JP3449391B2 - Optical cross connect device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention divides wavelength-multiplexed signal light input from a plurality of input optical transmission lines into signals of respective wavelengths, regenerates them, or regenerates them into predetermined wavelengths. The present invention relates to an optical cross-connect device for converting and cross-connecting to a predetermined output optical transmission line.

[0002]

2. Description of the Related Art Development of an optical path cross-connect system in which a wavelength routing technique making full use of the broadband property of light is introduced into an optical path has become active. Optical path realization methods include a WP (Wavelength Path, one wavelength is used for end-to-end) method and a VWP (Virtual Wavelength Path, wavelength conversion for each node) method (reference: Atsushi WA
TANABE et al., "Optical Path Cross-Connect Node Ar
chitecture with High Modularity for Photonic Trans
port Networks, "IEICE TRANS. COMMUN., VOL. E77-B.
NO. 10 OCTOBER 1994).

An optical cross-connect device used in the WP system demultiplexes wavelength-multiplexed signal light input from a plurality of input optical transmission lines into signal lights of respective wavelengths and cross-connects to a predetermined output optical transmission line. Here, in order to secure the transmission quality of the optical path, in the optical cross connect device of the WP system, when the optical path for passing the multiplexed signal light of M waves is received from different N optical fibers, each signal light is transmitted. M × N reproducing circuits for reproducing the data are required. Since each reproduction circuit is provided with a laser light source, M × N laser light sources are required in this example. Therefore, in order to build a large-scale system, the cost increase is inevitable.

The optical cross-connect device used in the VWP system demultiplexes wavelength-multiplexed signal light input from a plurality of input optical transmission lines into signal lights of respective wavelengths, and further converts them into predetermined wavelengths. Cross connect to the output optical transmission line of. In the VWP method, wavelength conversion is involved in cross-connecting optical paths, so in the same example as above,
It is necessary to provide M × N wavelength conversion circuits in the optical cross connect device. The VWP method has the advantages that the optical path accommodation design can be simplified and network resources can be effectively used, as compared with the above-mentioned WP method. However, the bottleneck in the current technology is how to realize a wavelength conversion circuit. The wavelength conversion circuit includes a variable wavelength light source or a fixed wavelength light source. A tunable wavelength light source includes a distributed Bragg reflection laser (DBR-LD) as a typical optical device, but the tunable wavelength range that can be practically used is as narrow as 2-3 nm. Further, since the wavelength is changed in an analog manner by the electric current, there is a problem that the set wavelength becomes unstable. Therefore, in the state of the art, it is difficult to apply the variable wavelength circuit including the variable wavelength light source to the optical cross connect device from the viewpoint of the variable wavelength range. On the other hand, when a fixed wavelength output laser light source is used, it is necessary to provide a wavelength multiplexing number of light sources (M in this case) in each wavelength conversion circuit, and the total number of optical cross-connect devices is M ² × N. A laser light source is required.

As described above, the conventional optical cross-connect device has a problem that a large number of light sources are required for both the WP system and the VWP system. Further, as the number of light sources used in the optical cross-connect device increases, the size of the device for performing wavelength monitoring and stabilization control also increases, and the cost increases. Therefore, in order to construct an economical optical cross-connect device, it is required to reduce the number of required light sources.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an optical cross-connect device which can reduce the number of required light sources as compared with conventional ones and which has a high feasibility.

[0007]

In order to solve the above-mentioned problems, the invention according to claim 1 is N pieces (N is an integer of 2 or more).
M waves (M is 2 or more) respectively input from the input optical transmission lines of
Demultiplex the wavelength-multiplexed signal light of the above integer) into signal light of each wavelength
Demultiplexing means and M number of M
K sets of light sources (K is a divisor of N) and light from each of the light sources
M × that outputs N light for each wavelength
Output from the K optical distributors and the M × K optical distributors.
From one set of M wavelengths of light, one set of M wavelengths of light
Input each, rearrange the input light, M
N optical space switches that output light of each wavelength
And converting the M × N signal lights of respective wavelengths into electric signals
M × N opto-electrical converters,
Electrical signal obtained by converting signal light and the N optical space switches
The N lights for each wavelength output from the
M that modulates and outputs the light of the corresponding wavelength by the air signal
× N external modulators, and the N demultiplexing means
Wavelengths of M × N signal lights of each wavelength are exchanged.
And a wavelength switching means for reproducing and outputting the wavelength
The routes of M × N signal lights output from the stages are recombined,
Output to any of N output optical transmission lines (M × N)
And a wavelength switching unit having a power N output cross-connecting means.
A stage after the light source and a stage before or after the external modulator.
An optical amplifier arranged in a stage and a stage before the external modulator or
Tunable wavelength placed after the optical amplifier placed after
And a filter .

The invention according to claim 2 is the optical space.
The switch has multiple optical gate switches to allow the optical signal to pass.
Turn on the optical gate switch to prevent the optical signal from passing.
Crosstalk component when the optical gate switch is turned off
It is characterized by blocking the passage of .

Further, the invention according to claim 3 is the wave of each light source.
Monitors length or frequency and stabilizes at a specified wavelength or frequency
It is characterized by having a stabilizing circuit for

According to a fourth aspect of the invention, the light source is
The optical amplifier arranged in the latter stage uses a semiconductor optical amplifier
Configuration that superimposes the modulation component specific to each wavelength when amplifying light
It is characterized by being.

Further, the invention according to claim 5 is the external change.
The optical amplifier placed before or after the modulator is a semiconductor optical
When the light is amplified by the amplifier, the change of the input optical transmission line
The feature is that the tonal components are superimposed .

The invention according to claim 6 is N pieces (where N is
Input from each input optical transmission line of 2 or more)
M wavelength (M is an integer greater than or equal to 2) wavelength multiplexed signal light of each wavelength
N demultiplexing means for demultiplexing into signal light, and (a) the N number of demultiplexing means.
N light source units corresponding to the input optical transmission line,
M light sources that output lights of different fixed wavelengths, and each of the lights
M input M output optical coupling that wavelength-multiplexes the output light of the source
It is divided by a combination distributor and the M input M output optical coupling distributor
Wavelength-division-multiplexed light is input, and only the light of the specified wavelength is transmitted.
And M variable wavelength filters that block light of other wavelengths.
Or ( b) paired with the N input optical transmission lines.
Corresponding N / K light sources (K is a divisor of N),
M light sources that output light of different fixed wavelengths,
M input K output that wavelength-multiplexes the output light of each light source and divides into K
Distribution by the optical coupling / distributing device and the M input / K output optical coupling / distributing device
K 1-input M that distributes each wavelength-division multiplexed light into M
The output optical distributor and the above-mentioned 1-input M-output optical distributor
Wavelength-division-multiplexed light is input and only the light of the specified wavelength is transmitted.
M × K variable wavelength filters that block light of other wavelengths
And a light source section including:
M × N opto-electrical converters that convert signal light of wavelengths to electrical signals
Converter and the M × N number of output signals from the photoelectric converters.
The electrical signal and the output from each variable wavelength filter of the light source unit
The light signals of M × N wavelengths are made to correspond to each other and
Therefore, the M × N units that modulate and output the light of the corresponding wavelength are output.
Partial modulator, and M demultiplexed by the N demultiplexing means
Wavelength conversion that converts the wavelength of signal light of N wavelengths and outputs.
And a path for the M × N wavelength-converted signal light
By wavelength-multiplexing any of the N output optical transmission lines
(M × N) input N output cross connect means
It is characterized in that it comprises and.

