JP2004198682A - Multiple wavelength signal light source, method for generating multiple wavelength signal light, optical wavelength conversion device, and method for converting optical wavelength - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multiple wavelength signal light source which generates multiple wavelength signal light by inputting an optical signal of an arbitrary modulation format and an arbitrary bit rate into an optical modulator driven by an electric signal applied from the outside and outputs wavelength conversion light, a method for generating the multiple wavelength signal light, an optical wavelength conversion device and a method for converting an optical wavelength. <P>SOLUTION: The multiple wavelength signal light source is provided with: the optical modulator to which the optical signal modulated with B [bit/s] transmission rate is inputted and which modulates the optical signal with the electric signal applied from the outside; and a repeating signal generator which generates an electric signal with a repeating frequency f [Hz] higher than the bandwidth of the optical signal and applies the resultant signal to the optical modulator. The multiple wavelength signal light with frequency interval f [Hz] is outputted from the optical modulator driven with f [Hz] modulation frequency by application of the electric signal. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention provides a multi-wavelength signal light source and a multi-wavelength signal light generation method for generating an optical signal of a plurality of wavelengths from an optical signal of a predetermined wavelength using an optical modulator driven by an externally applied electric signal, and The present invention relates to an optical wavelength converter and an optical wavelength conversion method for converting an optical signal of a predetermined wavelength into an optical signal of another wavelength using the multi-wavelength signal light source.
[0002]
[Prior art]
In the field of optical communication, research and development of a photonic network based on a wavelength division multiplexing transmission method is being promoted in order to increase the transmission capacity of an optical fiber and to construct a flexible network. In a photonic network, an optical cross-connect that switches a light path by converting a light wavelength, and an optical packet transfer that determines a path using the light wavelength as a label (wavelength routing) are used. In such a photonic network, an optical wavelength conversion technology for converting the wavelength of a transmitted optical signal into another wavelength has become important. Here, the optical wavelength conversion technique is to change information included in an optical signal of a certain wavelength to light of another wavelength. Conventionally, optical signals have been converted to electrical signals, and the optical signals have been used to modulate optical carriers of different wavelengths.In recent years, technology has been developed for converting optical wavelengths without converting them to electrical signals. Have been.
[0003]
Conventional optical wavelength conversion technologies that do not convert to electrical signals include many optical wavelength conversion technologies that use light-to-light interaction such as four-wave mixing, cross-phase modulation, and cross-gain modulation (here, "all-optical wavelength conversion"). Technology). For example, in the all-optical wavelength conversion technology using the mutual gain modulation of the semiconductor optical amplifier, the external continuous light is switched by the control light (input signal light) using the gain saturation of the semiconductor optical amplifier, so that the input signal light is converted. It realizes optical wavelength conversion that transfers information to external light. However, the all-optical wavelength conversion technique requires an external light source in addition to the input signal light, and requires adjustment according to the intensity and wavelength of the input signal light.
[0004]
In contrast to the all-optical wavelength conversion technology, the optical wavelength conversion technology using an optical modulator based on the interaction between light and electricity (electro-optic effect, Franz-Keldysh effect, QCSE, etc.) has a simple configuration that does not require an external light source. And has an excellent feature that adjustment according to the input signal light is unnecessary. The optical modulator changes the phase or intensity of light by changing the real part (phase) or the imaginary part (absorption) of the refractive index of a substance by an electric signal. Although a modulator is typical, the optical modulator used in the present invention is not limited to an electro-optic effect. Here, as an example of an optical wavelength conversion technique using an optical modulator using the electro-optic effect, there is an integrated optical SSB modulator / frequency shifter described in Non-Patent Document 1. FIG. 6 shows an example of the configuration.
[0005]
The integrated optical SSB modulator / frequency shifter applies an optical phase modulator 21 for applying a sine wave having an angular frequency Ω, and applies a phase shift of 0, π / 2, π, and 3π / 2 to the input signal light so that each light is applied. It is composed of a phase shifter 22 and a branching / combining means 23 input to the phase modulator. Each optical phase modulator generates a primary sideband separated from the input light by Ω, and cancels one sideband and the input light to generate only the other sideband (SSB). The wavelength (light frequency) of light can be shifted by the modulation angular frequency Ω.
