JP2004032469A - Optical path switching device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize an optical path switching device which can relay a high-speed optical signal without converting the optical signal into an electric signal. <P>SOLUTION: The optical path switching device branches a packet of the optical signal by an optical branching means, inputs the one branched optical signal to an optical switch, and drives the optical switch based on the electric signal converted from other optical signal to thereby switch a path of an optical network. Further improvement is given to the performance. This switching device includes a delay means provided between the optical branching means and the optical switch for delaying the optical signal until at least the optical switch is completely switched. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an optical path switching device that interconnects different networks and relays and transfers packetized data to a desired network, and more particularly, to an optical path switching device that can relay high-speed optical signals without converting them into electrical signals. The present invention relates to a path switching device.
[0002]
[Prior art]
In most of the Internet including a communication network such as a LAN (Local Area Network) and a WAN (Wide Area Network), data communication is performed by TCP / IP (Transmission Control Protocol / Internet Protocol) communication using electric signals. The data is packetized and transmitted, and a destination address, a source address, and the like are stored in a header portion of the packet.
[0003]
A router connects these networks, and the router is provided between a plurality of networks. The router selects a transmission route of the packet according to at least a destination address of the packet, and relays and transfers the packet to a desired network. .
[0004]
On the other hand, data communication is performed by an optical signal in a part of a backbone or a dedicated line where high-speed, large-volume data transmission is required. A different wavelength is assigned to the transmission path for each transmission destination, so that the transmitting side and the receiving side perform point-to-point communication on a one-to-one basis.
[0005]
However, in recent years, along with the expansion of transmission capacity, a photonic network that performs data communication by replacing an existing electric signal with an optical signal is being studied not only at the core of the network but also at the end, for example, to individual personal computers. . It is considered that the photonic network uses a packet switching method in which all data is packetized and a transmission path is determined based on the address of the packet, instead of determining a transmission path based on a wavelength.
[0006]
In addition, in order to realize a photonic network in which everything from a source to a destination is processed as an optical signal, there is a strong demand for an optical router that can relay and transfer a packet of an optical signal even in a router. However, at present, it is difficult to process the optical signal as it is, and the optical signal is once converted into an electric signal by an OE converter (for example, a high-speed photodiode), and the packet converted into the electric signal is converted into a router using a conventional electric circuit. To read the address and determine the transmission route. Then, the electrical signal distributed to the desired transmission path by the router is converted into an optical signal again by an EO converter (for example, an optical semiconductor element such as a laser diode or a light emitting diode), and further the optical signal is modulated by a modulator. Output to the desired network.
[0007]
[Problems to be solved by the invention]
As described above, by providing the OE converter on the input side of the conventional router and providing the EO converter and the modulator on the output side, it is possible to relay and transfer an optical signal to a desired network. However, for each output port, an EO converter, a modulator, and a driver for driving the modulator are required, so that a very large number of high-speed electronic circuit components and optical semiconductor elements are required.
[0008]
Thus, there is an optical router as a device for relaying and transferring an optical signal to a desired network. For example, it is described in JP-A-2001-255567, paragraphs 0002 to 0004, and FIG. 11 of the drawings. This device converts a part of an optical signal into an electric signal, determines a path from the converted electric signal, and outputs the remaining optical signal directly to a desired network.
[0009]
However, as described in paragraph 0005, there is a problem that it is difficult to construct an ultra-high-speed optical communication system in which the modulation speed of an optical signal exceeds 40 [Gbps] and 100 [Gbps].
[0010]
Therefore, an object of the present invention is to realize an optical path switching device that can relay a high-speed optical signal without converting it into an electric signal.
[0011]
[Means for Solving the Problems]
The invention according to claim 1 is
A packet of an optical signal is branched by an optical branching unit, and one of the branched optical signals is input to an optical switch, and the optical switch is driven based on an electric signal obtained by converting the other optical signal, thereby forming an optical network. In an optical path switching device that performs path switching,
A delay unit is provided between the optical branching unit and the optical switch and delays an optical signal at least until the switching of the optical switch is completed.