Further, the invention according to claim 7 is N pieces (where N is
Input from each input optical transmission line of 2 or more)
Wavelength multiplexed signal light of multiple M waves (M is an integer of 2 or more)
N demultiplexing means for demultiplexing into a long signal light, and (a) said N
N light source units corresponding to the two input optical transmission lines,
M light sources that output light of different fixed wavelengths,
M 1 input M output that distributes the output light of each light source to M respectively
Optical power distributor and each one-input M-output optical distributor
Input the light of each wavelength and select the light of that one wavelength
Light source with M M-input 1-output optical switches for outputting
Part or (b) N / K corresponding to the N input optical transmission lines
The number of light source units (K is a divisor of N) is different from each other.
M light sources that output light of a constant wavelength, and outputs of each of the light sources
M 1-input K-output optical splitters for splitting each light into K
And the light distributed by each of the 1-input K-output optical distributors
M × K 1-input M-output optical distributors for M distribution,
The light of each wavelength distributed by each 1-input M-output optical distributor is input.
Power and select the light of one wavelength to output it M × K
A light source unit having an M input 1 output optical switch, and
Converts the signal light of each wavelength demultiplexed by the demultiplexing means into an electrical signal
M × N opto-electrical converters and each of the opto-electrical converters
From the M × N electric signals output from
M output from each M input 1 output optical switch of the credit light source
Corresponds with light of each wavelength of × N pieces, and corresponds by electric signal
M × N external modulators that modulate and output light of the desired wavelength
And M × N number of demultiplexed signals by the N demultiplexing means are provided.
A wavelength conversion means for wavelength-converting and outputting the signal light of each wavelength and a path of the M × N wavelength-converted signal light are combined.
Alternatively, wavelength-multiplexed to any of the N output optical transmission lines and output.
Equipped with input (M × N) input N output cross connect means
The feature is to get.

The invention according to claim 8 is the M input.
1 output optical switch equipped with an optical gate switch at the input stage,
Turn on the optical gate switch on the input line where the optical signal is sent.
Switch the optical gate switches of the other output lines to the off state.
It is characterized by blocking the passage of the Rosstalk component .

According to a ninth aspect of the invention, the wave of each light source is
Monitors length or frequency and stabilizes at a specified wavelength or frequency
It is characterized by having a stabilizing circuit for

According to the invention of claim 10, the wavelength is
The conversion means includes a rear stage of the light source and a front stage of the external modulator.
Or, an optical amplifier arranged in the latter stage and a front of the external modulator
Can be placed after the optical amplifier
And a variable wavelength filter .

Further, the invention according to claim 11 is the light source.
The optical amplifier arranged in the subsequent stage uses a semiconductor optical amplifier.
When the light is amplified by
It is characterized by being successful.

Further, the invention according to claim 12 is the external device.
The optical amplifier arranged before or after the modulator is a semiconductor
When amplifying light using an optical amplifier,
The feature is that the modulation component is superimposed .

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment of an optical cross-connect device according to the present invention used in the WP system. In the present embodiment, M light sources that respectively output CW light having wavelengths λ _{1 to} λ _M , and output lights of M light sources are respectively output by N light sources.
It includes a reproducing unit 100 having M distributors for distribution, and a cross-connect unit 200 for cross-connecting the output of the reproducing unit 100 and outputting it to N optical fibers, and cross-connects M × N optical paths. To do. The present embodiment is characterized in that a set of M light sources corresponding to respective wavelengths is shared by N optical fibers. In FIG. 1, the M-wavelength multiplexed signal light input from the optical fiber 11-j (j = 1, 2, ..., N) has wavelengths of λ ₁ to λ _M at the optical demultiplexer 13-j. Separated into signal light. Wavelength λ _i (i = 1, 2, ...,
The signal light of M) is converted into an electric signal by the photoelectric conversion circuit (O / E) 21-ij and input to the external modulator 22-ij. On the other hand, the CW of the wavelength λ _i output from the light source 23-i
The light is divided into N by the light distributor 24-i, and the external modulator 22
-Is input to ij. The external modulator 22-ij has a wavelength λ.
modulating the CW light with a wavelength lambda _i in electrical signal corresponding to the _i signal light and outputs it as the signal light reproduced. Regenerated wavelength λ _i
Signal light of M input N output merging type switch 15-j, N
Optical fiber 18-via input 1 output optical coupler 16-j
cross connected to j. For example, the optical fiber 11-
When routing the signal light (optical path) of the wavelength λ _i input from 1 to the optical fiber 18-N, the signal light of the wavelength λ _i is switched by the M input N output merging type switch 15-1 and the N input 1 It is output to the optical fiber 18-N via the output optical coupler 16-N. Thus, N M-input N-output merging type switches 15 and N N-input 1-output optical couplers 1
6 constitutes (M × N) input N output cross-connecting means, and M × N optical paths can be cross-connected to N routes.

The M-wave signal light input to one M-input / N-output merging type switch 15 is output to any of the output ports of N routes. At this time, signals of two or more waves may be output to one output port. However, a predetermined wavelength is arranged so that signal lights of the same wavelength do not collide when they are multiplexed by the N-input 1-output optical coupler 16.

As the external modulator 22, a semiconductor absorption type intensity modulator or a Mach-Zehnder type intensity modulator can be used.

Although one light source is provided for each wavelength in this embodiment, a plurality of light sources may be provided for each wavelength. In this case, when K sets of light sources of each wavelength are provided, M × N laser lights can be obtained by using M × K distributors that distribute the output light of each light source N / K. . For example, when two light sources are provided for each wavelength, an N / 2 distribution optical distributor can be used in place of the N distribution distributor, so that the loss in the optical distributor can be reduced. The light intensity can be secured.

