JP4387234B2 - Optical add / drop device and optical add / drop device - Google Patents

Description

  The present invention is provided in the middle of a transmission line of a wavelength division multiplexing optical network, selects an optical signal of a predetermined wavelength from among the wavelength multiplexed optical signals, transmits the transmitted optical signal, and transmits optical signals of other wavelengths. The present invention relates to an optical add / drop device that branches and inserts and an optical add device body that includes a plurality of such devices.

  With regard to the optical add / drop multiplexer, only an optical signal having a specific wavelength among the wavelength multiplexed optical signals is selectively transmitted at a relay point called a node provided in the middle of the transmission path of the optical network. A network having an ADM (Add-Drop Multiplexer) function has been proposed in which an optical signal of a wavelength other than that is received at that node, or another optical signal is inserted from this node and transmitted to another node. .

  FIG. 16 is a block diagram of a conventional optical add / drop multiplexer. The optical add / drop device adds / drops an optical signal having an arbitrary wavelength to an arbitrary user port. Wavelength multiplexed optical signals of wavelengths λ1 to λn (n is an integer) input from the optical cable 1 are demultiplexed into n optical signals having different wavelengths in the optical demultiplexer 2, and are 2n × 2n matrix light. Input to switch 3. The 2n × 2n matrix optical switch 3 outputs the input n-wavelength optical signal to either the optical multiplexer 4 or an arbitrary branch port based on a setting from an optical switch control unit (not shown). . Similarly, the 2n × 2n optical switch 3 selects either an optical signal from an arbitrary insertion port or an optical signal from the optical demultiplexer 2 based on a setting from an optical switch control unit (not shown). And output to the optical multiplexer 4. The optical multiplexer 4 wavelength-multiplexes the n-wavelength optical signal from the 2n × 2n matrix optical switch 3 and outputs it to the optical cable 5 (for example, Non-Patent Document 1).

  In the configuration shown in FIG. 16, the 2n × 2n optical switch 3 receives an optical signal of an arbitrary wavelength from among the wavelength multiplexed optical signals from the optical cable 1 based on the setting from the optical switch control unit (not shown). An optical signal branching and inserting device is realized by outputting to an arbitrary branching port and connecting an optical signal from the arbitrary insertion port to an arbitrary port connected to the optical multiplexer 4.

  FIG. 17 is a block diagram of another conventional optical add / drop multiplexer similarly proposed in Non-Patent Document 1. In FIG. 17, the optical add / drop multiplexer includes two n × m matrix optical switches 6 and 7 each having a pass-through port between the optical demultiplexer 2 and the optical multiplexer 4. An n × m (n is an integer greater than or equal to m) matrix optical switch 6 outputs an optical signal from the optical demultiplexer 2 to any branch port or a corresponding pass-through port for each wavelength, and an n × m matrix By selecting whether the optical switch 7 outputs an optical signal from the pass-through port or an optical signal from an arbitrary insertion port to the optical multiplexer 4 for each wavelength, an optical signal add / drop device is realized. ing.

Micro mechanical wavelength Add / Drop switching, from device to network architecture TUESDAY AFTERNOON OFC2003, VOL.1, TuN3

  However, since the conventional optical add / drop multiplexer shown in FIGS. 16 and 17 has the above-described configuration, it has the following problems. For example, the optical add / drop device shown in FIG. 16 requires a large-scale matrix optical switch of 2n × 2n even when there are few optical signals to be added / dropped to the add / drop ports. Equipment cost at the time of introduction is high and the system is not economical. In the optical add / drop multiplexer shown in FIG. 17, if an optical switch having a scale of n = 4 m, for example, is applied to the n × m matrix optical switch, the apparatus cost at the time of initial introduction can be reduced and the economic efficiency can be reduced. However, when the number of optical signals to be added / dropped exceeds m, it must be replaced with an optical switch of n = 2m scale. Alternatively, a new optical switch must be added between the pass-through ports of the two n × m matrix optical switches 6 and 7. In this replacement work or addition work, work to remove the matrix optical switch from all the pass-through ports once occurs. Therefore, there is an unsolved problem that communication is temporarily interrupted.

  The present invention has been made to solve the above-mentioned problems, and realizes a highly economical optical add / drop apparatus by reducing the apparatus cost at the time of initial introduction, and communication is not interrupted even when the number of wavelengths is increased. An object of the present invention is to obtain an optical add / drop device excellent in expandability and an optical add / drop device having a plurality of such devices.

  An optical add / drop multiplexer of the present invention is provided in the middle of a transmission line of a wavelength division multiplexing optical network, selects an optical signal having a predetermined wavelength from among wavelength multiplexed optical signals, transmits the transmitted optical signal, and other than that In an optical add / drop multiplexer that branches and inserts an optical signal having a wavelength of λ, an optical demultiplexer that demultiplexes a wavelength multiplexed optical signal input from an input side optical cable into n (n is an integer) optical signals for each wavelength, N are provided so that n optical signals demultiplexed by the optical demultiplexer are respectively input, and the optical signal is output as a transmitted optical signal to a pass-through signal line or output as a branched optical signal to a branch line. A switch optical switch for switching to any one of them, n branch lines extending from the switch optical switch are connected, and branch optical signals inputted by the branch lines are respectively m (m is an integer smaller than n) branch ports and n Min The first branch-side n × m matrix optical switch, the switching optical switch, and the first branch-side n × m matrix optical switch that distribute the output to which port of the side through port are controlled, and each of the demultiplexed optical signals Switch control circuit for switching whether to output to a pass-through signal line, a branch port or a branch-side through port, and a wavelength-multiplexed optical signal generated by wavelength-multiplexing a transmitted optical signal transmitted through at least the pass-through signal line An optical add / drop unit having an optical multiplexer that outputs to the output side optical cable, and an optical receiving unit that is connected to the branch port and converts the optical signal output to the branch port into an electrical signal and outputs the electrical signal to the outside. Yes.

