Time division multiplexing(TDM)architecture is an important approach to creating sensor arrays for massive scale monitoring.But it is paradoxical for the TDM interferometric sensor array to keep a short delay fiber fo...Time division multiplexing(TDM)architecture is an important approach to creating sensor arrays for massive scale monitoring.But it is paradoxical for the TDM interferometric sensor array to keep a short delay fiber for high sensing resolution and meanwhile use low sampling rate for practical applications.In this paper,a phase matching sampling(PMS)paradigm is proposed to address the above contradiction.By matching the phase of the sampling clock with the delay fiber length,combining with multiple-pulses sampling strategy,the proposed PMS method can avoid collecting the redundant information,facilitating the decreasing of sampling rate as well as delay fiber length of the TDM sensing system.The proof-of-concept experiments on an 8-channel TDM interferometric system demonstrate that when the sampling rate is fixed at 20 MS/s,by applying the PMS algorithm,the delay fiber length can be shortened from 100 m to 1 m,compared with applying the conventional sampling method.It reduced the phase noise of the system by a factor of 10 at 1 mHz and by a factor of 50 at 1 Hz.The PMS algorithm for greatly reducing the sampling rate is expected to fuel the TDM interferometric sensor arrays for many applications.展开更多
Optical fiber interferometric sensors are of great importance in chemistry,biology,and medicine disciplines owing to high-sensitivity and high-quality factor.However,due to the limitation of free spectral range,the in...Optical fiber interferometric sensors are of great importance in chemistry,biology,and medicine disciplines owing to high-sensitivity and high-quality factor.However,due to the limitation of free spectral range,the inherent trade-off between wide measurement range and high sensitivity poses a persistent challenge in interference sensor development,which has fundamentally hindered their widespread adoption in precision measurement applications.In this work,a long short-term memory neural network is utilized in a Mach-Zehnder interference-based refractive index sensor to break the free spectral range limitation.Unique gating mechanism in long short-term memory neural network enables it to efficiently process long-term dependent sequence information,such as interference spectrum,avoiding the need for complex spectral signal analysis.A one-to-one mapping relationship is established between the interference spectrum and refractive index with root mean square error of 3.029×10^(−4)and a coefficient of determination of 0.99971.The measurement range is extended from a single free spectral range of 1.3333–1.3561 to approximately three free spectral ranges of 1.3333–1.3921 without sacrificing sensitivity.Moreover,a wider measurement range can be achieved with sufficient training data.This work successfully resolves the inherent contradiction between high sensitivity and wide dynamic measurement range in optical interference-based sensors,opening up a path for the next generation of intelligent sensing systems.展开更多
Optical fiber interferometric sensors based on [3×3] couplers have been used in many fields. A new technique is proposed to demodulate output signals of this kind of sensors. The technique recovers the signal of ...Optical fiber interferometric sensors based on [3×3] couplers have been used in many fields. A new technique is proposed to demodulate output signals of this kind of sensors. The technique recovers the signal of interest by fitting coefficients of elliptic （Lissajous） curves between each fiber pair. Different from other approaches, this technique eliminates the dependence on the idealization of [3×3] coupler, provides enhanced tolerance to the variance of photoelectric converters, and is anti-polarization in a certain extent. The main algorithm has been successfully demonstrated both by numerical simulation and experimental result.展开更多
Good linearity and wide dynamic range are the advantages of asymmetric Fabry-Pérot （F-P） interferometric cavity, whose realization has been long for. Based on optical thin film characteristic matrix theory, an ...Good linearity and wide dynamic range are the advantages of asymmetric Fabry-Pérot （F-P） interferometric cavity, whose realization has been long for. Based on optical thin film characteristic matrix theory, an asymmetric F-P interferometric cavity with good linearity and wide dynamic range is designed. And by choosing the material of two different thin metallic layers, the asymmetric F-P interferometric cavity is successfully fabricated. The design theory and method of this asymmetric F-P interferometric cavity have been described in detailed. In this paper an asymmetric F-P interferometric cavity used in fiber optical sensor is reported.展开更多
In view of the problem that the sensing characteristics of the multi-mode interferometric fiber sensors cannot be accurately analyzed,an analysis method based on the fast Fourier transform(FFT)and inverse fast Fourier...In view of the problem that the sensing characteristics of the multi-mode interferometric fiber sensors cannot be accurately analyzed,an analysis method based on the fast Fourier transform(FFT)and inverse fast Fourier transform(IFFT)is proposed and demonstrated theoretically and experimentally.The suitabilities of the rectangular window function with the narrow main lobe(high spectrum resolution)and low side lobe(high main mode energy leakage)and the Hanning window function with the wide main lobe(low spectrum resolution)and high side lobe(high energy concentration)in this kind of sensor analysis are discussed,respectively.This method can not only realize the sensing performance analysis of the various modes,but also overcome the inconsistency of the different interference wavelength(dip)sensing characteristics in the conventional analysis methods.At the same time,this method is also beneficial to solve the repetitive problem of such sensors.展开更多
