CN113589236B - Double-chirp waveform signal generator based on photoelectric oscillation loop structure - Google Patents
Double-chirp waveform signal generator based on photoelectric oscillation loop structure Download PDFInfo
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- G—PHYSICS
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- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
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- G—PHYSICS
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- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
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- G01S13/06—Systems determining position data of a target
- G01S13/08—Systems for measuring distance only
- G01S13/32—Systems for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated
- G01S13/34—Systems for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated using transmission of continuous, frequency-modulated waves while heterodyning the received signal, or a signal derived therefrom, with a locally-generated signal related to the contemporaneously transmitted signal
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Abstract
A double-chirp waveform signal generator based on stimulated Brillouin scattering effect and photoelectric oscillation loop structure belongs to the technical field of microwave photonics. The device consists of a first laser, a first optical coupler, an optical phase modulator, an optical isolator, a high nonlinear optical fiber, an optical circulator, an erbium-doped optical fiber amplifier, a first optical filter, a second optical coupler, a photoelectric detector, a radio frequency amplifier, a radio frequency power divider, a low-pass filter, a second laser, a Mach-Zehnder modulator, a second optical filter, an arbitrary waveform generator and a direct current stabilized power supply. According to the invention, the photoelectric oscillator based on the stimulated Brillouin scattering effect generates a single-sideband modulation signal with the modulation sideband equal to the optical carrier power, and the single-sideband modulation signal and the sweep laser are mixed to generate a double-chirp waveform signal, and the generated double-chirp signal has smaller harmonic components; the bandwidth and period of the dual chirp signal can be adjusted by adjusting the bandwidth and period of the single chirp signal generated by the arbitrary waveform generator.
Description
Technical Field
The invention belongs to the technical field of microwave photonics, and particularly relates to a double-chirp waveform signal generator based on stimulated Brillouin scattering effect and a photoelectric oscillation loop structure.
Background
With the development of wireless communication and detection technologies, radar technology has been widely used in various aspects of the military and civilian fields. In radar technology, radar waveforms are an important part for determining the performance of a radar system, and in various radar waveforms, double chirp signals can provide a larger detection range and higher range resolution for the radar system, and meanwhile, can reduce range-Doppler coupling and improve the range-Doppler resolution of the radar system; in addition, the double chirp signal can also reduce power fading during signal transmission. Therefore, the generation of the double-chirp waveform signal has important significance for improving the performance of the radar system and has important practical value. Dan Zhu et al use a dual drive mach-zehnder modulator to mix the fundamental frequency signal with the chirp signal and then filter out the clutter component by a high pass filter to obtain a dual chirp signal. The center frequency of the double chirp signal generated by the structure is 6GHz, and the bandwidth can reach 2GHz (Dan Zhu, jianping Yao, dual-Chirp Microwave Waveform Generation Using a Dual-Parallel Mach-Zehnder Modulator, IEEE photon. Technology. Lett., vol.27, no.13, pp.1410-1413, jul.2015).
Disclosure of Invention
The invention aims to provide a large-bandwidth double-chirp waveform signal generator based on stimulated Brillouin scattering effect and a photoelectric oscillation loop structure.
The structure of the double-chirp waveform signal generator is shown in figure 1, and the double-chirp waveform signal generator consists of a first laser, a first optical coupler, an optical phase modulator, an optical isolator, a high-nonlinearity optical fiber, an optical circulator, an erbium-doped optical fiber amplifier, a first optical filter, a second optical coupler, a photoelectric detector, a radio frequency amplifier, a radio frequency power divider, a low-pass filter, a second laser, a Mach-Zehnder modulator, a second optical filter, an arbitrary waveform generator and a direct-current stabilized power supply; the first laser, the first optical coupler, the optical phase modulator, the optical isolator, the high nonlinear optical fiber, the optical circulator, the erbium-doped optical fiber amplifier, the first optical filter, the second optical coupler, the photoelectric detector, the radio frequency amplifier, the radio frequency power divider and the low-pass filter form a photoelectric oscillation loop.
