A novel fiber inline Mach-Zehnder interferometer(MZI)is proposed for simultaneous measurement of curvature and temperature.The sensor composes of single mode-multimode-dispersion compensation-multimode-single mode fib...A novel fiber inline Mach-Zehnder interferometer(MZI)is proposed for simultaneous measurement of curvature and temperature.The sensor composes of single mode-multimode-dispersion compensation-multimode-single mode fiber(MMF-DCF-MMF)structure,using the direct fusion technology.The experimental results show curvature sensitivities of−12.82 nm/m^(−1) and−14.42 nm/m^(−1) in the range of 0−0.65 m^(−1) for two resonant dips,as well as temperature sensitivities of 57.6 pm/and 74.3℃pm/within the range of 20℃℃−150.In addition,℃the sensor has unique advantages of easy fabrication,low cost,high fringe visibility of 24 dB,and high sensitivity,which shows a good application prospect in dual-parameters of sensing of curvature and temperature.展开更多
A fiber in-line Fabry-Perot interferometer is presented. The sensing head consists of a micro ellipsoidal air cavity and a small section of solid-core photonic crystal fiber. The reflective index （RI） and temperatur...A fiber in-line Fabry-Perot interferometer is presented. The sensing head consists of a micro ellipsoidal air cavity and a small section of solid-core photonic crystal fiber. The reflective index （RI） and temperature can be interrogated simultaneously through a fast Fourier transform and by tracing the dip wavelength shift of the reflective spectrum. Experimental results show that the RI amplitude and wavelength sensitivities are 5.30/ RIU and 8.46 × 10-1 nm/RIU in the range from 1.34 to 1.43, and the temperature amplitude and wavelength sensitivities are 6.8 × 10-4/℃ and 2.48 × 10-3 nm/℃ in the range from 15℃ to 75℃, respectively. Easy fabrication, a simple system, and simultaneous measurement make it appropriate for aluM-parameter sensing application.展开更多
Based on a single-channel laser self-mixing interferometcr, we present a new silnultaneous measurement of the vibration amplitude and tile rotation angle of objects that both affect the power spectrum containing two p...Based on a single-channel laser self-mixing interferometcr, we present a new silnultaneous measurement of the vibration amplitude and tile rotation angle of objects that both affect the power spectrum containing two peaks of the interferometer signals. The fitted results indicate that the curve of the peak frequency versus the vibration amplitude follows a linear distribution, and the curve of the difference of the two-peak power values versus the angle follows a Gaussian distribution. A vibration amplitude with an error less than 3.0% and a rotation angle with an error less than 11.7% are calculated from the fitted results.展开更多
In this study, an improved phase-shi^ng diffraction interferometer for measuring the surface topography of a microsphere is developed. A common diode-pumped solid state laser is used as the light source to facilitate ...In this study, an improved phase-shi^ng diffraction interferometer for measuring the surface topography of a microsphere is developed. A common diode-pumped solid state laser is used as the light source to facilitate ap- paratus realization, and a new polarized optical arrangement is designed to filter the bias light for phase-shifting control. A pinhole diffraction self-calibration method is proposed to eliminate systematic errors introduced by optical elements. The system has an adjustable signal contrast and is suitable for testing the surface with low reflectivity. Finally, a spherical ruby probe of a coordinate measuring machine is used as an example tested by the new phase-shifting diffraction interferometer system and the WYKO scanning white light interferometer for experimental comparison. The measured region presents consistent overall topography features, and the resulting peak-to-valley value of 84.43 nm and RMS value of 18.41 nm are achieved. The average roughness coincides with the manufacturer＇s specification value.展开更多
Real-time monitoring of wavelength is important for high-speed wavelength phase-shifting interferometry.In this paper,a wavelength sensor based on a polarization-maintaining fiber interferometer with four-quadrant dem...Real-time monitoring of wavelength is important for high-speed wavelength phase-shifting interferometry.In this paper,a wavelength sensor based on a polarization-maintaining fiber interferometer with four-quadrant demodulation was proposed.We built the wavelength sensing system with resolution better than 0.005 pm and 0.1 ms sampling interval and measured the response time of the tuned wavelength at 35 ms in the phase-shifting process of a commercial wavelength phase-shifting free-space interferometer,as well as the wavelength drift velocity of 0.01 pm per second in the hysteresis process.The optical fiber wavelength sensor with four-quadrant demodulation provides a real-time wavelength sensing scheme for high-speed wavelength phase-shifting interferometers.展开更多