FIG. 2 is a block diagram showing a second embodiment of the optical cross connect device according to the present invention. The second embodiment is different from the first embodiment in that the reproducing unit 100a.
In addition, an optical amplifier for compensating for the loss in the optical distributor 24-i is arranged. Optical distributor 24-i
2 can be compensated by placing an optical amplifier 30-i in front of the optical distributor 24-i as shown in FIG. Further, since a predetermined loss also occurs in the external modulator 22-ij, the optical amplifier 31-ij is arranged in the preceding stage or the latter stage (the latter stage in FIG. 2) of the external modulator 22-ij to compensate for the loss and secure a predetermined SNR. As the optical amplifier used here, an erbium-doped optical fiber amplifier, a semiconductor laser optical amplifier, a Raman amplifier, a Brillouin amplifier, or the like can be used.

Since the semiconductor laser optical amplifier can modulate the gain at high speed, it is possible to superimpose a weak modulation component (pilot tone signal) for identifying the wavelength and the input port. For example, the optical amplifier 30-i arranged in front of the optical distributor 24-i has a pilot signal for wavelength identification.
The tone signal is superimposed, and the pilot tone signal for identifying the input port is superimposed on the optical amplifier 31-ij arranged in the subsequent stage of the external modulator 22-ij. As this pilot tone signal, a unique frequency is determined for each wavelength and each input port. The intermediate node in the WP type optical path cross-connect system monitors the optical path of each wavelength by monitoring the pilot tone signal without terminating the signal light and detecting the level of the pilot tone signal of each frequency. And the status of cross-connects can be monitored.

Further, at the intermediate node, the inputted optical signal can be branched and O / E converted, and only the pilot tone signal can be taken out by using a synchronous detection circuit or the like for monitoring. This synchronous detection circuit is set to a desired frequency.

Further, by monitoring the optical signal of each output line of the merging type switch 15-j or the output line of the optical coupler 16-j by the same method as described above, the merging type switch in its own device can be operated. You can know whether it is set correctly.

Next, a third embodiment of the optical cross-connect device according to the present invention will be described with reference to FIG. In the first and second embodiments, for example, the external modulator 22-1
The CW light having the wavelength λ ₁ is input to ₁ , and the external modulator 22-
As CW light of wavelength λ _M is input to M1,
The correspondence between each optical path and wavelength was fixed. here,
As shown in FIG. 3, N optical space switches 27-j are provided between the optical distributor 24-i and the external modulator 22-ij in the wavelength switching unit 100b corresponding to the reproducing units 100 and 100a.
, And a pseudo variable wavelength light source can be configured by switching the wavelength of the CW light input to each external modulator 22-ij. In the optical cross-connect device of the first or second embodiment, the wavelength of the optical signal output from the regenerator 100 or 100a is fixed in advance to the M input terminals of each converging type switch 15-i. In the third embodiment of the optical cross-connect device shown in FIG. 3, the wavelengths λ ₁ to λ _M can be arbitrarily exchanged for each converging type switch 15-i. However, also in the optical cross-connect device of the third embodiment, as in the optical cross-connect devices of the first and second embodiments of the WP system, the same converging type switch 15-i receives an optical signal of the same wavelength. You cannot enter duplicates. In this regard, the third embodiment is V
This is different from the WP type optical cross connect device.

Also in the third embodiment, an optical amplifier can be added in the wavelength switching unit 100b as in the second embodiment described with reference to FIG. Further, also in the third embodiment, when a semiconductor optical amplifier is used as the optical amplifier as in the second embodiment, it is possible to monitor light using a pilot tone signal. At this time, in the wavelength switching unit 100b, after the desired wavelength of the CW light on which the pilot tone for wavelength identification is superimposed is selected by the optical space switch 27, the desired tone is monitored by monitoring the pilot tone signal. It can be monitored whether the wavelength has been selected.

FIG. 4 is a block diagram showing an example of the configuration of the optical space switch 27 shown in FIG. 3, and this diagram shows an example of the configuration when the wavelength multiplexing number M is eight. In FIG.
Input side 1-input 8-output optical switch 41-1 to 41-8
And the 8-input 1-output optical switches 42-1 to 42- on the output side
8 are connected to each other. The 1-input 8-output optical switches 41-1 to 41-8 on the input side have CWs of wavelengths λ _{1 to} λ ₈ , respectively.
Light is input, and by switching the switch, one of the external modulators 22 shown in FIG. 3 that outputs CW light is selected. 8-input 1-output optical switch 42-1 on the output side
At 42-8, the wavelength to be transmitted to the external modulator 22 is selected. In this configuration, the spatial switch (1 input 8
By switching the output optical switches 41-1 to 41-8) and the wavelength selective switch (8-input 1-output optical switches 42-1 to 42-8) independently, a plurality of lights having different wavelengths are temporarily switched. It is possible to prevent the signal from being mixed into one external modulator 22.

By the way, in the optical cross-connect apparatus having the optical signal reproducing section shown in FIG. 1, there are N signals of wavelength λ _M. Wavelength allocation is performed in advance so that wavelength collision does not occur in the output optical fiber 18,
ON / OFF ratio (ON / OFF in the confluence type switch 15
When the ratio (Ratio) is not infinity, the undesired (N-1) leaked lights of the same wavelength are switched from the cross connect unit 200 to the output optical fiber 18. Assuming that the power penalty is kept within 0.2 dB, the total leaked light of the same wavelength is -28 dB.
Must be: For example, the number of input / output fibers N =
16 and the number of wavelength division multiplexing M = 8, (N-
1) = 15, and the ON / OFF ratio of the merging type switch is required to be 40 dB (28 + ₁₀ log ₁₀ 15 [dB]) or more.

In the cross-connect device of FIG. 3, since the CW light of the desired wavelength (eg, λ ₁ ) is selected by the optical space switch 27, the output of the optical space switch 27 has another wavelength (eg, λ ₁ ). CW light other than ₁ ) leaks. This leaked light passes through the cross connect unit 200 together with the signal light (wavelength λ ₁ ) and is output to the output fiber 18, so that the wavelength switching unit 100b also turns ON / O.
An FF ratio of 40 dB or more is required. Therefore, the optical space switch 27 also requires an ON / OFF ratio of 40 dB or more.

Therefore, when an optical switch is used, achieving an ON / OFF ratio of 40 dB or more for the optical switch is a standard for realizing an optical cross-connect device.
In the wavelength conversion unit 300 in the embodiment described later, the requirements for the ON / OFF ratio of the optical switch are the same.