[0012]
The invention according to claim 2 is
In an optical path switching device that performs optical network path switching based on a packet destination address,
Optical branching means for receiving an optical signal from the network and branching at least two;
Delay means for delaying an optical signal from one output end of the optical branching means;
An optical path switching unit that receives an optical signal from the delay unit and switches the path of the network;
An OE converter that converts an optical signal from the other output end of the optical branching unit into an electric signal;
A path control unit that controls switching of a path of the optical path switching unit based on a destination address of the electric signal from the OE conversion unit;
Wherein the delay time of the delay unit is at least until the path control unit completes the switching of the path by the optical path switching unit.
[0013]
The invention according to claim 3 is the invention according to claim 2,
The delay means is an optical fiber or an optical waveguide.
[0014]
The invention according to claim 4 is the invention according to claim 2,
The delay means
A delay optical switch unit that receives one optical signal from the optical branching unit, switches the optical signal to a delay loop to delay, switches to an optical path switching unit, and outputs
A delay switch driver for switching the path of the delay optical switch based on the output of the OE converter and the output of the path controller;
Which is characterized by having
[0015]
The invention according to claim 5 is the invention according to any one of claims 2 to 4,
The optical path switching unit is an optical switch.
[0016]
The invention according to claim 6 is the invention according to claim 5,
The optical path switching unit is an optical switch using a dielectric thin film optical waveguide or an electro-optical thin film optical waveguide.
[0017]
The invention according to claim 7 is the invention according to any one of claims 2 to 6,
An optical amplifier for amplifying the optical power of an optical signal is provided at a stage before the optical branching unit, between the optical branching unit and the optical path switching unit, or at least one place after the optical path switching unit. is there.
[0018]
The invention according to claim 8 is the invention according to any one of claims 2 to 7,
The optical branching means is one of an optical coupler, an optical tap, and an optical splitter.
[0019]
The invention according to claim 9 is the invention according to any one of claims 2 to 8,
The route control unit
A routing table that stores network routing information;
An address identification circuit for extracting a transfer destination address from the electric signal of the OE conversion unit and selecting a route based on the route information read from the routing table;
An optical switch driver for switching the path of the optical path switching unit based on the selection result from the address identification circuit;
Is provided.
[0020]
The invention according to claim 10 is the invention according to claim 9,
The path control unit is characterized in that a change unit that changes the path information of the routing table is provided according to the path information included in the electric signal from the OE conversion unit.
[0021]
The invention according to claim 11 is the invention according to claim 9,
The route control unit is electrically connected to the external device, and includes a change unit that changes the route information in the routing table according to the route information from the external device.
[0022]
The invention according to claim 12 is the invention according to any one of claims 2 to 11,
An optical coupler for combining a specific optical signal among optical signals output from the optical path switching unit and outputting the combined optical signal to a network is provided.
[0023]
The invention according to claim 13 is the invention according to any one of claims 2 to 12,
The OE converter is a photodiode.
[0024]
The invention according to claim 14 is the invention according to claim 13,
The OE conversion unit is characterized in that at least one of InP, GaAs, SiGe, and Si is used as a base material of the light receiving element.
[0025]
The invention according to claim 15 is the invention according to any one of claims 2 to 14,
The path control unit and the optical path switching unit are characterized in that at least one of InP, GaAs, SiGe, and Si is used as a material.
[0026]
The invention according to claim 16 is the invention according to any one of claims 2 to 13,
The optical branching unit, the delaying unit, the optical switching unit, the OE conversion unit, and the route determination unit are integrally formed on a Si substrate.
[0027]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
FIG. 1 is a configuration diagram showing a first embodiment of the present invention. In FIG. 1, each of an input port IN1 and output ports OUT1 to OUT4 is connected to a network (separate optical fiber) not shown.
[0028]
The optical coupler 10 is an optical branching unit. The input side is connected to the input port IN1. The optical coupler 10 branches the optical power of the input optical signal into, for example, a branching ratio of 1: 100, and outputs the resulting signal. Here, the optical coupler 10 is used as the optical branching unit, but an optical tap, an optical splitter, or the like may be used.
