JP2008233218A - Optical wavelength multiplexing demultiplexing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an N×N optical wavelength multiplexing demultiplexing device capable of freely increasing the number of wavelengths of optical signals usable for communication and allocating the necessary number of wavelengths of optical signals between ports. <P>SOLUTION: An optical wavelength multiplexing demultiplexing device includes: a first array waveguide diffraction grating comprising a plurality of first input waveguides 101, a first slab waveguide 102, a first waveguide array 103, a second slab waveguide 104 and a first output waveguide 105; a second array waveguide diffraction grating comprising a plurality of second input waveguides 107, a third slab waveguide 108, a second waveguide array 109, a fourth slab waveguide 110 and a second output waveguide 111; and a connection waveguide 106 which optically couples an (m)th first output waveguide 105 of the first array waveguide diffraction grating and a (c)th second input waveguide 107 of the second array waveguide diffraction grating with each other so that the difference between the (c) and (m) is one of intgers of ≥2 having equal intervals. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to an optical wavelength multiplexing / demultiplexing device that demultiplexes or multiplexes a plurality of optical wavelength multiplexed signals according to the wavelength.

  A wavelength division multiplexing (WDM) transmission system in which a plurality of optical signals are placed on light of different wavelengths and transmitted through a single optical fiber can greatly increase the capacity of the transmission path, Introduction is progressing mainly in mission-critical systems.

  Furthermore, in recent years, not only is the wavelength of an optical signal applied to an increase in transmission path capacity, but wavelength routing used for network path setting is also being studied. One example is a full mesh WDM optical signal transmission system.

  In a full mesh WDM optical signal transmission system as shown in FIG. 11, an N-input N-output (hereinafter referred to as N × N) optical wavelength multiplexing / demultiplexing device 1101 is installed at the center, and a plurality of WDM signal transmission / reception devices are provided. The communication node 1102 is connected by an optical fiber 1103 and has a star-shaped physical shape centered on an N × N optical wavelength multiplexer / demultiplexer 1101. Here, when a wavelength characteristic between the input and output ports of the N × N optical wavelength multiplexer / demultiplexer having characteristics as shown in FIG. 12 is used, a full-mesh optical fiber is laid between the communication nodes 1102 The same connectivity is obtained. Therefore, it is possible to transmit and receive large amounts of data between communication nodes with low delay. (For example, see Non-Patent Document 1)

  Conventionally, as a method of obtaining an N × N optical wavelength multiplexing / demultiplexing device, there has been a method using an arrayed waveguide diffraction grating type optical multiplexing / demultiplexing circuit (hereinafter referred to as AWG) as shown in FIG. The operation principle of the prior art is shown below.

  In FIG. 13, 1301 is an arrayed waveguide having a predetermined optical path length difference, 1302 is a slab waveguide, 1303 is N input waveguides, and 1304 is N output waveguides.

By appropriately designing the arrayed waveguide 1301, the slab waveguide 1302, and the input / output waveguides 1303 and 1304, the AWG multiplexing / demultiplexing characteristics can be designed. When the number of input / output waveguides of the AWG is N and the wavelength interval of the multiplexing / demultiplexing is Δλ, if the AWG basic period (FSR: Free Spectral Range) is designed to be sufficiently larger than Δλ × N, the coupling between the input / output ports is reduced. A demultiplexing characteristic can be obtained with uniform loss. FIG. 14 shows an example in which the number of input / output waveguides is four. There are 16 paths between the 4 input 4 output waveguides according to the input waveguide and the input wavelength. Using this input / output characteristic, a full-mesh connection is established between the four communication nodes by installing a WDM signal transmission / reception device that transmits / receives signals of each of four wavelengths from λ ₁ to λ ₇ to the communication node 1102. Sex can be obtained. (For example, see Non-Patent Document 2)

K. Kato et al. , “32 × 32 full-mesh (1024 paths) wavelength-routing WDM network based on uniform-frequency cyclic-frequency arrayed-wave guiding, ElectroL. 36, Electronics. 1294-1296, 2000 H. Takahashi et al. , “Transmission charactaristics of arrayed waveguide N × N wavelength multiplexer”, J. et al. Lightwave Technol. , 13, pp. 447-455, 1995.

  However, in the full mesh WDM optical signal transmission system realized using this conventional technology, the number of wavelengths of optical signals that can be used for communication between communication nodes of the same combination is limited to 1 and extended to 2 or more. I couldn't. Due to this limitation, the degree of freedom in designing the network has been narrowed, and it has been difficult to expand the optical line in the network in accordance with communication demand.

  When the optical fiber 1103 between the optical wavelength multiplexer / demultiplexer 1101 and the communication node 1102 is cut, the communication node 1102 connected to the cut optical fiber cuts off communication with all other communication nodes. There was also the problem of being isolated.

  The present invention has been made in view of such a problem, and an object of the present invention is to freely extend the number of wavelengths of an optical signal that can be used for communication between ports of an N × N optical wavelength multiplexing / demultiplexing device. An object of the present invention is to provide an N × N optical wavelength multiplexing / demultiplexing device capable of assigning as many optical signal wavelengths as necessary.

  At the same time, when constructing a full mesh WDM optical signal transmission system, in order to prepare for the disconnection of the optical fiber provided between the N × N optical wavelength multiplexing / demultiplexing device and the communication node, the path is duplicated so that the node is not isolated. An object of the present invention is to provide an N × N optical wavelength multiplexing / demultiplexing device.

  In order to achieve such an object, the present invention according to claim 1 has a plurality of input ports and a plurality of output ports, and multiplexes and demultiplexes the wavelength division multiplexed optical signal. An optical wavelength multiplexing / demultiplexing device, a plurality of first input waveguides, a first slab waveguide optically coupled to the first input waveguide, and optically coupled to the first slab waveguide. A first waveguide array composed of a plurality of waveguides that are sequentially longer with a predetermined waveguide length difference, a second slab waveguide optically coupled to the first waveguide array, and the second A plurality of first output waveguides optically coupled to the slab waveguide, and input from the a-th of the first input waveguides to the b-th of the first output waveguides. A first analog signal having an input / output characteristic where the wavelength of the output optical signal is λ (a + b−1). A waveguide diffraction grating, a plurality of second input waveguides, a third slab waveguide optically coupled to the second input waveguide, and a predetermined optically coupled to the third slab waveguide Second waveguide array configured by a plurality of waveguides that are sequentially increased by a difference in waveguide length, a fourth slab waveguide optically coupled to the second waveguide array, and the fourth slab waveguide Light that is input from the b-th of the second input waveguides and output to the a-th of the second output waveguides. A second arrayed-waveguide diffraction grating having input / output characteristics with a signal wavelength of λ (a + b−1), and the m-th and second output waveguides of the first arrayed-waveguide diffraction grating. The c-th of the second input waveguide of the arrayed waveguide diffraction grating of FIG. To be either equally spaced values, characterized in that a connection means for optical coupling.