The output frequency of the first laser is f c Is divided into two branches by a first optical coupler, wherein the optical signal of one branch enters an erbium-doped fiber amplifier and is marked as a first branch 101; the optical signal of the other branch enters the optical phase modulator as an optical carrier, denoted as a second branch 201; after the optical signal of the first branch 101 is subjected to power amplification through an erbium-doped optical fiber amplifier, the optical signal enters into a high-nonlinearity optical fiber through a 1 port of an optical circulator and is used as pump light of stimulated Brillouin scattering effect; the optical carrier of the second branch 201 is modulated by the output signal from the radio frequency power divider, whichThe output signal of the amplifier initially comes from the noise floor of the rf amplifier, and the spectrum of the optical signal after phase modulation is shown in fig. 2 (1), where the phase modulation forms modulation sidebands with equal power on both sides of the optical carrier. The modulated optical signal enters the high-nonlinearity optical fiber after passing through the optical isolator, the optical isolator does not change the frequency of the optical signal, and has small optical loss for forward transmission optical signals and large loss for reverse input light, so that the optical isolator can block the propagation of reverse optical signals. When the frequency f input by the port of the circulator 1 c When the pump light reaching power reaches the Brillouin threshold of the high-nonlinearity optical fiber, stimulated Brillouin scattering effect occurs in the high-nonlinearity optical fiber, and the stimulated Brillouin scattering effect generates a gain spectrum and a loss spectrum, as shown by a curve in FIG. 2 (2); the gain spectrum appears in the down-conversion region of the pump light, the loss spectrum appears in the up-conversion region of the pump light, and the difference between the center frequencies of the gain spectrum and the loss spectrum and the frequency of the pump light is defined as Brillouin frequency shift f b The method comprises the steps of carrying out a first treatment on the surface of the After the stimulated Brillouin scattering effect, the lower sideband of the optical phase modulation signal is amplified, the upper sideband is suppressed, and the power balance relation of the sidebands of the phase modulation signal is broken; the stimulated brillouin scattering effect gain spectrum and loss spectrum have good narrow-band characteristics, can be used for frequency selection of a photoelectric oscillator, and only frequency components meeting the requirement that the open-loop gain is greater than 1 can form stable oscillation in the oscillator loop in the photoelectric oscillation loop, so when the system reaches a stable state, only frequency components in the brillouin gain spectrum can be selected to form stable oscillation, other frequency components cannot form stable oscillation in the photoelectric oscillation loop because of insufficient loop gain, a spectrum diagram in stable oscillation is shown in fig. 2 (3), and frequency components in the gain spectrum generate stable modulation sidebands and other noise components are restrained in the photoelectric oscillation loop; because the power of the radio frequency modulation signal is smaller and the modulation depth is lower in the invention, the power of the high-order sidebands is smaller and can be ignored, thus in theoryOnly positive and negative first-order sidebands are considered in analysis, the left-side sideband of the optical carrier is marked as a negative first-order sideband, and the right-side sideband of the optical carrier is marked as a positive first-order sideband. In addition, the gain of the stimulated Brillouin scattering effect is related to the power of the pump light, the power of the pump light in the stimulated Brillouin scattering effect can be set by adjusting the gain of the 101-branch erbium-doped optical fiber amplifier, so that the Brillouin gain of the stimulated Brillouin scattering effect is adjusted, the power of the 101-branch, which is injected into the high-nonlinearity optical fiber through the port 1 of the optical circulator, is reasonably set, the power of the negative first-order sideband of the optical signal of the 201-branch after the stimulated Brillouin scattering effect is equal to the optical carrier power, and the two opposite-direction chirped radio frequency components have the same power when the double-chirp signal is generated later; the optical modulation signal subjected to stimulated Brillouin scattering is output to a first optical filter from a 3 port of a circulator; the first optical filter is a bandpass filter, and the passband is between the optical carrier and the negative first-order sideband, as shown in the curve in fig. 3; the first optical filter is used for filtering out optical frequency components except the optical carrier and the negative first-order sidebands, and simultaneously