[0029]
The delay means 20 is provided with a delay fiber 21 and has an input side connected to one output side (branch ratio 100) of the optical coupler 10. The delay fiber 21 is an optical fiber having a desired length, and outputs the optical signal from the optical coupler 10 with a desired time delay.
[0030]
The optical switch 30 is an optical path switching unit and is, for example, an optical waveguide type optical switch, and uses a dielectric multilayer optical waveguide or an electro-optical thin-film waveguide. In this case, the path can be switched at a higher speed than a mechanical optical switch or a MEMS (Micro Electro Mechanical System) optical switch. The optical switch 30 has, for example, one input and four outputs, and switches and connects paths so as to output an optical signal from the input side to a desired output side. And each output side is connected to output ports OUT1 to OUT4.
[0031]
The OE converter 40 is, for example, a high-speed photodiode capable of receiving a modulation signal of 10 [Gbps] or more. The input side is connected to the other output side (branch ratio 1) of the optical coupler 10, and the optical signal is converted to an electric signal. Convert to The photodiode has a different base material of the light receiving element depending on the wavelength of the optical signal. For example, in a short wavelength region (visible light region to around 850 [nm]) which is often used for short-distance communication, the base material is Is Si, SiGe, or the like. In a long wavelength region (around 1300 to 1600 [nm]) used for long-distance communication, InP, GaAs, or the like is used as a base material.
[0032]
The path control unit 50 has a routing table 51, an address identification circuit 52, and an optical switch driver 53. The input side is connected to the output side of the OE conversion unit 40, and based on an electric signal from the OE conversion unit 40, an optical switch The switching control of 30 routes is performed. The path control unit 50 and the optical switch 30 are manufactured using InP, GaAs, SiGe, Si, or the like as a material.
[0033]
The routing table 51 is a storage unit that stores network route information. The address identification circuit 52 extracts a transfer destination address from the packet converted into the electric signal by the OE conversion unit 40, and selects a transfer path from the extracted address and the path information read from the routing table 51. The optical switch driver 53 switches the connection of the optical switch 30 so that the path is selected by the address identification circuit 52.
[0034]
The operation of such a device will be described. An optical signal packet is input to the optical coupler 10 from the input port IN1. Then, the optical coupler 10 splits the optical signal into two, outputs one to the delay means 20, and outputs the other to the OE converter 40.
[0035]
Then, the OE converter 40 converts the optical signal into an electric signal and outputs the electric signal to the path controller 50. Further, the address identification circuit 52 of the route control unit 50 extracts the address from the header portion of the packet converted into the electric signal, reads the route information from the routing table 51, and inputs the route information from the extracted address and the route information. Select the network to which the optical signal is relayed and transferred. For example, a network connected to the output port OUT1 is selected as a transfer destination.
[0036]
Based on the result selected by the address identification circuit 52, the optical switch driver 53 switches the path of the optical switch 30, and connects the input side to the output port OUT1.
[0037]
On the other hand, the delay fiber 21 delays the optical signal from the optical coupler 10 until the path switching of the optical switch 30 is completed by the path control unit 50. Then, after the path of the optical switch 30 is switched, the optical signal from the delay unit 20 enters the optical switch 30 and is output from the output port OUT1 to a desired network.
[0038]
As described above, the delay unit 20 delays the optical signal for a desired time, that is, until the path control unit 50 completes switching the path of the optical switch 30 based on the electric signal converted by the OE conversion unit 40. . Then, since the delayed optical signal is relayed and transferred to a desired network via the optical switch 30, it is not necessary to convert the signal converted into an electric signal into an optical signal again and output it to the network. As a result, high-speed optical signals can be relayed and transferred without being converted into electrical signals. Therefore, it is not necessary to provide an EO converter, a modulator, and a driver for driving the modulator for each of the output ports OUT1 to OUT4, and the apparatus can be simplified and the cost can be reduced.
