Ultrafast optical fiber smart sensing and processing system

Abstract

The present disclosure provides an ultrafast optical fiber intelligent sensing processing system, wherein the optical fiber sensing layer is used for outputting laser of a narrow linewidth laser through an optical coupler to obtain corresponding first and second optical signals through upper and lower branches respectively, and injecting the first and second optical signals into a sensing optical fiber; the optoelectronic sensing interface is connected with the optical fiber sensing layer, and is used for mapping the first and second optical signals obtained through the sensing optical fiber from time sequence distribution to spatial distribution to obtain an analog optical signal; and the optical computing layer is connected with the optoelectronic sensing interface, and is used for performing optical computing on the analog optical signal through an integrated photonic chip to obtain corresponding sensing information. The present disclosure can realize a great improvement in demodulation speed, complete dimension reduction of optical domain signals to greatly reduce the bandwidth and sampling rate pressure of the rear-end electrical processor, effectively improve the system limit frequency response, and meet the demand of real-time processing of a large number of sensing signals.

Description

Technical Field

[0001] This disclosure relates to the intersection of optoelectronic intelligent computing and distributed fiber optic sensing, and in particular to an ultrafast fiber optic intelligent sensing and processing system. Background Technology

[0002] With the rapid development of economy and technology, the scale of large-scale infrastructure construction continues to expand, and the technological level has significantly improved. Therefore, how to build a robust sensor network to ensure the long-term safe and stable operation of critical infrastructure has become an urgent problem to be solved. Among these technologies, Brillouin distributed fiber optic sensing, with its low loss and high gain from stimulated Brillouin scattering, is emerging as a revolutionary technology for long-distance sensing, showing great application potential in areas such as Earth activity detection and structural health monitoring of large-scale infrastructure.

[0003] With ongoing research, significant breakthroughs have been achieved in the performance of Brillouin distributed fiber optic sensing systems. Currently, centimeter-level spatial resolution can be achieved over sensing distances of hundreds of kilometers, and a single fiber can enable the dense deployment of millions of effective sensing points. However, faced with the resulting massive amounts of high-bandwidth sensing signals, existing electronically based data processing units, limited by their operating mechanisms and physical bandwidth, suffer from severely lagging demodulation speeds. This causes the high-speed advantage of the measurement system to be completely negated by the lengthy data processing, making it unable to effectively capture and diagnose high-speed dynamic changes in infrastructure during practical applications. Therefore, current distributed Brillouin fiber optic sensing systems are generally limited by the small physical bandwidth and low data processing efficiency of their data post-processing units, making it difficult to meet the demands of real-time processing of large volumes of sensing signals. Summary of the Invention

[0004] This disclosure aims to at least partially address one of the technical problems in the related art.

[0005] Therefore, the first objective of this disclosure is to propose an ultrafast fiber optic intelligent sensing and processing system. Through a fiber optic sensing layer, an optoelectronic sensing interface, and an optical computing layer, the demodulation process of high-speed sensing signals is converted from the electrical digital domain to the optical analog domain. This significantly improves demodulation speed while simultaneously reducing the optical domain signal dimensionality, thereby greatly reducing the bandwidth and sampling rate pressure on the backend electronic processor. This effectively improves the system's maximum frequency response and meets the real-time processing requirements of large volumes of sensing signals. Furthermore, the optoelectronic sensing interface and optical computing layer can significantly suppress computational errors caused by adverse factors, thus exhibiting ultra-high robustness and long-term stability.

[0006] To achieve the above objectives, a first aspect of this disclosure proposes an ultrafast fiber optic intelligent sensing and processing system, the system comprising a fiber optic sensing layer, a photoelectric sensing interface, and an optical computing layer, wherein...

[0007] The optical fiber sensing layer is used to obtain the corresponding first optical signal and second optical signal from the laser output by the narrow linewidth laser through the upper branch and the lower branch respectively via the optical coupler, and to inject the first optical signal and the second optical signal into the sensing optical fiber.

[0008] The photoelectric sensing interface is connected to the optical fiber sensing layer and is used to map the first optical signal and the second optical signal obtained through the sensing optical fiber from the temporal distribution to the spatial distribution to obtain the analog optical signal.

[0009] The optical computing layer is connected to the photoelectric sensing interface and is used to perform optical calculations on the analog optical signal through an integrated photonic chip to obtain the corresponding sensing information.

[0010] Optionally, the fiber optic sensing layer includes a light source and signal distribution unit, a pump pulse light emitting unit, a frequency-hopping continuous probe light emitting unit, and a sensing fiber; the step of obtaining corresponding first and second optical signals from the laser output of the narrow linewidth laser through an optical coupler via an upper branch and a lower branch, respectively, and injecting the first and second optical signals into the sensing fiber, includes:

[0011] The light source and signal distribution unit divides the light source into pump light and probe light according to a preset coupling ratio;

[0012] The pump pulse light emitting unit is connected to the light source and signal distribution unit, and processes the pump light through the upper branch to obtain the first optical signal;

[0013] The frequency-hopping continuous probe light emitting unit is connected to the light source and signal distribution unit, and processes the probe light through the lower branch to obtain the second optical signal;

[0014] The sensing optical fiber is connected to the pump pulse light emitting unit and the frequency hopping continuous probe light emitting unit to acquire the first optical signal and the second optical signal.

[0015] Optionally, the pump pulse light emitting unit includes a semiconductor optical amplifier, a function generator, a pulsed erbium-doped fiber amplifier, and a fiber circulator; the step of processing the pump light through the upper branch to obtain a first optical signal includes:

[0016] The pump light passes sequentially through the semiconductor optical amplifier driven by the function generator, the pulsed erbium-doped fiber amplifier, and the fiber circulator to obtain the first optical signal.