The optical Vernier effect has garnered significant research attention and found widespread applications in enhancing the measurement sensitivity of optical fiber interferometric sensors.Typically,Vernier sensor inter...The optical Vernier effect has garnered significant research attention and found widespread applications in enhancing the measurement sensitivity of optical fiber interferometric sensors.Typically,Vernier sensor interrogation involves measuring its optical spectrum across a wide wavelength range using a high-precision spectrometer.This process is further complicated by the intricate signal processing required for accurately extracting the Vernier envelope,which can inadvertently introduce errors that compromise sensing performance.In this work,we introduce a novel approach to interrogating Vernier sensors based on a coherent microwave interferenceassisted measurement technique.Instead of measuring the optical spectrum,we acquire the frequency response of the Vernier optical fiber sensor using a vector network analyzer.This response includes a characteristic notch that is highly sensitive to external perturbations.We discuss in detail the underlying physics of coherent microwave interference-based notch generation and the sensing principle.As a proof of concept,we construct a Vernier sensor using two air-gap Fabry–Perot interferometers arranged in parallel,demonstrating high-sensitivity strain sensing through microwave-domain measurements.The introduced technique is straightforward to implement,and the characteristic sensing signal is easy to demodulate and highly sensitive,presenting an excellent solution to the complexities of existing optical Vernier sensor systems.展开更多
基金financial supports from Ministry of Science and Technology of the People’s Republic of China under Grant(No.2022YFC2203904)in part by Open Projects Foundation under Grant of State Key Laboratory of Optical Fiber and Cable Manufacture Technology(YOFC)(No.SKLD2306).
文摘Time division multiplexing(TDM)architecture is an important approach to creating sensor arrays for massive scale monitoring.But it is paradoxical for the TDM interferometric sensor array to keep a short delay fiber for high sensing resolution and meanwhile use low sampling rate for practical applications.In this paper,a phase matching sampling(PMS)paradigm is proposed to address the above contradiction.By matching the phase of the sampling clock with the delay fiber length,combining with multiple-pulses sampling strategy,the proposed PMS method can avoid collecting the redundant information,facilitating the decreasing of sampling rate as well as delay fiber length of the TDM sensing system.The proof-of-concept experiments on an 8-channel TDM interferometric system demonstrate that when the sampling rate is fixed at 20 MS/s,by applying the PMS algorithm,the delay fiber length can be shortened from 100 m to 1 m,compared with applying the conventional sampling method.It reduced the phase noise of the system by a factor of 10 at 1 mHz and by a factor of 50 at 1 Hz.The PMS algorithm for greatly reducing the sampling rate is expected to fuel the TDM interferometric sensor arrays for many applications.
基金supported by the National Natural Science Foundation of China(Grant No.12074331)Natural Science Foundation of Hebei Province of China(Grant No.F2021203112)Open project of Hebei Key Laboratory of Advanced Laser Technology and Equipment(Grant No.HBKL-ALTE2025006).
文摘Optical fiber interferometric sensors are of great importance in chemistry,biology,and medicine disciplines owing to high-sensitivity and high-quality factor.However,due to the limitation of free spectral range,the inherent trade-off between wide measurement range and high sensitivity poses a persistent challenge in interference sensor development,which has fundamentally hindered their widespread adoption in precision measurement applications.In this work,a long short-term memory neural network is utilized in a Mach-Zehnder interference-based refractive index sensor to break the free spectral range limitation.Unique gating mechanism in long short-term memory neural network enables it to efficiently process long-term dependent sequence information,such as interference spectrum,avoiding the need for complex spectral signal analysis.A one-to-one mapping relationship is established between the interference spectrum and refractive index with root mean square error of 3.029×10^(−4)and a coefficient of determination of 0.99971.The measurement range is extended from a single free spectral range of 1.3333–1.3561 to approximately three free spectral ranges of 1.3333–1.3921 without sacrificing sensitivity.Moreover,a wider measurement range can be achieved with sufficient training data.This work successfully resolves the inherent contradiction between high sensitivity and wide dynamic measurement range in optical interference-based sensors,opening up a path for the next generation of intelligent sensing systems.