[0006]
However, this optical frequency shift amount is equal to the frequency of the electric signal applied to the optical phase modulator, and a high frequency optical frequency shift that cannot be realized by an electric circuit cannot be realized. In addition, there is a problem that an angular frequency of -3Ω component is generated as spurious, and one side band or input light which is supposed to cancel if the optical phase modulator is not completely balanced remains and is output. Was. Further, Non-Patent Document 1 assumes that continuous light is used as input light, and does not assume that signal light with information is input and the wavelength (optical frequency) is converted.
[0007]
As a technique for collectively generating multi-wavelength light using an optical modulator using an electro-optic effect, there is a multi-wavelength collective light source described in Patent Document 1. FIG. 7 shows an example of this configuration. The multi-wavelength collective light source includes a continuous light source 24 that generates continuous light (CW light) having a single center wavelength, a plurality of optical modulators 25 that perform amplitude modulation or phase modulation on the continuous light, and a predetermined light source. And a power adjuster 27 that adjusts a predetermined repetition period signal voltage and applies it to each optical modulator 25. In each optical modulator, a function for modulating the amplitude and phase of continuous light having a single center wavelength is appropriately set, and the amplitude modulation and the phase modulation are performed by adjusting the power of the signal voltage and setting the bias in accordance with the function. Thus, multi-wavelength light with improved flatness of the output light spectrum can be generated at once.
[0008]
However, the multi-wavelength collective generation light source collectively generates multi-wavelength light from single-wavelength continuous light, and it is not assumed that a modulated signal light is input to generate multi-wavelength light.
[0009]
On the other hand, an optical wavelength converter that inputs an optical pulse signal to an optical fiber and cuts out an arbitrary wavelength from white pulse light generated by the nonlinear optical effect of the optical fiber to convert the wavelength of the input optical pulse signal is used. It has been proposed (Patent Document 2). FIG. 8 shows an example of this configuration. This optical wavelength converter includes an optical fiber 28 that receives an optical pulse signal and generates white pulse light, and an optical filter 29 that extracts an arbitrary wavelength from the white pulse light. Here, the optical pulse signal is a signal in which the presence or absence of a pulse corresponds to information 1 or 0.
[0010]
[Non-patent document 1]
M.Izutsu, S.Shikama, and T.Sueta, "Integrated Optical SSB Modulator / Frequency Shifter", IEEE Journal of Quantum Electronics, Vol.QE-17, No.11, pp.2225-2227, 1998
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2002-82323 [Patent Document 2]
JP-A-8-122833
[Problems to be solved by the invention]
Conventional optical wavelength converters using an optical modulator using the electro-optic effect or a multi-wavelength batch generation light source are supposed to be continuous light of a single wavelength as input light. Alternatively, generation of multi-wavelength light was not assumed. Therefore, the relationship between the bandwidth of the signal light and the modulation frequency of the applied electric signal has not been studied.
[0012]
On the other hand, in an optical wavelength converter using a broadband optical spectrum due to the nonlinear optical effect of an optical fiber, an input signal is limited to an optical pulse signal, and an optical signal of an arbitrary modulation format (for example, NRZ code) is wavelength-converted. Can not. In addition, the repetition frequency of the pulse train must match the code modulation speed (bit rate), and a high-power input signal is required to cause a nonlinear optical effect.
[0013]
According to the present invention, an optical signal having an arbitrary modulation format and an arbitrary bit rate is input to an optical modulator driven by an externally applied electric signal to generate multi-wavelength signal light, and further take out wavelength-converted light. It is an object of the present invention to provide a multi-wavelength signal light source and a multi-wavelength signal light generation method, and an optical wavelength converter and an optical wavelength conversion method that can perform the method.
[0014]
[Means for Solving the Problems]
A multi-wavelength signal light source according to the present invention receives an optical signal modulated at a transmission rate B [bit / s], modulates the optical signal with an externally applied electric signal, and a bandwidth of the optical signal. A repetition signal generator for generating an electric signal having a repetition frequency f [Hz] higher than the width and applying the same to the optical modulator, wherein the frequency is supplied from the optical modulator driven at the modulation frequency f [Hz] by application of the electric signal. It is configured to output multi-wavelength signal light at an interval of f [Hz] (claim 1).
