JP2008259135A - Optical cross-connect device, and signal control method in optical cross-connect device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical cross-connect device which attains cost reduction by decreasing the numbers of not only optical switches, but also wavelength selection switches. <P>SOLUTION: The optical cross-connect device has a plurality of wavelength selection switches which select specified wavelength light input thereto respectively and are disposed in parallel, a plurality of optical circulators which are disposed in front of and behind the wavelength selection switches, respectively, and output light input from a first port to a second port through a nonreciprocal part and light input from the second port to a third port through the nonreciprocal part, and an optical switch connected to an optical circulator disposed behind the wavelength selection switch or the wavelength selection switch and switching input wavelength light. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an optical cross-connect device in a wavelength division multiplexing transmission system and a signal control method in the optical cross-connect device, and in particular, edits each wavelength in a batch and performs signal processing such as route setting for each generated wavelength group. The present invention relates to an optical cross-connect device using a wavelength selective switch that selects and extracts a signal of a specific wavelength from wavelength-multiplexed signal light for performing the above and a signal control method in the optical cross-connect device.

  In an optical communication system, the transmission capacity is increased by using a wavelength division multiplexing (WDM) technology capable of propagating a plurality of different wavelength lights in one optical fiber. In this WDM, an optical cross-connect device using a wavelength selective switch that extracts a specific wavelength signal from wavelength multiplexed signal light is used.

  A conventional optical cross-connect device will be described.

  FIG. 5 shows a configuration of a conventional optical cross-connect device.

  The optical cross-connect device shown in the figure includes a control unit 2 that manages wavelengths and outputs a wavelength editing signal and a route switching signal, and four wavelength selective switches 1 on each of the input side and the output side. When a wavelength is input to the wavelength selection switch 1 on the input side, the wavelength selected based on the wavelength editing signal and the route switching signal from the control unit 2 is output to one of the wavelength selection switches 1 on the output side. (For example, refer nonpatent literature 1).

  The configuration of the wavelength selective switch in the configuration of FIG. 5 is shown in FIG.

  The wavelength selective switch 1 shown in FIG. 6 has one input and N outputs (1 × N), and is connected to one duplexer 10, a plurality of optical switches 20 connected to the duplexer 10, and the optical switch 20. It is composed of a plurality of multiplexers 30.

The demultiplexer 10 shown in the figure demultiplexes wavelength multiplexed signal light consisting of n channels of λ ₁ , λ ₂ ,..., Λ _n input from one input port into n based on the wavelength editing signal. , Output to n optical switches 20, combine the wavelength light output from each optical switch 20 in the multiplexer 30, and output it. That is, the same number of optical switches as the number of channels of wavelength multiplexed signal light are required. In the example shown in the figure, the wavelength multiplexed signal light of λ ₁ , λ ₂ ,..., Λ ₁₁ is demultiplexed into 11 and output to 11 optical switches 20.

  Each optical switch 20 has one input port and M (M is the number of multiplexers) output ports, and switches any of the input WDM input light based on the route switching signal. Is output to the multiplexer 30.

The multiplexer 30 combines and outputs the wavelengths input from the optical switch 20. In the example of FIG. 6, four multiplexers are provided, and the combined wavelengths λ _{1 to} λ ₃ , wavelengths λ _{4 to} λ ₆ , wavelengths λ _{7 to} λ ₈ , and wavelengths λ _{9 to} λ ₁₁ are output. Is done.
Lei Zong, Philip Ji, Ting Wang, Osamu Matsuda, Milorad Cvijetic, "Study on Wave length Cross-Connect Realized with Wavelength Selective Switches", Optical Fiber Communications 2006.

  However, the optical cross-connect device using the wavelength selective switch having the same number of optical switches as the number of channels of the conventional wavelength multiplexed signal light is proportional to the number of optical switches as the number of wavelength selective switches increases. Because of the increase, the insertion loss of the wavelength selective switch becomes very large.

  The present invention has been made in view of the above points. An optical cross-connect device capable of reducing the number of wavelength selective switches as well as optical switches and reducing the cost, and a signal control method in the optical cross-connect device are provided. The purpose is to provide.

  FIG. 1 is a principle configuration diagram of the present invention.