  The optical transmission unit further includes an optical transmission unit that converts an electrical signal input from the outside into an optical signal to generate an insertion optical signal, and the optical add / drop unit is provided connected to the optical transmission unit and receives the insertion optical signal. First insertion side n × m matrix optical switch having n insertion ports and n insertion side through ports, n insertion signal lines and n pass through signals extending from the first insertion side n × m matrix optical switch And n integrated optical switches that output the inserted optical signal and the transmitted optical signal input from either the inserted signal line or the pass-through signal line, respectively, and the switch control circuit includes the first optical switch. It also controls the switching of the insertion side n × m matrix optical switch and the integrated optical switch.

  According to the optical add / drop multiplexer of the present invention, the optical demultiplexer and the optical demultiplexer for demultiplexing the wavelength multiplexed optical signal input from the input side optical cable into n optical signals (n is an integer) for each wavelength. N optical signals are provided so that n optical signals that have been demultiplexed are respectively input, and the optical signal is output as a transmitted optical signal to a pass-through signal line extending to the optical multiplexer side or output to a branch line as a branched optical signal. Switch optical switch for switching to any one of the above, and n branch lines extending from the switch optical switch are connected to each of m branch optical signals (m is an integer smaller than n) and n branch optical signals input by the branch lines. It is possible to easily branch an optical signal of a predetermined wavelength from the network because the branch side n × m matrix optical switch that outputs or distributes to any one of the branch side through ports is provided. In addition, by using a small-scale switch called an n × m matrix optical switch, it is possible to cope with a wasteless optical signal to be added to a branching port or an insertion port, and to achieve an economical system. Since the n branch side through ports are provided, when a new optical switch needs to be added in the future, it is possible to easily add switches without interrupting communication. As a result, the device cost at the time of initial introduction can be reduced, and the addition and maintenance of switches can be performed easily and in a short time in the future. it can.

  The optical transmission unit further includes an optical transmission unit that converts an electrical signal input from the outside into an optical signal to generate an insertion optical signal, and the optical add / drop unit is provided connected to the optical transmission unit and receives the insertion optical signal. An insertion-side n × m matrix optical switch having n insertion ports and n insertion-side through ports, and n insertion signal lines and n pass-through signal lines extending from the insertion side n × m matrix optical switch are connected to each other. And n integrated optical switches that output the inserted optical signal and the transmitted optical signal input from either the inserted signal line or the pass-through signal line, so that an optical signal having a predetermined wavelength can be easily inserted into the network. can do.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Embodiment 1 FIG.
FIG. 1 is a block diagram showing an optical ring network to which an optical add / drop multiplexer of the present invention is applied. In FIG. 1, four optical add / drop devices 100 are connected in a ring shape by connecting adjacent devices with optical cables 1, 5, 8, 9. The optical add / drop multiplexer 100 adds / drops an optical signal having an arbitrary wavelength flowing on the network.

  The optical add / drop multiplexer 100 includes an optical add / drop unit 101 for adding / dropping an optical signal, an optical receiving unit 102 for performing optical signal processing for converting the branched optical signal into an electric signal, and outputting the electric signal to a user port, and a user port The optical transmission unit 103 is configured to perform optical signal processing on the electrical signal input from the optical signal, convert it to an optical signal, and output the optical signal to the optical add / drop unit 101.

  FIG. 2 is a structural diagram showing details of the optical add / drop unit 101 in the optical add / drop device 100 of FIG. In FIG. 2, the optical add / drop unit 101 includes an optical demultiplexer 2, an optical multiplexer 4, a switch control circuit 7, a 1 × 2 optical switch array 10, a 2 × 1 optical switch array 11, and a first branch side n × m. (M is an integer smaller than n) The matrix optical switch 12 and the first insertion side n × m (m is an integer smaller than n) matrix optical switch 13 are provided. The 1 × 2 optical switch array 10 is an optical switch array in which n 1 × 2 optical switches that are switching optical switches are integrally provided. The 2 × 1 optical switch array 11 is an optical switch array 11 in which n 2 × 1 optical switches that are integrated optical switches are integrally provided.

  The optical demultiplexer 2 is optically connected to the optical cable 1 that is an optical transmission path on the input side. The optical demultiplexer 2 receives the wavelength multiplexed optical signal input from the optical cable 1 and demultiplexes it into n (n is an integer) optical signals having different wavelengths λ1 to λn. Each of the n optical signals is input to the 1 × 2 optical switch. Therefore, the 1 × 2 optical switch array 10 is provided with n 1 × 2 optical switches. Each 1 × 2 optical switch selects an arbitrary optical signal from the input optical signals of wavelengths λ1 to λn based on the setting from the optical switch control circuit unit 7, and transmits the selected optical signal. An optical signal is output to the corresponding one of the pass-through signal lines P1 to Pn extending to the optical multiplexer 4 side, or is output as a branched optical signal to a branch line that branches to the first branch side n × m matrix optical switch 12 side. Select to switch.

