JP2003098491A - Method and device for carrier suppressed light pulse generation and method and device for multi-wavelength light source generation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the generation of light pulses having narrower spectrum width than before and the simultaneous generation of light pulses having more wavelengths than before. SOLUTION: Light pulses generated by a light source are shifted in phase while demultiplexed and delayed, and then multiplexed to generate light pulses which are alternately in phase with each other while a light pulse between them is shifted by π in phase. The light pulses have their carrier frequency suppressed and then have narrow spectrum width. Consequently, problems of crosstalk that an AWG multiplexer has can be solved when the constitution that generates multi-wavelength light pulses at the same time by inputting the carrier-suppressed light pulses generated as mentioned above to a super- continuum light source composed of a super-continuum fiber and the AWG multiplexer is employed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a carrier suppressing optical pulse generation method and device for generating a carrier suppressing optical pulse from an optical pulse generated by a light source, and a carrier suppressing optical pulse generated by the carrier suppressing optical pulse generating method. The present invention relates to a multi-wavelength light source generation method and apparatus that simultaneously generate optical pulses of wavelengths.

[0002]

2. Description of the Related Art In order to realize wavelength multiplexing of an optical communication system, it has been practiced to generate optical pulses of many wavelengths by using a supercontinuum light source.

In this supercontinuum light source,
When a light pulse of a certain wavelength is input, a supercontinuum fiber (SCF) that generates a light pulse of a certain wavelength region according to a non-linear effect and a light output by the supercontinuum fiber according to a diffraction grating configuration AWG multiplexer that splits pulses (AW
G: arrayed waveguide diffraction grating) is used to realize simultaneous generation of optical pulses of many wavelengths.

On the other hand, in recent optical communication systems, transmission capacity of terabit level is required, and in order to cope with this, an optical pulse RZ signal (Return Return) of 40 Gbit / s level is required.
toZero signal) is being generated.

Conventionally, when such a 40 Gbit / s optical pulse is generated, as shown in FIG. 14, for example, a 10 Gbit / s optical pulse generated by a laser diode is divided into two at a ratio of 1: 1. A first optical demultiplexer 10 that demultiplexes and inputs one of the optical pulses to the optical waveguide 11 at the subsequent stage and inputs the other optical pulse to the optical waveguide 12 that delays the optical pulse by 50 ps from the optical waveguide 11. , The first optical multiplexer 13 that combines the optical pulses output from the two optical waveguides 11 and 12, and the optical pulse output from the first optical multiplexer 13 is divided into two at a ratio of 1: 1. A second optical demultiplexer 14 that oscillates and inputs one of the optical pulses to the optical waveguide 15 in the subsequent stage, and inputs the other optical pulse to the optical waveguide 16 that delays the optical pulse by 25 ps from the optical waveguide 15. Of the two optical waveguides 15 and 16 Using a second optical multiplexer 17 for multiplexing the power light pulses, and to generate optical pulses of 40 Gbit / s.

In the prior art, when a 40 Gbit / s optical pulse generated in this way is used to generate optical pulses of many wavelengths, the 40 G generated in this way is used.
By inputting a bit / s optical pulse to a supercontinuum light source composed of a supercontinuum fiber and an AWG multiplexer, optical pulses of many wavelengths are generated.

[0007]

However, according to such a conventional technique, the problem of crosstalk between the channels of the optical pulse generated by the supercontinuum light source cannot be avoided.

That is, in the prior art, a 40 Gbit / s level optical pulse is generated according to the configuration shown in FIG. 14 and is input to the supercontinuum light source. 40 Gbit /
When generating s-level optical pulses,
As shown in FIG. 5, a spectrum based on 40 GHz is generated to the left and right of the carrier frequency of the generated optical pulse (center frequency of the optical pulse generated by the laser diode that is the generation source), and thus the generated optical pulse of the generated optical pulse is generated. The spectral width is widened, which causes the problem of crosstalk between the channels of the optical pulse.

Therefore, according to the conventional technique, there is a problem that the transmission distance of the optical pulse generated by the supercontinuum light source cannot be increased.