  A second aspect of the present invention is the optical wavelength multiplexing / demultiplexing device according to the first aspect, wherein the two or more equal intervals of the first input waveguides of the first arrayed waveguide diffraction grating are provided. A plurality of optical couplers optically coupled to two of the second output waveguides of the second arrayed-waveguide diffraction grating that outputs optical signals input from input waveguides spaced apart by a distance equal to It is characterized by that.

  The invention according to claim 3 is an optical wavelength multiplexing / demultiplexing device having a plurality of input ports and a plurality of output ports, and for multiplexing / demultiplexing wavelength division multiplexed optical signals, wherein N + M inputs A waveguide, a first slab waveguide optically coupled to the input waveguide, and a plurality of waveguides that are sequentially increased by a predetermined waveguide length difference optically coupled to the first slab waveguide. A waveguide array; a second slab waveguide optically coupled to the waveguide array; and N + M output waveguides optically coupled to the second slab waveguide. An arrayed waveguide diffraction grating having an input / output characteristic in which the wavelength of an optical signal input from the first input waveguide and output from the bth of the output waveguides is λ (a + b-1-N); Part of the output waveguide and part of the input waveguide. A second, the difference between c and m are such that any two or more equally spaced values, characterized in that a connection means for optical coupling.

  According to a fourth aspect of the present invention, there is provided the optical wavelength multiplexing / demultiplexing device according to the third aspect, wherein the input waveguides are spaced apart by a distance equal to the two or more equally spaced values of the N input waveguides. A plurality of optical couplers optically coupled to two of the N output waveguides that output optical signals input from the waveguide are provided.

  A fifth aspect of the present invention is the optical wavelength multiplexing / demultiplexing device according to any one of the first to fourth aspects, wherein the connecting means is one of a plurality of optical waveguides and optical switches. Features.

  As described above, according to the present invention, the number of wavelengths of optical signals that can be used for communication between ports of an N × N optical wavelength multiplexing / demultiplexing device can be freely expanded, and as much light as necessary can be transmitted between ports. An N × N optical wavelength multiplexing / demultiplexing device capable of assigning the number of signal wavelengths can be realized.

  At the same time, when constructing a full mesh WDM optical signal transmission system, in order to prepare for the disconnection of the optical fiber provided between the N × N optical wavelength multiplexing / demultiplexing device and the communication node, the path is duplicated so that the node is not isolated. An N × N optical wavelength multiplexing / demultiplexing device can be realized.

  Embodiments of an N × N optical wavelength multiplexing / demultiplexing device (hereinafter also simply referred to as an optical wavelength multiplexing / demultiplexing device) according to the present invention will be described below in detail with reference to the drawings.

[First Embodiment]
A first embodiment of an optical wavelength multiplexing / demultiplexing device according to the present invention will be described with reference to FIGS.

  The present invention can be implemented as an optical wavelength multiplexing / demultiplexing device including an array waveguide diffraction grating having N inputs and M outputs and an array waveguide diffraction grating having M inputs and N outputs. Here, N and M are integers of 2 or more. FIG. 1 shows a configuration example of an optical wavelength multiplexer / demultiplexer when N = 6 and M = 8.

  The optical wavelength multiplexing / demultiplexing device shown in FIG. 1 includes N first input waveguides 101, a first slab waveguide 102, a first array waveguide 103 having a predetermined optical path length difference, a second slab waveguide 104, and A first arrayed waveguide diffraction grating composed of M first output waveguides 105, an M second input waveguide 107, a third slab waveguide 108, and a second array waveguide having a predetermined optical path length difference. M connecting the first output waveguide 105 and the second input waveguide 107 to the second arrayed waveguide diffraction grating constituted by the waveguide 109, the fourth slab waveguide 110 and the N second output waveguides 111. Connection waveguide 106 of the book.

The principle of optical wavelength multiplexing / demultiplexing in the optical wavelength multiplexing / demultiplexing device of this embodiment will be described below.
The optical signal input to the first input waveguide 101 is input to the first slab waveguide 102 from a predetermined position that differs for each waveguide. The optical signal input to the first slab waveguide 102 propagates through the first slab waveguide 102 and is distributed and input to the first array waveguide 103 with a phase relationship determined according to the input position. The first arrayed waveguide 103 is composed of a plurality of waveguides that become longer with a predetermined waveguide length difference. The optical signal input to the first array waveguide 103 is input to the second slab waveguide 104 with a phase relationship determined for each wavelength. The optical signal input to the second slab waveguide is condensed at a position determined according to the input phase relationship and output from the first output waveguide 105.

  In this way, the first input waveguide 101, the first slab waveguide 102, the first arrayed waveguide 103, the second slab waveguide 104, and the first output waveguide 105 provide N input M output. The first arrayed waveguide diffraction grating is formed, and the function of outputting the input optical signal from the input port of the signal and the output port determined according to the wavelength of the signal is realized.

  Similarly, the optical signal input to the second input waveguide 107 is input to the third slab waveguide 108 from a predetermined position that differs for each waveguide. The optical signal input to the third slab waveguide 108 propagates through the third slab waveguide 108 and is distributed and input to the second array waveguide 109 with a phase relationship determined according to the input position. The second arrayed waveguide 109 is composed of a plurality of waveguides that are sequentially longer with a predetermined waveguide length difference. The optical signal input to the second array waveguide 109 is input to the fourth slab waveguide 110 with a phase relationship determined for each wavelength. The optical signal input to the fourth slab waveguide is condensed at a position determined according to the input phase relationship and output from the second output waveguide 111.