The n branch lines extending from the 1 × 2 optical switch array 10 are optically connected to the first branch side n × m matrix optical switch 12. The 1 × 2 optical switch array 10 inputs an optical signal that is not selected as a transmitted optical signal via the n branch lines. The first branch side n × m matrix optical switch 12 has m branch ports D _{1 to} D _m and n branch side through ports TD _{1 to} TD _n, and selects the input optical signal. Select whether to output to the port. That is, the first branch side n × m matrix optical switch 12 branches the optical signals of wavelengths λ1 to λn input from the 1 × 2 optical switch array 10 to any branch ports D _{1 to} D _m , or , Whether to output to the branch side through ports TD ₁ to TD _n corresponding to each wavelength is selected. If the optical signal of the wavelength λ1~λn is through respectively, for example, an optical signal of wavelength λ1 to the through port TD ₁ is an optical signal having a wavelength λ2 to the through port TD ₂ is the through port TD _n is The optical signal having the wavelength λn is output in a predetermined order. On the other hand, the optical receiver 102 is optically connected to the _m branch ports D _{1 to} D _m . Accordingly, the optical signal selected to be branched is input to the optical receiver 102. That is, an optical signal selected as a transmitted optical signal among n optical signals having wavelengths λ1 to λn demultiplexed by the optical demultiplexer 2 uses any one of the pass-through signal lines P1 to Pn. The other optical signals output to the optical multiplexer 4 side are input to the first branch side n × m matrix optical switch 12, and the optical signals further selected as branch signals from these are the branch ports D _{1 to} D. _m is output to the optical receiver 102 via _m , and the remaining optical signals are output from the branch side through ports TD _{1 to} TD _n .

Meanwhile, the first insertion-side n × m matrix optical switch 13, 2 × 1 except that the n branch lines extending from the optical switch array 11 is connected, the insertion side through the m pieces of the insertion port A ₁ to A _m Ports TA _{1 to} TA _n are provided. m branch lines extending from the optical transmission unit 103 are connected to the _m insertion ports A _{1 to} Am. Then, the inserted optical signal input via the optical transmitter 103 passes through the first insertion side n × m matrix optical switch 13 via the _m insertion ports A _{1 to} Am and 2 × 1. Input to the optical switch array 11.

First insertion side n × m matrix optical switch 13 selects one of the optical signals input optical signals input from the insertion side through port TA ₁ to Ta _n and from the insertion port A ₁ to A _m for each wavelength And output to the 2 × 1 optical switch array 11. Here, when the optical signal of the wavelength λ1~λn is through each optical signal of the wavelength λ1 is input to the insertion side through port TA _1, the optical signal of the wavelength λ2 is input to the thru port TA ₂ The optical signal having the wavelength λn is input to the through port ADn.

  In the 2 × 1 optical switch array 11, n insertion signal lines extending from the first insertion side n × m matrix optical switch 13 and n pass-through signal lines P1 to Pn extending from the 1 × 2 optical switch array 10 are optical. Connected. The 2 × 1 optical switch array 11 selects one of the inserted optical signal and the transmitted optical signal input from the inserted signal line and the pass-through signal lines P <b> 1 to Pn and outputs the selected optical signal to the optical multiplexer 4. The optical multiplexer 4 wavelength-multiplexes the optical signals from the 2 × 1 optical switch array 11 to generate wavelength-multiplexed optical signals having wavelengths λ1 to λn and outputs them to the output side optical cable 5.

  A switch control circuit 7 is electrically connected to the 1 × 2 optical switch array 10, the 2 × 1 optical switch array 11, the first branch side n × m matrix optical switch 12, and the first insertion side n × m matrix optical switch 13. It is connected. The switch control circuit 7 controls these switches so that an arbitrary optical signal is directed to an arbitrary port.

Next, the operation will be described. For example, when an optical signal having a wavelength λ1 is added by branching and an optical signal having another wavelength is passed through, the 1 × 2 optical switch array 10 transmits the optical signal having the wavelength λ1 to the first branch side n × m matrix optical switch. 12 and output optical signals of other wavelengths using the pass-through optical signal lines P2 to Pn. The first branch side n × m matrix optical switch 12 outputs an optical signal having a wavelength λ1 to the optical receiving unit 102 via, for example, the branch port D ₁ based on the setting of the switch control circuit 7.

On the other hand, the optical signal having the wavelength λ1 input from the optical transmission unit 103 is input via the insertion port A ₁ , and is 2 by the first insertion side n × m matrix optical switch 13 based on the setting of the switch control circuit 7. It is output to the 2 × 1 optical switch corresponding to the wavelength λ1 of the × 1 optical switch array 11, and the 2 × 1 optical switch array 11 is not an optical signal via the pass-through optical signal line P1, but the first insertion side n × m matrix. An optical signal corresponding to the wavelength λ1 from the optical switch 13 is selected and output to the optical multiplexer 4, and the optical signals input from the pass-through optical signal lines P2 to Pn are selected for wavelengths other than the wavelength λ1. Output to the optical multiplexer 4. With the above operation, the optical signal having the wavelength λ1 can be branched and inserted to pass through the optical signals having the wavelengths λ2 to λn.