[0039]
Further, since the delay means 20 delays the optical signal from one output terminal of the optical coupler 10 by a desired time, the OE converter 40 converts the optical signal from the other output terminal into an electric signal, and converts the electric signal. Even if the path is determined by an electric signal, unlike the method disclosed in Japanese Patent Application Laid-Open No. 2001-255567, relay and transfer can be performed without changing the modulation speed of an optical signal modulated at a very high speed. That is, high-speed optical signals can be relayed and transferred without being converted into electric signals.
[0040]
Further, since the address identification circuit 52 selects a path based on the electric signal converted from the optical signal by the OE conversion unit 40, general-purpose components used for a router of a conventional electric circuit can be used. Thus, there is no need to newly develop the address identification circuit 52, and the development period and the development cost can be reduced.
[0041]
[Second embodiment]
FIG. 2 is a configuration diagram showing a second embodiment of the present invention. Here, the same components as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. 2, an optical amplifier 60 is provided between the delay unit 20 and the optical switch 30. The optical amplifier 60 includes, for example, an erbium-doped quartz fiber amplifier, a fiber Raman amplifier utilizing a stimulated Raman scattering phenomenon which is a kind of nonlinear optical effect of the quartz optical fiber itself, and the like.
[0042]
Such an apparatus is almost the same as the operation of the apparatus shown in FIG. 1 except that the optical amplifier 60 amplifies the optical power of the optical signal from the delay means 20 and outputs it to the optical switch 30. .
[0043]
As described above, since the optical power of the optical signal is amplified, it is possible to output the optical signal from the output ports OUT1 to OUT4 without reducing the optical power of the optical signal from the input port IN1. As a result, the information of the optical signal input from the network can be accurately relayed and transferred to a desired network.
[0044]
For example, the optical power of the optical signal is as follows: (1) connection loss caused at each connection between the input port IN1, the optical coupler 10, the delay unit 20, the optical switch 30, and the output ports OUT1 to OUT4; It is reduced due to branching of the optical signal, and (3) crosstalk in the optical switch 30, and the signal-to-noise ratio is deteriorated. However, since the reduced optical power is amplified by the optical amplifier 60, the signal-to-noise ratio is improved, and the optical signal can be accurately relayed and transferred to a desired network.
[0045]
Although one amplifier 60 is provided to amplify an optical signal once, a configuration in which a plurality of optical amplifiers 60 are provided in series may be used to further increase the amplification factor. Further, the optical amplifier 60 may be provided anywhere as long as it is between IN1 and OUT1 to OUT4. For example, in FIG. 2, a new optical amplifier 60 is provided between the optical switch 30 and the output port OUT1, A configuration in which an optical amplifier 60 is newly provided between the port IN1 and the optical coupler 10 is exemplified.
[0046]
Here, since the optical signal is also delayed by the optical amplifier 60, the time until the switching of the optical switch 30 is completed can be determined by the delay time between the delay fiber 21 and the optical amplifier 60. That is, the delay fiber 21 and the optical amplifier 60 serve as delay means.
[0047]
[Third embodiment]
FIG. 3 is a configuration diagram showing a third embodiment of the present invention. Here, the same components as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. 3, a delay fiber 22, a delay optical switch (hereinafter abbreviated as a delay switch) 23, and a delay switch driver 24 are provided in place of the delay fiber 21 of the delay means 20. Here, the delay fiber 22 and the delay switch 23 are a delay optical switch unit.
[0048]
The delay fiber 22 is an optical fiber that delays an optical signal by a desired time. The delay switch 23 has, for example, two inputs and two outputs. One input terminal 23a is connected to one output terminal of the optical coupler 10, and the other input terminal 23b is connected to one end of the delay fiber. One output terminal 23 c is connected to the input terminal of the optical switch 30, and the other output terminal 23 d is connected to the other end of the delay fiber 22.
[0049]
The delay switch driver 24 switches the path of the delay switch 23 based on the electric signal from the OE conversion unit 40 and the electric signal from the path control unit 50.