The present invention (Claim 1) is an optical cross-connect device using a wavelength selective switch that selects and extracts a signal of a specific wavelength from wavelength multiplexed signal light used for wavelength multiplexing transmission,
A plurality of wavelength selective switches 100 arranged in parallel for selecting a specific wavelength light from the wavelength multiplexed signal light input to each;
The light is input from the first port through the nonreciprocal part and output to the second port, and the light input from the second port is disposed at the front and rear stages of the wavelength selective switch 100. A plurality of optical circulators 121 and 122 that pass through the non-reciprocal portion and output to the third port;
An optical switch 300 that is connected to a second optical circulator 122 disposed at a subsequent stage of the wavelength selective switch 100 and switches input wavelength light;
A control means 50 for outputting a wavelength editing signal for selecting a wavelength to the wavelength selective switch 100 and outputting a path switching signal for switching the path of the wavelength light to the optical switch 300;
Have
The wavelength selective switch 100 is
When wavelength multiplexed signal light is input from the input port via the first optical circulator 121 provided in the preceding stage of the wavelength selective switch 100, the wavelength selective switch selects the wavelength light based on the wavelength editing signal. 100 to the second optical circulator 122 provided in the subsequent stage,
The second optical circulator 122 provided at the subsequent stage of the wavelength selective switch 100 is:
The wavelength light input from the wavelength selective switch 100 is output to the optical switch 300, and
The optical switch 300 is
The path of the wavelength light input from the second optical circulator 122 is switched based on the path switching signal, and is output to the second optical circulator 122.
The second optical circulator 122 is
The wavelength light input from the optical switch 300 is output to the wavelength selective switch 100,
Wavelength selective switch
The wavelength light input from the second optical circulator 122 is selected based on the wavelength editing signal and output to the first optical circulator 121 by selecting the wavelength light,
The first optical circulator 121 is
The wavelength light input from the wavelength selective switch 100 is output to the output port.

The wavelength selective switch 100 of the present invention (Claim 2) includes:
Based on the wavelength editing signal, it has an N-stage band division filter that divides into each wavelength band of the input wavelength multiplexed signal light and outputs from the output port;
1 to N-1 stage band division filter, one wavelength light divided for each wavelength band is directly output to the outside from the first output port, and the other wavelength light is output to the next stage band division filter The N-stage band dividing filter is configured to output the wavelength light divided for each wavelength band to the outside as it is, and select the selected wavelength for each arbitrary wavelength based on the wavelength editing signal. Output from the output port.

The wavelength selective switch 100 of the present invention (Claim 3) includes:
Demultiplexing means for mapping the input wavelength-multiplexed signal light for each wavelength based on the wavelength editing signal and outputting from the N output ports;
When a plurality of mapped wavelength lights outputted from the demultiplexing means are inputted from a plurality of input ports, the wavelength lights are spatially recombined, and an arbitrary wavelength is selected based on the wavelength editing signal. A plurality of multiplexing means for outputting from the output port for each wavelength.

The present invention (Claim 4) is a signal control method in an optical cross-connect device using a wavelength selective switch that selects and extracts a signal of a specific wavelength from wavelength multiplexed signal light used for wavelength multiplexing transmission,
A plurality of wavelength selective switches arranged in parallel to select a specific wavelength light from the wavelength multiplexed signal light input to each;
Each of the wavelength selective switches is arranged at the front stage and the rear stage, and the light input from the first port passes through the nonreciprocal part to be output to the second port, and the light input from the second port is not A plurality of optical circulators that pass through the reciprocal part and output to the third port;
An optical switch that is connected to an optical circulator disposed at a subsequent stage of the wavelength selective switch and switches the input wavelength light;
A control means for outputting a wavelength editing signal for selecting a wavelength to the wavelength selective switch, and outputting a path switching signal for switching the path of the wavelength light to the optical switch;
In an optical cross-connect device having
Wavelength selective switch
When wavelength multiplexed signal light is input from the input port via the first optical circulator provided in the previous stage of the wavelength selective switch, the wavelength light is selected based on the wavelength editing signal, and the subsequent stage of the wavelength selective switch. Output to the optical circulator
The second optical circulator provided after the wavelength selective switch is:
Outputs the wavelength light input from the wavelength selective switch to the optical switch,
Optical switch
The path of the wavelength light input from the second optical circulator is switched based on the path switching signal, and is output to the second optical circulator.
The second optical circulator is
Outputs the wavelength light input from the optical switch to the wavelength selective switch,
Wavelength selective switch
The wavelength light input from the second optical circulator or the optical switch is selected based on the wavelength editing signal and output to the first optical circulator.
The first optical circulator is
Wavelength light input from the wavelength selective switch is output to the output port.

  As described above, according to the present invention, by using a wavelength selective switch that does not include an optical switch and having a folded configuration in which an optical circulator is inserted before and after the wavelength selective switch, the wavelength selective switch and the optical switch are provided. Therefore, the cost can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 2 shows the configuration of the optical cross-connect device according to the first embodiment of the present invention.