Similarly, regarding the operation of branching and inserting the optical signal having the wavelength λ3 through the branch port D ₃ and the insertion port A ₃ , the setting of the switch control circuit 7 is similarly changed to change the first branch side n. The switching path of the × m matrix optical switch 12 and the first insertion side n × m matrix optical switch 13 is changed, and the insertion / branching port can be changed without affecting other optical signals passing through.

Further, by changing the pass-through the optical signal of the wavelength .lambda.1, describing a case of changing the operation of branch inserted through the optical signal drop port D ₂ and insertion ports A ₂ wavelength .lambda.2. The switches of the 1 × 2 optical switch array 10 and the 2 × 1 optical switch array 11 are switched so that the optical signal of wavelength λ1 is pass-through connected between the optical demultiplexer 2 and the optical multiplexer 4, and the light of wavelength λ2 The switches are switched so that signals are output to the first branch side n × m matrix optical switch 12 and the first insertion side n × m matrix optical switch 13, respectively. Further, the first branch side n × m matrix optical switch 12 and the first insertion side n × m matrix optical switch 13 are switched so that the optical signal of wavelength λ2 is output to the branch port D ₃ and the insertion port A ₃ . As described above, in the optical add / drop multiplexer 100 of the present embodiment, it is possible to add / drop between any wavelength and any add / drop port, and changing the add / drop wavelength also affects other wavelengths. do not do.

  FIG. 3 shows how an n × m matrix optical switch is added when the wavelength to be added / dropped exceeds m in the optical add / drop device shown in FIG. In FIG. 3, only the main part of the optical add / drop unit 101 is shown, and the switch control circuit 7 is omitted. In FIG. 3, a second branch side n × m (2m is an integer smaller than n) matrix optical switch 14 and a first insertion side n × m matrix optical switch are respectively provided downstream of the first branch side n × m matrix optical switch 12. A second insertion side n × m (2 m is an integer smaller than n) matrix optical switch 15 is added to the subsequent stage of 13.

For example, in the case of changing to the operation of branching and inserting the optical signal with the wavelength λn via the branching port D _{m + 1} and the insertion port A _{m + 1} , the 1 × 2 optical switch array 10 has the light with the wavelength λn. The first switching side n × m matrix optical switch 12 switches the optical signal of wavelength λn from the 1 × 2 optical switch array 10 to the second branch side. The second branch side n × m matrix optical switch 14 is switched to output the wavelength λn to the branch port D _{m + 1} . Similarly, the second insertion side n × m matrix optical switch 15 switches to output the optical signal from the insertion port _{Am + 1} to the first insertion side n × m matrix optical switch 13, and the first insertion side n × m The matrix optical switch 13 outputs to the 2 × 1 optical switch array 11, and the 2 × 1 optical switch array 11 receives the optical signal from the first insertion side n × m matrix optical switch 13 instead of the pass-through optical signal lines P1 to Pn. The wavelength is selected and output to the optical multiplexer 4 as the wavelength λn.

In the optical add / drop multiplexer configured as described above, the wavelength division multiplexed optical signal input from the input side optical cable 1 is demultiplexed by the optical demultiplexer 2 and the optical demultiplexer 2 for demultiplexing into n optical signals for each wavelength. N optical signals are input so that n optical signals are respectively input, and the optical signals are output as transmitted optical signals to the pass-through signal lines P1 to Pn extending to the optical multiplexer side or branched optical signals to the branch lines. A 1 × 2 optical switch (1 × 2 optical switch array 10) that switches to either one of the outputs is connected to n branch lines extending from the 1 × 2 optical switch array 10, and the branched optical signal input by the branch line is Since each of the n branch ports D _{1 to} D _m and the n branch side through ports TD _{1 to} TD _n has a branch side n × m matrix optical switch 12 for distribution or distribution, Network Well it is able to easily branch the optical signal of a predetermined wavelength, by using a small switch that n × m matrix optical switch 12, to the branch port D ₁ to D _m and the insertion port A ₁ to A _m When there are few optical signals to be added / dropped, the system can be used without waste, and the system can be made economical, and has n number of through ports TD _{1 to} TD _n. When it becomes necessary to add an optical switch, it is possible to easily add a switch without interrupting communication. As a result, it is possible to reduce the device cost at the time of initial introduction, and to easily add and maintain switches in the future in a short time. can do.

The optical transmission unit 103 generates an insertion optical signal by converting an electrical signal input from the outside into an optical signal, and the optical add / drop unit 101 is connected to the optical transmission unit 103 and receives the insertion optical signal. An insertion side n × m matrix optical switch 13 having _m insertion ports A _{1 to} Am and n insertion side through ports TA _{1 to} TA _n to be input, and extends from the insertion side n × m matrix optical switch 13. The n insertion signal lines and the n pass-through signal lines P1 to Pn are connected to each other, and n 2 × that output the inserted optical signal and the transmitted optical signal input from either the insertion signal line or the pass-through signal line. Since it further includes one optical switch (2 × 1 optical switch array 11), it is possible to easily insert an optical signal having a predetermined wavelength into the network.

Furthermore, depending on the number of wavelengths and dropping, because the n × m matrix optical switch can be a multi-stage cascade-connected via a branch side through port TD ₁ ~TD _n and the insertion-side through port TA ₁ to Ta _n, Since it is possible to increase / decrease the number of add / drop wavelengths without affecting the pass-through optical signal lines P1 to Pn and other wavelengths that are added / dropped, the economical efficiency and wavelength at the time of initial introduction with a small number of added / dropped wavelengths It is possible to provide flexible extensibility with respect to increase / decrease of the number.

