CN111966960A - All-optical short-time Fourier transform system and method - Google Patents
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Abstract
The all-optical short-time Fourier transform system and the method provided by the embodiment of the invention have the advantages that communication information carried in a radio frequency signal to be detected is added into an optical frequency comb to obtain a modulated optical signal, frequency components are extracted, and the frequency components are mapped onto a target free spectral range to obtain an optical signal with amplified bandwidth; cutting by using a pulse scissors to obtain light pulses; after phase modulation, the modulated optical pulse passes through a dispersion medium to obtain the change of the frequency component of the input signal along with the time; the optical signal passing through the dispersion medium passes through a photodetector to obtain a corresponding electrical signal. Therefore, through bandwidth-amplified electro-optic conversion, the requirement of dispersion Fourier transform on a dispersion value is reduced, and the limited dispersion is utilized to obtain higher spectral analysis precision. Because the short-time Fourier transform can obtain a calculation result directly on the optical signal, the method is not limited by the digital signal processing capability and the processing delay any more, and the analysis speed of the radio frequency spectrum is improved.
Description
Technical Field
The invention relates to the technical field of information, in particular to an all-optical short-time Fourier transform system and method.
Background
The short-time Fourier transform can not only obtain the frequency spectrum components of the signal, but also obtain the transformation of the frequency spectrum components of the signal along with time. The dynamic acquisition of the frequency spectrum components of the radio frequency signals is widely applied to various fields such as communication, military radars, electronic warfare and the like.
In the prior art, a dynamic spectrum is generally obtained by processing a digital signal to analyze a spectrum component, however, due to the limited sampling rate and digital signal processing capability of an analog-to-digital converter, a change of a broadband signal spectrum component with time cannot be detected quickly and accurately, and an analysis speed and an analysis accuracy of the spectrum component cannot be high at the same time.
Disclosure of Invention
The embodiment of the invention aims to provide an all-optical short-time Fourier transform system and method, which are used for solving the problems of low analysis speed and low analysis precision of spectral components. The specific technical scheme is as follows:
in a first aspect of the embodiments of the present invention, an all-optical short-time fourier transform system is provided, including:
an optical frequency comb generator for generating an optical frequency comb;
the intensity modulator is used for receiving the radio frequency signal to be detected; adding communication information carried in a radio frequency signal to be detected into an optical frequency comb to obtain a modulated optical signal;
the optical fiber Fabry-Perot interferometer is used for extracting frequency components of the modulated optical signals and mapping the frequency components to a target free spectral range to obtain optical signals with amplified bandwidth, wherein the target spectral range is larger than the free spectral range of the modulated optical signals;
the intensity modulator is used for cutting the optical signal with the amplified bandwidth through pulse scissors to obtain optical pulses;
the phase modulator is used for carrying out phase modulation on the optical pulse to obtain a modulated optical pulse;
the dispersion compensation optical fiber is used for modulating the modulated optical pulse into a dispersion medium for propagation to obtain the change of the frequency component of the input signal along with time on a time domain;
and the photoelectric detector is used for converting the optical signal passing through the dispersion medium into an electric signal to obtain the converted electric signal.
Optionally, the system further includes:
and the digital acquisition card is used for extracting the communication information in the converted electric signals to obtain the information of the time variation of the one-dimensional radio frequency time frequency along with the time, and converting the information of the time variation of the one-dimensional radio frequency time frequency along with the time into the frequency-time combined two-dimensional representation of the radio frequency signals.
Optionally, the system further includes:
a microwave source for generating a radio frequency signal;
the phase modulator is specifically configured to perform phase modulation on the optical pulse through the radio frequency signal, acquire a secondary phase in a time window where the optical pulse is located, and perform pre-chirp processing on the optical pulse.
Optionally, the dispersion compensation fiber is specifically configured to map optical signals in different frequency domains to a time domain with a distance Δ t;
Δt＝2πβ2Δf
wherein, beta2Is the second-order dispersion value of the dispersion compensation fiber, Δ f is the frequency difference of the optical signals of different frequency domains, and Δ t is the distance in the time domain.
Optionally, the optical frequency comb generator includes:
the laser generating module is used for generating laser beams;
the secondary phase modulation module is used for carrying out phase modulation on the laser beam and generating a high-order sideband;
and the intensity modulation module is used for flattening the high-order sideband to obtain the optical frequency comb.