  In this way, the second input waveguide 107, the third slab waveguide 108, the second array waveguide 109, the fourth slab waveguide 110, and the second output waveguide 111 provide an M input N output. The second arrayed waveguide diffraction grating is formed, and the function of outputting the input optical signal from the input port of the signal and the output port determined according to the wavelength of the signal is realized.

  Here, the wavelength input / output characteristics of the first arrayed waveguide diffraction grating are input from the a-th input waveguide among the N first input waveguides 101, and the M first output waveguides 105 The waveguide structure is designed so that the wavelength of the optical signal output to the b-th output waveguide is λ (a + b−1) using an appropriately defined wavelength number. . Here, a is an integer of 1 ≦ a ≦ N, and b is an integer of 1 ≦ b ≦ M.

  Similarly, the wavelength input / output characteristics of the second arrayed waveguide grating are input from the a-th output waveguide of the N second output waveguides 111, and the M second input waveguides 107 are connected. The waveguide structure is designed so that the wavelength of the optical signal output to the b-th input waveguide is λ (a + b−1) using an appropriately defined wavelength number. . That is, an optical signal that is input from the b-th input waveguide of the N second input waveguides 107 and output to the a-th output waveguide of the M second output waveguides 111. The waveguide structure is designed so that the wavelength becomes λ (a + b−1) using an appropriately defined wavelength number.

  The optical wavelength multiplexing / demultiplexing device of this embodiment uses N input waveguides of the first arrayed waveguide diffraction grating as input ports. Further, the M output waveguides of the first array waveguide diffraction grating are connected to the M input waveguides of the second array waveguide diffraction grating through the M connection waveguides 106, respectively. Further, the N output waveguides of the second arrayed waveguide diffraction grating are used as output ports.

  At this time, the wavelength input / output characteristics of the entire optical wavelength multiplexing / demultiplexing device of the present embodiment are as follows.

  When the mth output waveguide of the first array waveguide diffraction grating is connected to the c (m) th input waveguide of the second array waveguide diffraction grating, the optical wavelength multiplexer / demultiplexer A signal of wavelength λ (A + m−1) input to the Ath input port is output to (1) the mth output waveguide of the first array waveguide diffraction grating, and (2) the second array conductor. The signal is input to the c (m) th input waveguide of the waveguide diffraction grating, and (3) is output from the {A + mc (m)} th output port of the optical wavelength multiplexing / demultiplexing device. Here, A is an integer of 1 ≦ A ≦ N, and m is an integer of 1 ≦ m ≦ M. c (m) is an integer of 1 or more and M or less determined by m, and is an integer such that C described below becomes a different value by a constant of 2 or more.

  That is, when the difference between the number of the input waveguide 107 of the second array waveguide diffraction grating and the number of the output waveguide 105 of the first array waveguide diffraction grating connected by the connection waveguide 106 is C, the connection The optical signal passing through the waveguide is output from the (AC) -th output port of the optical wavelength multiplexing / demultiplexing device.

  Therefore, the number of optical signals that are input from the Ath input port of the optical wavelength multiplexer / demultiplexer and output from the (AC) th output port is the difference between the waveguide numbers connected by the connection waveguide 106. Corresponds to the number of waveguides where C is C.

  From this, in the optical wavelength multiplexing / demultiplexing device of this embodiment, a desired wavelength input / output characteristic can be obtained by appropriately arranging the connection waveguide 106.

  In particular, it should be noted that the number of wavelengths that can be used for communication between the same input / output ports can be expanded by providing a plurality of connection waveguides 106 having the same difference in waveguide number to be connected.

  In the present embodiment shown in FIG. 1, the M connecting waveguides 106 are connected to the output waveguide 105 of the first array waveguide diffraction grating as the input waveguide 107 of the second array waveguide diffraction grating as follows. Connected.

The first output waveguide is connected to the first input waveguide (C = 0).
The second output waveguide is connected to the fourth input waveguide (C = 2).
The third output waveguide is connected to the seventh input waveguide (C = 4).
The fourth output waveguide is connected to the second input waveguide (C = −2).
The fifth output waveguide is connected to the fifth input waveguide (C = 0).
The sixth output waveguide is connected to the eighth input waveguide (C = 2).
The seventh output waveguide is connected to the third input waveguide (C = -4).
The eighth output waveguide is connected to the sixth input waveguide (C = −2).

  In this manner, when the connection waveguide 106 is provided, the wavelength input / output characteristics shown in FIG. 2 can be obtained.

When attention is paid to the difference C between the waveguide numbers connected by the connecting waveguide 106,
Since there is one waveguide with C = 4, there is one wavelength output from the input port number 6 to the output port number 2, and from the input port number 5 to the output port number 1,
Since there are two waveguides with C = 2, input port number 6 to output port number 4, input port number 5 to output port number 3, input port number 4 to output port number 2, and output from input port number 3 There are two wavelengths output to port number 1,
Since there are two waveguides with C = 0, input port number 6 to output port number 6, input port number 5 to output port number 5, input port number 4 to output port number 4, and output from input port number 3 There are two wavelengths output from port number 3, input port number 2 to output port number 2, input port number 1 to output port number 1,
Since there are two waveguides with C = -2, input port number 4 to output port number 6, input port number 3 to output port number 5, input port number 2 to output port number 4, and input port number 1 There are two wavelengths output to output port number 3,
This is because there is one wavelength output from the input port number 2 to the output port number 6 and from the input port number 1 to the output port number 5 because there is one waveguide with C = -4.

  Here, it should be noted that the difference C between the waveguide numbers connected by the connection waveguide 106 is a value (0 or a multiple of 2) that differs by <2>.

  By providing the waveguides in this way, a full mesh connection is realized when attention is paid to input / output waveguides that are different by <2>. (Numbers in <> always match on the principle of operation.) That is, when only the odd-numbered input ports and odd-numbered output ports are noted, 3 × 3 full mesh connection is realized, and even-numbered Similar attention is paid to only the input port and the even-numbered output port, and the same 3 × 3 full mesh connection is realized.

  By using the N × N optical wavelength multiplexing / demultiplexing device (here, 6 × 6 optical wavelength multiplexing / demultiplexing device), a full mesh WDM optical signal transmission system in which a path is duplexed and a node is not isolated when an optical fiber is cut is obtained. Can be formed.

