A new multi-band and high-speed endoscope diagnostic for the observation of visible light has been successfully developed on the Experimental Advanced Superconducting Tokamak.The mirror with an aperture is designed at...A new multi-band and high-speed endoscope diagnostic for the observation of visible light has been successfully developed on the Experimental Advanced Superconducting Tokamak.The mirror with an aperture is designed at the head of the optical system.Based on two dichroic mirrors,the system is divided into three imaging mirror groups with different bands,i.e.B(380-500 nm),G(500-580 nm)and R(580-750 nm)bands,and its focal length is 16 mm with a relatively large aperture of D/f=1:4.The spatial resolution is less than 5 mm near the object distance of 1750 mm with the camera NAC ACS-1 M60.This optical system will be used to contrastively study both the spatial distribution and time evolution of different impurities in the same field of view.The experimental results confirm that it can be applied to the recognition of plasma boundary and related physical research.展开更多
Chalcogenide superlattices Sb_(2)Te_(3)-GeTe is a candidate for interfacial phase-change memory(iPCM) data storage devices.By employing terahertz emission spectroscopy and the transient reflectance spectroscopy togeth...Chalcogenide superlattices Sb_(2)Te_(3)-GeTe is a candidate for interfacial phase-change memory(iPCM) data storage devices.By employing terahertz emission spectroscopy and the transient reflectance spectroscopy together,we investigate the ultrafast photoexcited carrier dynamics and current transients in Sb_(2)Te_(3)-GeTe superlattices.Sample orientation and excitation polarization dependences of the THz emission confirm that ultrafast thermo-electric,shift and injection currents contribute to the THz generation in Sb_(2)Te_(3)-GeTe superlattices.By decreasing the thickness and increasing the number of GeTe and Sb_(2)Te_(3) layer,the interlayer coupling can be enhanced,which significantly reduces the contribution from circular photo-galvanic effect(CPGE).A photo-induced bleaching in the transient reflectance spectroscopy probed in the range of~1100 nm to~1400 nm further demonstrates a gapped state resulting from the interlayer coupling.These demonstrates play an important role in the development of iPCM-based high-speed optoelectronic devices.展开更多
Bi-activated photonic materials are promising for various applications in high-capacity telecommunication,tunable laser,and advanced bioimaging and sensing.Although various Bi-doped material candidates have been explo...Bi-activated photonic materials are promising for various applications in high-capacity telecommunication,tunable laser,and advanced bioimaging and sensing.Although various Bi-doped material candidates have been explored,manufacturing of Bi heavily doped fiber with excellent optical activity remains a long-standing challenge.Herein,a novel viscosity evolutional behavior mediated strategy for manufacturing of Bi-doped active fiber with high dopant solubility is proposed.The intrinsic relation among the evolution of Bi,reaction temperature and viscosity of the glass system is established.Importantly,the effective avenue to prevent the undesired deactivation of Bi during fiber drawing by tuning the temperature dependent viscosity evolution is built.By applying the strategy,for the first time we demonstrate the success in fabrication of heavily doped Bi active fiber.Furthermore,the principal fiber amplifier device is constructed and broadband optical signal amplification is realized.Our findings indicate the effectiveness of the proposed temperature dependent viscosity mediated strategy for developing novel photonic active fiber,and they also demonstrate the great potential for application in the next-generation high-capacity telecommunication system.展开更多
The direct implicit particle-in-cell is a powerful kinetic method for researching plasma characteristics.However,it is time-consuming to obtain the future electromagnetic field in such a method since the field equatio...The direct implicit particle-in-cell is a powerful kinetic method for researching plasma characteristics.However,it is time-consuming to obtain the future electromagnetic field in such a method since the field equations contain time-dependent matrix coefficients.In this work,we propose to explicitly push particles and obtain the future electromagnetic field based on the information about the particles in the future.The new method retains the form of implicit particle pusher,but the future field is obtained by solving the traditional explicit equation.Several numerical experiments,including the motion of charged particle in electromagnetic field,plasma sheath,and free diffusion of plasma into vacuum,are implemented to evaluate the performance of the method.The results demonstrate that the proposed method can suppress finite-grid-instability resulting from the coarse spatial resolution in electron Debye length through the strong damping of high-frequency plasma oscillation,while accurately describe low-frequency plasma phenomena,with the price of losing the numerical stability at large time-step.We believe that this work is helpful for people to research the bounded plasma by using particle-in-cell simulations.展开更多