Classical wisdom of wave-particle duality regulates that a quantum object shows either the particle or wave nature but never both.Consequently,it would be impossible to observe simultaneously the complete wave and par...Classical wisdom of wave-particle duality regulates that a quantum object shows either the particle or wave nature but never both.Consequently,it would be impossible to observe simultaneously the complete wave and particle nature of the quantum object.Mathematically the principle requests that the interference visibility V and whichpath distinguishability D satisfy an orthodox limit of V^2+D^2≤1.The present work reports a new waveparticle duality test experiment using single photons in a modified Mach-Zehnder interferometer to demonstrate the possibility of breaking the limit.The key element of the interferometer is a weakly scattering total internal reflection prism surface,which exhibits a pronounced single-photon interference with a visibility of up to 0.97and simultaneously provides a path distinguishability of 0.83.Apparently,the result of V^2+D^2≈1.63 exceeds the orthodox limit set by the classical principle of wave-particle duality for single photons.We expect that more delicate experiments in the future should be able to demonstrate the ultimate limit of V^2+D^2≈2 and shed new light on the foundations of con temporary quantum mechanics.展开更多
A Fourier analysis applied to the Mach-Zehnder interferometer （MZI） transmission spectrum for simultaneous refractive index （RI） and temperature measurements is proposed and experimentally demonstrated in this Let...A Fourier analysis applied to the Mach-Zehnder interferometer （MZI） transmission spectrum for simultaneous refractive index （RI） and temperature measurements is proposed and experimentally demonstrated in this Letter. In the fast Fourier transform （FFT） spectrum of the MZI transmission spectrum, several frequency components are generally observed, which means that the transmission spectrum of the MZI is formed by the superposition of some dual-mode interference （DMI） spectra, and each frequency component represents different core-cladding interferences. We can select some dominant frequency components in the FFT spectrum of the MZI transmission spectrum to take the inverse FFT （IFFT）. Then, the corresponding DMI patterns can be obtained. Due to the shift of the wavelength of these DMI spectra with changes in the environmental parameters, we can use the coefficient matrix of these DMI spectra for multi-parameter sensing. In this Letter, two DMI patterns are separated from the resultant transmission spectrum of the MZI. As the RI and temperature change, the shifts of the two DMI patterns with respect to the RI and temperature will be observed. The sensitivities of the RI and temperature are -137.1806 nm/RIU （RI unit） and 0.0860 nm/℃, and -22.9955 nm/RIU and 0.0610 nm/℃ for the two DMIs. Accordingly, it can be used to simultaneously measure RI and temperature changes. The approach can eliminate the influence of multiple interferences and improve the accuracy of the sensor.展开更多
A grating is an important element of a phase-shifting point diffraction interferometer, and the grating constant and duty cycle have a great impact on the interferometer, so the design of a grating becomes significant...A grating is an important element of a phase-shifting point diffraction interferometer, and the grating constant and duty cycle have a great impact on the interferometer, so the design of a grating becomes significant. In order to measure the projection objective with a numerical aperture of 0.2, we present a joint optimization method of a pinhole and grating based on scalar diffraction and the finite difference time domain method. The grating constant and the film thickness are selected, and the duty cycle of the grating is optimized. The results show that in the grating processing the material chromium is adopted, the thickness is 200 nm, and the grating constant is 15 μm. When the duty cycle is 55%, the interference fringe contrast is the greatest. The feasibility of the design result is further verified by experiment.展开更多