  For example, as shown in FIG. 3, a 6 × 6 optical wavelength multiplexing / demultiplexing device 301 is installed at the center, and the first of the WDM signal transmitting / receiving device and the 6 × 6 optical wavelength multiplexing / demultiplexing device 301 included in the first communication node. And the second input / output port through an optical fiber 303, and the WDM signal transmitting / receiving device provided in the second communication node and the third and fourth input / output ports of the 6 × 6 optical wavelength multiplexer / demultiplexer 301 are connected to each other. The optical fiber 303 is connected, and the WDM signal transmitting / receiving device included in the third communication node is connected to the fifth and sixth input / output ports of the 6 × 6 optical wavelength multiplexer / demultiplexer 301 via the optical fiber 303.

In this way, by connecting the 6 × 6 optical wavelength multiplexing / demultiplexing device 301 and the three communication nodes 302 including the WDM signal transmission / reception device, a 6 × 6 optical wavelength is provided between the first to third communication nodes. A full mesh connection formed via the first, third, and fifth input / output ports of the multiplexer / demultiplexer 301, and the second, fourth, and sixth input / output ports of the 6 × 6 optical wavelength multiplexer / demultiplexer 301 <2> two full mesh connections having the same connection relationship, that is, a full mesh connection formed through the network, can be obtained at the same time. (The number of full mesh connections equal to the number in <> above is obtained.)
Therefore, even when any one of the optical fibers is disconnected, a full mesh connection that does not include the corresponding optical fiber is maintained, so that node isolation can be avoided.

  In the N × N optical wavelength multiplexing / demultiplexing device of this embodiment, there may be a case where the crosstalk characteristics between adjacent ports (a phenomenon in which an output optical signal leaks to an adjacent port) is poor. In such a case, interference due to a leakage signal can be prevented by flowing one of the two full mesh connections in the opposite direction.

  Specifically, in the full mesh connection formed through the first, third, and fifth input / output ports of the 6 × 6 optical wavelength multiplexing / demultiplexing device 301, the 6 × 6 optical wavelength multiplexing / demultiplexing device 301 is used. A signal is input from the input port and a signal is output from the output port.

  On the other hand, in the full mesh connection formed via the second, fourth, and sixth input / output ports of the 6 × 6 optical wavelength multiplexer / demultiplexer 301, the output of the 6 × 6 optical wavelength multiplexer / demultiplexer 301 is reversed. A signal is input from the port, and the signal is output from the input port.

  With such a configuration, the signal leaking from the adjacent port is input to the transmitter instead of the receiver, so that communication quality is not affected and communication quality can be improved.

  By configuring the optical wavelength multiplexing / demultiplexing device as described above, the number of wavelengths of optical signals that can be used for communication between the ports of the N × N optical wavelength multiplexing / demultiplexing device can be freely expanded and required between the ports. An N × N optical wavelength multiplexing / demultiplexing device that can allocate the number of wavelengths of the optical signal as much as possible can be realized.

  At the same time, when constructing a full mesh WDM optical signal transmission system, N × N can be used to duplex the path in preparation for the disconnection of the optical fiber between the N × N optical wavelength multiplexing / demultiplexing device and the communication node so that the node is not isolated. An N optical wavelength multiplexer / demultiplexer can be realized.

  In the above description, an example has been described in which the difference C is different by <2> (0 or a multiple of 2). However, the difference C may be set to have a different value by two or more constants. For example, the difference C may be set to be different values (0, ± 3, ± 6...) By <3>. Also, the difference C is set to be different values (± 1, ± 3, ± 5... Or..., -2, 1, 4, 7,...) By two or more constants other than 0. Also good. That is, the difference C can be set to any one of two or more equally spaced integers. That is, when p is an integer constant of 2 or more, q is an integer constant, and k is an arbitrary integer, the difference C can be expressed by p × k + q.

  In the above description, as an example of connecting M output waveguides 105 of the first array waveguide diffraction grating and M input waveguides 107 of the second array waveguide diffraction grating, the number of connection waveguides 106 is used. However, two or more output waveguides 105 and input waveguides 107 may be connected, and there may be output waveguides 105 and input waveguides 107 that are not connected.

[Second Embodiment]
A second embodiment of the optical wavelength multiplexing / demultiplexing device according to the present invention will be described with reference to FIG.
The present invention is implemented as an optical wavelength multiplexing / demultiplexing device including an N-input M-output arrayed waveguide diffraction grating, an M-input N-output arrayed waveguide diffraction grating, and an M-input M-output optical switch. Can do. FIG. 4 shows a configuration example of the optical wavelength multiplexing / demultiplexing device when N = 6 and M = 8.

  The optical wavelength multiplexing / demultiplexing device shown in FIG. 4 includes N first input waveguides 101, a first slab waveguide 102, a first array waveguide 103 having a predetermined optical path length difference, and a second slab waveguide 104. And the first arrayed waveguide diffraction grating constituted by the M first output waveguides 105, the M second input waveguides 107, the third slab waveguides 108, and the second having a predetermined optical path length difference. A second arrayed waveguide diffraction grating constituted by the arrayed waveguide 109, the fourth slab waveguide 110, and the N second output waveguides 111, and the first output waveguide 105 and the second input waveguide 107 are connected. And an input M output optical switch 401.

The principle of optical wavelength multiplexing / demultiplexing in the optical wavelength multiplexing / demultiplexing device of this embodiment will be described below.
Since the configurations and functions of the first arrayed waveguide diffraction grating and the second arrayed waveguide diffraction grating in the present embodiment are the same as those shown in the first embodiment, description thereof will be omitted.

  A feature of the present embodiment is that an M input M output optical switch 401 is provided instead of the M connection waveguides 106 in the first embodiment.

  The optical switch 401 can arbitrarily set the combination of the connection between the output waveguide 105 of the first arrayed waveguide grating and the input waveguide 107 of the second arrayed waveguide grating by changing the setting. Can do.

  Therefore, as in the first embodiment, the difference C between the input / output waveguide numbers connected by the optical switch 401 is set to be a different value by two or more constants.

  As a specific configuration of the optical switch 401, for example, a planar optical waveguide (PLC) type switch that combines a Mach-Zehnder interferometer and switches the path by the thermo-optic effect of the waveguide material can be used.