In a second aspect of the embodiments of the present invention, an all-optical short-time fourier transform method is provided, including:
generating an optical frequency comb;
receiving a radio frequency signal to be detected;
adding communication information carried in a radio frequency signal to be detected into an optical frequency comb to obtain a modulated optical signal;
extracting frequency components of the modulated optical signal, and mapping the frequency components onto a target free spectral range to obtain an optical signal with amplified bandwidth, wherein the target spectral range is larger than the free spectral range of the modulated optical signal;
cutting the amplified optical signal through a pulse scissor to obtain an optical pulse;
carrying out phase modulation on the optical pulse to obtain a modulated optical pulse;
modulating the modulated optical pulse into a dispersion medium for propagation to obtain the change of the frequency component of the input signal along with time on a time domain;
and converting the optical signal passing through the dispersion medium into an electric signal by using a photoelectric detector to obtain the converted electric signal.
Optionally, the method further includes:
extracting communication information in the converted electric signal to obtain information of the change of the one-dimensional radio frequency time frequency along with time;
and converting the information of the change of the one-dimensional radio frequency time frequency along with the time into a radio frequency signal frequency-time combined two-dimensional representation.
Optionally, after the amplified optical signal is cut by the pulse shears to obtain the optical pulse, the method further includes:
generating a radio frequency signal;
the radio frequency signal is used for carrying out phase modulation on the optical pulse, obtaining the secondary phase of the optical pulse in a time window, and carrying out pre-chirp processing on the optical pulse.
Optionally, mapping the optical signals of different frequency domains to a time domain with a distance Δ t;
Δt＝2πβ2Δf
wherein, beta2Is the second-order dispersion value of the dispersion compensation fiber, Δ f is the frequency difference of the optical signals of different frequency domains, and Δ t is the distance in the time domain.
Optionally, generating an optical frequency comb, comprising:
generating a laser beam;
carrying out phase modulation on the laser beam and generating a high-order sideband;
and flattening the high-order sideband to obtain the optical frequency comb.
Embodiments of the present invention also provide a computer program product containing instructions which, when run on a computer, cause the computer to perform any of the above-described all-optical short-time fourier transform methods.
The embodiment of the invention has the following beneficial effects:
the all-optical short-time Fourier transform system and the method provided by the embodiment of the invention can generate an optical frequency comb; receiving a radio frequency signal to be detected; adding communication information carried in a radio frequency signal to be detected into an optical frequency comb to obtain a modulated optical signal; extracting frequency components of the modulated optical signal, and mapping the frequency components onto a target free spectral range to obtain an optical signal with amplified bandwidth; cutting the amplified optical signal through a pulse scissor to obtain an optical pulse; carrying out phase modulation on the optical pulse to obtain a modulated optical pulse; modulating the modulated optical pulse into a dispersion medium for propagation to obtain the change of the frequency component of the input signal along with time on a time domain; the optical signal passing through the dispersion medium is converted into an electrical signal, and the converted electrical signal is obtained. Therefore, through electro-optical conversion of bandwidth amplification, the requirement on a dispersion value in dispersion Fourier transform is equivalently reduced, higher spectral analysis precision can be obtained by using limited dispersion, and a calculation result of short-time Fourier transform of an input signal is obtained.
Of course, not all of the advantages described above need to be achieved at the same time in the practice of any one product or method of the invention.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other embodiments can be obtained by using the drawings without creative efforts.
FIG. 1 is a first schematic diagram of an all-optical short-time Fourier transform system according to an embodiment of the present invention;
FIG. 2 is a second schematic diagram of an all-optical short-time Fourier transform system according to an embodiment of the present invention;
FIG. 3 is an analysis diagram of the testing result of the dual tone signal according to the embodiment of the present invention;
FIG. 4 is a third schematic diagram of an all-optical short-time Fourier transform system according to an embodiment of the present invention;
FIG. 5 is a schematic diagram of an optical frequency comb generator according to an embodiment of the present invention;
fig. 6 is a flowchart of an all-optical short-time fourier transform method according to an embodiment of the present application.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In a first aspect of the embodiments of the present invention, an all-optical short-time fourier transform system is provided, including:
an optical frequency comb generator for generating an optical frequency comb;
the intensity modulator is used for receiving the radio frequency signal to be detected; adding communication information carried in a radio frequency signal to be detected into an optical frequency comb to obtain a modulated optical signal;
the optical fiber Fabry-Perot interferometer is used for extracting frequency components of the modulated optical signals and mapping the frequency components to a target free spectral range to obtain optical signals with amplified bandwidth, wherein the target spectral range is larger than the free spectral range of the modulated optical signals;
the intensity modulator is used for cutting the amplified optical signal through the pulse scissors to obtain an optical pulse;
the phase modulator is used for carrying out phase modulation on the optical pulse to obtain a modulated optical pulse;
the dispersion compensation optical fiber is used for modulating the modulated optical pulse into a dispersion medium for propagation to obtain the change of the frequency component of the input signal along with time on a time domain;
and the photoelectric detector is used for converting the optical signal passing through the dispersion medium into an electric signal to obtain the converted electric signal.