[0050]
The operation of such a device will be described. As an initial state, the delay switch driver 24 connects the input terminal 23a and the output terminal 23d of the delay switch 23. The optical signal from the input port IN1 is split into two by the optical coupler 10, and the optical signal from one output terminal is input to the delay fiber 22 via the delay switch 23. The optical signal from the other output terminal of the optical coupler 10 is converted into an electric signal by the OE conversion unit 40, and the electric signal is output to the path control unit 50 and the delay switch driver 24.
[0051]
Then, the delay switch driver 24 checks the end time of the packet based on the data length of the packet of the electric signal from the OE converter 40, and connects the input terminal 23b and the output terminal 23d of the delay switch 23. As a result, the optical signal propagates in the delay loop formed by the delay fiber 22 and the delay switch 23.
[0052]
Further, the path control unit 50 determines a path based on the electric signal from the OE conversion unit 40 and outputs the electric signal to the optical switch 30 and the delay switch driver 24. After the change of the electric signal, that is, after the path of the optical switch 30 is switched, or after a certain period of time after forming the delay loop, the delay switch driver 24 connects the output terminal 23b and the output terminal 23c, and switches the optical signal to the optical switch. Output to 30. After outputting the optical signal, the optical switch driver 24 connects the input terminal 23a and the output terminal 23d of the delay switch 23 again.
[0053]
The operation of the delay switch driver 24 other than switching the connection of the delay switch 23 by an electric signal from the OE conversion unit 40 and the path control unit 50 and delaying the optical signal by a desired time is the same as that of the device shown in FIG. The description is omitted because it is similar.
[0054]
As described above, since the delay switch driver 24 switches the connection of the delay switch 23 by the electric signal from the OE conversion unit 40 and the path control unit 50, the delay switch driver 24 does not correspond to the fixed delay time but the processing time of the path control unit 50. Delay the optical signal by time. As a result, the delay time of the delay means can be made variable, and the relay and transfer of the optical signal can be performed without adding an unnecessary delay time.
[0055]
[Fourth embodiment]
FIG. 4 is a configuration diagram showing a fourth embodiment of the present invention. Here, the same components as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. In FIG. 4, the path control unit 50 is provided with an address identification circuit 54 instead of the address identification circuit 52, and a new table change unit 55.
[0056]
The address identification circuit 54 extracts a transfer destination address from the packet converted into the electric signal by the OE conversion unit 40, selects a transfer route from the route information read from the routing table 51, and converts the route information into an optical switch. Output to the driver 53. When the extracted address is addressed to the own device, the address identification circuit 54 outputs a packet relating to route information from an external router or a network management device to the change unit 55. The change unit 55 changes the route information of the routing table 51 according to the route information of the packet.
[0057]
The operation of such a device will be described. The address identification circuit 54 extracts an address from the packet converted into an electric signal by the OE conversion unit 40. Then, when the address is addressed to the own device, the packet from the OE conversion unit 40 is output to the change unit 55. Then, the change unit 55 newly changes the route information of the routing table 51 based on the routing information from the packet.
[0058]
The operation other than the change unit 55 changing the route information of the routing table 51 by the packet from the address identification circuit 54 is the same as that of the apparatus shown in FIG.
[0059]
As described above, since the change unit 55 changes the route information in the routing table 51 according to the packet from the network, the route information corresponding to the network change or the failure can be stored in the routing table 51. Thereby, the address identification circuit 54 can determine an optimal path.
[0060]
[Fifth embodiment]
FIG. 5 is a configuration diagram showing a fifth embodiment of the present invention. Here, the same components as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. In FIG. 5, input ports IN2 to IN4 are newly provided, and an optical coupler 10, a delay unit 20, and an OE converter 40 are provided for each of the input ports IN1 to IN4.
[0061]
Further, instead of the optical switch 30, an optical switch 70 having N inputs and M outputs (N, M: integer) is provided. Further, an address identification circuit 56 is provided in the path control unit 50 instead of the address identification circuit 52.