[0017] Optionally, the frequency-hopping continuous probe light emitting unit includes a microwave source, a first DC source, a first Mach-Zehnder modulator, a waveform generator, a second DC source, a low-noise amplifier, a second Mach-Zehnder modulator, a first fiber detacher, a first polarization controller, a second polarization controller, a polarization combiner, a first erbium-doped fiber amplifier, a first optical bandpass filter, and an optical fiber isolator; the step of processing the probe light through the lower branch to obtain a second optical signal includes:

[0018] The probe light sequentially passes through a first Mach-Zehnder modulator driven by a microwave source and a first DC source, a second Mach-Zehnder modulator driven by a second DC source, a waveform generator, and a low-noise amplifier, and an orthogonal polarization light generator composed of a first fiber optic disconnector, a first polarization controller, a second polarization controller, and a polarization combiner to adjust the upper and lower sidebands to orthogonal polarization states to obtain orthogonal polarization frequency-hopping light.

[0019] The orthogonally polarized frequency-hopping light passes through the first erbium-doped fiber amplifier and the first optical bandpass filter, and then through the fiber isolator to obtain the second optical signal.

[0020] Optionally, the photoelectric sensing interface includes a frequency-modulated light source, a photoelectric-to-optical conversion module, and an optical buffer module; the step of mapping the first optical signal and the second optical signal obtained through the sensing optical fiber from a temporal distribution to a spatial distribution to obtain an analog optical signal includes:

[0021] The optical-to-electric-to-optical conversion module performs optical-to-electric-to-optical conversion on the first optical signal and the second optical signal obtained through the sensing optical fiber to obtain a third optical signal;

[0022] The optical buffer module maps the third optical signal and the frequency-hopping optical signal generated by the frequency-modulated light source from a temporal distribution to a spatial distribution to obtain an analog optical signal.

[0023] Optionally, the optical-to-electrical-to-optical conversion module includes a second fiber optic ionizer, a balanced detector, and a low-noise amplifier; the optical-to-electrical-to-optical conversion of the first optical signal and the second optical signal obtained through the sensing fiber to obtain a third optical signal includes:

[0024] The first optical signal and the second optical signal obtained through the sensing optical fiber are separated into upper and lower sidebands by the second optical fiber walk-off device and then enter the balanced detector to switch to the electrical domain to obtain an electrical sensing signal.

[0025] The electrical sensing signal is passed through the low-noise amplifier to obtain the third optical signal.

[0026] Optionally, the optical buffer module includes a third DC source, a third Mach-Zehnder modulator, a second erbium-doped fiber amplifier, and an optical buffer unit; the step of mapping the third optical signal and the frequency-hopping optical signal generated by the frequency-modulated light source from a temporal distribution to a spatial distribution to obtain an analog optical signal includes:

[0027] The third optical signal and the frequency-hopping optical signal generated by the frequency-modulated light source are passed through the third Mach-Zehnder modulator driven by the third DC source to obtain a sensing signal.

[0028] The sensing signal is sequentially mapped from a temporal distribution to a spatial distribution through the second erbium-doped fiber amplifier and the optical buffer unit to obtain an analog optical signal.

[0029] Optionally, the optical computing layer includes an integrated photonic chip and a second optical bandpass filter; the step of performing optical computing on the analog optical signal through the integrated photonic chip to obtain corresponding sensing information includes:

[0030] The integrated photonic chip and the second optical bandpass filter are used to perform optical calculations and extract sensing information from the analog optical signal to obtain the state information of objects along the optical fiber.

[0031] Optionally, the integrated photonic chip is an integrated photonic chip with an asymmetric spatial topology.

[0032] Optionally, the system further includes a photodetector and an oscilloscope; the sensing information is sequentially passed through the photodetector and the oscilloscope to obtain the corresponding digital waveform.

[0033] In summary, the ultrafast fiber optic intelligent sensing and processing system provided in this disclosure includes a fiber optic sensing layer, an optoelectronic sensing interface, and an optical computing layer. The fiber optic sensing layer is used to obtain a first optical signal and a second optical signal from the laser output of a narrow-linewidth laser via an optical coupler through an upper branch and a lower branch, respectively, and then injects the first and second optical signals into the sensing fiber. The optoelectronic sensing interface, connected to the fiber optic sensing layer, is used to map the first and second optical signals obtained through the sensing fiber from a temporal distribution to a spatial distribution, obtaining an analog optical signal. The optical computing layer, connected to the optoelectronic sensing interface, is used to perform optical calculations on the analog optical signal using an integrated photonic chip to obtain the corresponding sensing information. This disclosure, through the fiber optic sensing layer, optoelectronic sensing interface, and optical computing layer, converts the demodulation process of high-speed sensing signals from the electrical digital domain to the optical analog domain. This significantly improves the demodulation speed while simultaneously reducing the dimensionality of the optical domain signal, thereby greatly reducing the bandwidth and sampling rate pressure on the back-end electronic processor. This effectively improves the system's limiting frequency response and meets the needs of real-time processing of large amounts of sensing signals. Meanwhile, the photoelectric sensing interface and optical computing layer can significantly suppress calculation errors caused by adverse factors, thus exhibiting ultra-high robustness and long-term stability.

[0034] Additional aspects and advantages of this disclosure will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this disclosure. Attached Figure Description

[0035] The above and / or additional aspects and advantages of this disclosure will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, in which:

[0036] Figure 1 This is a schematic diagram of the structure of an ultrafast fiber optic intelligent sensing and processing system provided in an embodiment of the present disclosure;

[0037] Figure 2 This is a schematic diagram of the structure of an ultrafast fiber optic intelligent sensing and processing system provided in an embodiment of the present disclosure;

[0038] Figure 3 This is a schematic diagram of an optical buffer unit provided in an embodiment of the present disclosure;

[0039] Figure 4 A layout of an integrated photonic chip provided in an embodiment of this disclosure;

[0040] Figure 5 This is a schematic flowchart illustrating real-time calculation of frequency-hopping sensor optical signals provided in an embodiment of this disclosure.

[0041] Figure 6 This is a schematic diagram comparing the computational efficiency of partially coherent optical computation and coherent optical computation, provided in an embodiment of this disclosure.

