In this Letter, a low-frequency acoustic sensor based on an extrinsic Fabry–Pérot(FP) interferometer with a silicon nitride(Si3N4) membrane is demonstrated. Using micromachining techniques, the 800 nm thick Si3N...In this Letter, a low-frequency acoustic sensor based on an extrinsic Fabry–Pérot(FP) interferometer with a silicon nitride(Si3N4) membrane is demonstrated. Using micromachining techniques, the 800 nm thick Si3N4 membrane is deposited on an 8 mm × 8 mm × 400 μm silicon(Si) substrate. All the assembly procedures of the sensor are focused on the substrate to avoid any damage to the membrane itself, compared to general membrane transfer methods. The frequency response of the proposed sensor is discussed theoretically and experimentally demonstrated. The sensor exhibits an excellent flat response to the tested acoustic frequency range of 1 Hz to 250 Hz. The phase sensitivity is around-152 dB re 1 rad/μPa with sensitivity fluctuation less than 0.8 dB.The frequency response characteristic shows a promising potential of the sensor in low-frequency acoustic signal sensing applications.展开更多
Acoustic/ultrasonic sensors are devices that can convert mechanical energy into electrical signals.The Fabry–Perot cavity is processed on the end face of the double-clad fiber by a two-photon three-dimensional lithog...Acoustic/ultrasonic sensors are devices that can convert mechanical energy into electrical signals.The Fabry–Perot cavity is processed on the end face of the double-clad fiber by a two-photon three-dimensional lithography machine.In this study,the outer diameter of the core cladding was 250μm,the diameter of the core was 9μm,and the microcavity sensing unit was only 30μm.It could measure ultrasonic signals with high precision.The characteristics of the proposed ultrasonic sensor were investigated,and its feasibility was proven through experiments.Its design has a small size and can replace a larger ultrasonic detector device for photoacoustic signal detection.The sensor is applicable to the field of biomedical information technology,including medical diagnosis,photoacoustic endoscopy,and photoacoustic imaging.展开更多
A metal-insulator-metal(MIM)-based arc-shaped resonator coupled with a rectangular stub(MARS) structure is proposed. This structure can generate two tunable Fano resonances originating from two different mechanisms. T...A metal-insulator-metal(MIM)-based arc-shaped resonator coupled with a rectangular stub(MARS) structure is proposed. This structure can generate two tunable Fano resonances originating from two different mechanisms. The structure has the advantage of being sensitive to the refractive index, and this feature makes it favorable for application in various microsensors. The relationship between the structural parameters and Fano resonance is researched using the finite element method(FEM) based on the software COMSOL Multiphysics 5.4. The simulation reveals that the sensitivity reaches1900 nm/refractive index unit(RIU), and the figure of merit(FOM) is 23.75.展开更多
Pressure sensors based on fiber-optic extrinsic Fabry-Perot interferometer(EFPI)have been extensively applied in various industrial and biomedical fields.In this paper,some key improvements of EFPI-based pressure sens...Pressure sensors based on fiber-optic extrinsic Fabry-Perot interferometer(EFPI)have been extensively applied in various industrial and biomedical fields.In this paper,some key improvements of EFPI-based pressure sensors such as the controlled thermal bonding technique,diaphragm-based EFPI sensors,and white light interference technology have been reviewed.Recent progress on signal demodulation method and applications of EFPI-based pressure sensors has been introduced.Signal demodulation algorithms based on the cross correlation and mean square error(MSE)estimation have been proposed for retrieving the cavity length of EFPI.Absolute measurement with a resolution of 0.08 nm over large dynamic range has been carried out.For downhole monitoring,an EFPI and a fiber Bragg grating(FBG)cascade multiplexing fiber-optic sensor system has been developed,which can operate in temperature 300℃with a good long-term stability and extremely low temperature cross-sensitivity.Diaphragm-based EFPI pressure sensors have been successfully used for low pressure and acoustic wave detection.Experimental results show that a sensitivity of 31 mV/Pa in the frequency range of 100 Hz to 12.7 kHz for aeroacoustic wave detection has been obtained.展开更多
Flexible photodetectors(PDs)are indispensable components for next-generation wearable electronics.Recently,two-dimensional(2D)materials have been implemented as functional flexible optoelectronic devices due to their ...Flexible photodetectors(PDs)are indispensable components for next-generation wearable electronics.Recently,two-dimensional(2D)materials have been implemented as functional flexible optoelectronic devices due to their characteristics of atomically thin layers,excellent flexibility,and strain sensitivity.In this work,we developed a flexible photodetector based on MoS_(2)/NiO heterojunction,and Fabry-Perot(F-P)and piezo-phototronic effect have been employed to enhance the responsivity(R)and external quantum efficiency(EQE)of the devices.The F-P effect is utilized to improve the optical absorption of the MoS_(2),resulting in an enhancement in the photoluminescence(PL)of monolayer MoS_(2) and the EQE of the photodetector by 30 and 130 times,respectively.The flexible photodetector exhibits an ultrahigh detectivity(D*)of 2.6×10^(14) Jones,which is the highest value ever reported for flexible MoS_(2) PDs.The piezo-potential of monolayer MoS_(2) decreases the valence band offset at the interface of MoS_(2)/NiO,which increases the transfer efficiency of the photon-generated carriers significantly.Under 1.17%tensile strain,the R of the flexible photodetector can be enhanced by 271%.This research may provide a universal strategy for the design and performance optimization of 2D materials heterostructures for flexible optoelectronics.展开更多