[0015]
The optical modulator of the multi-wavelength signal light source according to the present invention is an optical intensity modulator or an optical phase modulator, or a combination of an optical intensity modulator and an optical phase modulator.
[0016]
An optical wavelength converter according to the present invention receives an optical signal modulated at a transmission rate B [bit / s], modulates the optical signal with an externally applied electric signal, and an optical signal band. A repetition signal generator for generating an electric signal having a repetition frequency f [Hz] higher than the width and applying the same to the optical modulator, and a frequency interval f [Hz] output from the optical modulator driven at the modulation frequency f [Hz] Optical wavelength demultiplexing means for inputting the multi-wavelength signal light, demultiplexing an optical signal having a predetermined wavelength, and outputting the wavelength-converted light for the optical signal input to the optical modulator (claim 3). .
[0017]
When the optical wavelength demultiplexing means is configured to demultiplex an optical signal of each wavelength from multi-wavelength signal light, an optical frequency interval for demultiplexing is f [Hz].
[0018]
An optical wavelength converter according to the present invention receives an optical signal modulated at a transmission rate B [bit / s], modulates the optical signal with an externally applied electric signal, and an optical signal band. A repetition signal generator for generating an electric signal having a repetition frequency f [Hz] higher than the width and applying the same to the optical modulator, and a frequency interval f [Hz] output from the optical modulator driven at the modulation frequency f [Hz] ], The optical signal of each wavelength is demultiplexed by inputting the multi-wavelength signal light, and an optical signal of a predetermined wavelength is selected from the optical signal of each wavelength, and is converted into a wavelength conversion light for the optical signal input to the optical modulator. And a wavelength selecting means for outputting.
[0019]
When the wavelength selecting means is configured to split the optical signal of each wavelength from the multi-wavelength signal light, the optical frequency interval for splitting is f [Hz].
[0020]
The optical modulator of the optical wavelength converter according to the present invention is an optical intensity modulator or an optical phase modulator, or a combination of an optical intensity modulator and an optical phase modulator.
[0021]
According to the multi-wavelength signal light generation method of the present invention, an optical signal modulated at a transmission rate B [bit / s] is input and an electric signal having a repetition frequency f [Hz] higher than the bandwidth of an optical signal applied from the outside. And modulates the optical signal to output multi-wavelength signal light having a frequency interval of f [Hz].
[0022]
According to the optical wavelength conversion method of the present invention, an optical signal modulated at a transmission rate B [bit / s] is input, and the optical signal is converted to an electrical signal having a repetition frequency f [Hz] higher than the bandwidth of an optical signal applied from the outside. The signal is modulated, a multi-wavelength signal light having a frequency interval of f [Hz] is output, the multi-wavelength signal light is input, and an optical signal of a predetermined wavelength is demultiplexed, and output as wavelength conversion light for the input optical signal. (Claim 9).
[0023]
According to the optical wavelength conversion method of the present invention, an optical signal modulated at a transmission rate B [bit / s] is input, and the optical signal is converted to an electrical signal having a repetition frequency f [Hz] higher than the bandwidth of an optical signal applied from the outside. The signal is modulated, a multi-wavelength signal light having a frequency interval of f [Hz] is output, the multi-wavelength signal light is input, and an optical signal of each wavelength is demultiplexed, and an optical signal of a predetermined wavelength is converted from the optical signal of each wavelength. Is selected and output as wavelength-converted light for the input optical signal (claim 10).
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
(Embodiment of multi-wavelength signal light source)
FIG. 1 shows an embodiment of the multi-wavelength signal light source of the present invention. In the figure, the multi-wavelength signal light source of the present invention includes an optical modulator 1 using an electro-optic effect and a repetitive signal generator 2 for generating a repetitive signal applied to the optical modulator 1.