[0042] Figure 7 This is a schematic diagram illustrating a real-time calculation result and network output result provided in an embodiment of this disclosure.

[0043] Explanation of reference numerals in the attached figures:

[0044] 1-Tunable narrow linewidth laser; 2-Optical coupler; 3-Semiconductor optical amplifier; 4-Function generator; 5-Pulsed erbium-doped fiber amplifier; 6-Fiber circulator; 7-Sensing fiber; 8-First Mach-Zehnder modulator; 9-Microwave source; 10-First DC source; 11-Second Mach-Zehnder modulator; 12-Second DC source; 13-Waveform generator; 14-Low noise amplifier; 15-First fiber detacher; 16-First polarization controller; 17-Second polarization controller; 8-Polarization combiner; 19-First erbium-doped fiber amplifier; 20-First optical bandpass filter; 21-Fiber isolator; 22-Second fiber detacher; 23-Balanced detector; 24-Low-noise amplifier; 25-Third DC source; 26-Third Mach-Zehnder modulator; 27-Frequency hopping light source; 28-Second erbium-doped fiber amplifier; 29-1-to-12 polarization-maintaining fiber coupler; 30-Integrated photonic chip; 31-Second optical bandpass filter; 32-Photodetector; 33-Oscilloscope. Detailed Implementation

[0045] Embodiments of this disclosure are described in detail below. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this disclosure, and should not be construed as limiting this disclosure.

[0046] In related technologies, neural networks and hardware acceleration methods (such as GPUs) can significantly accelerate the signal demodulation process. However, the demodulation time for a single gain spectrum is still on the order of μs, and the overall demodulation speed is on the order of Hz (i.e., demodulating all gain spectra along the fiber). This is 2-3 orders of magnitude slower than the current fiber optic sensing systems, which have single-gain spectrum measurement times on the order of nanoseconds and overall measurement speeds on the order of kHz (i.e., measuring all gain spectra along the fiber). Therefore, the time required for signal demodulation essentially negates the system's measurement speed advantage, preventing the sensing system from detecting high-speed dynamic physical quantities in practical applications.

[0047] In one embodiment of this disclosure, the following technical problems still need to be solved to achieve real-time processing of high-speed, high-bandwidth sensor signals: 1) Due to the limitations of electronic processor operation and physical bandwidth, the demodulation time of a single gain spectrum (in μs) is 2-3 orders of magnitude longer than the measurement time (in ns). The mismatch between demodulation and measurement times negates the measurement speed advantage brought by the fast gain spectrum measurement method, and the BOTDA response speed is still limited by the data post-processing process; 2) Currently, gain spectrum measurement and demodulation are independent of each other (sensing / computing separation). The sensor signal needs to undergo analog-to-digital conversion, data transmission, buffering, and other processes before it can be demodulated, all of which introduce additional time consumption; 3) The entire data post-processing process is carried out under redundant sampling data, and the large data volume further exacerbates the difficulty of real-time signal processing and hardware costs. Therefore, to achieve real-time high-speed BOTDA, it is necessary to significantly reduce the data volume while eliminating the gain spectrum demodulation time, thereby shortening the single gain spectrum processing time to the ns level.

[0048] The ultrafast fiber optic intelligent sensing and processing system of this disclosure will be described in detail below with reference to specific embodiments.

[0049] Figure 1 This disclosure provides an ultrafast fiber optic intelligent sensing and processing system as an embodiment. For example... Figure 1 As shown, this ultrafast fiber optic intelligent sensing and processing system can include a fiber optic sensing layer, a photoelectric sensing interface, and an optical computing layer.

[0050] The fiber optic sensing layer is used to obtain the first and second optical signals respectively by passing the laser output from the narrow linewidth laser through the upper and lower branches via optical couplers, and then inject the first and second optical signals into the sensing fiber.

[0051] The photoelectric sensing interface is connected to the fiber optic sensing layer and is used to map the first and second optical signals obtained through the sensing fiber from the temporal distribution to the spatial distribution to obtain the analog optical signal.

[0052] The optical computing layer is connected to the photoelectric sensing interface and is used to perform optical calculations on analog optical signals through integrated photonic chips to obtain corresponding sensing information.

[0053] In one embodiment of this disclosure, the aforementioned optical fiber sensing layer is used for long-distance optical fiber status detection.

[0054] In one embodiment of this disclosure, the fiber optic sensing layer includes a light source and signal distribution unit, a pump pulse light emitting unit, a frequency-hopping continuous probe light emitting unit, and a sensing fiber.

[0055] In one embodiment of this disclosure, the method of obtaining corresponding first and second optical signals by passing the laser output from a narrow linewidth laser through an upper branch and a lower branch respectively via an optical coupler, and injecting the first and second optical signals into a sensing fiber, may include the following steps:

[0056] Step 1: The light source and signal distribution unit divides the light source into pump light and probe light according to the preset coupling ratio.

[0057] In one embodiment of this disclosure, Figure 2 An ultrafast fiber optic intelligent sensing and processing system is proposed in the embodiments of this disclosure, such as... Figure 2 As shown, the above-mentioned light source and signal distribution unit includes a tunable narrow linewidth laser 1 and an optical coupler 2.

[0058] In one embodiment of this disclosure, the laser output from the tunable narrow linewidth laser 1 is divided into an upper branch and a lower branch by an optical coupler 2 according to a preset coupling ratio, wherein the upper branch is used for pump light and the lower branch is used for probe light.

[0059] In one embodiment of this disclosure, the preset coupling ratio of the fiber optic coupler 2 can be 20:80.

[0060] Furthermore, in one embodiment of this disclosure, the tunable narrow linewidth laser 1 outputs a laser with a center wavelength of 1549.232 nm and a power of 13 dBm, which is split into two paths by an optical coupler 2 according to a preset coupling ratio of 20:80.

[0061] Step 2: Connect the pump pulse light emitting unit to the light source and signal distribution unit, and process the pump light through the upper branch to obtain the first optical signal.