The present invention has been made in view of the above circumstances, and by generating an optical pulse with carrier suppression,
Providing a new carrier-suppressed optical pulse generation technology that enables generation of optical pulses with a narrower spectrum width than before,
By using the carrier-suppressed optical pulse generated by the carrier-suppressed optical pulse generation technology to simultaneously generate multi-wavelength optical pulses, it is possible to simultaneously generate a larger number of multi-wavelength optical pulses than before. The purpose is to provide a new multi-wavelength light source generation technology.

[0011]

In order to achieve this object, according to the present invention, an optical pulse having a period twice that of a carrier-suppressing optical pulse to be generated is generated from an optical pulse generated by a light source. And one optical pulse is delayed more than the other optical pulse in accordance with the period of the carrier suppressing optical pulse, and the phase of one optical pulse is n × π (n : Odd number) shift and combine these optical pulses, the phase of every other optical pulse is the same, and the phase of the optical pulse entering between them is shifted by n × π (n: odd number) Processing is performed so as to generate a carrier-suppressed optical pulse that is the same as the above-described one.

In this configuration, first, the optical pulse generated from the light source is processed so as to generate an optical pulse having a period twice that of the carrier-suppressing optical pulse. Instead, however, first, the optical pulse is generated. The optical pulse generated by the light source is processed so as to be divided into a number according to the ratio value of the period of this optical pulse and the period of the carrier-suppressing optical pulse, and these divided optical pulses are subjected to the carrier-suppressing optical pulse. By delaying for a predetermined time that is allocated according to the cycle of, the phase of every other optical pulse is temporally shifted by n × π (n: odd number), and these optical pulses are combined, Even if processing is performed to generate carrier-suppressing optical pulses in which the phases of every other optical pulse are the same and the phases of the optical pulses entering between them are shifted by n × π (n: odd number) Good.

Then, the carrier-suppressed optical pulse thus generated is used as a trigger to generate an optical pulse in a certain wavelength region, and the generated optical pulse is dispersed to simultaneously generate multiple-wavelength optical pulses. To process.

In the present invention thus constructed, for example, when a 40 Gbit / s optical pulse having a period of 25 ps is generated, first, a 20 Gbit / s optical pulse having a period of 50 ps, which is twice the period of 25 ps, is generated. Generate a pulse.

Subsequently, the generated 20 Gbit / s optical pulse having a period of 50 ps is demultiplexed into two, and one of the optical pulses is delayed by 25 ps from the other optical pulse, and The phase of one optical pulse is shifted by n × π (n: odd number) from the phase of the other optical pulse, and then the two optical pulses are combined.

As shown in FIG. 1, the optical pulses thus generated have a period of 25 ps, and the phases of every other optical pulse are the same, and the phases of the optical pulses which enter between them are the same. For example, π-shifted 40Gbi
It becomes a light pulse of t / s.

The Fourier transform of a certain time waveform f (t) is F
If (ω), then exp (jω ₀ in the time domain
The multiplication of t) (corresponding to the operation of modulating the frequency ω ₀ ) is f (t) × exp (jω ₀ t) = F (ω−ω ₀ ).
This corresponds to moving (ω) by ω ₀ .

Therefore, the optical pulse generated as shown in FIG. 1 returns to its original state at 50 ps, which corresponds to the modulation of 20 GHz, which corresponds to 20 GHz in the frequency domain.
Shift occurs, and as a result, the spectrum of the carrier frequency (center frequency) is suppressed as shown in FIG.

In this way, according to the present invention, it is possible to generate a carrier-suppressed optical pulse, so that it is possible to generate an optical pulse having a narrower spectrum width than that of the prior art.

Moreover, according to the present invention, this carrier-suppressed optical pulse can be generated by an all-optical configuration.

In the present invention, the carrier-suppressed optical pulse thus generated is used as a trigger to generate an optical pulse in a certain wavelength region, and the generated optical pulse is dispersed to generate an optical pulse of multiple wavelengths. Since they are processed so as to occur at the same time, it becomes possible to simultaneously generate a larger number of multi-wavelength optical pulses than ever.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail according to embodiments.

FIG. 2 illustrates an embodiment of the carrier suppression waveguide 1 according to the present invention.

The carrier suppression waveguide 1 having the present invention shown in this figure is a 10 G emitting laser diode or the like.
Carrier suppressed 4 with bit / s optical pulse as input
It operates so as to generate an optical pulse of 0 Gbit / s, and is realized in the size of a business card, for example.