Therefore, the 1 × M optical switch 41 shown in FIG. 4 is used.
The M × 1 optical switch 42 is required to have an ON / OFF ratio of 40 dB or more under the above conditions, for example. As a switch for obtaining this level difference, a switch in the PLC (Planar Lightwave Circuit) technology using the thermo-optic effect is currently used (reference: Masayuki OK
UNO et al., "8 × 8 Optical Matrix Switch Using Sili
ca-Based Planar Lightwave Circuits ", IEICE TRANS.
ELECTRON., VOL. E76-C, NO. 7 JULY 1993, R. Nagase e
t al., "Silica-Based 8 × 8 Optical Matrix Switch Mo
dule with Hybrid Integrated Driving Circuits, "ECO
C '93 Mop1.2 Sep. 12-16, 1993), a polymer-based optical switch that also uses the thermo-optic effect (reference: "Active Com
ponents for Optical Networks Using Polymer Technol
ogy ", IOOC '95 (Integrated Optics and Optical Fibr
e Communication), June 26-30, 1995, "Solid State O
ptical Switches Newsletter, "AKZO NOBEL Corp. Sep.
1995), or mechanical switch. However,
A large number of M × 1 optical switches or 1 × M optical switches are required in the cross-connect device in order to deal with each signal light. Therefore, from the viewpoint of downsizing in the existing technology, a switch using the thermo-optic effect is superior. ing. However, since the M × 1 or 1 × M switch using the thermo-optic effect is slightly inferior to the mechanical one in the crosstalk characteristic, it is desired to improve this characteristic.

The optical space switch 2 according to the present invention shown in FIG.
The configuration of No. 7 improves the crosstalk characteristic by adding an optical gate switch to the configuration of FIG. In the optical space switch 27 shown in FIG. 5, 1 × 8
(1 input and 8 output) Optical switches 41-1 to 41-8 and 8 × 1 (8 input and 1 output) optical switch 42-1
42-8 are provided with optical gate switches 43, 43, 43, ..., respectively. In each optical gate switch 43, the optical gate switch 4 of the desired output line
3 is turned on and the other optical gate switches 43, 43,
By turning off 43, ..., Only one optical signal can be passed through each 1 × 8 optical switch 41 or 8 × 1 optical switch 42. As a result, the optical gate switch 4
The crosstalk characteristic can be improved as compared with the case where 3 is not present. Further, when the optical gate switch 43 is a switch using the thermo-optical effect, it is possible to adjust the output level of the signal light by changing the drive power of the optical gate switch. The level deviation due to the difference can be absorbed. In the configuration shown in FIG. 5, each output terminal of the 1 × 8 optical switch 41 and 8 × 1
Although the optical gate switch 43 is installed on both of the input terminals of the optical switch 42, the optical gate switch may be installed on only one of the switches. In the configuration of FIG. 5, considering the output level adjusting function of the optical gate switch, the entire optical space switch 27 is turned on.
The / OFF ratio is required to be 40 [dB] or more plus a desired level adjustment amount. For example, if the level adjustment amount is 3 dB, the ON / OFF ratio becomes 43 dB or more.

It should be noted that the 8-input / 8-output optical space switch 27 shown in FIG. 4 or 5 is disadvantageous in terms of loss and crosstalk, but it is an input-side 1-input / 8-output optical switch 41-1 to 41-. 8 is replaced by a 1-input 8-output optical distributor, or an 8-input 1-output optical switch 42 on the output side
It is possible to replace -1 to 42-8 with an 8-input 1-output optical coupler. Further, as an optical space switch 27 with 8 inputs and 8 outputs, a crossbar type 8 inputs and 8 outputs optical switch ("I
mproved 8 * 8 Integrated Optical Matrix Switch Using
Silica-Based Planar Lightwave Circuit ", IEEE Jour
nal of Lightwave Technology 1994, vol. 12, No. 9)
Can be used. By using such an optical space switch, even if it is difficult to secure a predetermined wavelength tunable range with a tunable wavelength light source alone, it is possible to artificially change the tunable wavelength by preparing and switching a plurality of fixed wavelength light sources. It can function as a light source. In particular, this configuration is effective in a network in which it is preferable to arrange wavelengths at unequal intervals. In this way, the network is a transmission system in which the signal light wavelength band and the zero-dispersion wavelength of the optical fiber used as the transmission line are overlapped with each other and the signal light waveform deterioration is expected due to the generation of the four-wave mixing light.

In the conventionally used DBR-LD, the wavelength generally changes discontinuously, and the discontinuous intervals are equal frequency intervals determined by the resonator length of the laser. It could not be applied to networks that require wavelengths to be placed in. On the other hand, in the configuration of the present invention, since each light source is independent, it is possible to easily set unequal wavelengths. Further, with the configuration of the present invention, it is not necessary to switch the wavelength in an analog manner, so stable wavelength characteristics can be obtained.

Further, in the optical cross-connect device of the present invention, since the light source corresponding to each wavelength is shared, the configuration for monitoring each wavelength and wavelength stabilization control can be integrated. As a wavelength monitoring device for monitoring each wavelength of the wavelength multiplexed light, there is, for example, one using an arrayed waveguide diffraction grating optical multiplexer / demultiplexer or a swept Fabry-Perot interferometer.
A wavelength monitoring circuit using an arrayed-waveguide diffraction grating optical multiplexer / demultiplexer uses the periodic bandpass transmission characteristics of the arrayed-waveguide diffraction grating optical multiplexer / demultiplexer to determine the level ratio of the output light from its adjacent port. Is a configuration for performing wavelength discrimination that does not depend on fluctuations in incident light intensity. Further, a wavelength monitoring device using a swept Fabry-Perot interferometer has a configuration in which the transmission center wavelength of the swept Fabry-Perot interferometer is temporally swept, and a wavelength error is converted into a time domain to perform wavelength discrimination ( References:
Takashi MIZUOCHI et al., "Frequency Stabilized 622
-Mb / s 16-Channel Optical FDM System and Its Perfor
mance in 1.3 / 1.55mm Zero-Dispersion Fiber Transmis
sion, "Journal of Lightwave Technology, Vol. 13, N
o. 10, October 1995).

FIG. 6 shows an example of a wavelength monitoring circuit using an arrayed waveguide diffraction grating optical multiplexer / demultiplexer. In FIG. 6, the arrayed-waveguide diffraction grating optical multiplexer / demultiplexer has a waveguide array 52 including N input waveguides 51 and M waveguides that are sequentially lengthened by a predetermined waveguide length difference on a substrate 50. , N output waveguides 53, an input-side fan-shaped slab waveguide 54 that connects the input waveguide 51 and the waveguide array 52, and an output-side fan-shaped slab that connects the waveguide array 52 and the output waveguide 53 The waveguide 55 is formed. Light source of each wavelength 23-
CW light with a wavelength lambda ₁ to [lambda] _M output from the 1 to 23-M is,
The wavelengths are multiplexed by the optical multiplexer 56 and input to one of the input waveguides 51. The transmission characteristic of each port of the output waveguide 53 at this time is as shown in FIG. FIG. 7 shows that the crossing wavelengths of the transmission characteristics of the adjacent ports correspond to the respective light source wavelengths. The photodetector 5 is provided at each of the adjacent ports of the output waveguide 53.
7, 58 and a logarithmic amplifier 59 that takes the output ratio are connected. The output of the logarithmic amplifier 59 becomes zero at the cross wavelength. That is, it is possible to detect the relative wavelength error between each light source wavelength and the cross wavelength depending on the polarity and level of the error signal output from the logarithmic amplifier 59. By using this wavelength error signal, wavelength stabilization control of the light source can be performed.