suppressing spontaneous radiation noise generated by stimulated brillouin scattering to a certain extent, and the spectrum diagram after filtering is shown in fig. 3. At the same time, the second laser emits a laser beam with the same frequency as f c Is input to the mach-zehnder modulator as a third leg, denoted as leg 301; the DC stabilized power supply is used for providing DC bias voltage for the Mach-Zehnder modulator, and the voltage value of the DC bias voltage is set as V π Operating the Mach-Zehnder modulator in a double sideband modulation state of optical carrier rejection, where V π Is the half-wave voltage of the Mach-Zehnder modulator; the arbitrary waveform generator is used for sending out a single chirped fundamental frequency modulation signal f chirp As a radio frequency modulation signal of the Mach-Zehnder modulator, the spectrum of the optical signal modulated by the Mach-Zehnder modulator is shown in FIG. 4 (1), and the influence of the high-order sidebands is ignored because the power of the high-order sidebands is small, the frequencies of the two first-order sidebands are f c ±f chirp Each modulation sideband is a linearly chirped swept-frequency optical sideband, the sweep bandwidth and sweep period of each modulation sideband and the single chirp generated by the arbitrary waveform generatorThe sweep bandwidth and the sweep period of the signal are the same; the second optical filter is used for selecting modulation sidebands of the down-conversion and suppressing other spectral components, so that a swept optical signal output is obtained as shown in fig. 4 (2); the sweep frequency optical signal output by the second optical filter is marked as f FS As can be seen from FIG. 4 (2), f FS ＝f c -f chirp The method comprises the steps of carrying out a first treatment on the surface of the The output signal of the second optical filter is coupled with the output signal of the first optical filter in the second optical coupler to form a signal, the spectrum diagram of the combined optical signal is shown in fig. 5 (1), and the combined optical signal has three spectral components, which are respectively optical carrier wave f c Negative first-order sideband f of optical phase modulation signal c -f b And swept optical signal f FS The method comprises the steps of carrying out a first treatment on the surface of the The output light of the second optical coupler is sent to a photoelectric detector for beat frequency, the photoelectric detector outputs the difference frequency of each spectrum component, and the spectrum components of the radio frequency signals generated after photoelectric conversion of the photoelectric detector are shown in fig. 5 (2); the generated frequency spectrum component of the radio frequency signal has three components, namely a fixed frequency component and two chirp components f 1 、f 2 The method comprises the steps of carrying out a first treatment on the surface of the Wherein the fixed frequency component is an optical carrier wave f from the first optical filter c And negative first-order side band f c -f b The radio frequency component generated by beat frequency has the frequency equal to the brillouin frequency shift f b The method comprises the steps of carrying out a first treatment on the surface of the Swept optical signal f output by the second optocoupler FS Respectively with the optical carrier wave f from the first optical filter c And a negative first-order sideband f c -f b The beat frequency generates two chirp components f with opposite chirp directions 1 、f 2 Two chirp components f 1 、f 2 The frequency of (2) can be expressed as:
as can be seen from the formula, the two chirp components have opposite frequency chirp directions, and the sweep bandwidth is determined by the bandwidth of the swept optical signal; the radio frequency signal output by the photoelectric detector is divided into two paths of electric signals with equal power by the radio frequency power divider after being amplified by radio frequency, one path of electric signal is fed back to the optical phase modulator to form a closed loop, which is recorded as a branch 401, when the gain of the radio frequency amplifier is large enough to enable the open loop gain of the photoelectric oscillator loop to be larger than 1, the radio frequency signal shown in the figure 5 (2) forms stable oscillation in the photoelectric oscillator loop, and when the system reaches a stable state, the two output ports of the radio frequency power divider can continuously output the radio frequency signal shown in the figure 5 (2) with certain power; the other path of electric signal is taken as an output signal of the system and is input into a low-pass filter and is marked as a branch circuit 501; the cut-off frequency of the low-pass filter is set between the highest frequency of the chirp signal and the brillouin frequency shift, and is used for filtering the fixed frequency component in the radio frequency signal, so as to obtain a double-chirp waveform signal, and the output of the low-pass filter is shown in fig. 5 (3).