A maximum of 5.5 W of cw TEM_(00) mode output at 532nm has been obtained by intracavity frequency doubling with a KTP crystal in an Nd:YVO_(4) laser doubly-pumped with 20 W diode pumping power.The optical-optical conv...A maximum of 5.5 W of cw TEM_(00) mode output at 532nm has been obtained by intracavity frequency doubling with a KTP crystal in an Nd:YVO_(4) laser doubly-pumped with 20 W diode pumping power.The optical-optical conversion efficiency is 27.5%.The influence of thermal lensing at high pumping power in the end-pumped Nd:YVO_(4) laser is discussed.The Nd:YVO_(4) laser has a good power stability of 1.6%.展开更多
The separation between s- and p-polarization components invariably affects thin film edge filters used for tilted incidence and is a difficult problem for many applications, especially for optical communication. This ...The separation between s- and p-polarization components invariably affects thin film edge filters used for tilted incidence and is a difficult problem for many applications, especially for optical communication. This paper presents a novel design method to obtain edge filters with non-polarization at incidence angle of 45°. The polarization separation at 50% trans-mittance for a long-wave-pass filter and a short-wave-pass filter is 0.3 nm and 0.1 nm respectively. The design method is based on a broadband Fabry-Perot thin-film interference filter in which the higher or lower interference band at both sides of the main transmittance peak can be used for initial design of long-wave-pass filter or short-wave-pass filter and then can be refined to reduce the transmittance ripples. The spacer 2H2L2H or 2L2H2L of the filter is usually taken. Moreover, the method for expanding the bandwidth of rejection and transmission is explained. The bandwidth of 200 nm for both rejection region and transmission band is obtained at wavelength 1550 nm. In this way, the long-wave-pass and short-wave-pass edge filters with zero separation between two polarization components can easily be fabricated.展开更多
Flexible strain sensors play an important role in electronic skins,wearable medical devices,and advanced robots.Herein,a highly sensitive and fast response optical strain sensor with two evanescently coupled optical m...Flexible strain sensors play an important role in electronic skins,wearable medical devices,and advanced robots.Herein,a highly sensitive and fast response optical strain sensor with two evanescently coupled optical micro/nanofibers(MNFs)embedded in a polydimethylsiloxane(PDMS)film is proposed.The strain sensor exhibits a gauge factor as high as 64.5 for strain≤0.5%and a strain resolution of 0.0012%which corresponds to elongation of 120 nm on a 1 cm long device.As a proof-of-concept,highly sensitive fingertip pulse measurement is realized.The properties of fast temporal frequency response up to 30 kHz and a pressure sensitivity of 102 kPa^(−1) enable the sensor for sound detection.Such versatile sensor could be of great use in physiological signal monitoring,voice recognition and micro-displacement detection.展开更多
Colorimetric characterization is to transform the device-dependent responses to device-independent colorimetric values, and is usually conducted in CIEXYZ space. However, the optimal solution in CIEXYZ space does not ...Colorimetric characterization is to transform the device-dependent responses to device-independent colorimetric values, and is usually conducted in CIEXYZ space. However, the optimal solution in CIEXYZ space does not mean the mini-mization of perceptual error. A novel method for colorimetric characterization of imaging device based on the minimization of total color difference is proposed. The method builds the transform between RGB space and CIELAB space directly using the downhill simplex algorithm. Experimental results showed that the proposed method performs better than traditional least-square (LS) and total-least-square (TLS) methods, especially for colors with low luminance values.展开更多