One of the biggest obstacles to the application of orbital angular momentum(OAM)in the microwave field is its divergence problem.This paper presents a full analysis of generating and focusing OAM waves using original ...One of the biggest obstacles to the application of orbital angular momentum(OAM)in the microwave field is its divergence problem.This paper presents a full analysis of generating and focusing OAM waves using original and improved Fabry-Perot(F-P)cavities.Utilizing combination of microstrip antenna and original F-P cavity,the gain of the OAM antenna is enhanced from 4.0 dBi to 9.3 dBi and the corresponding divergence angle is decreased from 41to 24.To further improve the performance of the OAM antenna,the improved F-P cavity is introduced.The simulated results show that the gain is further enhanced to 12.0 dBi and the divergence angle is further decreased to be 15.展开更多
Fabry-Perot(F-P)-based phase demodulation of heterodyne light-induced thermoelastic spectroscopy(H-LITES)was demonstrated for the first time in this study.The vibration of a quartz tuning fork(QTF)was detected using t...Fabry-Perot(F-P)-based phase demodulation of heterodyne light-induced thermoelastic spectroscopy(H-LITES)was demonstrated for the first time in this study.The vibration of a quartz tuning fork(QTF)was detected using the F-P interference principle instead of an electrical signal through the piezoelectric effect of the QTF in traditional LITES to avoid thermal noise.Given that an Fabry-Perot interferometer(FPI)is vulnerable to disturbances,a phase demodulation method that has been demonstrated theoretically and experimentally to be an effective solution for instability was used in H-LITES.The sensitivity of the F-P phase demodulation method based on the H-LITES sensor was not associated with the wavelength or power of the probe laser.Thus,stabilising the quadrature working point(Q-point)was no longer necessary.This new method of phase demodulation is structurally simple and was found to be resistant to interference from light sources and the surroundings using the LITES technique.展开更多
基金supported by the National Key R&D Program of China (No. 2018YFF01011800)the National Natural Science Foundation of China (No. 61775070)the Fundamental Research Funds for the Central Universities (Nos. 2017KFYXJJ032 and 2019kfyXMBZ052)
文摘In this Letter, a low-frequency acoustic sensor based on an extrinsic Fabry–Pérot(FP) interferometer with a silicon nitride(Si3N4) membrane is demonstrated. Using micromachining techniques, the 800 nm thick Si3N4 membrane is deposited on an 8 mm × 8 mm × 400 μm silicon(Si) substrate. All the assembly procedures of the sensor are focused on the substrate to avoid any damage to the membrane itself, compared to general membrane transfer methods. The frequency response of the proposed sensor is discussed theoretically and experimentally demonstrated. The sensor exhibits an excellent flat response to the tested acoustic frequency range of 1 Hz to 250 Hz. The phase sensitivity is around-152 dB re 1 rad/μPa with sensitivity fluctuation less than 0.8 dB.The frequency response characteristic shows a promising potential of the sensor in low-frequency acoustic signal sensing applications.
基金This work was supported in part by the Natural Science Foundation of Guangdong Province,No.2020A1515010958Key Project of Shenzhen Science and Technology Plan,No.JCYJ20200109113808048.
文摘Acoustic/ultrasonic sensors are devices that can convert mechanical energy into electrical signals.The Fabry–Perot cavity is processed on the end face of the double-clad fiber by a two-photon three-dimensional lithography machine.In this study,the outer diameter of the core cladding was 250μm,the diameter of the core was 9μm,and the microcavity sensing unit was only 30μm.It could measure ultrasonic signals with high precision.The characteristics of the proposed ultrasonic sensor were investigated,and its feasibility was proven through experiments.Its design has a small size and can replace a larger ultrasonic detector device for photoacoustic signal detection.The sensor is applicable to the field of biomedical information technology,including medical diagnosis,photoacoustic endoscopy,and photoacoustic imaging.
基金supported in part by the National Natural Science Foundation of China (Grant Nos. 61875250 and 61975189)the Zhejiang Provincial Natural Science Foundation of China (Grant Nos. LD21F050001 and Y21F040001)+3 种基金the Key Research Project by Department of Water Resources of Zhejiang Province (Grant No. RA2101)the Key Research and Development Project of Zhejiang Province (Grant No. 2021C03019)the Key R&D Projects of Shanxi Province (Grant Nos. 201903D421032 and 01804D131038)the Scientific Research Foundation of Zhejiang University of Water Resources and Electric Power (Grant No. xky2022032)。
文摘A metal-insulator-metal(MIM)-based arc-shaped resonator coupled with a rectangular stub(MARS) structure is proposed. This structure can generate two tunable Fano resonances originating from two different mechanisms. The structure has the advantage of being sensitive to the refractive index, and this feature makes it favorable for application in various microsensors. The relationship between the structural parameters and Fano resonance is researched using the finite element method(FEM) based on the software COMSOL Multiphysics 5.4. The simulation reveals that the sensitivity reaches1900 nm/refractive index unit(RIU), and the figure of merit(FOM) is 23.75.