Therefore, through the all-optical short-time Fourier transform system provided by the embodiment of the application, the requirement on a dispersion value in dispersion Fourier transform can be equivalently reduced through electro-optical conversion of bandwidth amplification, higher spectral analysis precision can be obtained by using limited dispersion, the calculation result of the short-time Fourier transform of an input signal is obtained, and the analysis speed of a radio frequency spectrum is improved.
Referring to fig. 1, fig. 1 is a first schematic diagram of an all-optical short-time fourier transform system according to an embodiment of the present invention, in which a dashed line represents an electrical signal and a solid line represents an optical signal, including:
an optical frequency comb generator 101 for generating an optical frequency comb.
Wherein the optical frequency comb may be a spectrum spectrally composed of a series of uniformly spaced frequency components with coherently stable phase relationships. The optical frequency comb generator may be any device that generates an optical frequency comb in the prior art, and the present application does not limit the present invention.
The intensity modulator 102 is used for receiving a radio frequency signal to be detected; and adding the communication information carried in the radio frequency signal to be measured into the optical frequency comb to obtain the modulated optical signal.
The radio frequency signal to be measured may be a modulated electrical signal with a certain transmission frequency, such as a television signal, a radar signal, and the like. The communication information carried in the radio frequency signal to be measured is added to the optical frequency comb, or the optical frequency comb is modulated according to the radio frequency signal to be measured, and the frequency component in the radio frequency signal to be measured is copied and added to the optical frequency comb to obtain a modulated optical signal.
And the fiber Fabry-Perot interferometer 103 is used for extracting frequency components of the modulated optical signal and mapping the frequency components to a target free spectral range to obtain an optical signal with amplified bandwidth.
In the actual use process, the target spectral range is far larger than the free spectral range of the modulated optical signal. By using the optical fiber Fabry-Perot interferometer with the free spectral range larger than that of the optical frequency comb, the frequency components copied from the radio frequency signals to the original optical frequency comb are extracted, so that the frequency spectrum components which are close to each other on the radio frequency domain can be greatly pulled on the optical domain, and the equivalent bandwidth amplification is realized.
The spectral components in the radiofrequency spectrum from the difference between the free spectral range of the optical frequency comb and the free spectral range of the fiber fabry-perot interferometer are amplified in the optical domain to the free spectral range of the fiber fabry-perot, i.e.:
where M is a multiple of bandwidth amplification, FSRVCFIs the free spectral range, FSR, of a fiber Fabry-Perot interferometerOFCIs the free spectral range of the optical frequency comb.
In practical use, the fiber fabry-perot interferometer may be a periodic optical filter. And copying the radio frequency signal to the frequency component in the original optical frequency comb to be aligned to the passband of the filter, thereby realizing the extraction of the specific radio frequency component.
And the intensity modulator 104 is used for cutting the optical signal with the amplified bandwidth by using pulse scissors to obtain an optical pulse.
The optical pulse may be an optical signal that is emitted intermittently at a certain time interval. In the actual use process, the pulse scissors can endow the intensity modulator with a continuous optical signal time window according to the pulse generator, so that the optical signal of only the time window can be conveniently processed.
The phase modulator 105 is configured to perform phase modulation on the optical pulse to obtain a modulated optical pulse.
Wherein, the optical pulse generated after passing through the pulse scissors is subjected to phase modulation, and the phase modulation signal is a radio frequency signal generated by a microwave source. The optical pulse is phase-modulated, and a secondary phase of the pulse light output by the time window can be obtained by a phase modulator modulated by a radio frequency signal, which is equivalent to a time lens. The pre-chirp of the optical signal can be realized through the acquired secondary phase, so that the pulse is prevented from being spread due to transmission in the dispersion compensation optical fiber.