The device of the invention is characterized in that:
(1) The photoelectric oscillator based on the stimulated Brillouin scattering effect generates a single-sideband modulation signal with the modulation sidebands equal to the optical carrier power, and the single-sideband modulation signal and the sweep laser are mixed to generate a double-chirp waveform signal, and the generated double-chirp signal has smaller harmonic components.
(2) The bandwidth and period of the dual chirp signal can be adjusted by adjusting the bandwidth and period of the single chirp signal generated by the arbitrary waveform generator.
(3) The system can generate double chirp signals only by one sweep frequency signal source, simplifies the system structure and omits the time synchronization process in a multi-sweep frequency source system.
Drawings
Fig. 1: a double-chirp signal generator structure schematic diagram based on an optoelectronic oscillation structure;
fig. 2: stimulated brillouin scattering effect to obtain a spectrum schematic diagram of the signal;
fig. 3: a spectrum schematic diagram of the signal is obtained after the signal passes through a first optical filter;
fig. 4: a spectrum schematic diagram of the signal is obtained after passing through a second optical filter;
fig. 5: a double chirp signal generation process schematic;
fig. 6: a time-frequency diagram of the double chirp signals with different bandwidths generated by the double chirp signal generator;
fig. 7: a time-frequency diagram of the double chirp signals of different periods generated by the double chirp signal generator;
fig. 8: an autocorrelation function curve of the generated double chirp signal.
Detailed Description
Example 1:
the first laser is a TSL-510 tunable laser of Santec company with a frequency of 193.4145THz, and the second laser is a TSL-550 tunable laser of Santec company with a frequency of 193.4145THz; the optical phase modulator is MPZ-LN-40 of Photoine company, the bandwidth is 38GHz, and the half-wave voltage is 6.5V; ext> theext> photoelectricext> detectorext> isext> KGext> -ext> PDext> -ext> 50ext> Gext> -ext> Aext> -ext> FCext> ofext> Beijingext> Kangguanext> corporationext>,ext> theext> bandwidthext> isext> 50ext> GHzext>,ext> andext> theext> conversionext> rateext> isext> 0.55ext> Aext> /ext> Wext>;ext> The optical isolator is PISO-SA-1550 in the United kingdom Phoenix photonics, and the isolation is more than 40dB; the high-nonlinearity optical fiber is produced by a long-flying optical fiber cable company, and has a Brillouin gain linewidth of Γ B =30 MHz, brillouin frequency shift f b = 9.387GHz. The Mach-Zehnder modulator is MXAN-LN-20 of Photoine company, and the bandwidth is 20GHz; the arbitrary waveform generator is M8196A of Keysight corporation, and the bandwidth is 25GHz. The first optical filter and the second optical filter are both XTM-50 optical filters of EXFO company, the central frequency tuning range is 1450nm-1650nm, and the bandwidth tuning range is 50pm-950pm. The RF amplifier is MWLA-010265G27 of full-wave electronic technology Co., ltd, the signal gain is 27dB, and the saturated output power is 18dBm. The radio frequency power divider is an AV81311 power divider produced by forty-first research institute of China electronics and technology group, the frequency range is 0-26.5GHz, and the power ratio is 50:50; the voltage tunable range of the direct current stabilized power supply is 0-30V. The erbium-doped fiber amplifier was an EDFA-ILA from the Mai company with a maximum output power of 17dBm. The first optocoupler coupling ratio is 20:80, wherein the 101 branch is divided into 20% of optical power, and the 201 branch is divided into 80% of optical power. The coupling ratio of the second optocoupler is 50:50; the test equipment of the output signal is an MSOV254A oscilloscope of Keysight company.