[0062]
Each of the input ports IN1 to IN4 receives an optical signal from the network and outputs this optical signal to the optical coupler 10.
[0063]
The optical switch 70 is an optical path switching unit, has four inputs and four outputs corresponding to the number of input ports IN1 to IN4 and output ports OUT1 to OUT4, and outputs an optical signal from the input side to a desired output side. In this way, the paths are switched and connected according to an instruction from the path control unit 50. Further, each input side is connected to the output terminal of the delay means 20 provided for each of the input ports IN1 to IN4, and each output side is connected to the output ports OUT1 to OUT4.
[0064]
The address identification circuit 56 extracts a transfer destination address from a packet from the OE conversion unit 40 provided for each of the input ports IN1 to IN4, and extracts each of the input ports IN1 from the extracted address and the path information read from the routing table 51. The path of the optical signal from .about.IN4 is selected, and the connection of the optical switch 70 is switched by the optical switch driver 53.
[0065]
The operation of such a device will be described. In order to output the optical signal from each of the input ports IN1 to IN4 to a desired network, the address identification circuit 56 uses an electrical signal from the OE conversion unit 40 provided for each of the input ports IN1 to IN4 to switch the optical switch 70. Route selection. Then, based on the selection result of the address identification circuit 56, the optical switch driver 53 switches the path of the optical switch 70 and outputs an optical signal to a desired network. Except for such operations, the apparatus is the same as the apparatus shown in FIG.
[0066]
Thus, the optical signals from the plurality of input ports IN1 to IN4 are output to a desired network by the optical switch 70 having a plurality of inputs and outputs. Thereby, a plurality of high-speed optical signals inputted can be relayed and transferred without being converted into electric signals.
[0067]
The present invention is not limited to this, and may be as follows. (1) In the apparatus shown in FIGS. 1 to 4, the number of output ports OUT1 to OUT4 is four, but the number of ports may be any number. Of course, an output terminal of the optical switch is provided for each of the output ports OUT1 to OUT4.
[0068]
(2) In the device shown in FIG. 5, the number of input ports IN1 to IN4 and the number of output ports OUT1 to OUT4 are four inputs and four outputs, but the number of ports may be any number. Of course, the input / output terminals of the optical switch 70 are also provided for each of the input ports IN1 to IN4 and the output ports OUT1 to OUT4.
[0069]
(3) In the apparatus shown in FIGS. 1 to 5, the optical fiber is used as the delay fibers 21 and 22 for the delay means 20, but an optical waveguide may be used instead of the optical fiber. If the optical signal is in a short wavelength region, all components such as the input ports IN1 to IN4, the optical coupler 10, and the delay unit 20 may be integrally formed on a Si substrate.
[0070]
(4) In the devices shown in FIGS. 1 to 5, the optical coupler 10 has a branching ratio of 1: 100, but this branching ratio may be any value.
[0071]
(5) In the apparatus shown in FIG. 4, the configuration is shown in which the changing unit 55 changes the route information of the routing table 51 based on the electric signal converted from the optical signal by the OE conversion unit 40. Or an external device (not shown) that outputs path information from a network management device, and the change unit 55 may be connected by an electric wire. Then, the route information in the routing table 51 may be changed based on the route information from an external device (not shown).
[0072]
(6) In the apparatus shown in FIG. 5, an optical switch 70 having N inputs and M outputs is used to output a plurality of input optical signals to a desired network. To output a plurality of input optical signals to a desired network. For example, the configuration is as shown in FIG. In FIG. 6, if the number of input ports IN1 and IN2 to which optical signals from the network are input is two, two devices shown in FIG. 1 are provided in parallel. The optical coupler 80 is provided for each of the output ports OUT1 to OUT4 between the plurality of optical switches 30 provided in parallel and the output ports OUT1 to OUT4, and couples the optical signal from each of the optical switches 30 to the output port OUT1. Output to OUT4
[0073]
Such an apparatus is substantially similar to the operation of the apparatus shown in FIG. 1, except that the optical coupler 80 couples a specific optical signal from the optical switch 30 provided in parallel to the output port OUT1. OUT4 to a desired network. Of course, in FIG. 6, the number of input ports IN1 and IN2 may be any number.