And a dispersion compensation fiber 106 for obtaining a temporal change of a frequency component of the input signal in a time domain by modulating the modulated optical pulse into a dispersion medium for propagation.
By inputting the modulated optical pulse into the dispersion compensation fiber, the time delay of different frequency components in the optical signal in the dispersion medium is different, so that the separation of the different frequency components in the time domain can be realized after the optical signal passes through the dispersion compensation fiber. The different frequency components correspond to different positions of the pulse in the time domain, so that the change of the frequency components of the radio frequency signal along with time can be represented in the time domain, thereby realizing the frequency domain and time domain mapping of the optical signal and obtaining the change of the frequency components of the input signal along with time.
And a photodetector 107 for converting the optical signal passing through the dispersive medium into an electrical signal, and obtaining the converted electrical signal.
After the optical fiber is subjected to dispersion compensation, the spectral components of the mapped optical signals are all reflected on a time domain along with the change of time, the optical signals pass through a dispersion medium and are converted into electric signals, the waveform change of the electric signals is obtained, and therefore the short-time Fourier transform result of the input signals is obtained.
Therefore, through the all-optical short-time Fourier transform system provided by the embodiment of the application, the requirement on a dispersion value in dispersion Fourier transform can be equivalently reduced through electro-optical conversion of bandwidth amplification, higher spectrum analysis precision can be obtained by using limited dispersion, and a calculation result of the short-time Fourier transform of an input signal can be obtained.
Optionally, referring to fig. 2, the system further includes:
and the digital acquisition card 108 is used for extracting the communication information in the converted electric signals, obtaining the information of the one-dimensional radio frequency time frequency changing along with the time, and converting the information of the one-dimensional radio frequency time frequency changing along with the time into the combined two-dimensional representation of the radio frequency signal frequency-time.
The occurrence position of the pulse in each period can be acquired by a digital acquisition card, and the frequency component of the current frame signal is obtained. After the position information of the pulse in the signal is acquired by the data acquisition card, the pulses in different periods are stacked according to the time sequence, and the change of the frequency component of the signal along with the time, namely the short-time Fourier transform result of the input signal can be obtained.
When the experiment is performed by the method of the embodiment of the application, for example, when the bandwidth amplification factor is set to 165 times, the dispersion value of the dispersion compensation fiber is 2000ps/nm, the linear chirp signal with the bandwidth of 1.98GHz is input, and the duration is 125ns, the experiment is performed, and the all-optical short-time fourier transform with the bandwidth of 1.98GHz and the frame acquisition rate of 160MHz can be realized. When the two-tone signal with an input frequency of 60MHz apart was used to test the resolution of the system, the test results are shown in fig. 3. In the experiment, the two-tone signals with the frequencies of 1.59GHz and 1.65GHz can be clearly distinguished.
Optionally, referring to fig. 4, the system further includes:
a microwave source 109 for generating a radio frequency signal.
The phase modulator is specifically configured to perform phase modulation on the optical pulse through the radio frequency signal, acquire a secondary phase in a time window where the optical pulse is located, and perform pre-chirp processing on the optical pulse.
In the practical use process, the system may further include a pulse generator 110, the pulse generator 110 and the intensity modulator may equivalently form a pulse scissor, the microwave source and the phase modulator may equivalently form a time lens, and the pulse scissor, the time lens and the dispersive optical fiber may equivalently form a frequency domain-time domain mapping system.
The time window of the optical pulse is subjected to phase modulation through a radio frequency signal by a phase modulator; so that the optical pulse obtains a secondary phase, thereby completing the pre-chirp processing of the optical pulse. The pre-chirp process is equivalent to passing through a time lens, and pulse broadening can be avoided by offsetting chirp caused by dispersion through the time lens.
Optionally, the dispersion compensation fiber is specifically configured to map optical signals in different frequency domains to a time domain with a distance Δ t;
Δt＝2πβ2Δf
wherein, beta2Is the second-order dispersion value of the dispersion compensation fiber, Δ f is the frequency difference of the optical signals of different frequency domains, and Δ t is the distance in the time domain.
Through the bandwidth amplification of the dispersion compensation fiber, the frequency interval delta f of the input signal can be improved, thereby equivalently reducing the dispersion beta of the frequency domain-time domain mapping system2So that high resolution can also be achieved.