  Furthermore, n number of 1 × 2 optical switches that are switching optical switches and n number of 2 × 1 optical switches that are integrated optical switches are integrated together to form an array, thereby reducing the number of components. Therefore, the cost can be reduced and the assembly process can be facilitated.

  FIG. 4 shows the optical add / drop multiplexer shown in FIGS. 2 and 3, in which the 1 × 2 optical switch array 10 that is a switching optical switch and the 2 × 1 optical switch array 11 that is an integrated optical switch are replaced with 2 × 2 light. A 2 × 2 optical switch array 16 in which a plurality of switches are provided is arranged. In the optical add / drop device having such a configuration, since the switching optical switch and the integrated optical switch are configured by one 2 × 2 optical switch, the number of components can be reduced and the cost can be reduced. Reliability can be improved.

If the path loss n × m matrix optical switch branch side through port TD ₁ ~TD _n and TD ₁ ~TD _n optical drop unit 101 shown in the above FIGS. 2 4 is large, the light receiving portion during multistage dependent It is difficult to ensure the optical characteristics of the optical transmission unit 102 and the optical transmission unit 103. In this case, as shown in FIG. 5, the 1 × 2 optical switch array 18 and the n × m matrix optical switch 18 may be combined to form an n × m matrix optical switch with a through port. Similarly, when the 1 × 4 optical switch array 21 and the n × m matrix optical switches 18, 20, 22, 23 are combined as shown in FIG. 6, the path loss to the branch ports D _{1 to} D _4m is averaged. It is possible to reduce the loss of the subsequent path.

  5 and 6, the configuration for reducing the loss at the time of multi-stage dependency on the branch port side has been described. However, the same configuration as that on the insertion port side has the same effect as described above.

Embodiment 2. FIG.
FIG. 7 is a configuration diagram of an optical add / drop multiplexer for explaining the second embodiment. In the present embodiment, n 1 × 2 optical couplers are integrally provided in place of the 1 × 2 optical switch array 10 shown in the configuration of the optical add / drop multiplexer of FIGS. 2 and 3 in the first embodiment. A 1 × 2 optical coupler array 24 is provided. The 1 × 2 optical coupler array 24 branches optical signals of wavelengths λ1 to λn from the optical demultiplexer 2 to the first branch side n × m matrix optical switch 12 and the 2 × 1 optical switch array 11, respectively. The same effects as in the first mode are obtained. A similar function can be realized by selecting the branched wavelength by the 2 × 1 optical switch array 11 and outputting it to the multiplexer 4.

  In the optical add / drop multiplexer having such a configuration, at least one of the 1 × 2 optical switch array 10 that is a switching optical switch and the 2 × 1 optical switch array 11 that is an integrated optical switch is configured by an optical coupler. Therefore, the apparatus can be made compact, and the installation area and installation space of the apparatus can be reduced.

Embodiment 3 FIG.
FIG. 8 is a configuration diagram of an optical add / drop multiplexer for explaining the third embodiment. In this embodiment, the 2 × 1 optical switch array 11, the first insertion side n × m matrix optical switch 13 and the second insertion side shown in the configuration of the optical add / drop multiplexer of FIGS. 2 and 3 in the first embodiment are used. Instead of the n × m matrix optical switch 15, the collective optical coupler 26 that collects and connects the optical signals from the insertion ports A _{1 to} A _{m1 at the subsequent} stage of the optical multiplexer 4, and the wavelength of the output side optical cable 5 A superposition optical coupler 25 that overlaps the multiplexed optical signal is provided.

  In the optical add / drop multiplexer having such a configuration, the collective optical coupler 26 that collects and connects n insertion signal lines extending from an optical transmission unit (not shown), and the collective optical coupler 26 provided on the output side optical cable 5 are connected. Since it has the superposition | polymerization optical coupler 25 which superimposes an output on the wavelength multiplexed optical signal of the output side optical cable 5, an apparatus can be produced compactly and the installation area and installation space of an apparatus can be reduced. On the branch port side, the n × m matrix optical switch may be subordinated depending on the increase / decrease of the branch wavelength, and the same effect as in the first embodiment can be obtained.

Embodiment 4 FIG.
FIG. 9 is a configuration diagram of an optical add / drop multiplexer for explaining the fourth embodiment. In this embodiment, a 1 × 2 optical coupler array 24 is provided in place of the 1 × 2 optical switch array 10 shown in the configuration of the optical add / drop multiplexer of FIG. 8 in the third embodiment, and n variable optical attenuations are provided. The variable optical attenuator array 27 formed integrally with the optical device is added to the pass-through signal lines P1 to Pn, and the optical signal from the insertion port is separated by blocking the wavelength branched by the variable optical attenuator array 27. In the optical signal from the 1 × 2 optical coupler array 24, the same wavelength is prevented from colliding, and the same effect as in the third embodiment can be obtained. The optical output power of the optical signal passing through by the variable optical attenuator array 27 can be adjusted for each wavelength.

  In the optical add / drop multiplexer configured as described above, the variable optical attenuator for adjusting the optical output power of the transmitted optical signal is provided in each of the pass-through signal lines P1 to Pn. It can be adjusted every time.

