Lying between radio frequency and infrared radiation, terahertz （THz） wave encounters lots of difficulties to produce, detect, transmit, and modulate. Great efforts have been made to construct THz devices, including...Lying between radio frequency and infrared radiation, terahertz （THz） wave encounters lots of difficulties to produce, detect, transmit, and modulate. Great efforts have been made to construct THz devices, including sources, detectors, switches, modulators, lenses, and filters. However, only moderate progresses have been made in THz generation and detection. Furthermore, the devices and techniques to control and manipulate THz waves are still in its infancy. Therefore, it is still a challenge to date to develop sophisticated THz application systems such as communication, sensing, safety inspection, imaging and medical diagnose systems. This difficult position of THz wave is essential due to the deficiency of THz materials having a suitable THz electromagnetic response, as compared to its neighboring microwave and infrared regime. Practicable material will largely push the THz technology to real-world applications. The GaAs/AlxGa~_xAs material system, for example, is the heart of THz quantum cascade lasers. High quality NbN films, again, set the basis of THz hot electron bolometer.展开更多
With the rapid development of terahertz technology,terahertz detectors are expected to play a key role in diverse areas such as homeland security and imaging,materials diagnostics,biology,medical sciences,and communic...With the rapid development of terahertz technology,terahertz detectors are expected to play a key role in diverse areas such as homeland security and imaging,materials diagnostics,biology,medical sciences,and communication.Whereas self-powered,rapid response,and room temperature terahertz photodetectors are confronted with huge challenges.Here,we report a novel rapid response and self-powered terahertz photothermoelectronic(PTE)photodetector based on a lowdimensional material:palladium selenide(Pd Se_(2)).An order of magnitude performance enhancement was observed in photodetection based on PdSe_(2)/graphene heterojunction that resulted from the integration of graphene and enhanced the Seebeck effect.Under 0.1-THz and 0.3-THz irradiations,the device displays a stable and repeatable photoresponse at room temperature without bias.Furthermore,rapid rise(5.0μs)and decay(5.4μs)times are recorded under 0.1-THz irradiation.Our results demonstrate the promising prospect of the detector based on Pd Se2 in terms of air-stable,suitable sensitivity and speed,which may have great application in terahertz detection.展开更多
Terahertz (THz)-wave generation has been conducted based on difference frequency mixing (DFM) process with phonon-polariton excitation of ε-GaSe single crystals implemented with liquid-phase solution growth using the...Terahertz (THz)-wave generation has been conducted based on difference frequency mixing (DFM) process with phonon-polariton excitation of ε-GaSe single crystals implemented with liquid-phase solution growth using the temperature difference method under controlled vapour pressure for the first time. The type-eoo phase matching condition for the DFM process at around 10 THz is satisfied by changing the incident angle into the crystal. The maximum conversion efficiency in the present DFG process is about 10-6?J-1?using a 0.1-mm-thick GaSe single crystal with the only ε- phase polytype, which can be greater than that of the commercially available Bridgman grown GaSe crystal including both ε- and γ-phase polytypes.展开更多
Terahertz(THz)technology has attracted great attention in the past few decades for its unique applications in various fields,including spectroscopy,noninvasive detection,wireless communications,and imaging.In parallel...Terahertz(THz)technology has attracted great attention in the past few decades for its unique applications in various fields,including spectroscopy,noninvasive detection,wireless communications,and imaging.In parallel to this,the practical,fast,and broadband modulation of THz waves is becoming indispensable.Two-dimensional(2D)materials exhibit unusual optical and electrical properties,which has prompted tremendous interest and significant advances in THz modulation.This review provides the recent progress in 2D materials-based THz modulators,outlining the operating principles,including all-optical,electro-optic,magneto-optic,and other exotic mechanisms.We focus on the recent advances in THz modulation by the designed photonic structures,such as heterostructure,metamaterial,capacitor,optical cavity,and waveguide integration.Lastly,we discussed the challenges and opportunities for 2D materials-based THz modulators and presented our prospects for the future development.展开更多
We presented the dielectric properties of three materials for bio-sample measurement using THz transmission spectroscopy.The materials,PE,COC and PVDF,have sufficient transmittance.The results demonstrate that PVDF me...We presented the dielectric properties of three materials for bio-sample measurement using THz transmission spectroscopy.The materials,PE,COC and PVDF,have sufficient transmittance.The results demonstrate that PVDF membranes are suitable media for THz transmission spectrum above 0.3 THz.However,it is not property to measure the solution sample because of the water existed after active processing by ethanol.In this paper,the refractive index,the absorption coefficient,and the complex dielectric functions in the THz region are compared for each material.From the measured dielectric properties,the loss mechanism of THz radiation for each material is also discussed.展开更多