A novel phase-shifted long-period fiber grating(PS-LPFG)for the simultaneous measurement of torsion and temperature is described and experimentally demonstrated.The PS-LPFG is fabricated by inserting a pretwisted stru...A novel phase-shifted long-period fiber grating(PS-LPFG)for the simultaneous measurement of torsion and temperature is described and experimentally demonstrated.The PS-LPFG is fabricated by inserting a pretwisted structure into the long-period fiber grating(LPFG)written in single-mode fiber(SMF).Experimental results show that the torsion sensitivities of the two dips are?0.114 nm/(rad/m)and?0.069 nm/(rad/m)in the clockwise direction,and?0.087 nm/(rad/m)and?0.048 nm/(rad/m)in the counterclockwise direction,respectively.The temperature sensitivities of the two dips are 0.057 nm/℃ and 0.051 nm/℃,respectively.The two dips of the PS-LPFG exhibit different responses to torsion and temperature.Simultaneous measurement of torsion and temperature can be implemented using a sensor.The feasibility and stabilization of simultaneous torsion and temperature measurement have been confirmed,and hence this novel PS-LPFG demonstrates potential for fiber sensing and engineering applications.展开更多
Simultaneous wireless information and power transfer(SWIPT)architecture is commonly applied in wireless sensors or Internet of Things(IoT)devices,providing both wireless power sources and communication channels.Howeve...Simultaneous wireless information and power transfer(SWIPT)architecture is commonly applied in wireless sensors or Internet of Things(IoT)devices,providing both wireless power sources and communication channels.However,the traditional SWIPT transmitter usually suffers from cross-talk distortion caused by the high peak-to-average power ratio of the input signal and the reduction of power amplifier efficiency.This paper proposes a SWIPT transmitting architecture based on an asynchronous space-time-coding digital metasurface(ASTCM).High-efficiency simultaneous transfer of information and power is achieved via energy distribution and information processing of the wireless monophonic signal reflected from the metasurface.We demonstrate the feasibility of the proposed method through theoretical derivations and experimental verification,which is therefore believed to have great potential in wireless communications and the IoT devices.展开更多
An all fiber magnetic field sensor with peanut-shape structure based on multimode fiber(MMF) is proposed and experimentally demonstrated. The sensing structure and magnetic fluid(MF) are both encapsulated in capillary...An all fiber magnetic field sensor with peanut-shape structure based on multimode fiber(MMF) is proposed and experimentally demonstrated. The sensing structure and magnetic fluid(MF) are both encapsulated in capillary, and the effective refractive index of MF is affected by surrounding magnetic field strength. The measurement of magnetic field is realized by observing the wavelength drift of interference peak. The transmission spectrum generated by Mach-Zehnder interferometer(MZI) includes core-core mode interference and core-cladding mode interference. Experimental results demonstrate that the core-cladding mode interference is sensitive to magnetic field, and the magnetic field sensitivity is 0.047 8 nm/mT. In addition, two kinds of interference dips are sensitive to temperature, and the sensitivities are 0.060 0 nm/°C and 0.052 6 nm/°C, respectively. So the simultaneous measurement of magnetic field strength and temperature can be achieved based on sensitivity matrix.展开更多
An in-fiber Mach-Zehnder interferometer is proposed for the discrimination of strain and temperature.The sensor is based on two cascaded standard single mode fibers using three peanut tapers fabricated by simple splic...An in-fiber Mach-Zehnder interferometer is proposed for the discrimination of strain and temperature.The sensor is based on two cascaded standard single mode fibers using three peanut tapers fabricated by simple splicing.The cascaded structure excites more frequency components,which induce four sets of interference dips in the transmission spectrum.One set of the spectrum dips have different sensitivities to temperature and strain from those of the other three.The sensor can discriminate strain and temperature by monitoring the wavelength shifts of two spectrum dips.Repeated experiments are taken both for strain and temperature increasing and decreasing scenarios.Experimental results show that Dip 1 has an average strain sensitivity of-0.911 pm/με and an average temperature sensitivity of 49.98pm/℃.The strain sensitivity for Dip 2 is negligible and its average temperature sensitivity is 60.52pm/℃.The strain and temperature resolutions are±3.82με and±0.33℃.展开更多
基金supported by the National Natural Science Foundation of China(NSFC)(Grant Nos.51875584 and 51875585)the National Key Research and Development Program of China(Grant Nos.2017YFB1104800 and 2018YFB1107803)the Fundamental Research Funds for the Central Universities of Central South University(Grant No.1053320170003).