[0074]
As described above, the optical signals from the optical switches 30 provided for the plurality of input ports IN1 and IN2 are combined by the optical coupler 80 and output to a desired network. Thereby, a plurality of high-speed optical signals inputted can be relayed and transferred without being converted into electric signals.
[0075]
(7) Although an optical router has been described as an example of the optical path switching device, it may be applied to an optical switching hub.
[0076]
【The invention's effect】
According to the present invention, the following effects can be obtained.
According to the first aspect, the packet of the optical signal is branched by the optical branching unit, and the optical switch is driven to switch the route of the optical network based on the converted electrical signal of the other branched optical signal. Then, one of the branched optical signals is delayed until the switching of the optical switch is completed by the delay means, and is output to a desired network via the optical switch. Therefore, the signal converted into the electric signal is converted into the optical signal again. No need to output to the network. As a result, high-speed optical signals can be relayed without being converted into electrical signals. Therefore, the apparatus can be simplified and the cost can be reduced.
[0077]
According to the second to sixteenth aspects, the other of the optical signals branched by the optical branching unit is converted into an electric signal by the OE conversion unit, and the path control unit switches the path of the optical path switching unit based on the electric signal. . Then, one of the branched optical signals is delayed until the switching of the optical path switching unit is completed by the delay unit, and is output to a desired network via the optical path switching unit. There is no need to convert to an optical signal again and output to the network. As a result, high-speed optical signals can be relayed without being converted into electrical signals. Therefore, the apparatus can be simplified and the cost can be reduced.
[0078]
Also, since the optical signal from one output terminal of the optical branching unit is delayed until the switching of the optical path switching unit is completed by the delay unit, the OE converter converts the optical signal from the other output terminal into an electric signal. Even if the path is determined by the converted electric signal, the signal can be relayed and transferred without changing the modulation speed of the optical signal modulated at a very high speed. That is, high-speed optical signals can be relayed and transferred without being converted into electric signals.
[0079]
According to the fourth aspect, the delay switch driver switches the connection of the delay switch section based on signals from the OE conversion section and the path control section, so that the delay switch driver responds not to a fixed delay time but to the processing time of the path control section. The optical signal is delayed by the specified time. As a result, the delay time of the delay means can be made variable, and the relay and transfer of the optical signal can be performed without adding an unnecessary delay time.
[0080]
According to the sixth aspect, since the dielectric thin film optical waveguide or the electro-optic thin film optical waveguide is used for the optical switch, the path can be switched at a higher speed than the mechanical optical switch or the MEMS optical switch.
[0081]
According to the seventh aspect, since the optical amplifier amplifies the optical power of the optical signal, the effect of the decrease in the optical power caused by the crosstalk of the optical path switching unit, the connection loss, the branching of the optical signal by the optical branching unit, and the like is eliminated. Can be reduced. As a result, the information of the optical signal input from the network can be accurately relayed and transferred to a desired network.
[0082]
According to the ninth aspect, since the address identification circuit selects a path based on the electric signal converted from the optical signal by the OE conversion unit, general-purpose components used for a router of a conventional electric circuit can be used. Thus, it is not necessary to newly develop an address identification circuit, and the development period and the development cost can be reduced.
[0083]
According to the tenth aspect, the change unit changes the route information in the routing table based on the optical signal from the network, so that the route information corresponding to the network change or the failure can be stored in the routing table. Thereby, the address identification circuit can determine an optimal path.
[0084]
According to the eleventh aspect, the change unit changes the route information of the routing table according to the route information from the external device electrically connected, so that the route information corresponding to the network change or the failure is stored in the routing table. can do. Thereby, the address identification circuit can determine an optimal path.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a first embodiment of the present invention.
FIG. 2 is a configuration diagram showing a second embodiment of the present invention.