Alternatively, referring to fig. 5, the optical frequency comb generator includes:
and the laser generating module 501 is used for generating a laser beam.
And the secondary phase modulation module 502 is used for performing phase modulation on the laser beam and generating a high-order sideband.
And the intensity modulation module 503 is configured to flatten the high-order sideband to obtain the optical frequency comb.
The two-stage phase modulation module can comprise two phase modulators, and the frequency of microwaves on the phase modulators is twice as high as the frequency of microwaves on the intensity modulator. Cascaded phase modulators are used to generate high order sidebands, and intensity modulators are used to flatten each order sideband to generate an optical frequency comb.
In a second aspect of the embodiments of the present invention, an all-optical short-time fourier transform method is provided, see fig. 6, where fig. 6 is a flowchart of an all-optical short-time fourier transform method according to an embodiment of the present application, and includes:
in step S61, an optical frequency comb is generated.
And step S62, receiving the radio frequency signal to be tested.
And step S63, adding the communication information carried in the radio frequency signal to be measured into the optical frequency comb to obtain the modulated optical signal.
Step S64, extracting frequency components of the modulated optical signal, and mapping the frequency components onto a target free spectral range to obtain an optical signal with amplified bandwidth.
Wherein the target spectral range is larger than the free spectral range of the modulated optical signal.
In step S65, the amplified optical signal is cut by the pulse scissors to obtain an optical pulse.
In step S66, the optical pulse is phase-modulated to obtain a modulated optical pulse.
In step S67, the modulated optical pulse is modulated into a dispersion medium and propagated, thereby obtaining the temporal change of the frequency component of the input signal in the time domain.
In step S68, the photodetector is used to convert the optical signal passing through the dispersive medium into an electrical signal, and the converted electrical signal is obtained.
Optionally, the method further includes:
extracting communication information in the converted electric signal to obtain information of the change of the one-dimensional radio frequency time frequency along with time;
and converting the information of the change of the one-dimensional radio frequency time frequency along with the time into a radio frequency signal frequency-time combined two-dimensional representation.
Optionally, after the amplified optical signal is cut by the pulse shears to obtain the optical pulse, the method further includes:
generating a radio frequency signal;
the radio frequency signal is used for carrying out phase modulation on the optical pulse, obtaining the secondary phase of the optical pulse in a time window, and carrying out pre-chirp processing on the optical pulse.
Optionally, mapping the optical signals of different frequency domains to a time domain with a distance Δ t;
Δt＝2πβ2Δf
wherein, beta2Is the second-order dispersion value of the dispersion compensation fiber, Δ f is the frequency difference of the optical signals of different frequency domains, and Δ t is the distance in the time domain.
Optionally, generating an optical frequency comb, comprising:
generating a laser beam;
carrying out phase modulation on the laser beam and generating a high-order sideband;
and flattening the high-order sideband to obtain the optical frequency comb.
Therefore, by the all-optical short-time fourier transform method of the embodiment of the application, mapping from time-domain change of an optical signal frequency domain to a time domain can be realized after an optical pulse with amplified bandwidth is transmitted in a dispersion medium, so that a calculation result of the short-time fourier transform of a radio-frequency signal to be measured can be directly obtained, the analysis speed of frequency components can be improved, and meanwhile, the calculation result can be directly obtained on the optical signal due to the short-time fourier transform, so that the method is not limited by the digital signal processing capability and processing delay, and the analysis accuracy of the frequency components is improved.
In a further embodiment provided by the present invention, there is also provided a computer-readable storage medium having a computer program stored therein, which when executed by a processor implements any of the above-described all-optical short-time fourier transform methods.
In a further embodiment provided by the present invention, there is also provided a computer program product containing instructions which, when run on a computer, cause the computer to perform any of the above-described all-optical short-time fourier transform methods.
In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, cause the processes or functions described in accordance with the embodiments of the invention to occur, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, from one website site, computer, server, or data center to another website site, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device, such as a server, a data center, etc., that incorporates one or more of the available media. The usable medium may be a magnetic medium (e.g., floppy Disk, hard Disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., Solid State Disk (SSD)), among others.
It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
All the embodiments in the present specification are described in a related manner, and the same and similar parts among the embodiments may be referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, as for the method embodiment, since it is substantially similar to the system embodiment, the description is simple, and the relevant points can be referred to the partial description of the system embodiment.