In the figure, the same components as those explained in FIG. 14 are designated by the same symbols, and 20 is the optical waveguide 11.
, A second phase shifter 21 provided in the optical waveguide 12, a second phase shifter 22 provided in the optical waveguide 15, and a fourth phase shifter 23 provided in the optical waveguide 16. Is.

Each of these phase shifters is composed of two electrodes provided so as to face the upper surface and the lower surface of the optical waveguide, and the two electrodes are formed in accordance with the current flowing between the two electrodes.
By heating the optical waveguide portion between the two electrodes, the refractive index of the optical waveguide portion is changed, whereby the phase of the optical pulse transmitted through the optical waveguide portion is changed.

The first phase shifter 20 and the second phase shifter 21 perform heat treatment so that the respective optical waveguide portions have the same temperature, whereby the optical pulse transmitted through the optical waveguide 11 and the optical pulse are transmitted. There is no phase difference with the optical pulse transmitted through the waveguide 12.

On the other hand, the fourth phase shifter 23
The phase of the optical pulse transmitted through the optical waveguide 16 is the optical waveguide 15.
May be π (n × π) rather than the phase of the optical pulse transmitted.
However, n is an odd number)
The heat treatment at a temperature higher than that of the phase shifter 22 is performed.

According to this structure, the carrier suppression waveguide 1 according to the present invention has 10 cycles of 100 ps.
When a Gbit / s optical pulse is input, the optical pulse is demultiplexed into two, one of them is delayed by 50 ps and then multiplexed, and the combined optical pulse is demultiplexed into two. Then, one of them is delayed by 25 ps and then multiplexed to generate a 40 Gbit / s optical pulse having a period of 25 ps. At this time, the phase of the optical pulse delayed by 25 ps is π. As a result of the shift, as shown in FIG. 2, it has a period of 25 ps, and the phase of every other optical pulse is the same, and the phase of the optical pulse entering between them is π-shifted with respect to that. Will be generated as a 40 Gbit / s optical pulse.

The Fourier transform of a certain time waveform f (t) is F
If (ω), then exp (jω ₀ in the time domain
The multiplication of t) (corresponding to the operation of modulating the frequency ω ₀ ) is f (t) × exp (jω ₀ t) = F (ω−ω ₀ ).
This corresponds to moving (ω) by ω ₀ .

Therefore, the optical pulse generated in this manner returns to the original at 50 ps and is equivalent to the modulation of 20 GHz, which corresponds to 20 GHz in the frequency domain.
Shift occurs, and as a result, the spectrum of the carrier frequency (center frequency) is suppressed as shown in FIG.

In the embodiment shown in FIG. 2, the first phase shifter 20, the second phase shifter 21, and the third phase shifter 22 are provided in addition to the fourth phase shifter 23. When the ambient temperature in which the carrier suppression waveguide 1 is placed is stable, the first phase shifter 20 / second
The phase shifter 21 / the third phase shifter 22 can be omitted.

In the embodiment shown in FIG. 2, the fourth phase shifter 23 performs a heat treatment at a temperature higher than that of the third phase shifter 22, so that the phase of the optical pulse transmitted through the optical waveguide 16 is optical. The phase is controlled to be delayed by π with respect to the phase of the optical pulse transmitted through the waveguide 15. On the contrary, the third phase shifter 22 causes the fourth phase shifter 2 to move.
By performing heat treatment at a temperature higher than 3, the optical waveguide 1
A configuration may be adopted in which the phase of the optical pulse transmitting 5 is delayed by π with respect to the phase of the optical pulse transmitting the optical waveguide 16.

Further, in the embodiment shown in FIG. 2, 10 Gbit /
The first optical demultiplexer 10 that demultiplexes the s optical pulse into two at a ratio of 1: 1 is used, but as shown in FIG. 3, the 10 Gbit / s optical pulse has the same ratio. It is also possible to adopt a configuration in which the optical demultiplexer 30 that demultiplexes into four is used.

