Recent conceptual demonstrations of direct photocurrent readout of light vortices have enabled the development of light orbital angular momentum-sensitive focal plane arrays and on-chip integration of orbital angular ...Recent conceptual demonstrations of direct photocurrent readout of light vortices have enabled the development of light orbital angular momentum-sensitive focal plane arrays and on-chip integration of orbital angular momentum detection.However,known orbital angular momentum-sensitive materials are limited to two topological Weyl Semimetals belonging to the C2v point group,namely,WTe2 and TaIrTe4.Both are fragile under ambient conditions and challenging for large-scale epitaxial growth.In this work,we demonstrate that multilayer graphene,which is complementary metal–oxide–semiconductor compatible and epitaxially growable at the wafer scale,is applicable for orbital angular momentum detection in the mid-infrared region.Using a multilayer graphene photodetector with a designed U-shaped electrode geometry,we demonstrate that the topological charge of orbital angular momentum can be detected directly through the orbital photogalvanic effect and that the orbital angular momentum recognition capability of multilayer graphene is an order of magnitude greater than that of TaIrTe4.We found that the detection capability of multilayer graphene is enabled by the enhanced orbital photogalvanic effect response due to the reduced dimensionality and scattering rate.Our work opens a new technical route to improve orbital angular momentum recognition capability and is immediately applicable for large-scale integration of ambient stable,midinfrared direct orbital angular momentum photodetection devices.展开更多
Recent progress in direct photodetection of light orbital angular momentum(OAM)based on the orbital photogalvanic effect(OPGE)provides an effective way for on-chip direct electric readout of orbital angular momentum,a...Recent progress in direct photodetection of light orbital angular momentum(OAM)based on the orbital photogalvanic effect(OPGE)provides an effective way for on-chip direct electric readout of orbital angular momentum,as well as large-scale integration focal-plane array devices.However,the recognition of OAM order from photocurrent response requires the extraction of circular polarization-dependent response.To date,the operation speed of such a detector is currently at the minute level and is limited by slow mechanical polarization modulation and low OAM recognition capability.We demonstrate that the operation speed can be greatly improved via an electrical polarization modulation strategy with a photoelastic modulator(PEM)accompanied by a phase-locked readout approach with a lock-in amplifier.We demonstrate an operation speed of up to kilohertz level with this new technology in the mid-infrared region(4μm)on an OAM detector using multilayer graphene as photosensitive material.In principle,with a new modulation and readout scheme,we can potentially increase the operation speed to megahertz with a PEM that operates at a state-ofthe-art speed.Our work paves the way toward high-speed operation of direct OAM detection devices based on the OPGE effect and pushes such technology to a more practical stage for focal plane array applications.展开更多
The on-chip measurement of polarization states plays an increasingly crucial role in modern sensing and imaging applications.While high-performance monolithic linearly polarized photodetectors have been extensively st...The on-chip measurement of polarization states plays an increasingly crucial role in modern sensing and imaging applications.While high-performance monolithic linearly polarized photodetectors have been extensively studied,integrated circularly polarized light(CPL)photodetectors are still hindered by inadequate discrimination capability.This study presents a broadband CPL photodetector utilizing achiral all-dielectric nanostructures,achieving an impressive discrimination ratio of~107 at a wavelength of 405 nm.Our device shows outstanding CPL discrimination capability across the visible band without requiring intensity calibration.It functions based on the CPL-dependent near-field modes within achiral structures:under left or right CPL illumination,distinct near-field modes are excited,resulting in asymmetric irradiation of the two electrodes and generating a photovoltage with directions determined by the chirality of the incident light field.The proposed design strategy facilitates ultra-compact CPL detection across diverse materials,structures,and spectral ranges,presenting a novel avenue for achieving high-performance monolithic CPL detection.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.62250065 and 62325401)the National Key Research and Development Program of China(Grant Nos.2021YFA1400100 and 2020YFA0308800)+2 种基金the authors also would like to thank the support from the National Natural Science Foundation of China(Grant Nos.12404389,12034001,12034003 and 62227822)the Natural Science Basic Research Program of Shaanxi(Program No.2024JC-YBQN-0063)the Open Fund of the State Key Laboratory of Infrared Physics(Grant No.SITP-NLIST-ZD-2023-02).