[0062] In one embodiment of this disclosure, such as Figure 2 As shown, the pump pulse light emitting unit includes a semiconductor optical amplifier 3, a function generator 4, a pulsed erbium-doped fiber amplifier 5, and a fiber optic circulator 6. In one embodiment of this disclosure, the method of processing the pump light through the upper branch to obtain a first optical signal may include: the pump light sequentially passes through the semiconductor optical amplifier 3, the pulsed erbium-doped fiber amplifier 5, and the fiber optic circulator 6 driven by the arbitrary function generator 4 to obtain the first optical signal.

[0063] In one embodiment of this disclosure, the semiconductor optical amplifier 3 is driven by an arbitrary function generator 4 with a pulse width of 40 nanoseconds.

[0064] In one embodiment of this disclosure, in the upper branch, a continuous optical signal accounting for 20% of the total emitted laser energy first enters a semiconductor optical amplifier 3 driven by an arbitrary function generator 4 and is modulated into a single pulse with a pulse width of 40 nanoseconds. Subsequently, the optical pulse signal is amplified by a pulsed erbium-doped fiber amplifier 5 and then passes through a circulator 6 to obtain the first optical signal, wherein the pulse peak power is approximately 25 dBm.

[0065] Step 3: The frequency-hopping continuous probe light emitting unit is connected to the light source and signal distribution unit, and the probe light is processed through the lower branch to obtain the second optical signal.

[0066] In one embodiment of this disclosure, such as Figure 2 As shown, the frequency-hopping continuous probe optical emission unit includes a microwave source 9, a first DC source 10, a first Mach-Zehnder modulator 8, a waveform generator 13, a second DC source 12, a low-noise amplifier 14, a second Mach-Zehnder modulator 11, a first fiber optic detacher 15, a first polarization controller 16, a second polarization controller 17, a polarization combiner 18, a first erbium-doped fiber amplifier 19, a first optical bandpass filter 20, and an optical fiber isolator 21.

[0067] In one embodiment of this disclosure, the method of processing the probe light through the lower branch to obtain the second optical signal may include: the probe light sequentially passes through a first Mach-Zehnder modulator 8 driven by a microwave source 9 and a first DC source 10, a second Mach-Zehnder modulator 11 driven by a second DC source 12, a waveform generator 13, and a low-noise amplifier 14, and an orthogonal polarization light generator composed of a first fiber optic disconnector 15, a first polarization controller 16, a second polarization controller 17, and a polarization combiner 18 to adjust the upper and lower sidebands to orthogonal polarization states to obtain orthogonal polarization frequency-hopping light; the orthogonal polarization frequency-hopping light passes through a first erbium-doped fiber amplifier 19 and a first optical bandpass filter 20, and then through an optical fiber isolator 21 to obtain the second optical signal.

[0068] In one embodiment of this disclosure, the first Mach-Zehnder modulator 8 is driven by a microwave source 9 and a first DC source 10, and the voltage of the first DC source 10 is controlled to make the first Mach-Zehnder modulator 8 operate in a carrier-suppressed double-sideband modulation mode.

[0069] In one embodiment of this disclosure, the second Mach-Zehnder modulator 11 is driven by an arbitrary waveform generator 13 and a second DC source 12, and the voltage of the second DC source 12 is controlled to make the second Mach-Zehnder modulator 11 operate in a carrier-suppressed double-sideband modulation mode.

[0070] In one embodiment of this disclosure, the first fiber optic walk-off unit 15, the first polarization controller 16, the second polarization controller 17, and the polarization combiner 18 together constitute a frequency division multiplexing orthogonal polarization probe light generation module.

[0071] In one embodiment of this disclosure, in the lower branch, the probe light, which accounts for 80% of the total emitted laser energy, is modulated into a frequency-hopping optical signal by a first Mach-Zehnder modulator 8 and a second Mach-Zehnder modulator 11. The microwave source driving the first Mach-Zehnder modulator 8 outputs a microwave signal with a center frequency of 9.3 GHz, and the arbitrary waveform generator driving the second Mach-Zehnder modulator outputs a continuous frequency-hopping electrical signal with a frequency range of 1 GHz to 2 GHz, a frequency interval of 50 MHz, and a frequency hopping period of 40 ns.

[0072] Step 4: Connect the sensing fiber to the pump pulse light emitting unit and the frequency hopping continuous probe light emitting unit to acquire the first optical signal and the second optical signal.

[0073] In one embodiment of this disclosure, the sensing fiber is a panda-type polarization-maintaining fiber. Also, in one embodiment of this disclosure, the sensing fiber can be a 1km long panda-type polarization-maintaining fiber.

[0074] In one embodiment of this disclosure, in order to achieve real-time measurement and demodulation of the fiber state in the fiber sensing layer, it is necessary to convert the Brillouin gain spectrum from the frequency domain to the time domain. The method used is based on stimulated Brillouin scattering of frequency-hopping probe light and pulse pump light.

[0075] In one embodiment of this disclosure, the frequency-hopping probe light period is 40 ns, the frequency-hopping interval is 40 MHz, and the frequency-hopping range is 1 GHz. The pump light pulse width is 30 ns.

[0076] In one embodiment of this disclosure, when the frequency-hopping probe light and the pulsed pump light meet at a certain position in the optical fiber, stimulated Brillouin scattering will occur at the position where the frequency shift of the two light rays is closest to the Brillouin frequency shift. This allows the gain spectrum to be directly displayed in the time domain, thus enabling the optical signal to be buffered by an optical fiber delay line array. This solves the problem of traditional frequency sweeping methods requiring long-term buffering of gain curves, laying the foundation for optical chips to process real-time sensing signals and forming an all-optical "sensing-storage-computing" integrated system. Specifically, after the frequency-hopping probe light and the single-frequency pulsed pump light interact in the optical fiber, they enter the receiving end, which consists of an optoelectronic sensing interface and an optical computing layer.