Polarizing beam splitter (PBS) is a critical optical component in projection display system because PBS performance greatly influences the contrast and brightness of the system. PBS performance is usually measured by ...Polarizing beam splitter (PBS) is a critical optical component in projection display system because PBS performance greatly influences the contrast and brightness of the system. PBS performance is usually measured by spectrophotometer after coating and cementing, but the measured result cannot represent the actual performance in practice because people usually change the incident angle in one plane (horizontal plane) and do not consider the other plane (vertical plane). Geometrical polarization rotation occurring at reduced F-number influences the measuring precision of s-polarization transmittance (Ts) and p-polarization reflectance (Rp). A more accurate and practical way to measure the performance of broadband, wide-angle PBS is presented in this paper.展开更多
Digital structured light （SL） profilometry is increasingly used in three-dimensional （3D） measurement technology. However, the nonlinearity of the off-the-shelf projectors and cameras seriously reduces the measure...Digital structured light （SL） profilometry is increasingly used in three-dimensional （3D） measurement technology. However, the nonlinearity of the off-the-shelf projectors and cameras seriously reduces the measurement accuracy. In this paper, first, we review the nonlinear effects of the projector-camera system in the phase-shifting structured light depth measurement method. We show that high order harmonic wave components lead to phase error in the phase-shifting method. Then a practical method based on frequency domain filtering is proposed for nonlinear error reduction. By using this method, the nonlinear calibration of the SL system is not required. Moreover, both the nonlinear effects of the projector and the camera can be effectively reduced. The simulations and experiments have verified our nonlinear correction method.展开更多
A new power divider, composed of a novel composite right/left-handed (CRLH) transmission line (TL) unit, is proposed. The properties of the power divider based on four CRLH TL unit cells are investigated theoretically...A new power divider, composed of a novel composite right/left-handed (CRLH) transmission line (TL) unit, is proposed. The properties of the power divider based on four CRLH TL unit cells are investigated theoretically. By adjusting the parameters of the capacitors and the inductors, the power divider shows perfectly symmetric power division at 5.13 GHz, return loss up to ?24 dB, with the transmitted power being close to ?3.1 dB. The phenomena are demonstrated by simulation results. Being compact in size and low-cost, the proposed power divider is very suitable for microwave and millimeter wave integrated circuits.展开更多
Since the 1990s,continuous technical and scientific advances have defied the diffraction limit in microscopy and enabled three-dimensional(3D)super-resolution imaging.An important milestone in this pursuit is the cohe...Since the 1990s,continuous technical and scientific advances have defied the diffraction limit in microscopy and enabled three-dimensional(3D)super-resolution imaging.An important milestone in this pursuit is the coherent utilization of two opposing objectives(4Pi geometry)and its combination with superresolution microscopy.Herein,we review the recent progress in 4Pi nanoscopy,which provides a 3D,non-invasive,diffraction-unlimited,and isotropic resolution in transparent samples.This review includes both the targeted and stochastic switching modalities of 4Pi nanoscopy.The schematics,principles,applications,and future potential of 4Pi nanoscopy are discussed in detail.展开更多
The power conversion efficiency (PCE) of perovskite solar cells (PSCs) swiftly increased from 3.8% to more than 20% during last 10 years, thanks to the advancement of perovskite film growth, device and interface engin...The power conversion efficiency (PCE) of perovskite solar cells (PSCs) swiftly increased from 3.8% to more than 20% during last 10 years, thanks to the advancement of perovskite film growth, device and interface engineering. However, solution-processed perovskites are usually polycrystalline, that is the photoactive films contain substantial structural disorders, such as grain boundaries, interfaces and crystallographic defects. These defects have detrimental impacts on the performance and stability of PSCs.展开更多
In this Letter we outline a dielectric multilayer spectrally selective filter designed for solar energy applications.The optical performance of this 78-layer interference filter constructed by TiOx and SiO_(2) is pres...In this Letter we outline a dielectric multilayer spectrally selective filter designed for solar energy applications.The optical performance of this 78-layer interference filter constructed by TiOx and SiO_(2) is presented.A hybrid system combining photovoltaic cells with a solar-powered Stirling engine using the designed filter is analyzed.The calculated results show the advantages of this spectrally selective method for solar power generation.展开更多