Embodiment 5.
FIG. 10 is a configuration diagram of an optical add / drop multiplexer for explaining the fifth embodiment. In this embodiment, instead of the 1 × 2 optical switch array 10 shown in the configuration of the optical add / drop device in FIGS. 2 and 3 in the first embodiment, n 1 × k branch optical switches are integrally provided. 1 × k optical switch array 28 (k is an integer) is provided, and instead of the 2 × 1 optical switch array 11, k × 1 optical switches are integrally provided with n k × 1 branching optical switches. An array 29 (k is an integer) is provided. Switching between pass-through connection by the 1 × k optical switch array 28 or connection and branching to the n × m matrix optical switch 18 or the n × m matrix optical switch 20 connected in cascade is performed, and similarly the k × 1 optical switch array 29 is switched between pass-through connection by 29 and connection to the n × m matrix optical switch 30 or n × m matrix optical switch 31 that are connected in cascade.

  In the optical add / drop multiplexer configured as described above, the switching optical switch is a 1 × k optical switch. Therefore, in the optical add / drop multiplexer configured so that the matrix optical switches are connected in multiple stages, the matrix optical switch is connected in multiple stages. Loss to the branch port and the insertion port can be reduced.

Embodiment 6 FIG.
FIG. 11 is a configuration diagram of an optical add / drop multiplexer for explaining the sixth embodiment. 10 is a configuration in which a 1 × k optical coupler array 32 (k is an integer) is provided in place of the 1 × k optical switch array 28 shown in the configuration of the optical add / drop multiplexer of FIG. 10 in the fifth embodiment. Equivalent effect to 5.

Embodiment 7 FIG.
FIG. 12 is a configuration diagram of an optical add / drop multiplexer according to the present invention. In FIG. 12, the optical add / drop multiplexer assembly according to the present embodiment is provided with two optical add / drop multiplexers according to the first embodiment, and an optical signal input from the input side optical cable 1 is odd-numbered according to the wavelength. An interleaver 33 that separates the wavelength λ _odd and the even wavelength λ _even is provided in front of the two demultiplexers 2, and an interleaver 34 that adds the even wavelength λ _even to the odd wavelengths λ _odd is located behind the two demultiplexers 2. 2 × 1 optical switch arrays 35, 36, 37, and 38 are provided for switching the branch ports and insertion ports for odd and even wavelengths.

The optical add / drop device body configured as described above is provided in the two optical add / drop devices provided in parallel and the input side optical cable 1, and when the wavelength of the incoming optical signal is an odd wavelength λ _odd , A first interleaver 33 that outputs to one of the two optical _{add / drop} devices and distributes the input to the other optical _{add / drop} device at an even wavelength λ _even , and an output And a second interleaver 34 that is provided in the side optical cable and integrates the outputs of the two optical add / drop multiplexers. Therefore, when the number of wavelengths required in the optical ring network at the time of initial introduction is small, as shown in FIG. 13, an optical multiplexer, an optical demultiplexer, and an optical switch required for branching and inserting an odd wavelength λ _odd and a pass-through path It is possible to provide an optical add / drop device that is highly economical and highly scalable, which can increase or decrease the number of add / drop wavelengths and pass-through wavelengths without affecting other wavelengths according to demand. it can.
In the present embodiment, as the optical add / drop multiplexer provided in two units, the one in the first embodiment is used, but another optical add / drop device may be used.

Embodiment 8 FIG.
FIG. 14 is a configuration diagram of a second optical add / drop multiplexer according to the present invention. In FIG. 14, the optical add / drop multiplexer body of the present embodiment is an optical add / drop multiplexer provided in a two-cable optical ring network in which two optical cables having different traveling directions of optical signals are arranged in a duplex manner. Two optical demultiplexers 2, 1 × 2 optical switch array 10, 2 × 1 optical switch array 11 and two optical multiplexers 4 are arranged corresponding to a two-cable optical ring network. The configuration is such that a 2 × 1 optical switch array 39 and a 1 × 2 optical switch array 40 that are switched so as to select either one of the optical signals in the direction are provided.

  That is, the optical add / drop device of the present embodiment is provided with the first and second optical add / drop devices, and the two optical add / drop devices are duplexed clockwise and counterclockwise. The optical fiber transmission line is provided in the signal traveling direction, and the branch side matrix optical switch and the insertion side matrix optical switch are shared by the first and second optical branching and inserting devices. As a result, for example, when a failure occurs in the optical transmission path on the WEST side, the optical signal of the wavelength to be added / dropped is switched to the EAST side by the 2 × 1 optical switch array 31 and the 1 × 2 optical switch array 32. Thus, the optical signal path can be made redundant, and a highly reliable optical ring network with excellent expandability can be provided.

  In the optical add / drop multiplexer according to the present embodiment, a 1 × 2 optical coupler array 24 may be provided instead of the 1 × 2 optical switch array 10 as shown in FIG. Furthermore, in the optical add / drop multiplexer of FIG. 12 according to the seventh embodiment, an optical switch for selecting one of the optical signals in the WEST direction and the EAST direction may be provided so as to correspond to the two-cable optical ring network. . Furthermore, in the present embodiment, basically, the optical add / drop multiplexer apparatus according to the first embodiment is used as two optical add / drop multiplexers, but other optical embodiments may be used.