  Alternatively, a two-dimensional or three-dimensional optical switch using a MEMS (Micro Electro Mechanical Systems) mirror, an optical waveguide switch using a thermocapillary phenomenon, or a mechanical switch may be used. The realization method does not ask | require.

  The wavelength input / output characteristics of the entire optical wavelength multiplexing / demultiplexing device of the present embodiment are the same as the wavelength input / output characteristics of the entire optical wavelength multiplexing / demultiplexing device described in the first embodiment, and thus description thereof is omitted.

  The first embodiment also shows that when the optical wavelength multiplexing / demultiplexing device of this embodiment is used, it is possible to form a full mesh WDM optical signal transmission system in which paths are duplicated and nodes are not isolated when an optical fiber is cut. The description is omitted because it is the same as the above.

  Further, in the optical wavelength multiplexing / demultiplexing device of this embodiment, when the crosstalk characteristic between adjacent ports is poor, it is possible to prevent interference due to a leakage signal by causing a signal to flow in the reverse direction. The description is omitted because it is the same as that shown.

  Therefore, by configuring the optical wavelength multiplexing / demultiplexing device as described above, the number of wavelengths of optical signals that can be used for communication between ports of the N × N optical wavelength multiplexing / demultiplexing device can be freely expanded, In addition to the feature of realizing an N × N optical wavelength multiplexing / demultiplexing device that can allocate the number of wavelengths of optical signals as necessary, it is possible to provide flexibility to change input / output characteristics according to demand.

  At the same time, when constructing a full mesh WDM optical signal transmission system, N × N can be used to duplex the path in preparation for the disconnection of the optical fiber between the N × N optical wavelength multiplexing / demultiplexing device and the communication node so that the node is not isolated. An N optical wavelength multiplexer / demultiplexer can be realized.

[Third Embodiment]
With reference to FIG. 5, a third embodiment of the optical wavelength multiplexer / demultiplexer according to the present invention will be described.
The present invention can be implemented as an optical wavelength multiplexing / demultiplexing device including an array waveguide diffraction grating having (N + M) input (N + M) output therein. FIG. 5 shows a configuration example of an optical wavelength multiplexing / demultiplexing device when N = 6 and M = 8.

  5 includes (N + M) input waveguides 501, first slab waveguides 502, arrayed waveguides 503 having a predetermined optical path length difference, second slab waveguides 504, and (N + M). ) An arrayed waveguide diffraction grating constituted by the output waveguides 505 and M connection waveguides 506 connecting the input waveguides 501 and the output waveguides 505.

The principle of optical wavelength multiplexing / demultiplexing in the optical wavelength multiplexing / demultiplexing device of this embodiment will be described below.
An array waveguide diffraction grating composed of an input waveguide 501, a first slab waveguide 502, an array waveguide 503 having a predetermined optical path length difference, a second slab waveguide 504, and an output waveguide 505. Since the function is the same as that of the arrayed waveguide grating shown in the first embodiment, the description thereof is omitted.

  In this embodiment, the wavelength input / output characteristics of the arrayed waveguide grating are appropriately defined as the wavelengths of the optical signals input from the a-th input waveguide and output to the b-th output waveguide. It is assumed that the waveguide structure is designed to be λ (a + b-1-N) using the wavelength number.

  The optical wavelength multiplexer / demultiplexer of this embodiment uses the first to Nth input waveguides of the arrayed waveguide diffraction grating as input ports. Also, the first to Nth output waveguides of the arrayed waveguide diffraction grating are used as output ports. In addition, the (N + 1) th to (N + M) th output waveguides of the arrayed waveguide grating are respectively connected to the (N + 1) th to (N + M) th of the arrayed waveguide grating via the M connection waveguides 106. It is configured by connecting to the first input waveguide.

At this time, the wavelength input / output characteristics of the entire optical wavelength multiplexing / demultiplexing device of the present embodiment are as follows.
When the (N + m) th output waveguide of the arrayed waveguide grating is connected to the c (N + m) th input waveguide of the arrayed waveguide grating, the Ath of the optical wavelength multiplexing / demultiplexing device The signal of wavelength λ (A + m−1) input to the th input port is output to the (N + m) th output waveguide of (1) the arrayed waveguide grating, and (2) the arrayed waveguide grating To the (c + N + m) th input waveguide, and (3) output from the {A + m−c (m)} th output port of the optical wavelength multiplexing / demultiplexing device.

  This wavelength input / output characteristic is the same as the wavelength input / output characteristic of the entire optical wavelength multiplexing / demultiplexing device shown in the first embodiment.

  The first embodiment also shows that when the optical wavelength multiplexing / demultiplexing device of this embodiment is used, it is possible to form a full mesh WDM optical signal transmission system in which paths are duplicated and nodes are not isolated when an optical fiber is cut. The description is omitted because it is the same as the above.

  Further, in the optical wavelength multiplexing / demultiplexing device of this embodiment, when the crosstalk characteristic between adjacent ports is poor, it is possible to prevent interference due to a leakage signal by causing a signal to flow in the reverse direction. The description is omitted because it is the same as that shown.

  Accordingly, similarly to the one shown in the first embodiment, the difference C between the input / output waveguide numbers connected by the M connection waveguides 506 is set to be different from each other by two or more constants, and the optical wavelength is set. By configuring the multiplexing / demultiplexing device, the number of wavelengths of optical signals that can be used for communication between the ports of the N × N optical wavelength multiplexing / demultiplexing device can be freely expanded, and the number of optical signal wavelengths between the ports can be increased. An N × N optical wavelength multiplexer / demultiplexer that can be assigned a number can be realized.

  At the same time, when constructing a full mesh WDM optical signal transmission system, N × N can be used to duplex the path in preparation for the disconnection of the optical fiber between the N × N optical wavelength multiplexing / demultiplexing device and the communication node so that the node is not isolated. An N optical wavelength multiplexer / demultiplexer can be realized.

[Fourth Embodiment]
A fourth embodiment of the optical wavelength multiplexing / demultiplexing device according to the present invention will be described with reference to FIG.
The present invention can be implemented as an optical wavelength multiplexer / demultiplexer including an (N + M) input (N + M) output arrayed waveguide diffraction grating and an M input M output optical switch. FIG. 6 shows a configuration example of an optical wavelength multiplexing / demultiplexing device when N = 6 and M = 8.