Near-field scanning optical microscopy is used to investigate the waveguiding properties of optical micro/nanofibres （MNFs） by means of detecting optical power carried by evanescent waves. Taper drawn silica and tel...Near-field scanning optical microscopy is used to investigate the waveguiding properties of optical micro/nanofibres （MNFs） by means of detecting optical power carried by evanescent waves. Taper drawn silica and tellurite MNFs, supported on low-index substrates, are used to guide a 532-nm-wavelength light beam for the test. Modification of the single-mode condition of the MNF in the presence of a substrate is observed. Spatial modulation of the longitudinal field intensity （with a 195-nm period） near the output end of a 760-nm-diameter silica MNF is well resolved. Energy exchange through evanescent coupling between two parallel MNFs is also investigated.展开更多
The phospholipid membrane plays a key role in myriad biological processes and phenomena, and the arrangement structure of membrane determines its function. However, the molecular arrangement structure of phospholipids...The phospholipid membrane plays a key role in myriad biological processes and phenomena, and the arrangement structure of membrane determines its function. However, the molecular arrangement structure of phospholipids in cell membranes is difficult to detect experimentally. On the basis of molecular dynamic simulations both in a non-destructive way and at native environment, we observed and confirmed that the phospholipids self-assemble to a hexagonal arrangement structure under physiological conditions. The underlying mechanism was revealed to be that there are hexagonal arrangement regions with a lower free energy around each lipid molecule. The findings potentially advance the understanding of biological functions of phospholipid bilayers.展开更多
基金supported by National Natural Science Foundation of China(No.12075281)the National Magnetic Confinement Fusion Research Program of China(Nos.2017YFE0301104 and 2017YFE0301105)Important Projects of Collaborative Innovation of the Hefei Science Center,CAS(No.2021HSC-CIP007)。
文摘A new multi-band and high-speed endoscope diagnostic for the observation of visible light has been successfully developed on the Experimental Advanced Superconducting Tokamak.The mirror with an aperture is designed at the head of the optical system.Based on two dichroic mirrors,the system is divided into three imaging mirror groups with different bands,i.e.B(380-500 nm),G(500-580 nm)and R(580-750 nm)bands,and its focal length is 16 mm with a relatively large aperture of D/f=1:4.The spatial resolution is less than 5 mm near the object distance of 1750 mm with the camera NAC ACS-1 M60.This optical system will be used to contrastively study both the spatial distribution and time evolution of different impurities in the same field of view.The experimental results confirm that it can be applied to the recognition of plasma boundary and related physical research.
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2023YFF0719200 and 2022YFA1404004)the National Natural Science Foundation of China(Grant Nos.62322115,61988102,61975110,62335012,and 12074248)+3 种基金111 Project(Grant No.D18014)the Key Project supported by Science and Technology Commission Shanghai Municipality(Grant No.YDZX20193100004960)Science and Technology Commission of Shanghai Municipality(Grant Nos.22JC1400200 and 21S31907400)General Administration of Customs People’s Republic of China(Grant No.2019HK006)。
文摘Chalcogenide superlattices Sb_(2)Te_(3)-GeTe is a candidate for interfacial phase-change memory(iPCM) data storage devices.By employing terahertz emission spectroscopy and the transient reflectance spectroscopy together,we investigate the ultrafast photoexcited carrier dynamics and current transients in Sb_(2)Te_(3)-GeTe superlattices.Sample orientation and excitation polarization dependences of the THz emission confirm that ultrafast thermo-electric,shift and injection currents contribute to the THz generation in Sb_(2)Te_(3)-GeTe superlattices.By decreasing the thickness and increasing the number of GeTe and Sb_(2)Te_(3) layer,the interlayer coupling can be enhanced,which significantly reduces the contribution from circular photo-galvanic effect(CPGE).A photo-induced bleaching in the transient reflectance spectroscopy probed in the range of~1100 nm to~1400 nm further demonstrates a gapped state resulting from the interlayer coupling.These demonstrates play an important role in the development of iPCM-based high-speed optoelectronic devices.