In this case, as shown in FIG. 3, the optical waveguide 31 for inputting and transmitting the first optical pulse output from the optical demultiplexer 30 and the second optical waveguide output by the optical demultiplexer 30. The optical waveguide 32, which receives the third optical pulse as an input and is delayed by 25 ps from the optical waveguide 31, and the third optical pulse output from the optical demultiplexer 30, are used as an input.
An optical waveguide 33 that transmits while delaying 50 ps more than
The fourth optical pulse output from the optical demultiplexer 30 is used as an input, and the optical waveguide 34 that transmits the optical pulse while delaying the optical waveguide 31 by 75 ps is provided in association with the optical waveguide 31, and the optical waveguide 31 is transmitted. The phase of the optical pulse transmitted through the optical waveguide 32 may be π (n × π, provided in association with the first phase shifter 40 that does not change the phase of the optical pulse to be transmitted, and the optical waveguide 32. The second phase shifter 41 for changing (odd number) and the third phase shifter 42 provided in association with the optical waveguide 33 so as not to change the phase of the optical pulse transmitted through the optical waveguide 33 and the optical waveguide 34 are associated with each other. And a fourth phase shifter 43 for changing the phase of the optical pulse transmitted through the optical waveguide 34 by π (n × π, where n is an odd number), and the four optical waveguides 31 and 3.
The optical multiplexer 35 that multiplexes the optical pulses output from the optical discs 2, 33, and 34 has a period of 25 ps and is 1
Every other optical pulse has the same phase, and the phase of the optical pulse entering between them is π-shifted by 40.
It will be processed so as to generate an optical pulse of Gbit / s.

Here, when the ambient temperature in which the carrier suppression waveguide 1 is placed is stable, the first phase shifter 40 / third phase shifter 42 can be omitted.

In the embodiment shown in FIG. 2, the optical demultiplexers 10 and 14 having two demultiplexing numbers are used, but the optical pulse of 10 Gbit / s suppresses the carrier of 80 Gbit / s. A configuration in which a plurality of optical demultiplexers having different demultiplexing numbers are used when generating an optical pulse or the like may be adopted.

That is, as shown in FIG. 4, by using only an optical demultiplexer having two demultiplexing numbers, a carrier suppressed optical pulse of 80 Gbit / s is generated from an optical pulse of 10 Gbit / s. In addition to the above, an optical demultiplexer having three demultiplexing numbers is used in the first stage as shown in FIG.
The optical demultiplexer having one demultiplexing number may be used in the second stage.

Further, when it is necessary to generate a carrier-suppressed optical pulse having a high bit rate, an optical demultiplexer having a larger demultiplexing number is used and the number of stages is increased. Good.

FIG. 6 shows an embodiment of the present invention in which the carrier suppression waveguide 1 having the present invention and a supercontinuum light source are combined to generate optical pulses having a larger number of wavelengths than in the prior art. Illustrate.

Here, this embodiment example was also used for verifying the effectiveness of the carrier suppression waveguide 1 provided with the present invention.

In the figure, 100 is a mode-locked laser diode that generates a light pulse having a wavelength of 1530.33 nm, 101 is a lithium niobate modulator that modulates the light pulse generated by the mode-locked laser diode 100, and 102 is a lithium niobate modulator. 101 is a pulse pattern generator that generates a pulse pattern required by 101.

Reference numeral 1 is a carrier suppression waveguide 1 and 103 according to the above-mentioned configuration in which the optical pulse output from the lithium niobate modulator 101 is input to suppress the carrier. Erbium fibers for amplifying the optical pulse output from the carrier suppression waveguide 1. An amplifier, 104 is a supercontinuum fiber that generates an optical pulse in a certain wavelength region by using the optical pulse output from the erbium fiber amplifier 103 as a trigger, and 105 is a supercontinuum fiber 10
AWG for spectrally slicing the optical pulse output from No. 4
Multiplexer 106 is an AWG multiplexer 105
It is an optical multiplexer that multiplexes the optical pulses sliced in the spectrum.

Reference numeral 107 designates a single mode fiber for performing chirp compensation on the optical pulse output from the optical multiplexer 106.
8 is a tellurite erbium fiber amplifier for amplifying the optical pulse output from the single mode fiber 107.
Reference numeral 9 is a single mode fiber for transmitting the optical pulse output from the tellurite erbium fiber amplifier 108 by 29.4 km, and 110 is an inverse dispersion fiber having a length of 10.6 km for dispersion compensation of the optical pulse output from the single mode fiber 109. , 111 is a single mode fiber that transmits the optical pulse output from the inverse dispersion fiber 110 by 28.4 km, and 112 is an inverse dispersion fiber having a length of 11.6 km that performs dispersion compensation of the optical pulse output from the single mode fiber 111. is there.