[0025]
The optical signal a modulated at the transmission rate B [bit / s] is input to the optical modulator 1. The repetitive signal generator 2 generates an electric signal (for example, a sine wave) having a repetition frequency f [Hz] higher than the bandwidth (for example, 2 B [Hz]) of the optical signal a, and applies the signal to the optical modulator 1. In the optical modulator 1, when the optical signal a is modulated by the electric signal, a duplicate of the input optical signal is generated in the optical spectrum at every interval of the modulation frequency f [Hz], and this is output as the multi-wavelength signal light b. . Since the optical frequency interval (f [Hz]) of the multi-wavelength signal light b is wider than the bandwidth of the input optical signal, the signal components do not overlap each other and can be separated by an optical filter or the like.
[0026]
The optical modulator 1 may be either an optical intensity modulator or an optical phase modulator, or a combination thereof (arbitrary order), or a combination of a plurality of optical modulators (arbitrary order). Here, when the optical modulator 1 is configured by a combination of the optical intensity modulator and the optical phase modulator, the voltage applied to the optical intensity modulator and the optical phase modulator is optimized to copy the optical signal. Are obtained, a flat multi-wavelength signal light b having the same light intensity is obtained. The spread of the light spectrum, that is, the number of wavelengths is proportional to the modulation degree of the optical phase modulator.
[0027]
In addition, as a general application, it is desirable that an optical spectrum is uniformly generated on both the short wavelength side and the long wavelength side of the input optical signal a. Not limited. In particular, when it is desired to generate the signal on the short wavelength side (or the long wavelength side), by shifting the phase of the applied voltage between the optical intensity modulator and the optical phase modulator by 90 degrees, more optical signal components are provided on one wavelength side. Can be generated. Further, by controlling the applied voltage and the phase of the optical intensity modulator and the optical phase modulator, it is possible to increase the intensity of an optical signal of a specific wavelength. Further, the electric signal having the repetition frequency f [Hz] is not limited to a sine wave, and may include a higher-order frequency component such as a triangular wave or a Gaussian pulse waveform. In this case, the shape of the light spectrum generated according to the waveform of the electric signal can be changed.
[0028]
Since the input optical signal a has a band, the modulation frequency f in the optical modulator 1 is limited, unlike the case where a multi-wavelength carrier is generated from continuous light in Patent Document 1. That is, if the optical signal components of the generated multi-wavelength signal light overlap each other, they cannot be separated by an optical filter or the like. Therefore, the modulation frequency f of the optical modulator 1 (the repetition frequency of the repetition signal generated by the repetition signal generator 2) is , Must be higher than the bandwidth of the optical signal a, and the present invention focuses on this.
[0029]
For example, assuming that the bandwidth of the optical signal a modulated at the transmission rate B [bit / s] is about 2 B [Hz], the modulation must be performed so that the optical signal components of the multi-wavelength signal light b do not overlap each other. It is necessary to set the frequency f higher than 2B [Hz]. Furthermore, in order to separate each optical signal component with an optical filter, considering that the transmission characteristic of the optical filter is not steep like a rectangle but a skirt such as a Gaussian type or a Lorentzian type, the light of the multi-wavelength signal light b is considered. It is necessary to set the modulation frequency f corresponding to the frequency interval to, for example, about 2.5 B [Hz].
[0030]
The standard of the absolute value and the interval of the optical signal wavelength of the current optical communication is defined by ITU-T. Therefore, when arranging optical signals along the ITU-T grid, the modulation frequency f may be set to the ITU-T grid width.
[0031]
FIG. 2 shows experimental results for confirming the operation of the multi-wavelength signal light source of the present invention. When an optical signal having a wavelength of 1553.73 nm, which is NRZ-modulated at 9.95328 Gbit / s, is input to an optical modulator (an optical intensity modulator and an optical phase modulator), and the optical modulator is driven by a sine wave of 25 GHz, FIG. The multi-wavelength signal light as shown is generated. Since each optical signal component has no overlapping band, it can be separated by an optical filter, and it can be seen that the multi-wavelength signal light source which is the object of the present invention is realized.
[0032]
(First Embodiment of Optical Wavelength Converter)
FIG. 3 shows a first embodiment of the optical wavelength converter of the present invention. Optical wavelength converter of the present embodiment, demultiplexing the optical signal c or optical signals c ₁ to c _n of each wavelength, the multi-wavelength signal light b a predetermined wavelength output from the multi-wavelength signal light source shown in FIG. 1 Configuration. Here, it is assumed that the optical modulator 1 includes an optical intensity modulator 11 and an optical phase modulator 12. 3 (1), 3 (2), and 3 (3) show configuration examples for demultiplexing the multi-wavelength signal light b.