FIG. 8 is a block diagram showing a fourth embodiment of the present invention. The fourth embodiment is a VWP type optical cross-connect device. The optical cross-connect device shown in FIG. 8 has a cross-connect unit 200 similar to that shown in FIG.
And a wavelength conversion unit 300 in which a wavelength conversion function is further added to the function of the reproduction unit 100 shown in FIG. This embodiment is also characterized in that the light source is shared by using the light source and the light distributor in combination, as in the first embodiment. In FIG. 8, the input optical fiber 11-j
The wavelength-multiplexed signal light of M waves input from (j = 1, 2, ..., N) is separated into signal light of each wavelength by the optical demultiplexer 13-j. The signal light of wavelength λ _i (i = 1, 2, ..., M) is converted into an electric signal by an opto-electric conversion circuit (O / E) 21-ij, and is input to the corresponding external modulator 22-ij. It On the other hand, the CW lights of wavelengths λ _{1 to} λ _M output from the light sources 23-1j to 23-Mj are input to the 1-input M-output optical distributors 24-1j to 24-Mj and are distributed by M.
The CW light of each wavelength distributed by the 1-input M-output optical distributors 24-1j to 24-Mj is M-input 1-output optical switch 25-1.
j to 25-Mj, and CW of one wavelength each
The light is selected and the corresponding external modulators 22-1j to 22-
Input to Mj. Here, the light sources 23-1j to 23-M
j, 1-input M-output optical distributors 24-1j to 24-Mj, M
Input 1 output optical switches 25-1j to 25-Mj
A wavelength multiplexing communication light source (light source unit) used for wavelength conversion of M optical paths input from the input optical fiber 11-j is configured. The external modulator 22-ij is an optical fiber 11-j.
Of the CW light having the wavelength λ _s selected by the M-input 1-output optical switch 25-ij by the electric signal corresponding to the signal light having the wavelength λ _i . As a result, the signal light having the wavelength λ _i is wavelength-converted into the signal light having the wavelength λ _s . The wavelength-converted signal light is output to the output optical fiber 18 via the M input N output merging type switch 15-j and the N input 1 output optical coupler 16-j.
-J is cross-connected.

The M-input 1-output optical switch 25 can be constructed by combining a 2-input 2-output thermo-optical effect optical switch having a Mach-Zehnder interferometer configuration (reference: Japanese Patent Laid-Open No. 8-36195 (Optical Space). switch)). The external modulator 22 is a semiconductor absorption type intensity modulator,
Alternatively, a Mach-Zehnder type intensity modulator can be used. As described above, in the present embodiment, it is sufficient to provide M fixed wavelength light sources (one wavelength multiplexing communication light source) for each input optical fiber, and the entire optical cross-connect device also has M light sources.
× N fixed wavelength light sources (N wavelength multiplexing communication light sources) can be used, and an economical optical cross-connect device can be realized. Further, by using the M-input 1-output optical switch 25, it is possible to reduce the crosstalk of the entire optical cross-connect device.

FIG. 9 shows a fifth embodiment of the optical cross connect device of the present invention. The feature of the present embodiment is that the wavelength conversion unit 300a is configured by adding M optical distributors to the wavelength conversion unit 300 in the fourth embodiment, and the same wavelength light source is shared. That is, the difference from the fourth embodiment shown in FIG.
It is provided with a 1-input N-output optical distributor 26-1 that distributes CW light of wavelength λ ₁ output from 1 to the 1-input M-output optical distributor 24-1j. And so on,
1-input N for distributing CW light of wavelength λ _M output from the light source 23-M to 1-input M-output optical distributor 24-Mj
The output light distributor 26-M and the like are provided. As a result, it is possible to reduce the number of N light sources of the same wavelength corresponding to each input optical fiber to one, and the number of fixed wavelength light sources of M can be used for the entire optical cross-connect device. The device can be realized.

Generally, when receiving an optical path for passing the multiplexed signal light of M waves from different N optical fibers, M fixed wavelength light sources (1
It is sufficient to provide one wavelength multiplexing communication light source), and the whole optical cross-connect device can be supported by (N / K) × M fixed wavelength light sources (N / K wavelength multiplexing communication light sources). An economical optical cross connect device can be realized. The configuration shown in FIG. 9 is for K = N. Further, when K is set to be a divisor of N, extra output light is not generated when a plurality of the same fixed wavelength light sources (or light sources for wavelength division multiplexing communication) are used.

FIGS. 10A and 10B are block diagrams showing an example of the internal configuration of the M-input 1-output optical switch 25 shown in FIGS. 8 and 9, respectively. In this case, the M input 1 output optical switch 25 shown in FIG.
Shows the case of 8. The 8-input 1-output optical switch shown in FIG. 10A finally obtains one output from the optical gate switch array 62 including eight optical gate switches 61 and the outputs of the eight optical gate switches 61. It comprises seven 2-input 1-output optical switches 63 for In this case, the two-input one-output optical switch 63 includes four two-input one-output optical switches 63 for selecting four outputs from the eight optical gate switches 61, as shown in FIG. Two 2-input 1-output optical switches 63 for selecting two outputs from the outputs of the four 2-input 1-output optical switches 63, and one for obtaining one output from those two outputs The two-input one-output optical switch 63 is arranged in three stages. On the other hand, 8 inputs 1 shown in FIG.
The output optical switch is an optical gate switch array 62 composed of eight optical gate switches 61, and one of the two inputs 1 connected to the output of each optical gate switch 61 and connected in series. It is composed of an output optical switch 63.

As each optical switch, it is possible to use a switch in the PLC technology utilizing the thermo-optic effect, a polymer optical switch, or a mechanical switch. However, as described in the case of FIG. 5, the former two switches are excellent. In addition, the gate array 62 is
It is provided in order to improve the above-mentioned crosstalk characteristics, in which only the optical gate switch 61 of a desired output line is turned on and the other optical gate switches 61 are turned off. Since the optical gate switch blocks or allows light to pass through regardless of the optical frequency, using an optical switch equipped with an optical gate switch not only reduces crosstalk, but also further increases the ASE (Amplif) of CW light other than the desired wavelength.
ied Spontaneous Emission (spontaneous emission) can be removed. In addition, the switch utilizing the thermo-optic effect can adjust the level of ON output.