基金support from the National Key R&D Program of China(2020YFB1805901)the National Science Fund for Distinguished Young Scholars(62125502)+7 种基金the National Natural Science Foundation of China(51972113,52302002 and 62305115)the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(2017BT01X137)Foshan Science and Technology Innovation Project(1920001000052)the Foundation of State Key Laboratory of Reactor System Design Technologythe Large Scientific Facility Open Subject of Songshan Lake,Dongguan,Guangdongthe Research Project supported by State Key Lab of Luminescent Materials and DevicesSouth China University of Technology(Skllmd2023-07)the Sponsored Research Project of Corning Incorporated。
文摘Bi-activated photonic materials are promising for various applications in high-capacity telecommunication,tunable laser,and advanced bioimaging and sensing.Although various Bi-doped material candidates have been explored,manufacturing of Bi heavily doped fiber with excellent optical activity remains a long-standing challenge.Herein,a novel viscosity evolutional behavior mediated strategy for manufacturing of Bi-doped active fiber with high dopant solubility is proposed.The intrinsic relation among the evolution of Bi,reaction temperature and viscosity of the glass system is established.Importantly,the effective avenue to prevent the undesired deactivation of Bi during fiber drawing by tuning the temperature dependent viscosity evolution is built.By applying the strategy,for the first time we demonstrate the success in fabrication of heavily doped Bi active fiber.Furthermore,the principal fiber amplifier device is constructed and broadband optical signal amplification is realized.Our findings indicate the effectiveness of the proposed temperature dependent viscosity mediated strategy for developing novel photonic active fiber,and they also demonstrate the great potential for application in the next-generation high-capacity telecommunication system.
基金Project supported by the National Key Research and Development Program of China (Grant No.2022YFE03050001)partly by the National Natural Science Foundation of China (Grant No.12175160)the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)。
文摘The direct implicit particle-in-cell is a powerful kinetic method for researching plasma characteristics.However,it is time-consuming to obtain the future electromagnetic field in such a method since the field equations contain time-dependent matrix coefficients.In this work,we propose to explicitly push particles and obtain the future electromagnetic field based on the information about the particles in the future.The new method retains the form of implicit particle pusher,but the future field is obtained by solving the traditional explicit equation.Several numerical experiments,including the motion of charged particle in electromagnetic field,plasma sheath,and free diffusion of plasma into vacuum,are implemented to evaluate the performance of the method.The results demonstrate that the proposed method can suppress finite-grid-instability resulting from the coarse spatial resolution in electron Debye length through the strong damping of high-frequency plasma oscillation,while accurately describe low-frequency plasma phenomena,with the price of losing the numerical stability at large time-step.We believe that this work is helpful for people to research the bounded plasma by using particle-in-cell simulations.
基金Supported by the National Advanced Materials Committee of the"863 Program"under Grant No.970311043。
文摘A maximum of 5.5 W of cw TEM_(00) mode output at 532nm has been obtained by intracavity frequency doubling with a KTP crystal in an Nd:YVO_(4) laser doubly-pumped with 20 W diode pumping power.The optical-optical conversion efficiency is 27.5%.The influence of thermal lensing at high pumping power in the end-pumped Nd:YVO_(4) laser is discussed.The Nd:YVO_(4) laser has a good power stability of 1.6%.