[0033]
(1) is a configuration using an optical filter 3 for splitting an optical signal c having a predetermined wavelength from the multi-wavelength signal light b. Here, an optical signal c corresponding to the transmission wavelength of the optical filter 3 is demultiplexed from the input optical signal a as wavelength-converted light. Since the optical filter 3 separates only one optical signal of a predetermined wavelength, the bandwidth of the optical filter is wider than the bandwidth of the optical signal of the predetermined wavelength, and the optical wavelength of the multi-wavelength signal light is increased. It is narrower than the frequency interval f [Hz]. The center frequency of the optical filter is equal to the center frequency of an optical signal having a predetermined wavelength, except in special cases such as when only one sideband is to be extracted. Further, the wavelength of the wavelength-converted light can be changed by changing the center frequency of the optical filter in units of the optical frequency interval f [Hz].
[0034]
(2) is an optical splitter 4 for n-branching the multi-wavelength signal light b, and an optical filter 3-1 for demultiplexing the optical signals c _{1 to} c _n of each wavelength from the n-branched multi-wavelength signal light b. ３−3-n. Here, the optical signal c ₁ to c _n of a plurality of wavelengths corresponding the input optical signal a to the transmission wavelengths of the optical filter is demultiplexed as the wavelength conversion light.
[0035]
(3) is a configuration using an optical wavelength demultiplexer 5 for demultiplexing the optical signals c _{1 to} c _n of each wavelength from the multi-wavelength signal light b. By making the transmission wavelength interval of the optical wavelength demultiplexer 3 and the modulation frequency f of the optical modulator 1 (the repetition frequency of the repetition signal generated by the repetition signal generator 2) coincide, the optical signals c _{1 to} c _{n of} each wavelength are obtained. Can be taken out. The wavelength-converted light to light signal a light signal c ₁ to c _n of each wavelength is input.
[0036]
Since the spread of the optical spectrum of the multi-wavelength signal light b, that is, the number of wavelengths is proportional to the degree of modulation of the optical phase modulator 12, the number n of wavelength converted light and the maximum optical frequency shift amount are also proportional to the degree of modulation.
[0037]
FIG. 4 shows experimental results for confirming the operation of the optical wavelength converter of the present invention. Here, the same diagram shows the optical spectrum of the optical signal of each wavelength output from the arrayed waveguide grating (AWG) used as the optical wavelength demultiplexer 5. When an optical signal having an optical frequency of 192.95 THz, which is NRZ-modulated at 9.95328 Gbit / s, is input to an optical modulator (optical intensity modulator and optical phase modulator) and this optical modulator is driven by a 25 GHz sine wave, FIG. As shown in (1), an optical signal whose wavelength has been converted from an optical frequency of 192.85 THz to 193.05 THz at an interval of 25 GHz can be obtained. In this experiment, when the time waveforms of the wavelength-converted optical signal and the input optical signal were compared, it was proved that they were the same.
[0038]
By the way, a deeply intensity-modulated signal becomes a pulse train. A feature of the multi-wavelength signal light source and the optical wavelength converter of the present invention is that the code modulation and the pulse train do not need to be synchronized. In the case where the code modulation and the pulse train are synchronized (RZ modulation), a configuration is known in which an optical signal of each wavelength is demultiplexed from a multi-wavelength signal light whose spectrum width is expanded as shown in Patent Document 2. Further, in this configuration, the code modulation frequency (repetition frequency of the pulse train) and the frequency interval of the optical wavelength demultiplexer are irrelevant, and according to our study, the spectrum of the signal obtained by asynchronously forming the code-modulated signal into a pulse train is considered. In the case where is expanded, the wavelength-converted optical signal is significantly deteriorated as compared with the input optical signal, and a wavelength-converted optical signal having the same information as the input optical signal cannot be obtained. On the other hand, in the optical wavelength converter of the present invention, even when the code-modulated signal is asynchronously converted into a pulse train, the same wavelength at a different wavelength from the input optical signal is obtained by the demultiplexing by the optical wavelength demultiplexer having the frequency interval equal to the repetition frequency. It was confirmed that a wavelength-converted optical signal having information was obtained. In addition, it was confirmed that it did not depend on the modulation format or transmission speed of the input signal light.