文摘Pressure sensors based on fiber-optic extrinsic Fabry-Perot interferometer(EFPI)have been extensively applied in various industrial and biomedical fields.In this paper,some key improvements of EFPI-based pressure sensors such as the controlled thermal bonding technique,diaphragm-based EFPI sensors,and white light interference technology have been reviewed.Recent progress on signal demodulation method and applications of EFPI-based pressure sensors has been introduced.Signal demodulation algorithms based on the cross correlation and mean square error(MSE)estimation have been proposed for retrieving the cavity length of EFPI.Absolute measurement with a resolution of 0.08 nm over large dynamic range has been carried out.For downhole monitoring,an EFPI and a fiber Bragg grating(FBG)cascade multiplexing fiber-optic sensor system has been developed,which can operate in temperature 300℃with a good long-term stability and extremely low temperature cross-sensitivity.Diaphragm-based EFPI pressure sensors have been successfully used for low pressure and acoustic wave detection.Experimental results show that a sensitivity of 31 mV/Pa in the frequency range of 100 Hz to 12.7 kHz for aeroacoustic wave detection has been obtained.
基金The authors thank for the support of the National Natural Science Foundation of China(Nos.11674290,U1704138,61804136,U1804155,and 11974317)Henan Science Fund for Distinguished Young Scholars(No.212300410020)+1 种基金Key Project of Henan Higher Education(No.21A140001)the Zhengzhou University Physics Discipline Improvement Program,and China Postdoctoral Science Foundation(Nos.2018M630829 and 2019T120630).
文摘Flexible photodetectors(PDs)are indispensable components for next-generation wearable electronics.Recently,two-dimensional(2D)materials have been implemented as functional flexible optoelectronic devices due to their characteristics of atomically thin layers,excellent flexibility,and strain sensitivity.In this work,we developed a flexible photodetector based on MoS_(2)/NiO heterojunction,and Fabry-Perot(F-P)and piezo-phototronic effect have been employed to enhance the responsivity(R)and external quantum efficiency(EQE)of the devices.The F-P effect is utilized to improve the optical absorption of the MoS_(2),resulting in an enhancement in the photoluminescence(PL)of monolayer MoS_(2) and the EQE of the photodetector by 30 and 130 times,respectively.The flexible photodetector exhibits an ultrahigh detectivity(D*)of 2.6×10^(14) Jones,which is the highest value ever reported for flexible MoS_(2) PDs.The piezo-potential of monolayer MoS_(2) decreases the valence band offset at the interface of MoS_(2)/NiO,which increases the transfer efficiency of the photon-generated carriers significantly.Under 1.17%tensile strain,the R of the flexible photodetector can be enhanced by 271%.This research may provide a universal strategy for the design and performance optimization of 2D materials heterostructures for flexible optoelectronics.
基金This work was supported by the National Natural Science Foundation(Grant Nos.61571298,61671416 and 61571289)the Natural Science Foundation of Shanghai(Grant No.17ZR1414300).
文摘One of the biggest obstacles to the application of orbital angular momentum(OAM)in the microwave field is its divergence problem.This paper presents a full analysis of generating and focusing OAM waves using original and improved Fabry-Perot(F-P)cavities.Utilizing combination of microstrip antenna and original F-P cavity,the gain of the OAM antenna is enhanced from 4.0 dBi to 9.3 dBi and the corresponding divergence angle is decreased from 41to 24.To further improve the performance of the OAM antenna,the improved F-P cavity is introduced.The simulated results show that the gain is further enhanced to 12.0 dBi and the divergence angle is further decreased to be 15.
基金support from the National Natural Science Foundation of China(Grant Nos.62022032,62275065,61875047,61505041)the Key Laboratory of Opto-Electronic Information Acquisition and Manipulation(Anhui University)the Ministry of Education(Grant No.OEIAM202202),and the Fundamental Research Funds for Central Universities.
文摘Fabry-Perot(F-P)-based phase demodulation of heterodyne light-induced thermoelastic spectroscopy(H-LITES)was demonstrated for the first time in this study.The vibration of a quartz tuning fork(QTF)was detected using the F-P interference principle instead of an electrical signal through the piezoelectric effect of the QTF in traditional LITES to avoid thermal noise.Given that an Fabry-Perot interferometer(FPI)is vulnerable to disturbances,a phase demodulation method that has been demonstrated theoretically and experimentally to be an effective solution for instability was used in H-LITES.The sensitivity of the F-P phase demodulation method based on the H-LITES sensor was not associated with the wavelength or power of the probe laser.Thus,stabilising the quadrature working point(Q-point)was no longer necessary.This new method of phase demodulation is structurally simple and was found to be resistant to interference from light sources and the surroundings using the LITES technique.