  The optical wavelength multiplexing / demultiplexing device shown in FIG. 6 includes (N + M) input waveguides 501, first slab waveguides 502, arrayed waveguides 503 having a predetermined optical path length difference, second slab waveguides 504, and (N + M). ) An arrayed waveguide diffraction grating constituted by the output waveguides 505, an input waveguide 501 and an M input M output optical switch 601 connected to the output waveguide 505.

The principle of optical wavelength multiplexing / demultiplexing in the optical wavelength multiplexing / demultiplexing device of this embodiment will be described below.
Since the configuration and function of the arrayed waveguide diffraction grating in the present embodiment are the same as those shown in the third embodiment, description thereof is omitted.

  A feature of this embodiment is that an M input M output optical switch 601 is provided instead of the M connection waveguides 506.

  The optical switch 601 can arbitrarily set the combination of connection between the output waveguide 505 of the arrayed waveguide grating and the input waveguide 501 of the arrayed waveguide grating by changing the setting.

  Therefore, as in the first embodiment, the difference C between the input / output waveguide numbers connected by the optical switch 601 is set to be different from each other by two or more constants.

  As a specific configuration of the optical switch 601, for example, a planar optical waveguide (PLC) type switch that combines a Mach-Zehnder interferometer and switches the path by the thermo-optic effect of the waveguide material can be used.

  Alternatively, a two-dimensional or three-dimensional optical switch using a MEMS (Micro Electro Mechanical Systems) mirror, an optical waveguide switch using a thermocapillary phenomenon, or a mechanical switch may be used. The realization method does not ask | require.

  Since the wavelength input / output characteristics of the entire optical wavelength multiplexing / demultiplexing device of this embodiment are the same as the wavelength input / output characteristics of the entire optical wavelength multiplexing / demultiplexing device shown in the third embodiment, the description thereof is omitted.

  The first embodiment also shows that when the optical wavelength multiplexing / demultiplexing device of this embodiment is used, it is possible to form a full mesh WDM optical signal transmission system in which paths are duplicated and nodes are not isolated when an optical fiber is cut. The description is omitted because it is the same as the above.

  Further, in the optical wavelength multiplexing / demultiplexing device of this embodiment, when the crosstalk characteristic between adjacent ports is poor, it is possible to prevent interference due to a leakage signal by causing a signal to flow in the reverse direction. The description is omitted because it is the same as that shown.

  Accordingly, as in the third embodiment, the optical wavelength multiplexer / demultiplexer is set by setting the difference C between the input and output waveguide numbers connected by the optical switch 601 to be different by a constant value of 2 or more. By freely configuring the number of optical signal wavelengths that can be used for communication between ports of the N × N optical wavelength multiplexing / demultiplexing device, and assigning as many optical signal wavelengths as possible between the ports. In addition to the feature that an N × N optical wavelength multiplexing / demultiplexing device capable of realizing the above can be realized, it is possible to provide flexibility to change input / output characteristics according to demand.

  At the same time, when constructing a full mesh WDM optical signal transmission system, N × N can be used to duplex the path in preparation for the disconnection of the optical fiber between the N × N optical wavelength multiplexing / demultiplexing device and the communication node so that the node is not isolated. An N optical wavelength multiplexer / demultiplexer can be realized.

[Fifth Embodiment]
A fifth embodiment of the optical wavelength multiplexing / demultiplexing device according to the present invention will be described with reference to FIGS.
The present invention can be implemented as an optical wavelength multiplexer / demultiplexer including an N-input M-output arrayed waveguide diffraction grating and an M-input N-output arrayed waveguide diffraction grating inside. FIG. 7 shows a configuration example of an optical wavelength multiplexing / demultiplexing device when N = 20 and M = 8.

  7 includes an N number of first input waveguides 101, a first slab waveguide 102, a first array waveguide 103 having a predetermined optical path length difference, a second slab waveguide 104, and A first arrayed waveguide diffraction grating composed of M first output waveguides 105, an M second input waveguide 107, a third slab waveguide 108, and a second array having a predetermined optical path length difference The second arrayed waveguide diffraction grating constituted by the waveguide 109, the fourth slab waveguide 110 and the N second output waveguides 111 is connected to the first output waveguide 105 and the second input waveguide 107. M / 2 connection waveguides 106 and N / 2 optical couplers 701 connected to the second output waveguide 111. In the present embodiment, N is an integer of 4 or more and a multiple of 2.

The principle of optical wavelength multiplexing / demultiplexing in the optical wavelength multiplexing / demultiplexing device of this embodiment will be described below.
Since the configurations and functions of the first arrayed waveguide diffraction grating and the second arrayed waveguide diffraction grating in the present embodiment are the same as those shown in the first embodiment, description thereof will be omitted.

  Further, the M connecting waveguides 106 that connect the first arrayed waveguide diffraction grating and the second arrayed waveguide diffraction grating in the present embodiment are similar to those shown in the first embodiment. Since the difference C between the input / output waveguide numbers is set to have different values by two or more constants, the description is omitted.

The wavelength input / output characteristics of the entire optical wavelength multiplexing / demultiplexing device of this embodiment will be described below.
FIG. 8 shows a case where only 10 ports from 5 to 14 are focused on the input ports, and up to 20 second output waveguides 111 included in the second arrayed waveguide diffraction grating are focused on the output ports. Wavelength input / output characteristics.

  In the optical wavelength multiplexing / demultiplexing device of this embodiment, the 20 second output waveguides 111 included in the second arrayed waveguide diffraction grating are further separated by 10 by using 10 optical couplers 701. The outputs from the second output waveguide are combined. That is, the outputs from the first and eleventh waveguides of the second output waveguide 111 are combined by the first optical coupler of the optical coupler 701, and the tenth of the second output waveguide 111. The outputs from the 20th and 20th waveguides are sequentially coupled by the 10th optical coupler of the optical couplers 701.

  In other words, each of N / 2 optical couplers 701 has an interval equal to the above-described two or more constants in N first input waveguides 101 of the first arrayed waveguide grating (numbers in <> above). Are optically coupled to two of the second output waveguides 111 of the second arrayed waveguide diffraction grating that outputs the optical signals input from the input waveguides separated by the same number). In particular, if the maximum value of C is Cmax and the minimum value is Cmin, the interval between the two waveguides of the second output waveguide 111 coupled by the optical coupler 701 is Cmax−Cmin + (the above-mentioned Desirable characteristics can be obtained by setting the number equal to the number in <>.