[0077] In one embodiment of this disclosure, the Brillouin sensing signal arriving at the photoelectric sensing interface carries strong background light (low effective sensing signal contrast), which reduces the computational efficiency of the optical neural network. Simultaneously, the optical delay array used for time-space conversion of the sensing signal amplifies environmental disturbances (such as temperature fluctuations, airflow, etc.) and the effects of laser temperature drift and phase noise on the relative phase of the input signal to the optical chip, thereby introducing noise and computational errors. Furthermore, the optical chip itself has a certain insertion loss, which affects the strength of the input signal. Therefore, to ensure accurate and efficient demodulation of the sensing signal by the optical chip, a photoelectric sensing interface needs to be set up between the sensing system and the optical chip to perform real-time preprocessing of the sensing signal, addressing issues such as strong background light, weak effective signal, weak robustness, and signal attenuation caused by optical chip insertion loss.

[0078] In one embodiment of this disclosure, the photoelectric sensing interface includes a frequency-modulated light source, a photoelectric-to-optical conversion module, and an optical buffer unit. In another embodiment of this disclosure, the method for mapping the first and second optical signals obtained through the sensing optical fiber from a temporal distribution to a spatial distribution to obtain an analog optical signal may include the following steps:

[0079] Step a: The optical-to-electrical-to-optical conversion module performs optical-to-electrical-to-optical conversion on the first and second optical signals obtained through the sensing optical fiber to obtain the third optical signal.

[0080] In one embodiment of this disclosure, such as Figure 2 As shown, the above-mentioned optical-electrical-optical conversion module may include a second fiber optic disconnector 22, a balanced detector 23, and a low-noise amplifier 24.

[0081] In one embodiment of this disclosure, the method of performing optical-to-electrical-to-optical conversion on the first and second optical signals obtained through the sensing optical fiber to obtain the third optical signal may include: separating the upper and lower sidebands of the first and second optical signals obtained through the sensing optical fiber through the second optical fiber walk-off device 22 and then switching them to the electrical domain through the balanced detector 23 to obtain an electrical sensing signal; the electrical sensing signal is then passed through the low-noise amplifier 24 to obtain the third optical signal.

[0082] In one embodiment of this disclosure, a second optical signal carrying the Stokes and anti-Stokes components of the probe light in the photoelectric sensing interface, which carries the Brillouin gain spectrum and loss spectrum, is separated by a second fiber optic walk-off device 22 and enters a balanced detector 23.

[0083] In one embodiment of this disclosure, the balanced detector 23 can not only effectively eliminate strong DC background light in the sensing signal to ensure computational efficiency, but also enhance the sensing signal by up to 3dB, thereby improving computational accuracy.

[0084] Step b: The optical buffer module maps the third optical signal and the frequency-hopping optical signal generated by the frequency-modulated light source from the temporal distribution to the spatial distribution to obtain the analog optical signal.

[0085] In one embodiment of this disclosure, the optical buffer module includes a third DC source 25, a third Mach-Zehnder modulator 26, a second erbium-doped fiber amplifier 28, and an optical buffer unit 29.

[0086] In one embodiment of this disclosure, the method of mapping the third optical signal and the frequency-hopping optical signal generated by the frequency-modulated light source from a temporal distribution to a spatial distribution to obtain an analog optical signal may include: passing the third optical signal and the frequency-hopping optical signal generated by the frequency-modulated light source 27 through a third Mach-Zehnder modulator 26 driven by a third DC source 25 to obtain a sensing signal; and sequentially passing the sensing signal through a second erbium-doped fiber amplifier 28 and an optical buffer unit 29 to map the temporal distribution to a spatial distribution to obtain an analog optical signal.

[0087] In one embodiment of this disclosure, the sensing electrical signal is amplified by the second erbium-doped fiber amplifier 24 and then drives the third Mach-Zehnder modulator 26 to bring the sensing signal back into the optical domain.

[0088] In one embodiment of this disclosure, the voltage of the third DC source 25 is controlled to enable the third Mach-Zehnder modulator 26 to operate in carrier rejection mode to ensure computational efficiency.

[0089] In one embodiment of this disclosure, the frequency-hopping light source 27 outputs a frequency-hopping continuous laser with a frequency range of 0.8 GHz to 3.2 GHz, a frequency hopping interval of 240 MHz, and a frequency hopping period of 10 ns (less than the signal period of 40 ns) and injects it into a third Mach-Zehnder modulator 26 to generate a frequency-hopping sensing optical signal.

[0090] In one embodiment of this disclosure, the optical buffer unit 29 is composed of a 1 / 12 polarization-maintaining fiber beam splitter and a polarization-maintaining fiber delay line array (e.g., Figure 3 As shown, the polarization-maintaining fiber delay line array consists of 10 polarization-maintaining fibers of equal length, with a length difference of 0.8 meters between adjacent fibers, corresponding to a signal delay of 4 ns.

[0091] In one embodiment of this disclosure, after the frequency-hopping optical signal passes through the optical buffer unit 29, the sensing signal (i.e., the Brillouin gain spectrum) is mapped from a temporal distribution to a spatial distribution, thereby enabling the optical neural network to identify the input Brillouin gain spectrum.

[0092] In one embodiment of this disclosure, since the period of the frequency-hopping light generated by the frequency-hopping light source 27 is less than the delay of the optical buffer unit 29, the optical signal entering each port of the optical neural network has 10 different frequencies, so that each signal interacts with the optical neural network separately and is superimposed on the baseband signal during photoelectric detection, thereby avoiding calculation errors caused by optical phase fluctuations and ensuring calculation accuracy.

[0093] In one embodiment of this disclosure, the frequency-hopping sensing optical signal passes through a second erbium-doped fiber amplifier 28 before entering the optical beam splitter 29 to further increase its energy in order to cope with the insertion loss of the optical buffer unit 29 and the integrated photonic chip 30, thereby ensuring the signal-to-noise ratio and measurement accuracy of the output signal.

[0094] In one embodiment of this disclosure, the aforementioned photoelectric sensing interface can effectively enhance the sensing signal strength of the feed light computing chip while eliminating the signal background light, thereby increasing its robustness to chip insertion loss.

