We report on an idler-resonant femtosecond optical parametrical oscillator(OPO)based on BiB_(3)O_(6)(BiBO)crystal,synchronously pumped by a frequency-doubled,mode-locked Yb:KGW laser at 515 nm.The idler wavelengths of...We report on an idler-resonant femtosecond optical parametrical oscillator(OPO)based on BiB_(3)O_(6)(BiBO)crystal,synchronously pumped by a frequency-doubled,mode-locked Yb:KGW laser at 515 nm.The idler wavelengths of OPO can be tuned from 1100 nm to 1540 nm.At a repetition rate of 75.5 MHz,the OPO generates as much as 400 mW of idler power with 3.1 W of pump power,the corresponding pulse duration is 80 fs,which is 1.04 times of Fourier transform-limited(FTL)pulse duration at 1305 nm.In addition,the OPO exhibits excellent beam quality with M^(2)<1.8 at 1150 nm.To the best of our knowledge,this is the first idler-resonant femtosecond OPO pumped by 515 nm.展开更多
Soliton microcombs,which require the hosting cavity to operate in an anomalous dispersion regime,are essential to integrate photonic systems.In the past,soliton microcombs were generated on cavity whispering gallery m...Soliton microcombs,which require the hosting cavity to operate in an anomalous dispersion regime,are essential to integrate photonic systems.In the past,soliton microcombs were generated on cavity whispering gallery modes(WGMs),and the anomalous dispersion requirement of the cavity made by normal dispersion material was achieved through structural dispersion engineering.This inevitably degrades the cavity optical quality factor(Q)and increases pump threshold power for soliton comb generation.To overcome the challenges,here,we report a soliton microcomb excited by cavity polygon modes.These modes display anomalous dispersion at near-infrared while optical Q factors exceeding 4×10^(6) are maintained.Consequently,a soliton comb spanning from 1450 nm to 1620 nm with a record low pump power of 11 m W is demonstrated,a three-fold improvement compared to the state of the art on the same material platform.展开更多
Long-term optical data storage(ODS)technology is essential to break the bottleneck of high energy consumption for information storage in the current era of big data.Here,ODS with an ultralong lifetime of 2×10^(7)...Long-term optical data storage(ODS)technology is essential to break the bottleneck of high energy consumption for information storage in the current era of big data.Here,ODS with an ultralong lifetime of 2×10^(7)years is attained with single ultrafast laser pulse induced reduction of Eu^(3+)ions and tailoring of optical properties inside the Eu-doped aluminosilicate glasses.We demonstrate that the induced local modifications in the glass can stand against the temperature of up to 970 K and strong ultraviolet light irradiation with the power density of 100 kW/cm^(2).Furthermore,the active ions of Eu^(2+)exhibit strong and broadband emission with the full width at half maximum reaching 190 nm,and the photoluminescence(PL)is flexibly tunable in the whole visible region by regulating the alkaline earth metal ions in the glasses.The developed technology and materials will be of great significance in photonic applications such as long-term ODS.展开更多
Investigating deuteron–deuteron(DD)fusion reactions in a plasma environment similar to the early stages of the Big Bang is an important topic in nuclear astrophysics.In this study,we experimentally investigated such ...Investigating deuteron–deuteron(DD)fusion reactions in a plasma environment similar to the early stages of the Big Bang is an important topic in nuclear astrophysics.In this study,we experimentally investigated such reactions,using eight laser beams with the third harmonic impacting on a deuterated polyethylene target at the ShenGuang-II Upgrade laser facility.This work focused on the application of range-filter(RF)spectrometers,assembled from a 70 lm aluminum filter and two CR-39 nuclear track detectors,to measure the yields of primary DD-protons.Based on the track diameter calibration results of 3 MeV protons used to diagnose the tracks on the RF spectrometers,an approximate primary DD-proton yield of(8.5±1.7)×10^6 was obtained,consistent with the yields from similar laser facilities worldwide.This indicates that the RF spectrometer is an effective way to measure primary DD-protons.However,due to the low yields of D^3He-protons and its small track diameter,CR-39 detectors were unable to distinguish it from the background spots.Using other accurate detectors may help to measure these rare events.展开更多