  At this time, as shown in FIG. 9, the wavelength input / output characteristics of the entire optical wavelength multiplexing / demultiplexing device according to the present embodiment focus on only 10 ports from 5 to 14 for the input ports, and the optical coupler 701 for the output ports. When attention is paid to the output from, it has the same characteristics as the characteristics shown in the first embodiment.

  Therefore, when the optical wavelength multiplexing / demultiplexing device of this embodiment is used, it is also shown in the first embodiment that a full-mesh WDM optical signal transmission system can be formed in which paths are duplicated and nodes are not isolated when an optical fiber is cut. The description is omitted because it is the same as the above.

  Further, in the optical wavelength multiplexing / demultiplexing device of this embodiment, when the crosstalk characteristic between adjacent ports is poor, it is possible to prevent interference due to a leakage signal by causing a signal to flow in the reverse direction. The description is omitted because it is the same as that shown.

  Therefore, by configuring the optical wavelength multiplexing / demultiplexing device as described above, the number of wavelengths of optical signals that can be used for communication between ports of the N × N optical wavelength multiplexing / demultiplexing device can be freely expanded, Thus, it is possible to realize an N × N optical wavelength multiplexing / demultiplexing device that can allocate the number of wavelengths of optical signals as necessary.

  At the same time, when constructing a full-mesh WDM optical signal transmission system, N × N can be used to duplex the path in preparation for disconnection of the optical fiber between the N × N optical wavelength multiplexing / demultiplexing device and the communication node so that the node is not isolated. An N optical wavelength multiplexer / demultiplexer can be realized.

  Similar to the relationship between the first embodiment and the second embodiment, the input / output waveguide numbers connected by the optical switch 401 even when the M connection waveguides 106 are replaced with the M input M output optical switch 401. If the difference C is set to have different values by two or more constants, an N × N optical wavelength multiplexing / demultiplexing device having the same function can be realized.

[Sixth Embodiment]
A sixth embodiment of the optical wavelength multiplexing / demultiplexing device according to the present invention will be described with reference to FIG.
The present invention can be implemented as an optical wavelength multiplexing / demultiplexing device including an array waveguide diffraction grating having (N + M) input (N + M) output therein. FIG. 10 shows a configuration example of an optical wavelength multiplexing / demultiplexing device when N = 20 and M = 8.

  The optical wavelength multiplexer / demultiplexer shown in FIG. 10 includes (N + M) input waveguides 501, first slab waveguides 502, arrayed waveguides 503 having a predetermined optical path length difference, second slab waveguides 504, and (N + M). ) Arrayed waveguide diffraction grating composed of one output waveguide 505, M connection waveguides 506 connecting the input waveguide 501 and the output waveguide 505, and N / 2 connected to the output waveguide 505 The optical coupler 701 is included. In the present embodiment, N is an integer of 4 or more and a multiple of 2.

The principle of optical wavelength multiplexing / demultiplexing in the optical wavelength multiplexing / demultiplexing device of this embodiment will be described below.
Since the configuration and function of the arrayed waveguide diffraction grating are the same as those shown in the third embodiment, description thereof is omitted.

  The M connection waveguides 506 are set so that the difference C between the input and output waveguide numbers becomes a different value by two or more constants, as in the third embodiment. Therefore, the description is omitted.

  N / 2 optical couplers 701 are connected to 20 waveguides out of the output waveguides 505 of the arrayed waveguide diffraction grating, and are separated from each other by 10 in the same manner as in the fifth embodiment. Combine the outputs from the two output waveguides.

  The wavelength input / output characteristics of the entire optical wavelength multiplexing / demultiplexing device of this embodiment are the same as those shown in the third embodiment because the input / output characteristics of the arrayed waveguide grating are the same. The description is omitted because it is the same as that shown in the fifth embodiment.

  The first embodiment also shows that when the optical wavelength multiplexing / demultiplexing device of this embodiment is used, it is possible to form a full mesh WDM optical signal transmission system in which paths are duplicated and nodes are not isolated when an optical fiber is cut. The description is omitted because it is the same as the above.

  Further, in the optical wavelength multiplexing / demultiplexing device of this embodiment, when the crosstalk characteristic between adjacent ports is poor, it is possible to prevent interference due to a leakage signal by causing a signal to flow in the reverse direction. The description is omitted because it is the same as that shown.

  Therefore, by configuring the optical wavelength multiplexing / demultiplexing device as described above, the number of wavelengths of optical signals that can be used for communication between ports of the N × N optical wavelength multiplexing / demultiplexing device can be freely expanded, In addition to the feature of realizing an N × N optical wavelength multiplexing / demultiplexing device that can allocate the number of wavelengths of optical signals as necessary, it is possible to provide flexibility to change input / output characteristics according to demand.

  At the same time, when constructing a full mesh WDM optical signal transmission system, N × N can be used to duplex the path in preparation for the disconnection of the optical fiber between the N × N optical wavelength multiplexing / demultiplexing device and the communication node so that the node is not isolated. An N optical wavelength multiplexer / demultiplexer can be realized.

  Similar to the relationship between the third embodiment and the fourth embodiment, even if M connection waveguides 506 are replaced with M input M output optical switches 601, input / output waveguide numbers connected by the optical switches 601. If the difference C is set to have different values by two or more constants, an N × N optical wavelength multiplexing / demultiplexing device having the same function can be realized.

[Deformation]
The present invention includes (N + M) input (N + M) output array waveguide diffraction grating, N input M output array waveguide diffraction grating, M input N output array waveguide diffraction grating, optical waveguide for connection, M input M A part or all of the output optical switch and the optical coupler can be implemented as an optical circuit configured on the same plane. By integrating, it is possible to reduce the number of devices and reduce the manufacturing cost.

  The present invention has been specifically described above. However, in view of many possible embodiments to which the principle of the present invention can be applied, the embodiments described here are merely examples, and the scope of the present invention is not limited. It is not limited. For example, the configuration and details of the array waveguide diffraction grating, the number of ports of the optical switch, the wavelength input / output characteristics of the array waveguide diffraction grating, and the method of realizing the optical switch can be changed without departing from the spirit of the present invention. Can be changed. The constituent elements for explanation may be changed, supplemented, or changed in order without departing from the spirit of the present invention.