[0039]
In addition, the transmission speed of optical communication has been increasing, and at the same time, the operation of optical modulators has been improved and improved. Therefore, the optical transmission rate in each era is equal to the operating band of the optical modulator. However, in the optical wavelength conversion using the electro-optic effect, the transmission speed of the input light needs to be less than half the operating frequency of the optical modulator in consideration of the overlap of the optical spectrum. In other words, it has been necessary to reduce the transmission speed to less than half the normal transmission speed, and it has been considered that optical wavelength conversion using the electro-optic effect has low practical value. On the other hand, in the experiment of the present invention, when a simple repetitive signal, particularly an electric signal having a frequency exceeding the operation speed of the optical modulator in the form of a sine wave, is input with a large power, the optical modulator operates but the modulation efficiency is reduced. It was confirmed that wavelength signal light was generated. Therefore, the optical wavelength converter of the present invention can be used for wavelength conversion of an optical signal having a normal speed.
[0040]
Further, the present invention can generate multi-wavelength signal light at wavelength intervals of the repetition frequency in proportion to the degree of modulation of the optical modulator, so that the optical frequency shift is smaller than that of the conventional integrated optical SSB modulator / frequency shifter. There is a feature that the amount is large. Further, since optical signal components other than the converted wavelength are removed using the optical filter, generation of unnecessary optical signals can be prevented.
[0041]
(Second Embodiment of Optical Wavelength Converter)
FIG. 5 shows a second embodiment of the optical wavelength converter according to the present invention. The optical wavelength converter of the present embodiment separates the multi-wavelength signal light b output from the multi-wavelength signal light source shown in FIG. 1 into optical signals of respective wavelengths by the optical wavelength demultiplexer 5 (up to here, FIG. Configuration (3)), the optical signals of each wavelength are connected to the optical multiplexer 7 via the optical switch 6, respectively. The opening and closing of each optical switch 6 is controlled by an optical switch control circuit 8, and the optical wavelength demultiplexer 5, the optical switch 6, and the optical multiplexer 7 function as wavelength selecting means. That is, an optical signal of the wavelength selected by the optical switch 6 and the optical switch control circuit 8 is output via the optical multiplexer 7. This wavelength selection means may be configured by combining individual optical components, or may be configured by integrating optical components on one substrate. Further, a hybrid wavelength selector in which a plurality of optical components are integrated may be configured.
[0042]
Here, when only the optical switch 6 corresponding to a certain wavelength λ ₁ is turned on, the optical switch 6 is turned off, and the optical switch 6 corresponding to another wavelength λ ₂ is turned on. At the output, high-speed wavelength conversion from wavelength λ ₁ to λ ₂ is realized. That is, since the wavelength conversion speed in the optical wavelength converter of the present embodiment is determined by the speed of the optical switch 6, high-speed wavelength conversion becomes possible by using a high-speed optical switch such as an optical switch using a semiconductor optical amplifier.
[0043]
【The invention's effect】
As described above, the present invention is configured to modulate with an electric signal having a repetition frequency higher than the bandwidth of the input optical signal. A separable multi-wavelength signal light source can be realized. Further, by separating an optical signal of an arbitrary wavelength from the multi-wavelength signal light by an optical filter or the like, an optical wavelength changer that performs wavelength conversion on an input optical signal can be realized.
[Brief description of the drawings]
FIG. 1 is a diagram showing an embodiment of a multi-wavelength signal light source according to the present invention.
FIG. 2 is a diagram showing experimental results of a multi-wavelength signal light source according to the present invention.
FIG. 3 is a diagram showing a first embodiment of the optical wavelength converter according to the present invention.
FIG. 4 is a view showing experimental results of the optical wavelength converter of the present invention.
FIG. 5 is a diagram showing a second embodiment of the optical wavelength converter according to the present invention.
FIG. 6 is a diagram showing a configuration example of an integrated optical SSB modulator / frequency shifter.
FIG. 7 is a diagram illustrating a configuration example of a multi-wavelength collectively generated light source.