  The optical cross-connect device shown in FIG. 1 includes a control unit 50, a plurality of wavelength selective switches 100 provided in parallel, a plurality of optical circulators 121 and 122, an optical circulator 122, and wavelengths provided before and after the wavelength selective switch 100. It comprises a plurality of optical switches 300 connected to the selection switch 100.

  The control unit 50 manages wavelength bands, wavelength mapping information, and wavelength paths in the form of a table in storage means (not shown), and the wavelength multiplexed signal light input to the wavelength selective switch 100. A wavelength editing signal for assigning a wavelength to be extracted from the optical switch 300 is output, and a path switching signal for switching the path of the wavelength input to the optical switch 300 is output.

  The optical circulators 121 and 122 are optical devices having a function of different ports to be coupled depending on the traveling direction of light, and use non-reciprocity of the magneto-optical effect. The optical circulator 121 is provided in front of the wavelength selective switch 100. The optical circulator 122 is provided after the wavelength selective switch 100. In the subsequent stage, the number of optical circulators 122 required is the product of the number of wavelength selective switches 100 and the number of optical switches 300. In the example of FIG. 2, three optical circulators 121 are provided at the front stage of the wavelength selective switch, and six optical circulators 122 are provided at the rear stage.

In the optical circulator 121 ₁ of the drawing, the light incident from the port a is passed through the non-reciprocal unit, and output to the input ports of the wavelength selective switch 100 _1. Moreover, light incident from the output port of the wavelength selective switch 100 ₁ is output to port b. The same applies to the other of the optical circulator ₁₂₁ 2-121 ₄ connected upstream of the wavelength selection switch 100.

  Each optical circulator 122 connected to the subsequent stage of the wavelength selective switch 100 inputs the wavelength light output from the wavelength selective switch 100 to the optical switch 300, and is switched by the optical switch 300, and the returned wavelength is the wavelength selective switch. Output to 100.

  As shown in FIG. 3, the wavelength selective switch 100 is a 1-input N-output (1 × N) switch, and includes a plurality of band division filters 110 as a wavelength selection function.

  When wavelength multiplexed light is input via the optical circulator 121, the wavelength selective switch 100 divides the wavelength multiplexed signal light input from the input port for each wavelength band in the first-stage band division filter 110a, One is output to the output port as it is, and the other wavelength light is output to the band division filter in the next stage. Further, the last-stage band division filter 110b outputs all the divided wavelength light to the output port. In the wavelength selective switch 100, which wavelength is selected and from which output port is output depends on the wavelength editing signal from the control unit 50.

In the example of FIG. 2, the wavelength selective switch 100 ₁ outputs the wavelength light divided by the band division filter 110 shown in FIG. 3 to the optical switches 300 ₁ and 300 ₂ via the optical circulator 122 ₁ .

The optical switch 300 ₁ on the basis of the route switching signal input from the control unit 50 switches the wavelength light inputted through the optical circulator 122. For example, when the optical switch 300 ₁ receives a path switching signal for switching the path from the control unit 50 to the optical circulator 122 ₁ connected to the wavelength selective switch 100 ₁ , the optical switch 300 ₁ inputs from the optical circulator 122 _1. and it outputs the wavelength light in the optical circulator 122 _1.

  In the optical cross-connect device shown in FIG. 2, for example, the wavelength editing signal from the control unit 50 “selects the wavelength light of the band divided by one stage in the wavelength selection switch”, and the path switching signal Will be described as “output to the optical circulator from which the wavelength light is input”.

In the wavelength selective switch 100 ₁ , wavelength multiplexed signal light λ _{1 to} λ ₁₁ are input from the optical circulator 121 ₁ on the left side of the wavelength selective switch 100 ₁ based on the wavelength editing signal input from the control unit 50. Then, λ ₁ to λ ₃ subjected to band division by the band division filter 110 a are output to the optical circulator 122 ₁ . The optical circulator 122 ₁ inputs the wavelength light λ _{1 to} λ ₃ to the optical switch 300 ₁ . In the optical switch 300 ₁ , the path of the wavelength light is switched based on the path switching signal from the control unit 50 and is output to the optical circulator 122 ₁ . The wavelength selective switch 100 ₁ connected to the optical circulator 122 ₁ causes the band division filter to function as a band synthesis filter based on the wavelength editing signal input from the control unit 50, contrary to the time of input. , and outputs it to the port b wavelength light band synthesis from the output port via the circulator 121 _1.