According to the above configuration, in the 8-input 1-output optical switch shown in FIG. 10A, desired output light is selected by driving 0 to a maximum of 3 2-input 1-output optical switches 63. To be done. In the 8-input 1-output optical switch shown in FIG. 10B, desired output light can be selected by always driving any one 2-input 1-output optical switch 63. Therefore, in the 8-input 1-output optical switch, since the number of stages of the optical switch passing through is always constant, the loss can be made uniform. On the other hand, the 8-input 1-output optical switch shown in FIG.
Since it is a single piece, the power for driving the switch is always constant, and when viewed from the optical cross-connect device, the power shown in FIG.
There is an effect that it is less than that of (a). In addition, adjustment of loss variation in each optical switch
This can be done by adjusting the driving power of the optical gate switch 61 as described above.

FIG. 11 shows a sixth embodiment of the VWP type optical cross-connect device of the present invention. In FIG. 11, the M-wavelength multiplexed signal light input from the input optical fiber 11-j is separated into signal lights of respective wavelengths by the optical demultiplexer 13-j. The signal light of the wavelength λ _i is converted into an electric signal by the opto-electric conversion circuit (O / E) 21-ij, and is input to the corresponding external modulator 22-ij. On the other hand, the CW lights of wavelengths λ _{1 to} λ _M output from the light sources 23-1j to 23-Mj in the wavelength conversion unit 300b are wavelength-multiplexed by the M-input M-output optical coupling / distributing device 33-j and M-divided. It The wavelength-division-multiplexed CW light distributed by the M-input M-output optical coupler / distributor 33-j is input to the variable wavelength filters 28-1j to 28-Mj,
CW light of one wavelength is selected and input to the corresponding external modulators 22-1j to 22-Mj. here,
Light sources 23-1j to 23-Mj, M input / M output optical coupling / distributing device 33-j, variable wavelength filters 28-1j to 28-Mj.
Thus, a wavelength multiplexing communication light source used for wavelength conversion of M optical paths input from the input optical fiber 11-j is configured. The external modulator 22-ij modulates and outputs the CW light of the wavelength λ _s selected by the tunable wavelength filter 28-ij with the electric signal corresponding to the signal light of the wavelength λ _i of the optical fiber 11-j. As a result, from the signal light of wavelength λ _i to wavelength λ _s
The wavelength is converted to the signal light of. The wavelength-converted signal light is
It is cross-connected to the output optical fiber 18-j via the M input N output merging type switch 15-j and the N input 1 output optical coupler 16-j.

As described above, in this embodiment, it is sufficient to provide M fixed wavelength light sources (one wavelength multiplexing communication light source: light source section) for each input optical fiber, and the entire optical cross-connect apparatus can also have M light sources. × N fixed wavelength light sources (N wavelength multiplexing communication light sources) can be used, and an economical optical cross-connect device can be realized.

FIG. 12 shows a seventh embodiment of the optical cross connect device of the present invention. The feature of this embodiment is that FIG.
In the wavelength conversion unit 300c, the same wavelength light source in the wavelength conversion unit 300b in the sixth embodiment is shared. The difference between the sixth embodiment shown in FIG. 11, the wavelength output from the light source _23-1~23-M λ ₁ ~λ M of CW
The light is wavelength-division-multiplexed by the M-input N-output optical coupler / distributor 29 to be N-divided, and each wavelength-multiplexed CW light is M-divided by the 1-input M-output optical splitter 24-j to be the variable wavelength filter 28-
1j to 28-Mj. As a result, it is possible to reduce the number of N light sources of the same wavelength corresponding to each input optical fiber to one, and the number of fixed wavelength light sources of M can be used for the entire optical cross-connect device. The device can be realized.

As described above, in general, it is sufficient to provide M fixed wavelength light sources (one wavelength multiplexing communication light source) for K input optical fibers, and the entire optical cross-connect device ( N / K) × M fixed wavelength light sources (N / K wavelength multiplexing communication light sources) can be used, and an economical optical cross-connect device can be realized. In addition,
The configuration shown in FIG. 12 is for K = N.

In the fourth to seventh embodiments, one input M
Output optical distributor 24, M input 1 output optical switch 25, 1 input N output optical distributor 26, M input M output optical coupling distributor 3
3, the loss in the variable wavelength filter 28, the M input N output optical coupling / distributing device 29, and the external modulator 22 can be compensated by placing an optical amplifier in each input line or output line. As a result, a predetermined signal-to-noise ratio (SN
R) can be secured. As the optical amplifier, an erbium-doped optical fiber amplifier, a semiconductor laser optical amplifier, a Raman amplifier, a Brillouin amplifier, or the like can be used.
However, spontaneous emission light (ASE light) is generated in the optical amplifier, and this causes deterioration of SNR. Therefore, this can be improved by providing a variable wavelength filter for removing the ASE light in the subsequent stage of the optical amplifier arranged in the output line of the external modulator 22, for example.

FIG. 13 shows an example of a configuration in which an optical amplifier / variable wavelength filter is added to the wavelength conversion section 300a of the fifth embodiment shown in FIG. In FIG. 13, the wavelength conversion unit 3
At 00d, the optical amplifiers 30-1 to 30-M are arranged on the respective output lines of the light sources 23-1 to 23-M. Further, the optical amplifier 31-1 is connected to each output line of the external modulators 22-11 to 22-MN.
1 to 31-MN are arranged, and variable wavelength filters 32-11 to 32-MN are arranged at the subsequent stage. The transmission center wavelengths of the tunable wavelength filters 32-11 to 32-MN are set corresponding to the wavelengths selected by the M-input 1-output optical switches 25-11 to 25-MN, respectively. That is, in FIG.
In the wavelength conversion unit 300d shown in FIG.
The transmission center wavelength of 2 is set corresponding to the wavelength selected by the M input 1 output optical switch 25. Therefore, if an M-input 1-output optical switch 25 with an optical gate switch as shown in FIG. 10A or 10B is used, the ASE light of the CW light of the desired wavelength (eg, λ ₁ ) is tunable by the variable wavelength filter. ASE of CW light other than the desired wavelength (other than λ ₁ )
The light can be removed by an optical gate switch.

The variable wavelength filter 32 used in this embodiment is the same as that of the optical amplifier arranged before or after the external modulator in the other configuration such as the second embodiment described with reference to FIG. It is also possible to arrange it in the latter stage, and in that case, the same effect can be obtained.