The energetic-particle-induced geodesic acoustic mode(EGAM)is studied using gyrokinetic particle simulations in tokamak plasmas.In our simulations,exponentially growing EGAMs are excited by energetic particles with a ...The energetic-particle-induced geodesic acoustic mode(EGAM)is studied using gyrokinetic particle simulations in tokamak plasmas.In our simulations,exponentially growing EGAMs are excited by energetic particles with a slowing-down distribution.The frequencies of EGAMs are always below the frequencies of GAMs,which is due to the non-perturbative contribution of energetic particles(EPs).The mode structures of EGAMs are similar to the corresponding mode structures of GAMs.Our gyrokinetic simulations show that a high EP density can enhance the EGAM growth rate,due to high EP free energy,and that EPs’temperature and the pitch angle of the distribution modify the EGAM frequency/growth rate by means of the resonance condition.Kinetic effects of the thermal electrons barely change the EGAM frequency,and have a weak damping effect on the EGAM.Benchmarks between the gyrokinetic particle simulations and a local EGAM dispersion relation exhibit good agreement in terms of EGAM frequency and growth rate.展开更多
In this paper,we propose a novel stacked laser dielectric acceleration structure.This structure is based on the inverse Cherenkov effect and represented by a parametric design formulation.Compared to existing dielectr...In this paper,we propose a novel stacked laser dielectric acceleration structure.This structure is based on the inverse Cherenkov effect and represented by a parametric design formulation.Compared to existing dielectric laser accelerators relying on the inverse Smith–Purcell effect,the proposed structure provides an extended-duration synchronous acceleration field without requiring the pulse front tilting technique.This advantage significantly reduces the required pulse duration.In addition,the easy to integrate layered structure facilitates cascade acceleration,and simulations have shown that low-energy electron beams can be cascaded through high gradients over extended distances.These practical advantages demonstrate the potential of this new structure for future chip accelerators.展开更多
Light shift is important and inevitably affects the long-term stability of an atomic clock.In this work,considering two unbalanced branches of the spontaneous decay rate in a three-level system,we studied the frequenc...Light shift is important and inevitably affects the long-term stability of an atomic clock.In this work,considering two unbalanced branches of the spontaneous decay rate in a three-level system,we studied the frequency shifts of electromagnetically induced transparency(EIT)and coherent population trapping(CPT)clocks operating under the pulse sequence regime by numerically solving the Liouville density matrix equations.The results show that the frequency shifts are larger when the two branches of spontaneous emission rate are not equal compared to the equal case.In addition,in EIT-Ramsey,the effect of the unbalanced branches of the spontaneous decay rate and relaxations of low-energy states on the frequency shift is greater than that of Rabi frequency.In CPT-Ramsey,the relaxations of low-energy states play a dominant role in frequency shift.展开更多
We demonstrated a nonlinear temporal filter based on the self-diffraction(SD)process.Temporal contrast enhancement,angular dispersion and spectrum broadening properties of the SD process are investigated in experiment...We demonstrated a nonlinear temporal filter based on the self-diffraction(SD)process.Temporal contrast enhancement,angular dispersion and spectrum broadening properties of the SD process are investigated in experiment and simulation.Driven by spectral phase well compensated laser pulses with bandwidth of 28 nm,the filter produced clean pulses with a temporal contrast higher than 10^(10) and excellent spatial profile,the spectrum of which was smoothed and broadened to 64 nm.After implementing this filter into a home-made 30 TW Ti:sapphire amplifier,temporal contrast of the amplified pulses was enhanced to 10^(10) within the time scale of−400 ps.展开更多
We experimentally demonstrate a low-noise phase-sensitive amplifier(PSA)scheme that is able to amplify bright entangled beams at a high level intensity gain of up to 4.4.Moreover,we demonstrate that the PSA scheme int...We experimentally demonstrate a low-noise phase-sensitive amplifier(PSA)scheme that is able to amplify bright entangled beams at a high level intensity gain of up to 4.4.Moreover,we demonstrate that the PSA scheme introduces much less uncorrelated extra noise to the entangled state than the phase-insensitive amplifier scheme with the same intensity gain.This PSA scheme has potential applications for quantum communication in continuous variable regimes.展开更多