基金This work was supported by the National Natural Science Foundation of China under Grant No.60673152
文摘Optical fiber interferometric sensors based on [3×3] couplers have been used in many fields. A new technique is proposed to demodulate output signals of this kind of sensors. The technique recovers the signal of interest by fitting coefficients of elliptic （Lissajous） curves between each fiber pair. Different from other approaches, this technique eliminates the dependence on the idealization of [3×3] coupler, provides enhanced tolerance to the variance of photoelectric converters, and is anti-polarization in a certain extent. The main algorithm has been successfully demonstrated both by numerical simulation and experimental result.
基金This work was supported by the National "863" Project of China (No. 2003AA311022)the National "973" Project of China (No. 2004CB719804)the National Natural Science Foundation of China (No. 10274108)the Natural Science Foundation of Guangdong Province of China.
文摘Good linearity and wide dynamic range are the advantages of asymmetric Fabry-Pérot （F-P） interferometric cavity, whose realization has been long for. Based on optical thin film characteristic matrix theory, an asymmetric F-P interferometric cavity with good linearity and wide dynamic range is designed. And by choosing the material of two different thin metallic layers, the asymmetric F-P interferometric cavity is successfully fabricated. The design theory and method of this asymmetric F-P interferometric cavity have been described in detailed. In this paper an asymmetric F-P interferometric cavity used in fiber optical sensor is reported.
基金This work was supported by the State Key Laboratory of Mining Disaster Prevention and Control,Shandong University of Science and Technology(Grant Nos.MDPC201602 and MDPC2022ZR04)Department of Education1of Shandong Province(Grant No.J06P14)+1 种基金The Qingdao Feibo Technology Co.,Ltd.(Grant No.02040102401)Postdoctoral Research Foundation of China(Grant Nos.200902574 and 20080441150).
文摘In view of the problem that the sensing characteristics of the multi-mode interferometric fiber sensors cannot be accurately analyzed,an analysis method based on the fast Fourier transform(FFT)and inverse fast Fourier transform(IFFT)is proposed and demonstrated theoretically and experimentally.The suitabilities of the rectangular window function with the narrow main lobe(high spectrum resolution)and low side lobe(high main mode energy leakage)and the Hanning window function with the wide main lobe(low spectrum resolution)and high side lobe(high energy concentration)in this kind of sensor analysis are discussed,respectively.This method can not only realize the sensing performance analysis of the various modes,but also overcome the inconsistency of the different interference wavelength(dip)sensing characteristics in the conventional analysis methods.At the same time,this method is also beneficial to solve the repetitive problem of such sensors.
文摘The optical Vernier effect has garnered significant research attention and found widespread applications in enhancing the measurement sensitivity of optical fiber interferometric sensors.Typically,Vernier sensor interrogation involves measuring its optical spectrum across a wide wavelength range using a high-precision spectrometer.This process is further complicated by the intricate signal processing required for accurately extracting the Vernier envelope,which can inadvertently introduce errors that compromise sensing performance.In this work,we introduce a novel approach to interrogating Vernier sensors based on a coherent microwave interferenceassisted measurement technique.Instead of measuring the optical spectrum,we acquire the frequency response of the Vernier optical fiber sensor using a vector network analyzer.This response includes a characteristic notch that is highly sensitive to external perturbations.We discuss in detail the underlying physics of coherent microwave interference-based notch generation and the sensing principle.As a proof of concept,we construct a Vernier sensor using two air-gap Fabry–Perot interferometers arranged in parallel,demonstrating high-sensitivity strain sensing through microwave-domain measurements.The introduced technique is straightforward to implement,and the characteristic sensing signal is easy to demodulate and highly sensitive,presenting an excellent solution to the complexities of existing optical Vernier sensor systems.