基金Project (No. 60078001) supported by the National Natural ScienceFoundation of China
文摘The separation between s- and p-polarization components invariably affects thin film edge filters used for tilted incidence and is a difficult problem for many applications, especially for optical communication. This paper presents a novel design method to obtain edge filters with non-polarization at incidence angle of 45°. The polarization separation at 50% trans-mittance for a long-wave-pass filter and a short-wave-pass filter is 0.3 nm and 0.1 nm respectively. The design method is based on a broadband Fabry-Perot thin-film interference filter in which the higher or lower interference band at both sides of the main transmittance peak can be used for initial design of long-wave-pass filter or short-wave-pass filter and then can be refined to reduce the transmittance ripples. The spacer 2H2L2H or 2L2H2L of the filter is usually taken. Moreover, the method for expanding the bandwidth of rejection and transmission is explained. The bandwidth of 200 nm for both rejection region and transmission band is obtained at wavelength 1550 nm. In this way, the long-wave-pass and short-wave-pass edge filters with zero separation between two polarization components can easily be fabricated.
基金We are grateful for financial supports from the National Natural Science Foundation of China(No.61975173)the National Key Research and Development Program of China(No.SQ2019YFC170311)+3 种基金the Major Scientific Research Project of Zhejiang Lab(No.2019MC0AD01)the Key Research and Development Project of Zhejiang Province(No.2021C05003)the Quantum Joint Funds of the Natural Foundation of Shandong Province(No.ZR2020LLZ007)the CIE-Tencent Robotics X Rhino-Bird Focused Research Program(No.2020-01-006).
文摘Flexible strain sensors play an important role in electronic skins,wearable medical devices,and advanced robots.Herein,a highly sensitive and fast response optical strain sensor with two evanescently coupled optical micro/nanofibers(MNFs)embedded in a polydimethylsiloxane(PDMS)film is proposed.The strain sensor exhibits a gauge factor as high as 64.5 for strain≤0.5%and a strain resolution of 0.0012%which corresponds to elongation of 120 nm on a 1 cm long device.As a proof-of-concept,highly sensitive fingertip pulse measurement is realized.The properties of fast temporal frequency response up to 30 kHz and a pressure sensitivity of 102 kPa^(−1) enable the sensor for sound detection.Such versatile sensor could be of great use in physiological signal monitoring,voice recognition and micro-displacement detection.
文摘Colorimetric characterization is to transform the device-dependent responses to device-independent colorimetric values, and is usually conducted in CIEXYZ space. However, the optimal solution in CIEXYZ space does not mean the mini-mization of perceptual error. A novel method for colorimetric characterization of imaging device based on the minimization of total color difference is proposed. The method builds the transform between RGB space and CIELAB space directly using the downhill simplex algorithm. Experimental results showed that the proposed method performs better than traditional least-square (LS) and total-least-square (TLS) methods, especially for colors with low luminance values.
基金(No. 2004C31107) supported by the Science and Technology Program of Zhejiang Province, China
文摘Polarizing beam splitter (PBS) is a critical optical component in projection display system because PBS performance greatly influences the contrast and brightness of the system. PBS performance is usually measured by spectrophotometer after coating and cementing, but the measured result cannot represent the actual performance in practice because people usually change the incident angle in one plane (horizontal plane) and do not consider the other plane (vertical plane). Geometrical polarization rotation occurring at reduced F-number influences the measuring precision of s-polarization transmittance (Ts) and p-polarization reflectance (Rp). A more accurate and practical way to measure the performance of broadband, wide-angle PBS is presented in this paper.
基金Project supported by the Science and Technology Major Projects of Zhejiang Province,China(Grant No.2013C03043-5)
文摘Digital structured light （SL） profilometry is increasingly used in three-dimensional （3D） measurement technology. However, the nonlinearity of the off-the-shelf projectors and cameras seriously reduces the measurement accuracy. In this paper, first, we review the nonlinear effects of the projector-camera system in the phase-shifting structured light depth measurement method. We show that high order harmonic wave components lead to phase error in the phase-shifting method. Then a practical method based on frequency domain filtering is proposed for nonlinear error reduction. By using this method, the nonlinear calibration of the SL system is not required. Moreover, both the nonlinear effects of the projector and the camera can be effectively reduced. The simulations and experiments have verified our nonlinear correction method.