The above description is only for the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention shall fall within the protection scope of the present invention.
Claims (10)
1. An all-optical short-time fourier transform system, comprising:
an optical frequency comb generator for generating an optical frequency comb;
the intensity modulator is used for receiving the radio frequency signal to be detected; adding communication information carried in the radio frequency signal to be detected into the optical frequency comb to obtain a modulated optical signal;
the optical fiber Fabry-Perot interferometer is used for extracting frequency components of the modulated optical signals and mapping the frequency components to a target free spectral range to obtain optical signals with amplified bandwidth, wherein the target spectral range is larger than the free spectral range of the modulated optical signals;
the intensity modulator is used for cutting the optical signal after the bandwidth amplification through pulse scissors to obtain optical pulses;
the phase modulator is used for carrying out phase modulation on the optical pulse to obtain a modulated optical pulse;
the dispersion compensation optical fiber is used for modulating the modulated optical pulse into a dispersion medium for propagation to obtain the change of the frequency component of the input signal along with time on a time domain;
and the photoelectric detector is used for converting the optical signal passing through the dispersion medium into an electric signal to obtain the converted electric signal.
2. The system of claim 1, further comprising:
and the digital acquisition card is used for extracting the communication information in the converted electric signals to obtain information of the time variation of the one-dimensional radio frequency time frequency along with the time, and converting the information of the time variation of the one-dimensional radio frequency time frequency along with the time into the frequency-time combined two-dimensional representation of the radio frequency signals.
3. The system of claim 1, further comprising:
a microwave source for generating a radio frequency signal;
the phase modulator is specifically configured to perform phase modulation on the optical pulse through the radio frequency signal, acquire a secondary phase within a time window of the optical pulse, and perform pre-chirp processing on the optical pulse.
4. The system of claim 1,
the dispersion compensation fiber is specifically used for mapping optical signals of different frequency domains to a time domain with a distance delta t;
Δt＝2πβ2Δf
wherein, beta2Is the second-order dispersion value of the dispersion compensation fiber, and Δ f is the frequency difference of the optical signals in different frequency domains.
5. The system of claim 1, wherein the optical-frequency comb generator comprises:
the laser generating module is used for generating laser beams;
the secondary phase modulation module is used for carrying out phase modulation on the laser beam and generating a high-order sideband;
and the intensity modulation module is used for flattening the high-order sideband to obtain the optical frequency comb.
6. An all-optical short-time Fourier transform method, comprising:
generating an optical frequency comb;
receiving a radio frequency signal to be detected;
adding communication information carried in the radio frequency signal to be detected into the optical frequency comb to obtain a modulated optical signal;
extracting frequency components of the modulated optical signal, and mapping the frequency components onto a target free spectral range to obtain an optical signal with amplified bandwidth, wherein the target spectral range is larger than the free spectral range of the modulated optical signal;
cutting the optical signal after the bandwidth amplification by using a pulse scissor to obtain an optical pulse;
performing phase modulation on the optical pulse to obtain a modulated optical pulse;
modulating the modulated optical pulse into a dispersion medium for propagation to obtain the change of the frequency component of the input signal along with time on a time domain;
and converting the optical signal passing through the dispersion medium into an electric signal by using a photoelectric detector to obtain the converted electric signal.
7. The method of claim 6, further comprising:
extracting communication information in the converted electric signal to obtain information of the change of the one-dimensional radio frequency time frequency along with time;
and converting the information of the one-dimensional radio frequency time frequency changing along with the time into a radio frequency signal frequency-time combined two-dimensional representation.
8. The method of claim 6, wherein after said cutting of said amplified optical signal by pulsed scissors resulting in optical pulses, said method further comprises:
generating a radio frequency signal;
and performing phase modulation on the optical pulse through the radio frequency signal to obtain a secondary phase in a time window of the optical pulse, and performing pre-chirp processing on the optical pulse.
9. The method of claim 6,
mapping optical signals of different frequency domains to a time domain with a distance delta t;
Δt＝2πβ2Δf
wherein, beta2Is the second-order dispersion value of the dispersion compensation fiber, and Δ f is the frequency difference of the optical signals in different frequency domains.
10. A computer-readable storage medium, characterized in that a computer program is stored in the computer-readable storage medium, which computer program, when being executed by a processor, carries out the method steps of any of the claims 6-9.