文摘A novel fiber inline Mach-Zehnder interferometer(MZI)is proposed for simultaneous measurement of curvature and temperature.The sensor composes of single mode-multimode-dispersion compensation-multimode-single mode fiber(MMF-DCF-MMF)structure,using the direct fusion technology.The experimental results show curvature sensitivities of−12.82 nm/m^(−1) and−14.42 nm/m^(−1) in the range of 0−0.65 m^(−1) for two resonant dips,as well as temperature sensitivities of 57.6 pm/and 74.3℃pm/within the range of 20℃℃−150.In addition,℃the sensor has unique advantages of easy fabrication,low cost,high fringe visibility of 24 dB,and high sensitivity,which shows a good application prospect in dual-parameters of sensing of curvature and temperature.
基金supported by the National Natural Science Foundation of China(Nos.61178044 and 51405240)the Natural Science Foundation of Jiangsu Province of China(No.BK20140925)+2 种基金the Major Project of the Nature Science Research for Colleges and Universities in Jiangsu Province(No.15KJA140002)the Program of Natural Science Research of the Jiangsu Higher Education Institutions of China(No.14KJB510015)the University Postgraduate Research and Innovation Project of Jiangsu Province(No.1812000002A422)
文摘A fiber in-line Fabry-Perot interferometer is presented. The sensing head consists of a micro ellipsoidal air cavity and a small section of solid-core photonic crystal fiber. The reflective index （RI） and temperature can be interrogated simultaneously through a fast Fourier transform and by tracing the dip wavelength shift of the reflective spectrum. Experimental results show that the RI amplitude and wavelength sensitivities are 5.30/ RIU and 8.46 × 10-1 nm/RIU in the range from 1.34 to 1.43, and the temperature amplitude and wavelength sensitivities are 6.8 × 10-4/℃ and 2.48 × 10-3 nm/℃ in the range from 15℃ to 75℃, respectively. Easy fabrication, a simple system, and simultaneous measurement make it appropriate for aluM-parameter sensing application.
基金supported by the National Natural Science Foundation of China under Grant Nos.61275165,61201401,and 61307098
文摘Based on a single-channel laser self-mixing interferometcr, we present a new silnultaneous measurement of the vibration amplitude and tile rotation angle of objects that both affect the power spectrum containing two peaks of the interferometer signals. The fitted results indicate that the curve of the peak frequency versus the vibration amplitude follows a linear distribution, and the curve of the difference of the two-peak power values versus the angle follows a Gaussian distribution. A vibration amplitude with an error less than 3.0% and a rotation angle with an error less than 11.7% are calculated from the fitted results.
基金supported by the National Natural Science Foundation of China under Grant Nos.61275096 and 51275120
文摘In this study, an improved phase-shi^ng diffraction interferometer for measuring the surface topography of a microsphere is developed. A common diode-pumped solid state laser is used as the light source to facilitate ap- paratus realization, and a new polarized optical arrangement is designed to filter the bias light for phase-shifting control. A pinhole diffraction self-calibration method is proposed to eliminate systematic errors introduced by optical elements. The system has an adjustable signal contrast and is suitable for testing the surface with low reflectivity. Finally, a spherical ruby probe of a coordinate measuring machine is used as an example tested by the new phase-shifting diffraction interferometer system and the WYKO scanning white light interferometer for experimental comparison. The measured region presents consistent overall topography features, and the resulting peak-to-valley value of 84.43 nm and RMS value of 18.41 nm are achieved. The average roughness coincides with the manufacturer＇s specification value.
基金This work was supported by the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX21_0277)the National Natural Science Foundation of China(No.61875087).
文摘Real-time monitoring of wavelength is important for high-speed wavelength phase-shifting interferometry.In this paper,a wavelength sensor based on a polarization-maintaining fiber interferometer with four-quadrant demodulation was proposed.We built the wavelength sensing system with resolution better than 0.005 pm and 0.1 ms sampling interval and measured the response time of the tuned wavelength at 35 ms in the phase-shifting process of a commercial wavelength phase-shifting free-space interferometer,as well as the wavelength drift velocity of 0.01 pm per second in the hysteresis process.The optical fiber wavelength sensor with four-quadrant demodulation provides a real-time wavelength sensing scheme for high-speed wavelength phase-shifting interferometers.