FIG. 14 shows an example of a configuration in which an optical amplifier and a variable wavelength filter are added to the wavelength conversion section 300c of the seventh embodiment shown in FIG. In FIG. 14, the wavelength conversion unit 300e includes 1-input M-output optical distributors 24-1 to 24-.
Optical amplifiers 30-11 to 30-MN are arranged on the respective N output lines. Further, the optical amplifiers 31-11 to 31-MN are arranged on the output lines of the external modulators 22-11 to 22-MN, and the variable wavelength filters 32-11 to 32-MN are arranged at the subsequent stage. The transmission center wavelengths of the variable wavelength filters 32-11 to 32-MN are equal to the variable wavelength filters 28-11 to 28-.
It is set corresponding to each wavelength selected by the MN.

Note that, also in the sixth and seventh embodiments shown in FIGS. 11 and 12, the second embodiment described with reference to FIG.
Similar to the embodiment described above, the wavelength conversion unit 300d or 300e.
An optical amplifier can be added inside. Also in the sixth and seventh embodiments, as in the second embodiment, when a semiconductor optical amplifier is used as the optical amplifier, it is possible to monitor light using a pilot tone signal. At this time, in the wavelength conversion unit 300d or 300e, the CW on which the pilot tone for wavelength identification is superimposed
It is possible to monitor whether or not the desired wavelength is selected by monitoring the pilot tone signal after selecting the desired wavelength of the light with the M-input 1-output optical switch 25 or the wavelength tunable filter 28.

[0061]

According to the above configuration, it is possible to achieve economic efficiency by sharing a light source, and to reduce the number of light sources that require wavelength monitoring / stabilization control, thereby constructing a stable cross-connect system. .

Further, by using the fixed wavelength light source in the wavelength conversion section, it is possible to avoid the difficulty of manufacturing the light source and the reduction of the yield.

Further, the crosstalk component can be lowered by the combination of the optical switch and the optical distributor.

In the optical cross-connect device, an optical amplifier may be required for loss compensation, but the accumulation of ASE light (spontaneous emission light) generated by adding the optical amplifier is SNR (signal pair). Noise ratio).
Therefore, when adding an optical amplifier, it is necessary to add means for cutting ASE. In the present invention, by providing an optical gate switch in the optical switch, not only is the crosstalk reduced, but the AS of CW light of a wavelength other than the desired wavelength is
It is also possible to remove E.

Further, a plurality of optical gate switches are provided at the input stage of the optical space switch or the M-input 1-output optical switch, the optical gate switch through which the optical signal passes is turned on, and the optical gate switch through which the optical signal does not pass is turned off. By setting the above, it is possible to obtain an effect that the passage of the crosstalk component can be blocked, and further, the ASE light of the CW light other than the desired wavelength can be removed.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of an optical cross-connect device according to the present invention.

FIG. 2 is a block diagram showing a second embodiment of an optical cross connect device according to the present invention.

FIG. 3 is a block diagram showing a third embodiment of an optical cross connect device according to the present invention.

FIG. 4 is a block diagram showing a configuration example of an M = 8 scale optical space switch 27.

FIG. 5: Optical space switch 2 with additional gate switch
7 is a block diagram showing a configuration example of 7.

FIG. 6 is a diagram showing an example of a wavelength monitoring circuit using an arrayed waveguide diffraction grating optical multiplexer / demultiplexer.

FIG. 7 is a diagram showing transmission characteristics of each port of the output waveguide 53.

FIG. 8 is a block diagram showing a fourth embodiment of an optical cross connect device of the present invention.

FIG. 9 is a block diagram showing a fifth embodiment of the optical cross-connect device of the present invention.

10 (a) and (b) of FIG.
8 is a block diagram showing a configuration example of an M-input 1-output optical switch 25 of 8 scales. FIG.

FIG. 11 is a block diagram showing a sixth embodiment of an optical cross connect device of the present invention.

FIG. 12 is a block diagram showing a seventh embodiment of an optical cross connect device of the present invention.

FIG. 13 is a diagram showing an example of a configuration in which an optical amplifier and a variable wavelength filter are added to the wavelength conversion section of the fifth embodiment of the present invention.

FIG. 14 is an optical amplifier in the wavelength conversion unit of the seventh embodiment,
It is a figure which shows an example of a structure which added the variable wavelength filter.

[Explanation of symbols]

100, 100a, reproducing section 100b wavelength switching section 200 cross-connect sections 300, 300b, 300c, 300d, 300e wavelength converting sections 11-1, ..., 11-N, 18-1, ..., 18-N optical fiber 13-1 , ..., 13-N optical demultiplexer 15-1 to 15-N M input N output merging type switch 16-1 to 16-N N input 1 output optical coupler 21-11, ..., 21-M1 ,. 21-1N, ..., 2
1-MN photoelectric conversion circuit (O / E) 22-11, ..., 22-M1, ..., 22-1N ,.
2-MN External modulator 23-1, ..., 23-M Light source 24-1, ..., 24-M, 24-11 ,.
1, ..., 24-1N, ..., 24-MN Optical distributor (1 input M output) 25-11, ..., 25-M1, ..., 25-1N ,.
5-MN M input 1 output optical switch 26-1, ..., 26-M optical distributor (1 input N output) 27-1, ..., 27-N optical space switch 28-11, ..., 28-M1 ,. , 28-1N, ..., 2
8-MN, 32-11, ..., 32-M1, ..., 32-1
N, ..., 32-MN variable wavelength filter 29 M input N output optical coupling / distributing device 30-1, ..., 30-M, 31-11, ..., 31-M
, ..., 31-1N, ..., 31-MN optical amplifier 33-1, ..., 33-NM input M output optical coupling / distributing device 41-1, ..., 41-8 1 input 8 output optical switch 42-1 , 42-8 8 input 1 output optical switch 43 optical gate switch 50 substrate 51 input waveguide 52 waveguide array 53 output waveguide 54 input side fan-shaped slab waveguide 55 output side fan-shaped slab waveguide 56 optical multiplexer 57, 58 Photodetector 59 Logarithmic Amplifier 61 Optical Gate Switch 62 Optical Gate Switch Array 63 2 Input 1 Output Optical Switch

─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A 1-220533 (JP, A) JP-A 4-119017 (JP, A) JP-A 5-102934 (JP, A) JP-A 62- 230128 (JP, A) JP-A 1-166594 (JP, A) JP-A 1-144888 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H04Q 3/52 H04Q 11 / 04

Claims (12)

