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
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
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.
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.