文摘Lying between radio frequency and infrared radiation, terahertz （THz） wave encounters lots of difficulties to produce, detect, transmit, and modulate. Great efforts have been made to construct THz devices, including sources, detectors, switches, modulators, lenses, and filters. However, only moderate progresses have been made in THz generation and detection. Furthermore, the devices and techniques to control and manipulate THz waves are still in its infancy. Therefore, it is still a challenge to date to develop sophisticated THz application systems such as communication, sensing, safety inspection, imaging and medical diagnose systems. This difficult position of THz wave is essential due to the deficiency of THz materials having a suitable THz electromagnetic response, as compared to its neighboring microwave and infrared regime. Practicable material will largely push the THz technology to real-world applications. The GaAs/AlxGa~_xAs material system, for example, is the heart of THz quantum cascade lasers. High quality NbN films, again, set the basis of THz hot electron bolometer.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61521005,61875217,91850208,61474130,and 62075230)the Natural Science Foundation of Shanghai,China(Grant Nos.19ZR1465400,21ZR1473800+1 种基金20142200600)the Fund from Zhejiang Laboratory(Grant No.2021MB0AB01)。
文摘With the rapid development of terahertz technology,terahertz detectors are expected to play a key role in diverse areas such as homeland security and imaging,materials diagnostics,biology,medical sciences,and communication.Whereas self-powered,rapid response,and room temperature terahertz photodetectors are confronted with huge challenges.Here,we report a novel rapid response and self-powered terahertz photothermoelectronic(PTE)photodetector based on a lowdimensional material:palladium selenide(Pd Se_(2)).An order of magnitude performance enhancement was observed in photodetection based on PdSe_(2)/graphene heterojunction that resulted from the integration of graphene and enhanced the Seebeck effect.Under 0.1-THz and 0.3-THz irradiations,the device displays a stable and repeatable photoresponse at room temperature without bias.Furthermore,rapid rise(5.0μs)and decay(5.4μs)times are recorded under 0.1-THz irradiation.Our results demonstrate the promising prospect of the detector based on Pd Se2 in terms of air-stable,suitable sensitivity and speed,which may have great application in terahertz detection.
文摘Terahertz (THz)-wave generation has been conducted based on difference frequency mixing (DFM) process with phonon-polariton excitation of ε-GaSe single crystals implemented with liquid-phase solution growth using the temperature difference method under controlled vapour pressure for the first time. The type-eoo phase matching condition for the DFM process at around 10 THz is satisfied by changing the incident angle into the crystal. The maximum conversion efficiency in the present DFG process is about 10-6?J-1?using a 0.1-mm-thick GaSe single crystal with the only ε- phase polytype, which can be greater than that of the commercially available Bridgman grown GaSe crystal including both ε- and γ-phase polytypes.
基金111 Project 2.0,Grant/Award Number:BP2018013National Key Research and Development Program of China,Grant/Award Numbers:2016YFB1102201,2018YFB0406502+1 种基金National Natural Science Foundation of China,Grant/Award Numbers:11804022,51572155,51932004,61975098Shandong University Multidisciplinary Research and Innovation Team of Young Scholars,Grant/Award Number:2020QNQT015。
文摘Terahertz(THz)technology has attracted great attention in the past few decades for its unique applications in various fields,including spectroscopy,noninvasive detection,wireless communications,and imaging.In parallel to this,the practical,fast,and broadband modulation of THz waves is becoming indispensable.Two-dimensional(2D)materials exhibit unusual optical and electrical properties,which has prompted tremendous interest and significant advances in THz modulation.This review provides the recent progress in 2D materials-based THz modulators,outlining the operating principles,including all-optical,electro-optic,magneto-optic,and other exotic mechanisms.We focus on the recent advances in THz modulation by the designed photonic structures,such as heterostructure,metamaterial,capacitor,optical cavity,and waveguide integration.Lastly,we discussed the challenges and opportunities for 2D materials-based THz modulators and presented our prospects for the future development.
基金The Natural Science Foundation of SZUgrant number:201115+5 种基金National Natural Science Foundation of Chinagrant number:61001185,61078018 and 61001057Foundation of Guangdong,Chinagrant number:LYM10113Research Fund for the Doctoral Program of Higher Educationgrant number:20104408120002
文摘We presented the dielectric properties of three materials for bio-sample measurement using THz transmission spectroscopy.The materials,PE,COC and PVDF,have sufficient transmittance.The results demonstrate that PVDF membranes are suitable media for THz transmission spectrum above 0.3 THz.However,it is not property to measure the solution sample because of the water existed after active processing by ethanol.In this paper,the refractive index,the absorption coefficient,and the complex dielectric functions in the THz region are compared for each material.From the measured dielectric properties,the loss mechanism of THz radiation for each material is also discussed.