基金Project supported by the National Natural Science Foundation of China (Nos. 60577023 and 60378037), the National Basic Research Program (973) of China (No. 2004CB719802), China Postdoctoral Science Foundation, and Education Ministry Key Laboratory of Photoelectric Information Technology Science Foundation (No. 2005-20), China
文摘A new power divider, composed of a novel composite right/left-handed (CRLH) transmission line (TL) unit, is proposed. The properties of the power divider based on four CRLH TL unit cells are investigated theoretically. By adjusting the parameters of the capacitors and the inductors, the power divider shows perfectly symmetric power division at 5.13 GHz, return loss up to ?24 dB, with the transmitted power being close to ?3.1 dB. The phenomena are demonstrated by simulation results. Being compact in size and low-cost, the proposed power divider is very suitable for microwave and millimeter wave integrated circuits.
基金financially supported by the grants from National Key Research and Development Program of China (2018YFA0701400 and 2018YFE0119000)the Fundamental Research Funds for the Central Universities (2019QNA5006)+2 种基金ZJU-Sunny Photonics Innovation Center (2019-01)Zhejiang Provincial Natural Science Foundation of China (LR18H180001)startup grant from Southern University of Science and Technology
文摘Since the 1990s,continuous technical and scientific advances have defied the diffraction limit in microscopy and enabled three-dimensional(3D)super-resolution imaging.An important milestone in this pursuit is the coherent utilization of two opposing objectives(4Pi geometry)and its combination with superresolution microscopy.Herein,we review the recent progress in 4Pi nanoscopy,which provides a 3D,non-invasive,diffraction-unlimited,and isotropic resolution in transparent samples.This review includes both the targeted and stochastic switching modalities of 4Pi nanoscopy.The schematics,principles,applications,and future potential of 4Pi nanoscopy are discussed in detail.
文摘The power conversion efficiency (PCE) of perovskite solar cells (PSCs) swiftly increased from 3.8% to more than 20% during last 10 years, thanks to the advancement of perovskite film growth, device and interface engineering. However, solution-processed perovskites are usually polycrystalline, that is the photoactive films contain substantial structural disorders, such as grain boundaries, interfaces and crystallographic defects. These defects have detrimental impacts on the performance and stability of PSCs.
基金Supported by the Research Foundation of Science and Technology Department of Zhejiang Province(2009C21023).
文摘In this Letter we outline a dielectric multilayer spectrally selective filter designed for solar energy applications.The optical performance of this 78-layer interference filter constructed by TiOx and SiO_(2) is presented.A hybrid system combining photovoltaic cells with a solar-powered Stirling engine using the designed filter is analyzed.The calculated results show the advantages of this spectrally selective method for solar power generation.
基金Supported by the National Natural Science Foundation of China under Grant Nos 60425517 and 60378036.
文摘Near-field scanning optical microscopy is used to investigate the waveguiding properties of optical micro/nanofibres （MNFs） by means of detecting optical power carried by evanescent waves. Taper drawn silica and tellurite MNFs, supported on low-index substrates, are used to guide a 532-nm-wavelength light beam for the test. Modification of the single-mode condition of the MNF in the presence of a substrate is observed. Spatial modulation of the longitudinal field intensity （with a 195-nm period） near the output end of a 760-nm-diameter silica MNF is well resolved. Energy exchange through evanescent coupling between two parallel MNFs is also investigated.
基金Project supported by the National Natural Science Foundation of China(Grant No.11904231)the National Key R&D Program of China(Grant Nos.2018YFE0205501 and 2018YFB1801500)Shanghai Sailing Program,China(Grant No.19YF1434100)。
文摘The phospholipid membrane plays a key role in myriad biological processes and phenomena, and the arrangement structure of membrane determines its function. However, the molecular arrangement structure of phospholipids in cell membranes is difficult to detect experimentally. On the basis of molecular dynamic simulations both in a non-destructive way and at native environment, we observed and confirmed that the phospholipids self-assemble to a hexagonal arrangement structure under physiological conditions. The underlying mechanism was revealed to be that there are hexagonal arrangement regions with a lower free energy around each lipid molecule. The findings potentially advance the understanding of biological functions of phospholipid bilayers.
