction grating (AWG)
101: Substrate 102, 106: Input / output waveguide 103, 105: Slab waveguide 104: Array waveguide 110: Multiplexing terminal group 111, 112: Multiplexing terminal 120: Demultiplexing terminal group 121, 122,. 12n: demultiplexing terminal 150: optical passive network (PON)
151, 251 and 351: Central optical transmission / reception device 152: trunk transmission line 153: optical signal splitter 155: transmission lines 161, 162,..., 16n: branch transmission lines 171, 172,. Transmission / reception devices 181, 182,..., 18n: terminal transmission path 200: optical wavelength division multiplexing optical passive network (WDM-PON)
203: Optical signal multiplexers / demultiplexers 271, 272,..., 27n: Terminal optical transceiver 300: Passive optical subscriber systems 303, 304, 305: Composite optical signal multiplexers / demultiplexers 371, 372,. .. 37n: Terminal optical transmitter / receiver

Claims (5)

m (m is a natural number) first multiplexing terminal, one second multiplexing terminal, a group of n (n is a natural number) first demultiplexing terminals, m groups, and n second demultiplexing terminals A first optical multiplexing / demultiplexing circuit comprising:
M second optical multiplexing / demultiplexing circuits each having one multiplexing terminal and n demultiplexing terminals, each corresponding to the group;
M first waveguides that connect the m first multiplexing terminals of the first optical multiplexing / demultiplexing circuit and the multiplexing terminals of the m second optical multiplexing / demultiplexing circuits in a one-to-one relationship;
For each group of first demultiplexing terminals of the first optical multiplexing / demultiplexing circuit, n first demultiplexing terminals in the group and n demultiplexing of the second optical multiplexing / demultiplexing circuit corresponding to the group. N second waveguides connecting the terminals one-to-one;
A combined optical signal multiplexer / demultiplexer. m (m is a natural number) first multiplexing terminal, one second multiplexing terminal, a group of n (n is a natural number) first demultiplexing terminals, m groups, and n second demultiplexing terminals A first optical multiplexing / demultiplexing circuit comprising:
There are m multiplexing terminals and m × n demultiplexing terminals, and the demultiplexing terminals are divided into m groups corresponding to the group of the first demultiplexing terminals of the first optical multiplexing / demultiplexing circuit. A second optical multiplexing / demultiplexing circuit,
M first waveguides that connect the m first multiplexing terminals of the first optical multiplexing / demultiplexing circuit and the m multiplexing terminals of the second optical multiplexing / demultiplexing circuit in a one-to-one relationship;
N second waveguides for connecting the n first demultiplexing terminals and the n demultiplexing terminals of the second optical multiplexing / demultiplexing circuit on a one-to-one basis for each group;
A combined optical signal multiplexer / demultiplexer.   The composite optical signal multiplexer / demultiplexer according to claim 1 or 2, further comprising a substrate on which both the first optical multiplexing / demultiplexing circuit and the second optical multiplexing / demultiplexing circuit are mounted.   4. The composite optical signal multiplexer / demultiplexer according to claim 3, wherein the substrate also includes the first waveguide and the second waveguide. A central optical transceiver for exchanging wavelength multiplexed signals with an external network;
5. The composite optical signal multiplexer / demultiplexer according to claim 1, wherein the wavelength division multiplexed signal is exchanged with the central optical transceiver through another multiplexing terminal of the first optical multiplexing / demultiplexing circuit,
N terminal optical transceivers connected one-to-one with the n second demultiplexing terminals of the first optical multiplexing / demultiplexing circuit;
A passive optical subscriber system comprising:

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