FIG. 3 is a configuration diagram showing a third embodiment of the present invention.
FIG. 4 is a configuration diagram showing a fourth embodiment of the present invention.
FIG. 5 is a configuration diagram showing a fifth embodiment of the present invention.
FIG. 6 is a configuration diagram showing a sixth embodiment of the present invention.
[Explanation of symbols]
10 Optical coupler
20 Delay means
21, 22 delay fiber
23 Delay switch
24 Delay switch driver
30, 70 Optical switch
40 OE converter
50 Route decision unit
51 Routing Table
52, 54, 56 address identification circuit
53 Optical Switch Driver
55 Changing means
80 optical coupler

Claims (16)

A packet of an optical signal is branched by an optical branching unit, and one of the branched optical signals is input to an optical switch, and the optical switch is driven based on an electric signal obtained by converting the other optical signal, thereby forming an optical network. In an optical path switching device that performs path switching,
An optical path switching device provided between the optical branching unit and the optical switch, the delay unit delaying an optical signal at least until the switching of the optical switch is completed. In an optical path switching device that performs optical network path switching based on a packet destination address,
Optical branching means for receiving an optical signal from the network and branching at least two;
Delay means for delaying an optical signal from one output end of the optical branching means;
An optical path switching unit that receives an optical signal from the delay unit and switches the path of the network;
An OE converter that converts an optical signal from the other output end of the optical branching unit into an electric signal;
A path control unit for controlling the switching of the path of the optical path switching unit based on the destination address of the electric signal from the OE conversion unit. An optical path switching device, wherein the switching of the path by the switching unit is completed. 3. The optical path switching device according to claim 2, wherein the delay unit is an optical fiber or an optical waveguide. The delay means
A delay optical switch unit that receives one optical signal from the optical branching unit, switches the optical signal to a delay loop to delay, switches to an optical path switching unit, and outputs
3. The optical path switching device according to claim 2, further comprising: a delay switch driver that performs the path switching of the delay optical switch section based on an output of the OE conversion section and an output of the path control section. The optical path switching device according to claim 2, wherein the optical path switching unit is an optical switch. 6. The optical path switching device according to claim 5, wherein the optical path switching unit is an optical switch using a dielectric thin film optical waveguide or an electro-optical thin film optical waveguide. An optical amplifier for amplifying the optical power of an optical signal is provided at a stage prior to the optical branching unit, between the optical branching unit and the optical path switching unit, or at least one place after the optical path switching unit. 7. The optical path switching device according to any one of 2 to 6. The optical path switching device according to claim 2, wherein the optical branching unit is any one of an optical coupler, an optical tap, and an optical splitter. The route control unit
A routing table that stores network routing information;
An address identification circuit for extracting a transfer destination address from the electric signal of the OE conversion unit and selecting a route based on the route information read from the routing table;
9. The optical path switching device according to claim 2, further comprising an optical switch driver for switching a path of the optical path switching unit based on a selection result from the address identification circuit. 10. The optical path switching device according to claim 9, wherein the path control unit includes a change unit that changes the path information of the routing table according to the path information included in the electric signal from the OE conversion unit. 10. The optical path switching device according to claim 9, wherein the path control unit is electrically connected to the external device, and further includes a change unit that changes the path information of the routing table according to the path information from the external device. The optical path switching device according to any one of claims 2 to 11, further comprising an optical coupler that couples a specific optical signal among optical signals output from the optical path switching unit and outputs the combined signal to a network. apparatus. The optical path switching device according to claim 2, wherein the OE converter is a photodiode. 14. The optical path switching device according to claim 13, wherein the OE conversion unit uses at least one of InP, GaAs, SiGe, and Si as a base material of the light receiving element. 15. The optical path switching device according to claim 2, wherein the path control unit and the optical path switching unit use at least one of InP, GaAs, SiGe, and Si as a material. 14. The optical path switching device according to claim 2, wherein the optical branching unit, the delay unit, the optical switching unit, the OE conversion unit, and the path determination unit are integrally formed on a Si substrate.

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