基金National Natural Science Foundation of China(11474114,11874166,11974119)Guangdong Province Introduction of Innovative RD Team(2016ZT06C594)Thousand-Young-Talent Program of China。
文摘Classical wisdom of wave-particle duality regulates that a quantum object shows either the particle or wave nature but never both.Consequently,it would be impossible to observe simultaneously the complete wave and particle nature of the quantum object.Mathematically the principle requests that the interference visibility V and whichpath distinguishability D satisfy an orthodox limit of V^2+D^2≤1.The present work reports a new waveparticle duality test experiment using single photons in a modified Mach-Zehnder interferometer to demonstrate the possibility of breaking the limit.The key element of the interferometer is a weakly scattering total internal reflection prism surface,which exhibits a pronounced single-photon interference with a visibility of up to 0.97and simultaneously provides a path distinguishability of 0.83.Apparently,the result of V^2+D^2≈1.63 exceeds the orthodox limit set by the classical principle of wave-particle duality for single photons.We expect that more delicate experiments in the future should be able to demonstrate the ultimate limit of V^2+D^2≈2 and shed new light on the foundations of con temporary quantum mechanics.
基金supported by the National Natural Science Foundation of China(Nos.61327012 and 61275088)the Research Foundation of Education Bureau of Shaanxi Province,China(No.14JS073)+2 种基金the Youth Science and Technology Innovation Fund of Xi’an Shiyou University(No.2014QN005)the Excellent MA Theses Fund of Xi’an Shiyou University(No.2014yp130816)the Graduate Student Innovation Fund(No.2014cx130842)
文摘A Fourier analysis applied to the Mach-Zehnder interferometer （MZI） transmission spectrum for simultaneous refractive index （RI） and temperature measurements is proposed and experimentally demonstrated in this Letter. In the fast Fourier transform （FFT） spectrum of the MZI transmission spectrum, several frequency components are generally observed, which means that the transmission spectrum of the MZI is formed by the superposition of some dual-mode interference （DMI） spectra, and each frequency component represents different core-cladding interferences. We can select some dominant frequency components in the FFT spectrum of the MZI transmission spectrum to take the inverse FFT （IFFT）. Then, the corresponding DMI patterns can be obtained. Due to the shift of the wavelength of these DMI spectra with changes in the environmental parameters, we can use the coefficient matrix of these DMI spectra for multi-parameter sensing. In this Letter, two DMI patterns are separated from the resultant transmission spectrum of the MZI. As the RI and temperature change, the shifts of the two DMI patterns with respect to the RI and temperature will be observed. The sensitivities of the RI and temperature are -137.1806 nm/RIU （RI unit） and 0.0860 nm/℃, and -22.9955 nm/RIU and 0.0610 nm/℃ for the two DMIs. Accordingly, it can be used to simultaneously measure RI and temperature changes. The approach can eliminate the influence of multiple interferences and improve the accuracy of the sensor.
基金supported by the Major Scientific Instrument Development Project of the National Natural Science Foundation of China(No.11627808)the National Natural Science Foundation of China(No.61675026)the National Science and Technology
文摘A grating is an important element of a phase-shifting point diffraction interferometer, and the grating constant and duty cycle have a great impact on the interferometer, so the design of a grating becomes significant. In order to measure the projection objective with a numerical aperture of 0.2, we present a joint optimization method of a pinhole and grating based on scalar diffraction and the finite difference time domain method. The grating constant and the film thickness are selected, and the duty cycle of the grating is optimized. The results show that in the grating processing the material chromium is adopted, the thickness is 200 nm, and the grating constant is 15 μm. When the duty cycle is 55%, the interference fringe contrast is the greatest. The feasibility of the design result is further verified by experiment.
基金supported by the National Natural Science Foundation of China(No.11527804)Joint Research Fund in Astronomy under cooperative agreement between the National Natural Science Foundation of China(NSFC)and Chinese Academy of Sciences(CAS)(Nos.U1831115 and U1631239)+3 种基金Open Project of Key Laboratory of Astronomical Optics&Technology,Nanjing Institute of Astronomical Optics&Technology,Chinese Academy of Sciences(No.CAS-KLAOT-KF201806)Fundamental Research Funds for the Central Universities111 Project(No.B13015)the Harbin Engineering University.