1 is a configuration diagram of an optical wavelength multiplexing / demultiplexing device according to a first embodiment of the present invention. It is a figure explaining the wavelength input-output characteristic of the optical wavelength multiplexer / demultiplexer which is the 1st Embodiment of this invention. It is a block diagram which shows schematic structure of the full mesh WDM optical signal transmission system to which the optical wavelength multiplexing / demultiplexing apparatus of this invention is applied. It is a block diagram of the optical wavelength multiplexer / demultiplexer which is the 2nd Embodiment of this invention. It is a block diagram of the optical wavelength multiplexer / demultiplexer which is the 3rd Embodiment of this invention. It is a block diagram of the optical wavelength multiplexer / demultiplexer which is the 4th Embodiment of this invention. It is a block diagram of the optical wavelength multiplexer / demultiplexer which is the 5th Embodiment of this invention. It is a figure explaining the wavelength input-output characteristic to the 2nd output waveguide of the optical wavelength multiplexing / demultiplexing apparatus which is the 5th Embodiment of this invention. It is a figure explaining the wavelength input-output characteristic of the optical wavelength multiplexer / demultiplexer which is the 5th Embodiment of this invention. It is a block diagram of the optical wavelength multiplexing / demultiplexing apparatus which is the 6th Embodiment of this invention. It is a block diagram which shows schematic structure of the conventional full mesh WDM optical signal transmission system. It is a figure explaining the wavelength input / output characteristic of the optical wavelength multiplexer / demultiplexer used for the conventional full mesh WDM optical signal transmission system. It is a block diagram of a conventional arrayed waveguide diffraction grating type multiplexing / demultiplexing circuit. It is a figure explaining the wavelength input-output characteristic of the conventional arrayed-waveguide diffraction grating type | mold multiplexer / demultiplexer circuit.

Explanation of symbols

101 N first input waveguides 102 First slab waveguide 103 First array waveguide having a predetermined optical path length difference 104 Second slab waveguide 105 M first output waveguides 106 M connection waveguides 107 M second input waveguides 108 Third slab waveguide 109 Second array waveguide having predetermined optical path length difference 110 Fourth slab waveguide 111 N second output waveguides 401 M input M output light Switch 501 (N + M) input waveguides 502 First slab waveguide 503 Array waveguide having a predetermined optical path length difference 504 Second slab waveguide 505 (N + M) output waveguides 506 M connection waveguides 601 M input M output optical switch 701 N / 2 optical couplers 1101 N × N optical wavelength multiplexer / demultiplexer 1102 Multiple communication nodes including a WDM signal transmitting / receiving device 11 03 Optical fiber 1301 Array waveguide having predetermined optical path length difference 1302 Slab waveguide 1303 N input waveguides 1304 N output waveguides

Claims (5)

An optical wavelength multiplexing / demultiplexing device having a plurality of input ports and a plurality of output ports, for multiplexing / demultiplexing wavelength division multiplexed optical signals,
A plurality of first input waveguides, a first slab waveguide optically coupled with the first input waveguide, and a predetermined waveguide length difference optically coupled with the first slab waveguide are sequentially increased. A first waveguide array constituted by a plurality of waveguides, a second slab waveguide optically coupled to the first waveguide array, and a plurality optically coupled to the second slab waveguide. The wavelength of the optical signal that is configured by the first output waveguide of the book and that is input from the a-th of the first input waveguides and is output at the b-th of the first output waveguides is λ ( a first arrayed waveguide grating having input / output characteristics of a + b-1);
A plurality of second input waveguides, a third slab waveguide optically coupled to the second input waveguide, and a predetermined waveguide length difference optically coupled to the third slab waveguide are sequentially increased. A second waveguide array constituted by a plurality of waveguides, a fourth slab waveguide optically coupled to the second waveguide array, and a plurality optically coupled to the fourth slab waveguide. The wavelength of the optical signal input from the b-th of the second input waveguides and output to the a-th of the second output waveguides is λ (a + b). -1) a second arrayed waveguide diffraction grating having input / output characteristics;
The m-th of the first output waveguide of the first arrayed-waveguide diffraction grating and the c-th of the second input waveguide of the second-arrayed-waveguide diffraction grating have a difference between c and m of 2 or more. An optical wavelength multiplexing / demultiplexing device comprising: a coupling means for optical coupling so as to have any of the equal spacing values.   The second array conductor that outputs an optical signal input from an input waveguide that is spaced apart at equal intervals between the two or more equally spaced values of the first input waveguides of the first array waveguide diffraction grating. 2. The optical wavelength multiplexer / demultiplexer according to claim 1, comprising a plurality of optical couplers optically coupled with two of the second output waveguides of the waveguide diffraction grating. An optical wavelength multiplexing / demultiplexing device having a plurality of input ports and a plurality of output ports, for multiplexing / demultiplexing wavelength division multiplexed optical signals,
N + M input waveguides, a first slab waveguide optically coupled with the input waveguides, and a plurality of waveguides sequentially lengthened by a predetermined waveguide length difference optically coupled with the first slab waveguide And the second slab waveguide optically coupled to the waveguide array, N + M output waveguides optically coupled to the second slab waveguide, and the input waveguide. Arrayed waveguide diffraction having input / output characteristics such that the wavelength of the optical signal input from the a-th input waveguide of the optical waveguide and output as the b-th of the output waveguide is λ (a + b-1-N) Lattice,
A connection means for optically coupling the mth part of the output waveguide and the cth part of the input waveguide so that the difference between c and m is any one of two or more equidistant values; An optical wavelength multiplexing / demultiplexing device comprising:   Of the N input waveguides, optically coupled to two of the N output waveguides that output optical signals input from the input waveguides spaced apart by an equal distance equal to or greater than the two or more equally spaced values. 4. The optical wavelength multiplexer / demultiplexer according to claim 3, further comprising a plurality of optical couplers.   5. The optical wavelength multiplexing / demultiplexing device according to claim 1, wherein the connecting means is one of a plurality of optical waveguides and optical switches.

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