  It has a node provided in the middle of the transmission path of the optical network, selectively transmits only an optical signal of a specific wavelength among the wavelength-multiplexed optical signals, and transmits optical signals of other wavelengths. It is suitable for a network having an ADM function for receiving the data in the network or transmitting another optical signal from this node to another node.

It is the block diagram which showed the optical ring network to which the optical add / drop device of this invention is applied. FIG. 2 is a structural diagram illustrating details of an optical add / drop unit of the optical add / drop device of FIG. 1. FIG. 3 is a structural diagram showing a state where a matrix optical switch is added to the optical add / drop multiplexer of FIG. 2. FIG. 4 is a structural diagram showing a state in which a 2 × 2 optical switch array is arranged in place of the 1 × 2 optical switch array and the 2 × 1 optical switch array in the optical add / drop device of FIG. 3. FIG. 3 is a structural diagram showing a state in which a matrix optical switch with a through port is configured by combining a 1 × 2 optical switch array and a matrix optical switch. FIG. 5 is a structural diagram showing a state in which matrix optical switches are respectively connected to the ends branched by a 1 × 4 optical switch array. It is a structural diagram which shows the detail of the optical add / drop part of the optical add / drop device of Embodiment 2 of this invention. It is a block diagram which shows the detail of the optical add / drop part of the optical add / drop device of Embodiment 3 of this invention. It is a structure figure which shows the detail of the optical add / drop part of the optical add / drop device of Embodiment 4 of this invention. FIG. 10 is a structural diagram illustrating details of an optical add / drop unit of an optical add / drop device according to a fifth embodiment of the present invention. It is a structural diagram showing the details of the optical add / drop unit of the optical add / drop device according to Embodiment 6 of the present invention. It is a block diagram of the optical add / drop multiplexer apparatus body of this invention. It is a block diagram which shows the part of the optical add / drop device corresponding to an odd wavelength in the optical add / drop device of the optical signal of FIG. It is a block diagram of the 2nd optical branching and inserting apparatus body of this invention. FIG. 13 is a structural diagram showing a configuration in which a 1 × 2 optical coupler array is provided in place of the 1 × 2 optical switch array in the optical signal add / drop optical device body of FIG. 12. It is a structural diagram of a conventional optical add / drop device. It is a structural diagram of another conventional optical add / drop multiplexer.

Explanation of symbols

1 Input side optical cable (optical transmission line)
2 Optical demultiplexer 5 Output side optical cable (optical transmission line)
4 Optical multiplexer 7 Switch control circuit 10 Optical switch array (switching optical switch)
11 Optical switch array (integrated optical switch)
12 first branch side n × m matrix optical switch 13 first insertion side n × m matrix optical switch 14 second branch side n × m matrix optical switch 15 second insertion side n × m matrix optical switch 25 polymerization optical coupler 26 set Optical coupler 27 Variable optical attenuator array (variable optical attenuator array)
28 1 × k optical switch array (1 × k branch optical switch)
29 k × 1 optical switch array (k × 1 branch optical switch)
100 OADM 101 optical drop unit 103 optical receiver 102 optical transmission unit P1~Pn passthrough optical signal line λ1~λn wavelength D ₁ to D _m branch port TD ₁ ~TD _n branched side through port A ₁ to A _m inserting port TA ₁ to Ta _n insertion side through port

Claims (16)