文摘A novel phase-shifted long-period fiber grating(PS-LPFG)for the simultaneous measurement of torsion and temperature is described and experimentally demonstrated.The PS-LPFG is fabricated by inserting a pretwisted structure into the long-period fiber grating(LPFG)written in single-mode fiber(SMF).Experimental results show that the torsion sensitivities of the two dips are?0.114 nm/(rad/m)and?0.069 nm/(rad/m)in the clockwise direction,and?0.087 nm/(rad/m)and?0.048 nm/(rad/m)in the counterclockwise direction,respectively.The temperature sensitivities of the two dips are 0.057 nm/℃ and 0.051 nm/℃,respectively.The two dips of the PS-LPFG exhibit different responses to torsion and temperature.Simultaneous measurement of torsion and temperature can be implemented using a sensor.The feasibility and stabilization of simultaneous torsion and temperature measurement have been confirmed,and hence this novel PS-LPFG demonstrates potential for fiber sensing and engineering applications.
基金supported by the Program of Song Shan Laboratory(included in the management of Major Science and Technology Program of Henan Province)(Nos.221100211300-03 and 221100211300-02)the National Key Research and Development Program of China(No.2018YFA0701904)+5 种基金the National Natural Science Foundation of China(Nos.62288101,61731010,62201139,and U22A2001)the 111 Project(No.111-2-05)the Jiangsu Province Frontier Leading Technology Basic Research Project(No.BK20212002)the Fundamental Research Funds for the Central Universities(No.2242022k60003)the National Natural Science Foundation(NSFC)for Distinguished Young Scholars of China(No.62225108)the Southeast University-China Mobile Research Institute Joint Innovation Center(No.R207010101125D9).
文摘Simultaneous wireless information and power transfer(SWIPT)architecture is commonly applied in wireless sensors or Internet of Things(IoT)devices,providing both wireless power sources and communication channels.However,the traditional SWIPT transmitter usually suffers from cross-talk distortion caused by the high peak-to-average power ratio of the input signal and the reduction of power amplifier efficiency.This paper proposes a SWIPT transmitting architecture based on an asynchronous space-time-coding digital metasurface(ASTCM).High-efficiency simultaneous transfer of information and power is achieved via energy distribution and information processing of the wireless monophonic signal reflected from the metasurface.We demonstrate the feasibility of the proposed method through theoretical derivations and experimental verification,which is therefore believed to have great potential in wireless communications and the IoT devices.
基金supported by the National High Technology Research and Development Program of China(No.2013AA014200)the National Natural Science Foundation of China(No.11444001)the Municipal Natural Science Foundation of Tianjin(No.14JCYBJC16500)
文摘An all fiber magnetic field sensor with peanut-shape structure based on multimode fiber(MMF) is proposed and experimentally demonstrated. The sensing structure and magnetic fluid(MF) are both encapsulated in capillary, and the effective refractive index of MF is affected by surrounding magnetic field strength. The measurement of magnetic field is realized by observing the wavelength drift of interference peak. The transmission spectrum generated by Mach-Zehnder interferometer(MZI) includes core-core mode interference and core-cladding mode interference. Experimental results demonstrate that the core-cladding mode interference is sensitive to magnetic field, and the magnetic field sensitivity is 0.047 8 nm/mT. In addition, two kinds of interference dips are sensitive to temperature, and the sensitivities are 0.060 0 nm/°C and 0.052 6 nm/°C, respectively. So the simultaneous measurement of magnetic field strength and temperature can be achieved based on sensitivity matrix.
基金supported by the National Natural Science Foundation of China(Grant Nos.62005011,61801017,and.62005013)the Beijing Municipal Natural Science Foundation(Grant No.4212009)the Fundamental Research Funds for the Central Universities(Grant No.2020RC015).
文摘An in-fiber Mach-Zehnder interferometer is proposed for the discrimination of strain and temperature.The sensor is based on two cascaded standard single mode fibers using three peanut tapers fabricated by simple splicing.The cascaded structure excites more frequency components,which induce four sets of interference dips in the transmission spectrum.One set of the spectrum dips have different sensitivities to temperature and strain from those of the other three.The sensor can discriminate strain and temperature by monitoring the wavelength shifts of two spectrum dips.Repeated experiments are taken both for strain and temperature increasing and decreasing scenarios.Experimental results show that Dip 1 has an average strain sensitivity of-0.911 pm/με and an average temperature sensitivity of 49.98pm/℃.The strain sensitivity for Dip 2 is negligible and its average temperature sensitivity is 60.52pm/℃.The strain and temperature resolutions are±3.82με and±0.33℃.