Besides the diverse investigations on the interactions between intense laser fields and molecular systems,extensive research has been recently dedicated to exploring the response of nanosystems excited by well-tailore...Besides the diverse investigations on the interactions between intense laser fields and molecular systems,extensive research has been recently dedicated to exploring the response of nanosystems excited by well-tailored femtosecond laser fields.Due to the fact that nanostructures hold peculiar effects when illuminated by laser pulses,the underlying mechanisms and the corresponding potential applications can make significant improvements in both fundamental research and development of novel techniques.In this review,we provide a summarization of the strong field ionization occurring on the surface of nanosystems.The molecules attached to the nanoparticle surface perform as the precursor in the ionization and excitation of the whole nanosystem,the fundamental processes of which are yet to be discovered.We discuss the influence on nanoparticle constituents,geometric shapes and sizes,as well as the specific waveforms of the excitation laser fields.The intriguing characteristics observed in surface ion emission reflect how enhanced near field affects the localized ionizations and nanoplasma expansions,thereby paving the way for further precision controls on the light-and-matter interactions in the extreme spatial temporal levels.展开更多
The past two decades have seen a drastic progress in the development of semiconducting metal-halide perovskites(MHPs)from both the fundamentally scientific and technological points of view.The excellent optoelectronic...The past two decades have seen a drastic progress in the development of semiconducting metal-halide perovskites(MHPs)from both the fundamentally scientific and technological points of view.The excellent optoelectronic properties and device performance make perovskites very attractive to the researchers in materials,physics,chemistry and so on.To fully explore the potential of perovskites in the applications,various techniques have been demonstrated to synthesize perovskites,modify their structures,and create patterns and devices.Among them,photo-processing has been revealed to be a facile and general technique to achieve these aims.In this review,we discuss the mechanisms of photo-processing of perovskites and summarize the recent progress in the photo-processing of perovskites for synthesis,patterning,ion exchange,phase transition,assembly,and ion migration and redistribution.The applications of photo-processed perovskites in photovoltaic devices,lasers,photodetectors,light-emitting diodes(LEDs),and optical data storage and encryption are also discussed.Finally,we provide an outlook on photo-processing of perovskites and propose the promising directions for future researches.This review is of significance to the researches and applications of perovskites and also to uncover new views on the light-matter interactions.展开更多
A two-dimensional dose detector for ion beam is required in many high energy density physics experiments.As a solid detector,the GAFChromic film offers a good spatial resolution and dosimetric accuracy.For an absolute...A two-dimensional dose detector for ion beam is required in many high energy density physics experiments.As a solid detector,the GAFChromic film offers a good spatial resolution and dosimetric accuracy.For an absolute dose measurement,the relative effectiveness,which represents the darkening efficiency of the film to a radiation source,needs to be taken into consideration.In this contribution,the dose-response of HD-V2 to argon ions is presented for the first time.The calibration was taken over the dose range of 65 Gy-660 Gy with 8-keV argon ions.The response of net optical density is from 0.01 to 0.05.Triple-color dose-response functions are derived.The relative effectiveness for the argon ion beams is about 5%,much lower than that of protons and carbon ions.To explain this effect,the inactivation probability based on track theory of ion bombardment is proposed.Furthermore,a theoretical prediction of the relative effectiveness for single ion is presented,showing the dependence of the darkening efficiency on the atomic number and the incident energy of ions.展开更多