FIG. 8 is a diagram showing a configuration example of an optical wavelength conversion device using a nonlinear optical effect of an optical fiber.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 optical modulator 11 optical intensity modulator 12 optical phase modulator 2 repetitive signal generator 3 optical filter 4 optical splitter 5 optical wavelength demultiplexer 6 optical switch 7 optical multiplexer 8 optical switch control circuit

Claims (10)

An optical modulator that receives an optical signal modulated at a transmission rate B [bit / s] and modulates the optical signal with an externally applied electric signal;
A repetition signal generator that generates an electric signal having a repetition frequency f [Hz] higher than the bandwidth of the optical signal and applies the signal to the optical modulator;
A multi-wavelength signal light source having a configuration in which multi-wavelength signal light having a frequency interval of f [Hz] is output from the optical modulator driven at a modulation frequency f [Hz] by application of the electric signal. The multi-wavelength signal light source according to claim 1, wherein the optical modulator is an optical intensity modulator or an optical phase modulator, or a combination of an optical intensity modulator and an optical phase modulator. An optical modulator that receives an optical signal modulated at a transmission rate B [bit / s] and modulates the optical signal with an externally applied electric signal;
A repetition signal generator that generates an electric signal having a repetition frequency f [Hz] higher than the bandwidth of the optical signal and applies the electric signal to the optical modulator;
A multi-wavelength signal light having a frequency interval of f [Hz] output from the optical modulator driven at a modulation frequency f [Hz] is input, and an optical signal of a predetermined wavelength is demultiplexed, and input to the optical modulator. An optical wavelength demultiplexer for outputting the converted optical signal as wavelength converted light. 4. The optical frequency demultiplexing means according to claim 3, wherein, when the optical wavelength demultiplexing means is configured to demultiplex an optical signal of each wavelength from the multi-wavelength signal light, an optical frequency interval for demultiplexing is f [Hz]. The optical wavelength converter according to the above. An optical modulator that receives an optical signal modulated at a transmission rate B [bit / s] and modulates the optical signal with an externally applied electric signal;
A repetition signal generator that generates an electric signal having a repetition frequency f [Hz] higher than the bandwidth of the optical signal and applies the electric signal to the optical modulator;
A multi-wavelength signal light with a frequency interval f [Hz] output from the optical modulator driven at a modulation frequency f [Hz] is input, and the optical signal of each wavelength is demultiplexed. Wavelength selecting means for selecting an optical signal having a wavelength of (i) and outputting the selected signal as wavelength-converted light for the optical signal input to the optical modulator. 6. An optical frequency interval for demultiplexing is f [Hz] when the wavelength selecting means is configured to demultiplex an optical signal of each wavelength from the multi-wavelength signal light. Optical wavelength converter. The optical wavelength converter according to claim 3, wherein the optical modulator is an optical intensity modulator, an optical phase modulator, or a combination of an optical intensity modulator and an optical phase modulator. An optical signal modulated at a transmission rate B [bit / s] is input,
The optical signal is modulated by an electric signal having a repetition frequency f [Hz] higher than the bandwidth of the optical signal applied from the outside, and a multi-wavelength signal light having a frequency interval of f [Hz] is output. Wavelength signal light generation method. An optical signal modulated at a transmission rate B [bit / s] is input,
Modulating the optical signal with an electric signal having a repetition frequency f [Hz] higher than the bandwidth of the optical signal applied from the outside, and outputting a multi-wavelength signal light having a frequency interval f [Hz];
An optical wavelength conversion method, comprising: inputting the multi-wavelength signal light, demultiplexing an optical signal having a predetermined wavelength, and outputting the wavelength-converted light with respect to the input optical signal. An optical signal modulated at a transmission rate B [bit / s] is input,
Modulating the optical signal with an electric signal having a repetition frequency f [Hz] higher than the bandwidth of the optical signal applied from the outside, and outputting a multi-wavelength signal light having a frequency interval f [Hz];
Inputting the multi-wavelength signal light, demultiplexing the optical signal of each wavelength, selecting an optical signal of a predetermined wavelength from the optical signal of each wavelength, and outputting the selected optical signal as wavelength-converted light for the input optical signal. Characteristic light wavelength conversion method.

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