Reference numeral 113 is a tellurite erbium fiber amplifier for amplifying the optical pulse output from the inverse dispersion fiber 112, and 114 is a tellurite erbium fiber amplifier 11.
3 from the optical pulse output from the AWG multiplexer 10
AWG that takes out the optical pulse with the spectrum slice of 5
Demultiplexer, 115 is AWG demultiplexer 1
A photodetector for converting the optical pulse selectively output by 14 into an electric signal, and a bit error rate measuring device 116 for measuring the bit error rate generated at the time of transmission of the optical pulse by using the electric signal output by the photodetector 115 as an input. .

In the present invention having such a configuration, the mode-locked laser diode 100 modulated by the lithium niobate modulator 101 generates, for example, 10 Gbit /
When the optical pulse of s 2 is input, the carrier suppression waveguide 1 according to the present invention operates in accordance with the above-described operation and has a period of 25p.
s, and the phase of every other light pulse is the same,
A 40 Gbit / s optical pulse is generated and output, in which the phase of the optical pulse that enters during that time is shifted by π with respect to that.

The optical pulse output at this time has a spectral width of about 1 nm according to the spectral width of the optical pulse generated by the mode-locked laser diode 100.

In response to this, when the optical pulse output from the carrier suppression waveguide 1 amplified by the erbium fiber amplifier 103 is input to the supercontinuum fiber 104, this optical pulse (wavelength 1530.33 nm, spectral width) 1 nm), an optical pulse in the wavelength region of 1530 nm to 1610 nm is generated and output as shown in the upper part of FIG.

The AWG multiplexer 105 receives the optical pulse output from the supercontinuum fiber 104, and executes spectrum slicing according to the diffraction grating configuration, thereby performing wavelength division 81 as shown in the middle stage of FIG. Generate a light pulse for the channel. The optical pulses generated at this time also have the same phase of every other optical pulse, and the phase of the optical pulse that enters between them is π.
It has been shifted.

The 81-channel optical pulse generated in this manner is combined by the optical multiplexer 106 and then about 80 k.
As a result, the AWG is transmitted as shown in the lower part of FIG.
It will be transmitted to the demultiplexer 114.

FIGS. 8 to 13 show the experimental results of the optical pulse thus transmitted.

FIG. 8 shows the carrier suppression waveguide 1 as shown in FIG.
The experimental result of the spectral distribution of the third channel when the one shown in FIG. 4 is used, and the experimental result of the upper stage is the experimental result when the fourth phase shifter 23 shifts the phase of the optical pulse by π. The results are shown below.
The experimental result (corresponding to the experimental result of the prior art) when the fourth phase shifter 23 does not shift the phase of the optical pulse is shown.

FIG. 9 shows the experimental results of the spectral distribution of the 43rd channel when the carrier suppression waveguide 1 shown in FIG. 2 is used. The phase shifter 23 changes the phase of the optical pulse by π
The experimental results obtained when the fourth phase shifter 23 does not shift the phase of the optical pulse are shown (corresponding to the experimental results of the conventional technique).

FIG. 10 shows the experimental result of the spectral distribution of the 73rd channel when the carrier suppressing waveguide 1 shown in FIG. 2 is used, and the experimental result of the upper stage is the fourth. The experimental result when the phase shifter 23 shifts the phase of the optical pulse by π is shown. The experimental result of the lower stage is the experimental result when the fourth phase shifter 23 does not shift the phase of the optical pulse (experiment of the prior art). Corresponding to the results).

As can be seen from the experimental results shown in FIGS. 8 to 10, it was verified that the carrier-suppressed optical pulse can be generated when the fourth phase shifter 23 shifts the phase of the optical pulse by π.

From this, it is verified that by using the carrier suppressing waveguide 1 according to the present invention, an optical pulse with carrier suppression can be generated, and thus an optical pulse with a narrower spectrum width can be generated than in the prior art. It was

Then, the carrier-suppressed optical pulse is sent to the supercontinuum fiber 104 and the AWG.
It was verified that by inputting it to the supercontinuum light source configured with the multiplexer 105, it is possible to generate optical pulses of many wavelengths spectrally sliced into 81 channels.