Lead halide hybrid perovskites(LHP)have emerged as one of the most promising photovoltaic materials for their remarkable solar energy conversion ability.The transportation of the photoinduced carriers in LHP could scr...Lead halide hybrid perovskites(LHP)have emerged as one of the most promising photovoltaic materials for their remarkable solar energy conversion ability.The transportation of the photoinduced carriers in LHP could screen the defect recombination with the help of the large polaron formation.However,the physical insight of the relationship between the superior optical-electronic performance of perovskite and its polaron dynamics related to the electron-lattice strong coupling induced by the substitution engineering is still lack of investigation.Here,the bandgap modulated thin films ofα-FAPbI_(3)with different element substitution is investigated by the time resolved Terahertz spectroscopy.We find the polaron recombination dynamics could be prolonged in LHP with a relatively smaller bandgap,even though the formation of polaron will not be affected apparently.Intuitively,the large polaron mobility in(FAPb I_(3))0.95(MAPbI_(3))0.05thin film is~30%larger than that in(FAPb I_(3))0.85(MAPbBr_(3))0.15.The larger mobility in(FAPb I_(3))0.95(MAPb I_(3))0.05could be assigned to the slowing down of the carrier scattering time.Therefore,the physical origin of the higher carrier mobility in the(FAPb I_(3))0.95(MAPbI_(3))0.05should be related with the lattice distortion and enhanced electron–phonon coupling induced by the substitution.In addition,(FAPbI_(3))0.95(MAPbI_(3))0.05will lose fewer active carriers during the polaron cooling process than that in(FAPb I_(3))0.85(MAPbBr_(3)),indicating lower thermal dissipation in(FAPbI_(3))0.95(MAPbI_(3))0.05.Our results suggest that besides the smaller bandgap,the higher polaron mobility improved by the substitution engineering inα-FAPbI_(3)can also be an important factor for the high PCE of the black phaseα-FAPbI_(3)based solar cell devices.展开更多
We investigate N_(2)^(+) air lasing at 391 nm,induced by strong laser fields in a nitrogen glow discharge plasma.We generate forward N_(2)^(+) air lasing on the B^(2)Σ_(u)^(+)(v’=0)-X^(2)Σ_(g)^(+)(v"=0) transi...We investigate N_(2)^(+) air lasing at 391 nm,induced by strong laser fields in a nitrogen glow discharge plasma.We generate forward N_(2)^(+) air lasing on the B^(2)Σ_(u)^(+)(v’=0)-X^(2)Σ_(g)^(+)(v"=0) transition at 391 nm by irradiating an intense 35-fs,800-nm laser in a pure nitrogen gas,finding that the 391-nm lasing quenches when the nitrogen gas is electrically discharged.In contrast,the 391-nm fluorescence measured from the side of the laser beam is strongly enhanced,demonstrating that this discharge promotes the population in the B^(2)Σ_(u)^(+)(v’=0) state.By comparing the lasing and fluorescence spectra of the nitrogen gas obtained in the discharged and laser-induced plasma,we show that the quenching of N_(2)^(+) lasing is caused by the efficient suppression of population inversion between the B^(2)Σ_(u)^(+) and X^(2)Σ_(g)^(+) states of N_(2)^(+),in which a much higher population occurs in the X^(2)Σ_(g)^(+) state in the discharge plasma.Our results clarify the important role of population inversion in generating N_(2)^(+) air lasing,and also indicate the potential for the enhancement of N_(2)^(+) lasing via further manipulation of the population in the X^(2)Σ_(g)^(+) state in the discharged medium.展开更多
The influences of the temperature gradient and toroidal effects on drift-tearing modes have been studied using the Gyrokinetic Toroidal code.After the thermal force term is introduced into the parallel electron force ...The influences of the temperature gradient and toroidal effects on drift-tearing modes have been studied using the Gyrokinetic Toroidal code.After the thermal force term is introduced into the parallel electron force balance equation,the equilibrium temperature gradient can cause a significant increase in the growth rate of the drift-tearing mode and a broadening of the mode structure.The simulation results show that the toroidal effects increase the growth rate of the drift-tearing mode,and the contours of the perturbation field“squeeze”toward the stronger field side in the poloidal section.Finally,the hybrid model for fluid electrons and kinetic ions has been studied briefly,and the dispersion relation of the drift-tearing mode under the influence of ion finite Larmor radius effects is obtained.Compared with the dispersion relation under the fluid model,a stabilizing effect of the ion finite Larmor radius is observed.展开更多
基金Key-Area Research and Development Program of Guangdong Province,China(Grant No.2018B090904003)the National Natural Science Foundation of China(Grant Nos.11774410 and 91850209)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB16030200).