文摘Recent conceptual demonstrations of direct photocurrent readout of light vortices have enabled the development of light orbital angular momentum-sensitive focal plane arrays and on-chip integration of orbital angular momentum detection.However,known orbital angular momentum-sensitive materials are limited to two topological Weyl Semimetals belonging to the C2v point group,namely,WTe2 and TaIrTe4.Both are fragile under ambient conditions and challenging for large-scale epitaxial growth.In this work,we demonstrate that multilayer graphene,which is complementary metal–oxide–semiconductor compatible and epitaxially growable at the wafer scale,is applicable for orbital angular momentum detection in the mid-infrared region.Using a multilayer graphene photodetector with a designed U-shaped electrode geometry,we demonstrate that the topological charge of orbital angular momentum can be detected directly through the orbital photogalvanic effect and that the orbital angular momentum recognition capability of multilayer graphene is an order of magnitude greater than that of TaIrTe4.We found that the detection capability of multilayer graphene is enabled by the enhanced orbital photogalvanic effect response due to the reduced dimensionality and scattering rate.Our work opens a new technical route to improve orbital angular momentum recognition capability and is immediately applicable for large-scale integration of ambient stable,midinfrared direct orbital angular momentum photodetection devices.
基金supported by the National Natural Science Foundation of China(Grant Nos.62250065,62325401,12404389,12034001,12034003,and 62227822)the National Key Research and Development Program of China(Grant Nos.2021YFA1400100 and 2020YFA0308800)+1 种基金the Natural Science Basic Research Program of Shaanxi(Grant No.2024JC-YBQN-0063)the Open Fund of the State Key Laboratory of Infra-red Physics(Grant No.SITP-NLIST-ZD-2023-02)。
文摘Recent progress in direct photodetection of light orbital angular momentum(OAM)based on the orbital photogalvanic effect(OPGE)provides an effective way for on-chip direct electric readout of orbital angular momentum,as well as large-scale integration focal-plane array devices.However,the recognition of OAM order from photocurrent response requires the extraction of circular polarization-dependent response.To date,the operation speed of such a detector is currently at the minute level and is limited by slow mechanical polarization modulation and low OAM recognition capability.We demonstrate that the operation speed can be greatly improved via an electrical polarization modulation strategy with a photoelastic modulator(PEM)accompanied by a phase-locked readout approach with a lock-in amplifier.We demonstrate an operation speed of up to kilohertz level with this new technology in the mid-infrared region(4μm)on an OAM detector using multilayer graphene as photosensitive material.In principle,with a new modulation and readout scheme,we can potentially increase the operation speed to megahertz with a PEM that operates at a state-ofthe-art speed.Our work paves the way toward high-speed operation of direct OAM detection devices based on the OPGE effect and pushes such technology to a more practical stage for focal plane array applications.
基金supported by the Guangdong Major Project of Basic and Applied Basic Research(Grant No.2020B0301030009)the National Key Research and Development Program of China(Grant No.2022YFA1604304)the National Natural Science Foundation of China(Grant No.92250305).
文摘The on-chip measurement of polarization states plays an increasingly crucial role in modern sensing and imaging applications.While high-performance monolithic linearly polarized photodetectors have been extensively studied,integrated circularly polarized light(CPL)photodetectors are still hindered by inadequate discrimination capability.This study presents a broadband CPL photodetector utilizing achiral all-dielectric nanostructures,achieving an impressive discrimination ratio of~107 at a wavelength of 405 nm.Our device shows outstanding CPL discrimination capability across the visible band without requiring intensity calibration.It functions based on the CPL-dependent near-field modes within achiral structures:under left or right CPL illumination,distinct near-field modes are excited,resulting in asymmetric irradiation of the two electrodes and generating a photovoltage with directions determined by the chirality of the incident light field.The proposed design strategy facilitates ultra-compact CPL detection across diverse materials,structures,and spectral ranges,presenting a novel avenue for achieving high-performance monolithic CPL detection.