[0095] In one embodiment of this disclosure, the optical buffer module maps the simulated optical signal from a temporal arrangement to a spatial arrangement before it enters the optical computing layer. In another embodiment, the use of frequency-hopping lasers allows the optical signals injected into each input port of the optical chip to have different carrier frequencies, thereby enabling partially coherent optical computation on-chip.

[0096] Specifically, in one embodiment of this disclosure, each input signal interacts with the chip independently to achieve optical computing, while interference between adjacent input signals is prevented. This completely eliminates random fluctuations caused by environmental disturbances, laser temperature drift, phase noise, etc., ensuring computational accuracy. It should be noted that in one embodiment of this disclosure, some coherent optical computing may result in a loss of network connectivity, potentially reducing network performance.

[0097] In one embodiment of this disclosure, such as Figure 2 As shown, the optical computing layer includes an integrated photonic chip 30 and a second optical bandpass filter 31. In one embodiment of this disclosure, the method for performing optical calculations on analog optical signals using the integrated photonic chip to obtain corresponding sensing information may include: performing optical calculations and extracting sensing information from the analog optical signals using the integrated photonic chip 30 and the second optical bandpass filter 31 to obtain the state information of objects along the optical fiber.

[0098] In one embodiment of this disclosure, based on the input-output characteristics of the Brillouin sensor signal demodulation task, Figure 4 This is a layout of an integrated photonic chip proposed in an embodiment of this disclosure, such as... Figure 4 As shown, the integrated photonic chip is an integrated photonic chip with an asymmetric spatial topology.

[0099] In one embodiment of this disclosure, the integrated photonic chip 30 is an integrated photonic chip composed of a Mach-Zehnder interferometer array, forming a cone-shaped network from input to output. The network parameters can be reconstructed by adjusting the bias voltage of each Mach-Zehnder interferometer through an external multi-channel voltage source.

[0100] Specifically, in one embodiment of this disclosure, the integrated photonic chip has an input dimension of 10 (Brillouin gain spectrum) and an output dimension of 1 (Brillouin frequency domain). The network has 7 columns of Mach-Zehnder interferometers, with each column containing [5, 4, 5, 4, 3, 2, 1] Mach-Zehnder interferometers, thus forming a conical network from the input to the output direction.

[0101] In one embodiment of this disclosure, under the current Brillouin sensing signal demodulation task, the lightweight asymmetric spatial topology structure integrating photonic chips can achieve the same computational accuracy as the traditional symmetric spatial topology structure, while reducing the total number of Mach-Zehnder interferometers in the network by nearly half. In one embodiment of this disclosure, the significant reduction in the complexity of the optical chip will significantly improve its robustness to adverse factors such as process errors, ambient temperature fluctuations, and bias voltage fluctuations, further improving computational accuracy. Furthermore, by integrating photonic chips through this asymmetric spatial topology, the signal dimension and data volume fed into the next-stage electronic processor can be compressed by a factor of 10, which will effectively alleviate the bandwidth and computational pressure on the electronic processor, further improving the real-time performance of the sensing system.

[0102] In one embodiment of this disclosure, the aforementioned asymmetric spatial topology integrated photonic chip can achieve data dimensionality reduction while demodulating sensing signals at high speed, effectively alleviating the pressure on subsequent electrical computing in terms of acquisition bandwidth, signal buffering, transmission and processing, and further improving the real-time performance of the system.

[0103] In one embodiment of this disclosure, the partially coherent optical computing method proposed in the above-mentioned asymmetric spatial topology integrated photonic chip can effectively improve the robustness of the optical chip to environmental disturbances (including temperature fluctuations, airflow, vibration, etc.) and laser defects (including temperature drift, phase noise, etc.), and achieve ultra-high robustness and ultra-high precision optical computing.

[0104] In one embodiment of this disclosure, the frequency division multiplexing input light scheme based on frequency hopping laser and fiber delay array can realize partially coherent optical computation with a single laser and a single intensity modulator, thereby avoiding the use of complex multi-wavelength lasers, intensity modulator arrays, RF line delay arrays and low-noise amplifier arrays, etc., which greatly reduces the system size, weight, complexity and cost, and has high feasibility and practicality.

[0105] Figure 5 This is a schematic diagram illustrating a process for real-time calculation of frequency-hopping sensor optical signals according to an embodiment of this disclosure. Figure 5As shown, the specific process for real-time calculation of frequency-hopping sensor optical signals can include two processes: time-space domain mapping of sensor signals and signal feature extraction and recognition.

[0106] In one embodiment of this disclosure, traditional optical neural networks based on Mach-Zehnder interferometer arrays rely on coherent optical computation using highly coherent light sources. However, in this disclosure, due to the need for optical buffers to achieve spatiotemporal mapping of the sensing signals, coherent optical computation is highly susceptible to environmental perturbations and laser defects, making stable signal processing impossible. To completely solve this problem, this invention proposes a photonic integrated chip based on an asymmetric spatial topology of a Mach-Zehnder interferometer array and a partially coherent optical computation method. Specifically, in one embodiment of this disclosure, the computational efficiency difference between partially coherent optical computation and coherent optical computation will be theoretically compared under the current task (Brillouin gain spectrum identification). It should be noted that the theoretical simulation assumes that coherent optical computation operates under ideal conditions without phase fluctuations to compare the theoretical performance difference between the two, but in reality, coherent optical computation will fail due to random phase fluctuations.

[0107] In one embodiment of this disclosure, the ultrafast fiber optic intelligent sensing and processing system further includes a photodetector 32 and an oscilloscope 33; sensing information is obtained through the above steps, and the sensing information is sequentially passed through the photodetector and the oscilloscope to obtain the corresponding digital waveform.