  When the optical circulators 121 and 122 are not provided before and after the wavelength selective switch 100, as shown in FIG. 5, the wavelength selective switch is twice as shown in FIG. By using the folded configuration in which the optical circulators 121 and 122 are provided at the front stage and the rear stage of the wavelength selective switch 100 to which is inputted, the number of wavelength selective switches can be greatly reduced.

[Second Embodiment]
In this embodiment, an example will be described in which a wavelength selective switch including a demultiplexing unit and a multiplexing unit is used in the optical cross-connect device.

  The configuration of the optical cross-connect device in the present embodiment is the same as the configuration shown in FIG. 2 of the first embodiment, but the configuration of the wavelength selective switch is different.

  FIG. 4 shows the configuration of the wavelength selective switch according to the second embodiment of the present invention. Hereinafter, the wavelength selective switch 100 in FIG. 2 will be described as the wavelength selective switch 200.

  The wavelength selective switch 200 shown in FIG. 4 includes one duplexer 210 and n (three in FIG. 4) multiplexers 220.

Duplexer 210, 1 × a N demultiplexer, a wavelength-multiplexed signal light lambda _1, lambda _2, ..., the lambda _n is inputted, the mapping for each wavelength based on a wavelength editing signal from the control unit 50 And output to the multiplexer 220.

  The multiplexer 220 spatially recombines the wavelength axes of the wavelength light input from the demultiplexer 210 and outputs it for each group.

Specifically, wavelength-multiplexed signal light having wavelengths λ _{1 to} λ ₁₄ is input to the wavelength selective switch 200, of which λ ₁ is a first group, λ ₂ and λ ₃ are a second group, and λ ₄ and λ ₅ are The third group, λ ₆ and λ ₇ will be described as the fourth group, λ ₈ and λ ₉ will be described as the fifth group, and λ ₁₀ and λ ₁₁ will be described as the sixth group.

When the wavelength multiplexed signal light λ _{1 to} λ ₁₄ is input from the input port of the duplexer 210, the duplexer 210 sends the wavelength light of the first group and the second group to the multiplexer 220 ₁ . the wavelength of the third group and the fourth group to the multiplexer 220 _2, it is possible to output the wavelength of the fifth group and group 6 to the multiplexer 220 _3.

Thus, each multiplexer 220 combines the wavelength light of each group input from the duplexer 210 for each wavelength based on the wavelength editing signal, and outputs the combined light from the selected output port. The first multiplexer 220 ₁ wavelength light of the first and second group, the second multiplexer 220 ₂ wavelength light of third and fourth group, the third multiplexer 220 ₃ Combines the wavelength lights of the fifth and sixth groups and outputs them to the optical circulator 121 on the left side of the wavelength selective switch 100.

  When the wavelength multiplexed signal light is input from the port a through the optical circulator 121, the wavelength selective switch 100 outputs the selected wavelength light to the optical circulator 122 at the subsequent stage of the wavelength selective switch 100, and the subsequent stage. When a wavelength is input from the optical circulator 122, it is output to the optical circulator 121 in the previous stage of the wavelength selective switch 100. At this time, in the wavelength selective switch 100, the multiplexer 220 functions as a demultiplexer, and the demultiplexer 210 functions as a multiplexer.

  Since the operations of the optical circulator 120 and the optical switch 300 are the same as those in the first embodiment, the description thereof will be omitted.

  In the first and second embodiments described above, the wavelength selective switch shown in FIGS. 3 and 4 is applied to the optical cross-connect device shown in FIG. 2, but the conventional wavelength selective switch shown in FIG. It can also be used as a wavelength selective switch shown in FIG.

  The present invention is not limited to the above-described embodiment, and various modifications and applications can be made within the scope of the claims.

  The present invention is applicable not only to an optical cross-connect device in a wavelength division multiplexing transmission system, but also to an OADM (Optical Add / Drop Multiplexer) port number expansion or inter-ring connection.

It is a principle block diagram of this invention. It is a block diagram of the optical cross-connect apparatus in the 1st Embodiment of this invention. It is a structural example of the wavelength selective switch utilized for the 1st Embodiment of this invention. It is a block diagram of the wavelength selective switch in the 2nd Embodiment of this invention. It is a block diagram of the conventional optical cross-connect apparatus. It is a block diagram of the wavelength selective switch used for the conventional optical cross-connect apparatus.