On the other hand, FIG. 11 shows the experimental result of the spectral distribution of the first channel when the fourth phase shifter 23 shifts the phase of the optical pulse by π, and the experimental result of the upper stage is the spectrum. The distribution is shown, and the experimental result in the lower part shows the eye pattern.

FIG. 12 shows the experimental result of the spectral distribution of the 81st channel when the fourth phase shifter 23 shifts the phase of the optical pulse by π,
The upper experimental result shows the spectrum distribution, and the lower experimental result shows the eye pattern.

From the experimental results shown in FIGS. 11 and 12, it was found that the carrier-suppressed optical pulse was generated, and it was verified that the eye pattern was well opened.

On the other hand, the experimental result shown in FIG. 13A is the measurement result of the bit error rate of each channel converted into an electric signal by the photodetector 115, and the experimental result shown in FIG. It is an experimental result of the receiving sensitivity of the light receiver 115 at this time.

This bit error rate is measured by the bit error rate measuring device 1
16 is measured, but the 40 Gbit / s bit error rate measuring device 116 is extremely expensive and difficult to obtain, so the AWG demultiplexer 114 and the photodetector 11
A converter for converting 40 Gbit / s to 10 Gbit / s is prepared between the 5 and 5, and a bit error rate measuring device 116 of 10 Gbit / s is provided.
We conducted an experiment using. Therefore, the experimental result shown in FIG. 13 is the experimental result measured at 10 Gbit / s.

From the experimental result shown in FIG. 13 (a), the bit error rate of all channels is 10 ^-9 or less, and the receiving sensitivity at the bit error rate 10 ^-9 is also -10 dbm or less, which shows sufficient practicality. It was verified.

[0064]

As described above, according to the present invention,
Since it becomes possible to generate an optical pulse with carrier suppression,
It becomes possible to generate an optical pulse having a narrower spectrum width than that of the conventional technique.

In addition, according to the present invention, the carrier-suppressing optical pulse can be generated by the all-optical configuration.

In the present invention, the carrier-suppressing optical pulse thus generated is used as a trigger to generate an optical pulse in a certain wavelength range, and the generated optical pulse is dispersed to generate an optical pulse of multiple wavelengths. Since they are processed so as to occur at the same time, it becomes possible to simultaneously generate a larger number of multi-wavelength optical pulses than ever.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of the present invention.

FIG. 2 is an example of an embodiment of the present invention.

FIG. 3 is another embodiment example of the present invention.

FIG. 4 is an example of an embodiment of the present invention.

FIG. 5 is another embodiment example of the present invention.

FIG. 6 is an example of an embodiment of the present invention.

FIG. 7 is an explanatory diagram of the present invention.

FIG. 8 is an explanatory diagram of the results of an experiment conducted to verify the effectiveness of the present invention.

FIG. 9 is an explanatory diagram of the results of an experiment conducted to verify the effectiveness of the present invention.

FIG. 10 is an explanatory diagram of the results of an experiment conducted to verify the effectiveness of the present invention.

FIG. 11 is an explanatory diagram of the results of an experiment conducted to verify the effectiveness of the present invention.

FIG. 12 is an explanatory diagram of the results of an experiment conducted to verify the effectiveness of the present invention.

FIG. 13 is an explanatory diagram of the results of an experiment conducted to verify the effectiveness of the present invention.

FIG. 14 is an explanatory diagram of a conventional technique.

FIG. 15 is an explanatory diagram of a conventional technique.

[Explanation of symbols]

1 Carrier suppression waveguide 10 First optical demultiplexer 11 Optical waveguide 12 Optical waveguide 13 First optical multiplexer 14 Second optical demultiplexer 15 Optical waveguide 16 Optical waveguide 17 Second optical multiplexer 20 First Phase Shifter 21 Second Phase Shifter 22 Third Phase Shifter 23 Fourth Phase Shifter

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Ken Ozeki             4-2-1 Kanaikitamachi, Koganei City, Tokyo Independent             Communications Research Institute F-term (reference) 2H079 AA06 AA12 BA03 CA04

Claims (6)