The corresponding test apparatus was connected according to FIG. 1, the wavelength of the first and second lasers was set at 1550nm, i.e. frequency f c = 193.4145THz, the first laser output power is 10mW, the second laser output powerThe rate is 15mW; the output power of the erbium-doped fiber amplifier is set to be 14.25mW; the passband of the first optical filter is set to 193.4000 THz-193.4165 THz, and the passband of the second optical filter is set to 193.4053 THz-193.4130 THz; the output voltage of the direct current stabilized power supply is 6.5V, and the cutoff frequency of the low-pass filter is set to be 8GHz. The single chirp signal generated by the arbitrary waveform generator has a center frequency of 4.6GHz, a period of 5.28 mus, and bandwidths of 1GHz,3GHz,5GHz, and 7GHz, respectively (corresponding to fig. 6 (1), 6 (2), 6 (3), and 6 (4), respectively). After the generated double-chirp signal is sampled by an oscilloscope, the sampled time domain waveform data is subjected to short-time Fourier transform to obtain a time-frequency diagram of the signal, which is shown in fig. 6.
The period of the dual chirp signal generated by the system can be changed by changing the period of the single chirp signal generated by the arbitrary waveform generator. The center frequency of the monocycle signal generated by the arbitrary waveform generator is set to 4.6GHz, the bandwidth is set to 3GHz, the period is set to 2.64 mu s and 1.32 mu s (corresponding to fig. 7 (1) and 7 (2) respectively), the generated double-chirp signal is sampled by an oscilloscope, and the time-frequency diagram of the sampled time-domain waveform data is obtained by performing short-time Fourier transform, as shown in fig. 7.
The pulse compression performance of the double chirp signal can be obtained by calculating the autocorrelation function of the generated signal, and fig. 8 is an image of the autocorrelation function of the double chirp signal generated by the system with a center frequency of 4.6GHz, a bandwidth of 3GHz, and a period of 5.28 mus. Fig. 8 (1) ranges from 1000ns, fig. 8 (2) ranges from 30ns, the autocorrelation bandwidth of the signal is 1.45ns, and the sidelobe suppression ratio is 5.2dB.
Claims (5)
1. A double-chirp waveform signal generator based on stimulated Brillouin scattering effect and photoelectric oscillation loop structure is characterized in that:
(1) The device consists of a first laser, a first optical coupler, an optical phase modulator, an optical isolator, a high nonlinear optical fiber, an optical circulator, an erbium-doped optical fiber amplifier, a first optical filter, a second optical coupler, a photoelectric detector, a radio frequency amplifier, a radio frequency power divider, a low-pass filter, a second laser, a Mach-Zehnder modulator, a second optical filter, an arbitrary waveform generator and a direct current stabilized power supply; the first laser, the first optical coupler, the optical phase modulator, the optical isolator, the high nonlinear optical fiber, the optical circulator, the erbium-doped optical fiber amplifier, the first optical filter, the second optical coupler, the photoelectric detector, the radio frequency amplifier, the radio frequency power divider and the low-pass filter form a photoelectric oscillation loop;
(2) The output frequency of the first laser is f c Is divided into two branches by a first optical coupler, wherein the optical signal of one branch enters an erbium-doped fiber amplifier and is marked as a first branch 101; the optical signal of the other branch enters the optical phase modulator as an optical carrier, denoted as a second branch 201; after the optical signal of the first branch 101 is subjected to power amplification through an erbium-doped optical fiber amplifier, the optical signal enters into a high-nonlinearity optical fiber through a 1 port of an optical circulator and is used as pump light of stimulated Brillouin scattering effect; the optical carrier of the second branch 201 is modulated by the output signal from the radio frequency power divider, the phase modulation forms modulation sidebands with equal power on two sides of the optical carrier, and the modulated optical signal enters the high nonlinear optical fiber after passing through the optical isolator; when the frequency f input by the port of the circulator 1 c When the pump light reaching power reaches the Brillouin threshold value of the high-nonlinearity optical fiber, stimulated Brillouin scattering effect occurs in the high-nonlinearity optical fiber, and the stimulated Brillouin scattering effect generates gain spectrum and loss spectrum; the gain spectrum appears in the down-conversion region of the pump light, the loss spectrum appears in the up-conversion region of the pump light, and the difference between the center frequencies of the gain spectrum and the loss spectrum and the frequency of the pump light is defined as Brillouin frequency shift f b The method comprises the steps of carrying out a first treatment on the surface of the After the stimulated Brillouin scattering effect, the lower sideband of the optical phase modulation signal is amplified, the upper sideband is suppressed, and the optical modulation signal after the stimulated Brillouin scattering is output to the first optical filter from the 3 port of the circulator; the first optical filter is a band-pass filter, and the passband is between the optical carrier and the negative first-order sideband;