Explanation of symbols

50 Control Unit 100 Wavelength Selection Switch 110 Band Division Filters 121 and 122 Optical Circulator 200 Wavelength Selection Switch 210 Demultiplexer 220 Multiplexer 300 Wavelength Selection Switch

Claims (4)

An optical cross-connect device using a wavelength selective switch that selects and extracts a signal of a specific wavelength from wavelength multiplexed signal light used for wavelength division multiplexing transmission,
A plurality of wavelength selective switches arranged in parallel to select a specific wavelength light from the wavelength multiplexed signal light input to each;
Each of the wavelength selective switches is arranged at the front and rear stages, and the light input from the first port passes through the nonreciprocal part and is output to the second port. The light input from the second port is output from the second port. A plurality of optical circulators that pass through the non-reciprocal portion and output to the third port;
An optical switch that is connected to an optical circulator disposed at a subsequent stage of the wavelength selective switch, and switches input wavelength light;
Control means for outputting a wavelength editing signal for selecting a wavelength to the wavelength selective switch, and outputting a path switching signal for switching a path of wavelength light to the optical switch,
Have
The wavelength selective switch is:
When wavelength multiplexed signal light is input from the input port via the first optical circulator provided in the previous stage of the wavelength selective switch, wavelength light is selected based on the wavelength editing signal, and the wavelength selective switch Output to the optical circulator provided in the latter stage,
The second optical circulator provided after the wavelength selective switch is:
The wavelength light input from the wavelength selective switch is output to the optical switch,
The optical switch is
The path of wavelength light input from the second optical circulator is switched based on the path switching signal, and output to the second optical circulator,
The second optical circulator is:
Outputting the wavelength light input from the optical switch to the wavelength selective switch;
The wavelength selective switch is:
The wavelength light input from the second optical circulator or the optical switch is selected based on the wavelength editing signal and output to the first optical circulator by selecting wavelength light,
The first optical circulator is:
An optical cross-connect device that outputs the wavelength light input from the wavelength selective switch to an output port. The wavelength selective switch is:
Based on the wavelength editing signal, an N-stage band division filter that divides into each wavelength band of the input wavelength multiplexed signal light and outputs from the output port;
1 to N-1 stage band division filter, one wavelength light divided for each wavelength band is directly output to the outside from the first output port, and the other wavelength light is output to the next stage band division filter The N-stage band division filter is configured to output the wavelength light divided for each wavelength band to the outside as it is, and the wavelength selected based on the wavelength editing signal is set to an arbitrary wavelength. The optical cross-connect device according to claim 1, wherein the optical cross-connect device outputs each output from an output port. The wavelength selective switch is:
Demultiplexing means for mapping the input wavelength-multiplexed signal light for each wavelength based on the wavelength editing signal and outputting from the N output ports;
When a plurality of mapped wavelength lights output from the demultiplexing means are input from a plurality of input ports, the wavelength lights are spatially recombined, and a wavelength selected based on the wavelength editing signal is obtained. A plurality of multiplexing means for outputting from an output port for each arbitrary wavelength;
The optical cross-connect device according to claim 1. A signal control method in an optical cross-connect device using a wavelength selective switch that selects and extracts a signal of a specific wavelength from wavelength multiplexed signal light used for wavelength division multiplexing transmission,
A plurality of wavelength selective switches arranged in parallel to select a specific wavelength light from the wavelength multiplexed signal light input to each;
Each of the wavelength selective switches is arranged at the front and rear stages, and the light input from the first port passes through the nonreciprocal part and is output to the second port. The light input from the second port is output from the second port. A plurality of optical circulators that pass through the non-reciprocal portion and output to the third port;
An optical switch that is connected to an optical circulator disposed at a subsequent stage of the wavelength selective switch, and switches input wavelength light;
Control means for outputting a wavelength editing signal for selecting a wavelength to the wavelength selective switch, and outputting a path switching signal for switching a path of wavelength light to the optical switch,
In an optical cross-connect device having
The wavelength selective switch is:
When wavelength multiplexed signal light is input from the input port via the first optical circulator provided in the previous stage of the wavelength selective switch, wavelength light is selected based on the wavelength editing signal, and the wavelength selective switch Output to the optical circulator provided in the latter stage,
The second optical circulator provided after the wavelength selective switch is:
The wavelength light input from the wavelength selective switch is output to the optical switch,
The optical switch is
The path of wavelength light input from the second optical circulator is switched based on the path switching signal, and output to the second optical circulator,
The second optical circulator is:
Outputting the wavelength light input from the optical switch to the wavelength selective switch;
The wavelength selective switch is:
The wavelength light input from the second optical circulator or the optical switch is selected based on the wavelength editing signal and output to the first optical circulator by selecting wavelength light,
The first optical circulator is:
A signal control method in an optical cross-connect device, wherein the wavelength light input from the wavelength selective switch is output to an output port.

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