[Claims] 1. A carrier-suppressed optical pulse generation method for generating an optical pulse for carrier suppression from an optical pulse generated by a light source, the optical pulse generated by a light source being demultiplexed, delayed and phase-shifted, and combined. By doing so, the phase of every other optical pulse is the same, and the phase of the optical pulse entering between them is n
A carrier-suppressed optical pulse generation method characterized by generating an optical pulse of carrier suppression that is shifted by π (n: odd number). 2. A carrier-suppressed optical pulse generator for generating an optical pulse for carrier suppression from an optical pulse generated by a light source, wherein the optical pulse generated by the light source has a period twice as long as that of the carrier-suppressed optical pulse. Means for generating an optical pulse having the same, and means for demultiplexing the optical pulse having the double cycle into two, and delaying one optical pulse more than the other optical pulse in accordance with the cycle of the carrier suppressing optical pulse. And a means for shifting the phase of one of the two demultiplexed optical pulses from the phase of the other optical pulse by n × π (n: odd number), and combining the two demultiplexed optical pulses. A carrier-suppressed optical pulse generation device characterized by comprising: 3. A carrier-suppressed optical pulse generator for generating an optical pulse for carrier suppression from an optical pulse generated by a light source, wherein the optical pulse generated by the light source is the period of the optical pulse and the carrier-suppressed optical pulse. Means for demultiplexing into a number corresponding to the ratio value with the cycle of the optical pulse and the optical pulse thus demultiplexed, and the paired optical pulse is assigned in accordance with the cycle of the carrier suppressing optical pulse. A means for delaying the time is provided in association with the optical pulses that are temporally separated by the delay of the demultiplexed optical pulses, and the phase of the paired optical pulses is n × π (n: A carrier-suppressed optical pulse generation device, characterized by comprising: means for shifting (odd number) and means for combining the demultiplexed optical pulses. 4. A multi-wavelength light source generation method for simultaneously generating multi-wavelength light pulses, wherein the light pulses generated by the light sources are demultiplexed, delayed, phase-shifted, and combined to generate every other pulse. The phase of the light pulse is the same, and the phase of the light pulse entering between them is n
A carrier-suppressed optical pulse that is shifted by π (n: odd number) is generated, an optical pulse in a certain wavelength region is generated by using the carrier-suppressed optical pulse as a trigger, and the generated optical pulse is dispersed. Thus, a multi-wavelength light source generation method characterized by simultaneously generating multi-wavelength optical pulses. 5. A multi-wavelength light source generation device for simultaneously generating multi-wavelength light pulses with a carrier-suppression optical pulse as an input, wherein a period twice as long as the carrier-suppression optical pulse is generated from the light pulse generated by the light source. Means for generating an optical pulse having the same, and means for demultiplexing the optical pulse having the double cycle into two, and delaying one optical pulse more than the other optical pulse in accordance with the cycle of the carrier suppressing optical pulse. And a means for shifting the phase of one of the two demultiplexed optical pulses from the phase of the other optical pulse by n × π (n: odd number), and combining the two demultiplexed optical pulses. Means for generating the carrier-suppressing light pulse by wave, and using the generated carrier-suppressing light pulse as a trigger,
A multi-wavelength light source generation device comprising: a unit that generates a light pulse in a certain wavelength region; and a unit that simultaneously generates a multi-wavelength light pulse by dispersing the generated light pulse. 6. A multi-wavelength light source generation device for simultaneously generating multi-wavelength light pulses with a carrier-suppression optical pulse as an input, wherein the light pulse generated by a light source is the period of the light pulse and the carrier-suppression optical pulse. Means for demultiplexing into a number corresponding to the ratio value with the cycle of the optical pulse and the optical pulse thus demultiplexed, and the paired optical pulse is assigned in accordance with the cycle of the carrier suppressing optical pulse. A means for delaying the time is provided in association with the optical pulses that are temporally separated by the delay of the demultiplexed optical pulses, and the phase of the paired optical pulses is n × π (n: (Odd number) shift means, means for generating the carrier suppression optical pulse by combining the demultiplexed optical pulses, and using the generated carrier suppression optical pulse as a trigger,
A multi-wavelength light source generation device comprising: a unit that generates a light pulse in a certain wavelength region; and a unit that simultaneously generates a multi-wavelength light pulse by dispersing the generated light pulse.