Provided in the middle of a transmission line of a wavelength division multiplexing optical network, selects an optical signal of a predetermined wavelength from among the wavelength multiplexed optical signals and transmits it as a transmitted optical signal, and branches and inserts optical signals of other wavelengths In the optical add / drop device to
An optical demultiplexer for demultiplexing a wavelength division multiplexed optical signal input from an input side optical cable into n optical signals for each wavelength;
N optical signals are provided so that n optical signals demultiplexed by the optical demultiplexer are respectively input, and the optical signal is output to the pass-through signal line as the transmitted optical signal or branched as the branched optical signal. Switch optical switch to switch to output to either
Any port of the n said branch line is connected the branch line thus inputted the branched optical signals, respectively less than n m pieces of branch ports and the n branch side through port extending from said switching optical switch The first branch side n × m matrix optical switch to output or distribute to
The switching optical switch and the first branch side n × m matrix optical switch are controlled, and the demultiplexed optical signals are output to any of the pass-through signal line, the branch port, and the branch side through port, respectively. An optical add / drop unit having a switch control circuit for switching between, and an optical multiplexer for wavelength-multiplexing the transmitted optical signal transmitted through at least the pass-through signal line and outputting the generated wavelength multiplexed optical signal to an output side optical cable As well as
An optical receiving unit connected to the branch port and converting the optical signal output to the branch port into an electrical signal and outputting the electrical signal;
The optical add / drop unit is:
The n branch lines provided between the first branch side n × m matrix optical switch and the optical receiver and extending from n branch side through ports of the first branch side n × m matrix optical switch. Is connected to the branch line, and the branch optical signal input through the branch line is output to or distributed to any one of m branch ports smaller than n / 2 and n branch side through ports. An optical add / drop device further comprising an m-matrix optical switch. Provided in the middle of a transmission line of a wavelength division multiplexing optical network, selects an optical signal of a predetermined wavelength from among the wavelength multiplexed optical signals and transmits it as a transmitted optical signal, and branches and inserts optical signals of other wavelengths In the optical add / drop device to
An optical demultiplexer for demultiplexing a wavelength division multiplexed optical signal input from an input side optical cable into an integer of n optical signals for each wavelength;
N optical signals are provided so that n optical signals demultiplexed by the optical demultiplexer are respectively input, and the optical signal is output to the pass-through signal line as the transmitted optical signal or branched as the branched optical signal. Switch optical switch to switch to output to either
The n branch lines extending from the switching optical switch are connected, and the branch optical signals input by the branch lines are respectively connected to any of m branch ports smaller than n and n branch side through ports. First branch side n × m matrix optical switch for output or distribution,
The switching optical switch and the first branch side n × m matrix optical switch are controlled, and the demultiplexed optical signals are output to any of the pass-through signal line, the branch port, and the branch side through port, respectively. An optical add / drop unit having a switch control circuit for switching between, and an optical multiplexer for wavelength-multiplexing the transmitted optical signal transmitted through at least the pass-through signal line and outputting the generated wavelength multiplexed optical signal to an output side optical cable As well as
An optical receiving unit connected to the branch port and converting the optical signal output to the branch port into an electrical signal and outputting the electrical signal;
The optical add / drop unit is:
A 1 × k branch optical switch connected to each branch side through port extending from the branch side matrix optical switch and branching the port into a plurality of k, and a branch destination of the 1 × k branch optical switch, respectively. An optical add / drop multiplexer further comprising k branch side matrix optical switches. Further comprising an optical transmitter that converts an electrical signal input from the outside into an optical signal to generate an insertion optical signal;
The optical add / drop unit is:
A first insertion side n × m matrix optical switch that is connected to the optical transmission unit and has m insertion ports for receiving the insertion optical signal and n insertion side through ports;
The n insertion signal lines extending from the first insertion side n × m matrix optical switch and the n pass through signal lines are connected to each other, and the insertion is input from either the insertion signal line or the pass through signal line. N integrated optical switches for outputting an optical signal and the transmitted optical signal to the optical multiplexer, and
The optical add / drop device according to claim 1, wherein the switch control circuit also controls switching of the first insertion side n × m matrix optical switch and the integrated optical switch. Further comprising an optical transmitter that converts an electrical signal input from the outside into an optical signal to generate an insertion optical signal;
The optical add / drop unit is:
An aggregate optical coupler that aggregates and connects n insertion signal lines extending from the optical transmitter;
The optical branching according to claim 1, further comprising: a superposition optical coupler provided on the output side optical cable and superimposing an output from the collective optical coupler on the wavelength multiplexed optical signal of the output side optical cable. Insertion device. 5. The optical add / drop device according to claim 1, wherein each of the pass-through signal lines is provided with a variable optical attenuator for adjusting an optical output power of the transmitted optical signal. The optical add / drop unit is:
The n branch lines provided between the first insertion side n × m matrix optical switch and the optical transmitter and extending from n insertion side through ports of the first branch side n × m matrix optical switch. A second insertion side n × m matrix having m insertion ports smaller than n / 2 and n insertion side through-ports that are connected to the optical transmission unit and that receive the insertion optical signal. The optical add / drop device according to any one of claims 2 to 5, further comprising an optical switch. The optical add / drop unit is:
A k × 1 branch optical switch connected to each insertion side through port extending from the insertion side matrix optical switch and inputting any one of k optical signals from the branch destination to the insertion side through port; 6. The optical add / drop device according to claim 2, further comprising k insertion-side matrix optical switches respectively connected to branch destinations of the k × 1 branch optical switch. 8. The optical add / drop device according to claim 1, wherein the switching optical switch is a 1 × k optical switch. The optical add / drop multiplexer according to any one of claims 2 to 7, wherein the integrated optical switch is a k × 1 optical switch. 8. The optical add / drop device according to claim 1, wherein the switching optical switch is a 1 × 2 optical switch. 8. The optical add / drop device according to claim 2, wherein the integrated optical switch is a 2 × 1 optical switch. 8. The optical add / drop device according to claim 2, wherein the switching optical switch and the integrated optical switch are configured by one 2 × 2 optical switch. 9. The at least one of the switching optical switch, the integrated optical switch, the 1 × k branch optical switch, and the k × 1 branch optical switch is configured by an optical coupler. 8. The optical add / drop device according to any one of claims 7 to 9. A plurality of the switching optical switch, the integrated optical switch, 1 × optical switch k least one group of branch optical switch and k × 1 branch optical switch claims, characterized in that are arranged, et al is an array Item 8. The optical add / drop device according to any one of Items 2 to 7. An optical add / drop device body comprising the first and second optical add / drop devices according to any one of claims 1 to 14,
Two optical add / drop devices provided side by side;
Provided to the input side optical cable, when the wavelength of the incoming optical signal is an odd wavelength, it is input to one of the two optical add / drop devices, and when the wavelength is an even wavelength, the other A first interleaver that distributes input to the optical add / drop device;
Provided on the output side optical cable, optical add-drop body, characterized in that a second interleaver for integrating an output of the two optical add-drop multiplexer. An optical add / drop device body comprising the first and second optical add / drop devices according to any one of claims 1 to 14,
It said first and second two optical add drop apparatus are provided toward the traveling direction of the respective signal in the transmission path is duplicated in the opposite direction around a predetermined direction around,
The branching-side matrix optical switch and the insertion-side matrix optical switch are shared by the first and second two optical branching-and-inserting devices.

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