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113610942A (en) * | 2021-06-11 | 2021-11-05 | 枫树谷(成都)科技有限责任公司 | Pulse waveform segmentation method, system, equipment and storage medium |
| CN113900316A (en) * | 2021-10-12 | 2022-01-07 | 浙江工业大学 | High-performance electrical sampling system and method based on time lens |
| CN114024611A (en) * | 2021-11-19 | 2022-02-08 | 华中科技大学 | Optical signal real-time vector analysis method and device with detection bandwidth larger than 1THz |
| CN114614907A (en) * | 2020-12-08 | 2022-06-10 | 军事科学院系统工程研究院网络信息研究所 | Microwave waveform compiling method based on optical domain inverse Fourier transform |
| CN114978303A (en) * | 2022-04-18 | 2022-08-30 | 北京邮电大学 | Optical fractional order Fourier transform method, system and signal receiver |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005195751A (en) * | 2004-01-05 | 2005-07-21 | Japan Science & Technology Agency | Optical fourier transformation device and method |
| CN106253980A (en) * | 2016-09-14 | 2016-12-21 | 华中科技大学 | A kind of ultrafast radio spectrum measuring method and system |
| CN107659361A (en) * | 2017-11-06 | 2018-02-02 | 北京邮电大学 | A kind of microwave signal process system and method |
-
2020
- 2020-07-21 CN CN202010702852.0A patent/CN111966960B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005195751A (en) * | 2004-01-05 | 2005-07-21 | Japan Science & Technology Agency | Optical fourier transformation device and method |
| CN106253980A (en) * | 2016-09-14 | 2016-12-21 | 华中科技大学 | A kind of ultrafast radio spectrum measuring method and system |
| CN107659361A (en) * | 2017-11-06 | 2018-02-02 | 北京邮电大学 | A kind of microwave signal process system and method |
Non-Patent Citations (4)
| Title |
|---|
| 蔺军涛: "基于光频梳与光学傅里叶变换的高频电磁波频率检测", 《中国优秀硕士学位论文全文数据库 工程科技Ⅱ辑》 * |
| 蔺军涛: "基于光频梳与光学傅里叶变换的高频电磁波频率检测", 《中国优秀硕士学位论文全文数据库 工程科技Ⅱ辑》, 15 January 2018 (2018-01-15), pages 3 - 4 * |
| 郑彦: "基于带宽放大的实时傅里叶变换技术研究", 《中国优秀硕士学位论文全文数据库 工程科技Ⅱ辑》 * |
| 郑彦: "基于带宽放大的实时傅里叶变换技术研究", 《中国优秀硕士学位论文全文数据库 工程科技Ⅱ辑》, 15 August 2019 (2019-08-15), pages 3 - 4 * |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114614907A (en) * | 2020-12-08 | 2022-06-10 | 军事科学院系统工程研究院网络信息研究所 | Microwave waveform compiling method based on optical domain inverse Fourier transform |
| CN114614907B (en) * | 2020-12-08 | 2024-03-12 | 军事科学院系统工程研究院网络信息研究所 | Microwave waveform compiling method based on optical domain inverse Fourier transform |
| CN113610942A (en) * | 2021-06-11 | 2021-11-05 | 枫树谷(成都)科技有限责任公司 | Pulse waveform segmentation method, system, equipment and storage medium |
| CN113610942B (en) * | 2021-06-11 | 2023-07-25 | 枫树谷(成都)科技有限责任公司 | Pulse waveform segmentation method, system, equipment and storage medium |
| CN113900316A (en) * | 2021-10-12 | 2022-01-07 | 浙江工业大学 | High-performance electrical sampling system and method based on time lens |
| CN114024611A (en) * | 2021-11-19 | 2022-02-08 | 华中科技大学 | Optical signal real-time vector analysis method and device with detection bandwidth larger than 1THz |
| CN114024611B (en) * | 2021-11-19 | 2023-02-28 | 华中科技大学 | Method and device for real-time vector analysis of optical signal with detection bandwidth larger than 1THz |
| CN114978303A (en) * | 2022-04-18 | 2022-08-30 | 北京邮电大学 | Optical fractional order Fourier transform method, system and signal receiver |
| CN114978303B (en) * | 2022-04-18 | 2023-08-01 | 北京邮电大学 | Optical fractional Fourier transform method, system and signal receiver |
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