(57) [Claims] 1. N input optical transmissions (N is an integer of 2 or more)
Of M waves (M is an integer of 2 or more)
Demultiplexing means for demultiplexing wavelength-multiplexed signal light into signal light of each wavelength
And K sets of M light sources that output light of different wavelengths (K
Is a divisor of N) and the light from the light source is divided into N / K
Then, M × K light distribution that outputs N lights for each wavelength
And N sets of M output from the M × K optical distributors.
Input a set of M wavelengths of light from each wavelength of light
Then, rearrange the input light to obtain light of M wavelengths.
Each of the N optical space switches for output, and the M × N
M × N lights that convert the signal lights of each wavelength to electrical signals
An electrical converter is used to convert the M × N signal lights of respective wavelengths.
Output from the N optical space switches
Correspond with N light of each wavelength
M × N external variables that modulate and output light of the corresponding wavelength
And M × N demultiplexed by the N demultiplexing means.
The signal light of each wavelength is exchanged and regenerated and output.
Wavelength switching means and M × N signal lights output from the wavelength switching means.
Change the line and output to any of the N output optical transmission lines.
(M × N) input N output cross-connecting means, the wavelength exchanging means is provided after the light source and the external modulation.
An optical amplifier arranged at the front stage or the rear stage of the device and the external converter.
Arranged after the optical amplifier that is arranged before or after the modulator
Tunable wavelength filter , and an optical cross-connect device. 2. The optical space switch comprises a plurality of optical gate switches.
Equipped with an optical switch to turn on the optical gate switch through which the optical signal passes.
The optical gate switch, which does not pass the optical signal, is turned off.
The optical cross-connect device according to claim 1, wherein the crosstalk component is prevented from passing through . 3. The wavelength or frequency of each light source is monitored and predetermined
3. The optical cross-connect device according to claim 1 , further comprising a stabilizing circuit that stabilizes the wavelength or the frequency . 4. An optical amplifier arranged after the light source.
But each wavelength solid when amplifying light using a semiconductor optical amplifier
A contract characterized by being configured to superimpose existing modulation components
The optical cross-connect device according to any one of claims 1 to 3 . 5. The external modulator is arranged before or after the external modulator.
Optical amplifier uses a semiconductor optical amplifier to amplify light
The optical cross-connect device according to any one of claims 1 to 3, wherein a modulation component peculiar to the input optical transmission line is superposed on the occasion. 6. N (N is an integer of 2 or more) input optical transmission
Of M waves (M is an integer of 2 or more)
N demultiplexers that demultiplex wavelength-multiplexed signal light into signal light of each wavelength
And (a) N light source units corresponding to the N input optical transmission lines.
Of M fixed wavelengths that output light of different fixed wavelengths.
The light source and the output light of each of the light sources are wavelength-multiplexed and M-distributed.
M input M output optical coupling distributor, and M input M output optical coupling
Input the wavelength division multiplexed light distributed by the distributor, and
M variable that allows only light to pass and blocks light of other wavelengths
A light source unit including a wavelength filter or (b) the N light sources
N / K light sources (K is a divisor of N) corresponding to the optical power transmission line
Parts that output light of fixed wavelengths different from each other
Light source and the output light of each light source are wavelength-multiplexed and K-distributed.
M input K output optical coupler / divider and the M input K output optical coupler
The wavelength division multiplexed light distributed by the combining / distributing device is divided into M parts respectively.
K 1-input M-output light distributors, and each 1-input M-output light
Input the wavelength division multiplexed light distributed by the distributor, and
M × K pieces that pass only light and block light of other wavelengths
A light source unit including a variable wavelength filter, and each demultiplexing unit
M × that converts the signal light of each wavelength demultiplexed by
N opto-electrical converters and outputs from each of the opto-electrical converters.
M × N electric signals and the variable wavelength filters of the light source unit.
The M × N light of each wavelength output from the
And modulate the light of the corresponding wavelength with an electrical signal and output
M × N external modulators, and the N branching hands
Wavelength conversion is performed on the signal light of each wavelength of M × N demultiplexed by the stage.
The wavelength converting means for outputting and the paths of the M × N wavelength-converted signal lights.
E, wavelength-multiplexed to one of N output optical transmission lines and output
(M × N) input N output cross-connecting means . 7. N (N is an integer of 2 or more) input optical transmission
Multiple M waves (M is 2 or more
N) that demultiplexes the number of wavelength-multiplexed signal lights into signal lights of each wavelength.
And demultiplexing means, (b) said N N-number of the light source unit corresponding to the input optical transmission path of the
Of M fixed wavelengths that output light of different fixed wavelengths.
A light source and M pieces for dividing the output light of each light source into M
1-input M-output optical distributor and each 1-input M-output optical distributor
Input the light of each wavelength distributed by the container,
M M input 1 output optical switches that select and output light
Or (b) paired with the N input optical transmission lines.
Corresponding N / K light sources (K is a divisor of N),
M light sources that output light of different fixed wavelengths,
M 1 input K output that distributes the output light of each light source to K respectively
The optical power distributor and the one-input K-output optical distributor
M × K 1-input M-output light components for dividing each light
And each wave distributed by the 1-input M-output optical distributor
Input long light, select light of one wavelength and output
Light source unit having M × K M input 1 output optical switches
And the signal light of each wavelength demultiplexed by each demultiplexing means is electrically
M × N photoelectric converters for converting into signals, and each photoelectric
M × N electric signals output from the gas converter, and
Output from each M input 1 output optical switch of the wavelength division multiplexing light source
Corresponds with the applied light of each wavelength of M × N to generate an electrical signal.
To output the light of the corresponding wavelength by modulating M × N
An external modulator is provided, which is demultiplexed by the N demultiplexing means.
Wavelengths that convert the wavelengths of M × N signal lights of each wavelength and output
The conversion means and the paths of the M × N wavelength-converted signal lights are recombined.
E, wavelength-multiplexed to one of N output optical transmission lines and output
To a (M × N) input N output cross-connect means
Optical cross-connect device, characterized in that that. 8. An input stage of the M-input 1-output optical switch
Equipped with an optical gate switch, the
The optical gate switch is turned on and the optical gate switches of other output lines are turned on.
Prevents crosstalk components from passing through by turning the switch off
The optical cross-connect device according to claim 7, wherein 9. The wavelength or frequency of each light source is monitored and predetermined
Optical cross-connect device according to any one of claims 6-8, characterized in that it comprises a stabilizing circuit for stabilizing the wavelength or frequency of. 10. The wavelength conversion means is provided after the light source.
And an optical amplifier arranged in a front stage or a rear stage of the external modulator
And an optical amplifier placed before or after the external modulator.
The optical cross-connect device according to any one of claims 6 to 9, further comprising a variable wavelength filter arranged at a stage subsequent to the width device. 11. An optical amplifier arranged after the light source.
However, when amplifying light using a semiconductor optical amplifier,
The optical cross-connect device according to claim 10 , wherein the optical modulation device has a configuration in which existing modulation components are superimposed . 12. Arranged in a stage before or after the external modulator.
Optical amplifier uses a semiconductor optical amplifier to amplify light
In this configuration, the modulation component specific to the input optical transmission line is superimposed when
Optical cross-connect device according to claim 10, wherein the that.