[0108] Figure 6 This diagram illustrates a comparison of computational efficiency between partially coherent optical computation and coherent optical computation, based on an embodiment of this disclosure. Figure 6 a shows the sensing signals input to the optical neural network model. Figure 6 b demonstrates the network output where the weights trained under coherent light computing are directly used for partial coherent light computing, such as... Figure 6 As shown in b, the network output under partial coherent optical computation exhibited a nonlinear amplitude-frequency relationship. However, after further fine-tuning the network parameters through Monte Carlo optimization, the network output regained a linear amplitude-frequency relationship. Furthermore, Figure 6 c shows the network output results for coherent and partially coherent optical computation under multiple measurements. Figure 6 d shows the standard deviation values ​​(representing stability) at various frequency points. The results show that partially coherent optical computation has similar computational accuracy to coherent optical computation, with the accuracy being only 0.48 dB lower. Based on this, their computational performance is almost identical.

[0109] Furthermore, experiments verified the long-term stability and linearity of the network output of this disclosure. Figure 7 This is a schematic diagram illustrating a real-time calculation result and network output result proposed in an embodiment of this disclosure. Figure 7The diagram (a) shows, from top to bottom, the real-time calculation results of 1000 measurement signals under coherent optical computation, partially coherent optical computation (frequency hopping period = signal period), and partially coherent optical computation with secondary subdivision frequency hopping (frequency hopping period = 0.5 times the signal period). It can be seen that the output waveform of coherent optical computation changes randomly throughout the 1000 measurements. Based on this, coherent optical computation completely fails due to environmental perturbations and laser defects. Furthermore, when the frequency hopping period equals the signal period, partially coherent optical computation still exhibits certain instability. This is because the actual refractive index of the delay fiber is not consistent with the theoretical refractive index of 1.46. The difference in refractive index leads to a difference in delay, resulting in interference between the ten input beams of the input optical neural network. However, by setting the frequency hopping period to half the signal period, the interference problem is completely resolved, and the results of the 1000 calculations almost overlap. Based on this, the proposed partially coherent optical computation scheme has high robustness to environmental perturbations and laser defects. Further... Figure 7 b shows the network output results (left) and amplitude-frequency relationship (right) under different Brillouin frequency domains, such as Figure 7 As shown in b, the output of the optical neural network based on partially coherent optical computation exhibits extremely high linearity and signal-to-noise ratio, which can fully meet the sensing requirements.

[0110] The ultrafast fiber optic intelligent sensing and processing system disclosed herein includes a fiber optic sensing layer, an optoelectronic sensing interface, and an optical computing layer. The fiber optic sensing layer is used to obtain a first optical signal and a second optical signal from the laser output of a narrow-linewidth laser via an optical coupler through an upper branch and a lower branch, respectively, and injects the first and second optical signals into the sensing fiber. The optoelectronic sensing interface, connected to the fiber optic sensing layer, is used to map the first and second optical signals obtained through the sensing fiber from a temporal distribution to a spatial distribution, obtaining an analog optical signal. The optical computing layer, connected to the optoelectronic sensing interface, is used to perform optical calculations on the analog optical signal using an integrated photonic chip to obtain the corresponding sensing information. This disclosure, through the fiber optic sensing layer, optoelectronic sensing interface, and optical computing layer, converts the demodulation process of high-speed sensing signals from the electrical digital domain to the optical analog domain. This significantly improves the demodulation speed while simultaneously reducing the dimensionality of the optical domain signal, thereby greatly reducing the bandwidth and sampling rate pressure on the back-end electronic processor. This effectively improves the system's maximum frequency response and meets the needs of real-time processing of large amounts of sensing signals. Meanwhile, the photoelectric sensing interface and optical computing layer can significantly suppress calculation errors caused by adverse factors, thus exhibiting ultra-high robustness and long-term stability.

[0111] The collection, storage, use, processing, transmission, provision, and disclosure of user personal information involved in this disclosure all comply with the provisions of relevant laws and regulations and do not violate public order and good morals.

[0112] It should be noted that personal information collected from users should be used for legitimate and reasonable purposes and should not be shared or sold outside of these legitimate uses. Furthermore, such collection / sharing should only be conducted after receiving the user's informed consent, including but not limited to notifying the user to read the user agreement / user notice and sign an agreement / authorization that includes authorization of relevant user information before the user uses the function. In addition, any necessary steps must be taken to protect and safeguard access to such personal information data and ensure that others with access to personal information data comply with their privacy policies and procedures.

[0113] This disclosure is intended to provide implementation schemes for users to selectively prevent the use or access to their personal information data. Specifically, this disclosure is intended to provide hardware and / or software to prevent or block access to such personal information data. Once personal information data is no longer needed, risks can be minimized by restricting data collection and deleting data. Furthermore, where applicable, such personal information is de-identified to protect user privacy.

[0114] The acquisition, transmission, storage, use, and processing of data in this disclosed technical solution all comply with the relevant provisions of national laws and regulations.

[0115] It should be noted that in the embodiments disclosed herein, certain software, components, models, and other existing solutions in the industry may be mentioned. These should be considered as exemplary and are intended only to illustrate the feasibility of implementing the technical solution of this application. However, they do not mean that the applicant has used or necessarily used such solutions.

[0116] In the foregoing descriptions of the embodiments, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0117] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this disclosure, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0118] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing custom logic functions or processes, and the scope of preferred embodiments of this disclosure includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as will be understood by those skilled in the art to which embodiments of this disclosure pertain.

[0119] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Furthermore, computer-readable media can even be paper or other suitable media on which programs can be printed, because programs can be obtained electronically, for example, by optically scanning the paper or other media, followed by editing, interpreting, or otherwise processing as necessary, and then stored in computer memory.

[0120] It should be understood that various parts of this disclosure can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0121] Those skilled in the art will understand that all or part of the steps of the methods described in the above embodiments can be implemented by a program instructing related hardware, and the program can be stored in a computer-readable storage medium. When executed, the program includes one or a combination of the steps of the method embodiments.

[0122] Furthermore, the functional units in the various embodiments of this disclosure can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0123] The storage medium mentioned above can be a read-only memory, a disk, or an optical disk, etc. Although embodiments of the present disclosure have been shown and described above, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present disclosure. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present disclosure.