(3) The second laser emits a laser beam with the same frequency f c Is input to the mach-zehnder modulator as a third leg, denoted as leg 301; the Mach-Zehnder modulator works in a double-sideband modulation state of optical carrier suppression; the arbitrary waveform generator being used to emit a single And the baseband modulation signal f cHirp As the radio frequency modulation signal of the Mach-Zehnder modulator, the influence of the high-order sidebands is ignored, and the frequencies of the two first-order sidebands are f c ±f cHirp Each modulation sideband is a linearly chirped sweep-frequency optical sideband, and the sweep-frequency bandwidth and the sweep-frequency period of each modulation sideband are the same as those of a single chirp signal generated by an arbitrary waveform generator;
(4) The second optical filter selects the modulation sideband of the down-conversion, suppresses other spectral components, and marks the sweep frequency optical signal output by the second optical filter as f FS ＝f c -f cHirp The method comprises the steps of carrying out a first treatment on the surface of the The output signal of the second optical filter is coupled with the output signal of the first optical filter in the second optical coupler to form a signal, and the combined optical signal has three spectral components, namely optical carrier f c Negative first-order sideband f of optical phase modulation signal c -f b And swept optical signal f FS The method comprises the steps of carrying out a first treatment on the surface of the The output light of the second optical coupler is sent to a photoelectric detector for beat frequency, the photoelectric detector outputs the difference frequency of each spectrum component, and the generated radio frequency signal spectrum component has three components, namely a fixed frequency component and two chirp components f 1 、f 2； wherein ,
(5) The radio frequency signal output by the photoelectric detector is divided into two paths of electric signals with equal power by the radio frequency power divider after being amplified by radio frequency, and one path of electric signal is fed back to the optical phase modulator to form a closed loop, which is marked as a branch 401; when the gain of the radio frequency amplifier is large enough to enable the open loop gain of the photoelectric oscillator loop to be larger than 1, the radio frequency signal forms stable oscillation in the photoelectric oscillator loop, and when the system reaches a stable state, the two output ports of the radio frequency power divider can continuously output the radio frequency signal with certain power; the other path of electric signal is taken as an output signal of the system and is input into a low-pass filter and is marked as a branch circuit 501; the cut-off frequency of the low-pass filter is set between the highest frequency of the chirp signal and the brillouin frequency shift, and is used for filtering out the fixed frequency component in the radio frequency signal, so as to obtain the double-chirp waveform signal.
2. The dual chirp waveform signal generator as set forth in claim 1, which is based on stimulated brillouin scattering effect and a photo-electric oscillation loop structure, wherein: the output signal of the radio frequency power divider initially comes from the noise floor of the radio frequency amplifier.
3. The dual chirp waveform signal generator as set forth in claim 1, which is based on stimulated brillouin scattering effect and a photo-electric oscillation loop structure, wherein: the first laser is a tunable laser with the frequency of 193.40THz; the second laser is a tunable laser, and the frequency of the laser is 193.40THz; the bandwidth of the optical phase modulator is 38GHz, and the half-wave voltage is 6.5V; the bandwidth of the photoelectric detector is 50GHz, and the conversion rate is 0.55A/W; the isolation of the optical isolator is more than 40dB; brillouin gain linewidth of high nonlinear optical fiber is gamma B =30 MHz, brillouin frequency shift f b = 9.387GHz; the bandwidth of the Mach-Zehnder modulator is 20GHz, the bandwidth of the arbitrary waveform generator is 25GHz, the central frequency tuning range of the first optical filter and the second optical filter is 1450nm-1650nm, and the bandwidth tuning range is 50pm-950 pm; the signal gain of the radio frequency amplifier is 27dB, and the saturated output power is 18dBm; the frequency range of the radio frequency power divider is 0-26.5GHz, and the power ratio is 50:50; the voltage tunable range of the direct current stabilized power supply is 0-30V; the maximum output power of the erbium-doped fiber amplifier is 17dBm, and the coupling ratio of the first optical coupler is 20:80, wherein the 101 branch circuit obtains 20% of optical power, and the 201 branch circuit obtains 80% of optical power; the coupling ratio of the second optocoupler is 50:50; the test equipment of the output signal is an oscilloscope.
4. A dual chirp waveform signal generator as defined in claim 3 based on stimulated brillouin scattering effect and a photo-electric oscillation loop structure, characterized in that: the wavelength of the first laser and the second laser is 1550nm, namely the frequency f c = 193.4145THz, the first laser output power is 10mW and the second laser output power is 15mW; erbium doped fiber amplifierThe output power was set to 14.25mW; the passband of the first optical filter is set to 193.4000 THz-193.4165 THz, and the passband of the second optical filter is set to 193.4053 THz-193.4130 THz; the output voltage of the direct current stabilized power supply is 6.5V; the cut-off frequency of the low-pass filter is set to 8GHz; the center frequency of a single chirp signal generated by the random waveform generator is 4.6GHz, the period is 5.28 mu s, the bandwidths are respectively set to be 1GHz,3GHz,5GHz and 7GHz, the generated double chirp signal is sampled by an oscilloscope, and the sampled time domain waveform data is subjected to short-time Fourier transform to obtain a time-frequency diagram of the signal.
5. The dual chirp waveform signal generator as defined in claim 4 which is based on stimulated brillouin scattering effect and an opto-electronic oscillation loop structure, wherein: the center frequency of a single-period signal generated by an arbitrary waveform generator is set to be 4.6GHz, the bandwidth is set to be 3GHz, the period is set to be 2.64 mu s and 1.32 mu s, the generated double-chirp signal is sampled by an oscilloscope, and the sampled time domain waveform data is subjected to short-time Fourier transform to obtain a time-frequency diagram of the signal.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103123285A (en) * | 2013-02-05 | 2013-05-29 | 太原理工大学 | Distributed optical fiber sensing device based on chaotic laser coherence method, and measurement method of distributed optical fiber sensing device |
| CN110132331A (en) * | 2019-05-22 | 2019-08-16 | 电子科技大学 | A kind of COTDR measurement method and its system extracted based on sub- chirped pulse |
| CN111092659A (en) * | 2019-11-29 | 2020-05-01 | 电子科技大学 | Double-chirp signal generation system based on stimulated Brillouin scattering |
| CN111307054A (en) * | 2020-02-29 | 2020-06-19 | 太原理工大学 | High-precision dynamic strain monitoring device and method based on time-delay-free chaotic laser |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| US6907052B2 (en) * | 2003-02-19 | 2005-06-14 | The Aerospace Corporation | Tunable optical local oscillator |
-
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103123285A (en) * | 2013-02-05 | 2013-05-29 | 太原理工大学 | Distributed optical fiber sensing device based on chaotic laser coherence method, and measurement method of distributed optical fiber sensing device |
| CN110132331A (en) * | 2019-05-22 | 2019-08-16 | 电子科技大学 | A kind of COTDR measurement method and its system extracted based on sub- chirped pulse |
| CN111092659A (en) * | 2019-11-29 | 2020-05-01 | 电子科技大学 | Double-chirp signal generation system based on stimulated Brillouin scattering |
| CN111307054A (en) * | 2020-02-29 | 2020-06-19 | 太原理工大学 | High-precision dynamic strain monitoring device and method based on time-delay-free chaotic laser |
Non-Patent Citations (2)
| Title |
|---|
| Weinan Zhou et al..High-speed frequency-hopping signal generator with a stimulated Brillouin scattering-based optelectronic ocsillator.Optical Engineering.2020,全文. * |
| 冉阳 ; 王小林 ; 粟荣涛 ; 周朴 ; 司磊 ; .窄线宽光纤放大器中受激布里渊散射抑制研究进展.激光与光电子学进展.2015,(04),全文. * |
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