Claims

1. An ultrafast fiber optic intelligent sensing and processing system, characterized in that, The system includes a fiber optic sensing layer, a photoelectric sensing interface, and an optical computing layer, wherein... The optical fiber sensing layer is used to obtain the corresponding first optical signal and second optical signal from the laser output by the narrow linewidth laser through the upper branch and the lower branch respectively via the optical coupler, and to inject the first optical signal and the second optical signal into the sensing optical fiber. The photoelectric sensing interface is connected to the optical fiber sensing layer and is used to map the first optical signal and the second optical signal obtained through the sensing optical fiber from the temporal distribution to the spatial distribution to obtain the analog optical signal. The optical computing layer is connected to the photoelectric sensing interface and is used to perform optical computing on the analog optical signal through an integrated photonic chip to obtain the corresponding sensing information. The photoelectric sensing interface includes a frequency-modulated light source, a photoelectric-to-optical conversion module, and an optical buffer module; the process of mapping the first optical signal and the second optical signal obtained through the sensing optical fiber from a temporal distribution to a spatial distribution to obtain an analog optical signal includes: The optical-to-electric-to-optical conversion module performs optical-to-electric-to-optical conversion on the first optical signal and the second optical signal obtained through the sensing optical fiber to obtain a third optical signal; The optical buffer module maps the third optical signal and the frequency-hopping optical signal generated by the frequency-modulated light source from a temporal distribution to a spatial distribution to obtain an analog optical signal. The optical buffer module includes a third DC source, a third Mach-Zehnder modulator, a second erbium-doped fiber amplifier, and an optical buffer unit; the process of mapping the third optical signal and the frequency-hopping optical signal generated by the frequency-modulated light source from a temporal distribution to a spatial distribution to obtain an analog optical signal includes: The third optical signal and the frequency-hopping optical signal generated by the frequency-modulated light source are passed through the third Mach-Zehnder modulator driven by the third DC source to obtain a sensing signal; The sensing signal is sequentially passed through the second erbium-doped fiber amplifier and the optical buffer unit to map from a temporal distribution to a spatial distribution, thereby obtaining an analog optical signal.

2. The system according to claim 1, characterized in that, The fiber optic sensing layer includes a light source and signal distribution unit, a pump pulse light emission unit, a frequency-hopping continuous probe light emission unit, and a sensing fiber; the step of obtaining corresponding first and second optical signals by passing the laser output from the narrow linewidth laser through an optical coupler via an upper branch and a lower branch, and injecting the first and second optical signals into the sensing fiber includes: The light source and signal distribution unit divides the light source into pump light and probe light according to a preset coupling ratio; The pump pulse light emitting unit is connected to the light source and signal distribution unit, and processes the pump light through the upper branch to obtain the first optical signal; The frequency-hopping continuous probe light emitting unit is connected to the light source and signal distribution unit, and processes the probe light through the lower branch to obtain the second optical signal; The sensing optical fiber is connected to the pump pulse light emitting unit and the frequency hopping continuous probe light emitting unit to acquire the first optical signal and the second optical signal.

3. The system according to claim 2, characterized in that, The pump pulse light emitting unit includes a semiconductor optical amplifier, a function generator, a pulsed erbium-doped fiber amplifier, and a fiber circulator; the step of processing the pump light through the upper branch to obtain a first optical signal includes: The pump light passes sequentially through the semiconductor optical amplifier driven by the function generator, the pulsed erbium-doped fiber amplifier, and the fiber circulator to obtain the first optical signal.

4. The system according to claim 2, characterized in that, The frequency-hopping continuous probe light emitting unit includes a microwave source, a first DC source, a first Mach-Zehnder modulator, a waveform generator, a second DC source, a low-noise amplifier, a second Mach-Zehnder modulator, a first fiber optic disconnector, a first polarization controller, a second polarization controller, a polarization combiner, a first erbium-doped fiber amplifier, a first optical bandpass filter, and an optical fiber isolator; the step of processing the probe light through the lower branch to obtain a second optical signal includes: The probe light sequentially passes through a first Mach-Zehnder modulator driven by a microwave source and a first DC source, a second Mach-Zehnder modulator driven by a second DC source, a waveform generator, and a low-noise amplifier, and an orthogonal polarization light generator composed of a first fiber detacher, a first polarization controller, a second polarization controller, and a polarization combiner to adjust the upper and lower sidebands to orthogonal polarization states to obtain orthogonal polarization frequency-hopping light. The orthogonally polarized frequency-hopping light passes through the first erbium-doped fiber amplifier and the first optical bandpass filter, and then through the fiber isolator to obtain the second optical signal.

5. The system according to claim 1, characterized in that, The optical-to-electrical-to-optical conversion module includes a second fiber optic disconnector, a balanced detector, and a low-noise amplifier; the optical-to-electrical-to-optical conversion of the first and second optical signals obtained through the sensing fiber to obtain a third optical signal includes: The first optical signal and the second optical signal obtained through the sensing optical fiber are separated into upper and lower sidebands by the second optical fiber walk-off device and then enter the balanced detector to switch to the electrical domain to obtain an electrical sensing signal. The electrical sensing signal is passed through the low-noise amplifier to obtain the third optical signal.

6. The system according to claim 1, characterized in that, The optical computing layer includes an integrated photonic chip and a second optical bandpass filter; the step of performing optical computing on the analog optical signal through the integrated photonic chip to obtain corresponding sensing information includes: By integrating a photonic chip and the second optical bandpass filter, optical calculations and sensing information extraction are performed on the simulated optical signal to obtain the state information of objects along the optical fiber.

7. The system according to claim 6, characterized in that, The integrated photonic chip is an integrated photonic chip with an asymmetric spatial topology.

8. The system according to claim 1, characterized in that, The system also includes a photodetector and an oscilloscope; the sensing information is passed sequentially through the photodetector and the oscilloscope to obtain the corresponding digital waveform.

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