文摘We report on an idler-resonant femtosecond optical parametrical oscillator(OPO)based on BiB_(3)O_(6)(BiBO)crystal,synchronously pumped by a frequency-doubled,mode-locked Yb:KGW laser at 515 nm.The idler wavelengths of OPO can be tuned from 1100 nm to 1540 nm.At a repetition rate of 75.5 MHz,the OPO generates as much as 400 mW of idler power with 3.1 W of pump power,the corresponding pulse duration is 80 fs,which is 1.04 times of Fourier transform-limited(FTL)pulse duration at 1305 nm.In addition,the OPO exhibits excellent beam quality with M^(2)<1.8 at 1150 nm.To the best of our knowledge,this is the first idler-resonant femtosecond OPO pumped by 515 nm.
基金supports from National Key R&D Program of China(Grants No.2019YFA0705000,2022YFA1404600,2022YFA1205100)National Natural Science Foundation of China(Grants No.62122079,12192251,62235019,12334014,12134001,12104159,11933005)+4 种基金Innovation Program for Quantum Science and Technology(No.2021ZD0301403)Shanghai Municipal Science and Technology Major Project(2019SHZDZX01)Science and Technology Commission of Shanghai Municipality(No.23ZR1481800)the Youth Innovation Promotion Association of Chinese Academy of Sciences(Grant No.2020249)Engineering Research Center for Nanophotonics&Advanced Instrument,Ministry of Education,East China Normal University(No.2023nmc005)
文摘Soliton microcombs,which require the hosting cavity to operate in an anomalous dispersion regime,are essential to integrate photonic systems.In the past,soliton microcombs were generated on cavity whispering gallery modes(WGMs),and the anomalous dispersion requirement of the cavity made by normal dispersion material was achieved through structural dispersion engineering.This inevitably degrades the cavity optical quality factor(Q)and increases pump threshold power for soliton comb generation.To overcome the challenges,here,we report a soliton microcomb excited by cavity polygon modes.These modes display anomalous dispersion at near-infrared while optical Q factors exceeding 4×10^(6) are maintained.Consequently,a soliton comb spanning from 1450 nm to 1620 nm with a record low pump power of 11 m W is demonstrated,a three-fold improvement compared to the state of the art on the same material platform.
基金supports from the National Key R&D Program of China (No. 2021YFB2802000 and 2021YFB2800500)the National Natural Science Foundation of China (Grant Nos. U20A20211, 51902286, 61775192, 61905215, and 62005164)+2 种基金Key Research Project of Zhejiang Labthe State Key Laboratory of High Field Laser Physics (Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences)China Postdoctoral Science Foundation (2021M702799)。
文摘Long-term optical data storage(ODS)technology is essential to break the bottleneck of high energy consumption for information storage in the current era of big data.Here,ODS with an ultralong lifetime of 2×10^(7)years is attained with single ultrafast laser pulse induced reduction of Eu^(3+)ions and tailoring of optical properties inside the Eu-doped aluminosilicate glasses.We demonstrate that the induced local modifications in the glass can stand against the temperature of up to 970 K and strong ultraviolet light irradiation with the power density of 100 kW/cm^(2).Furthermore,the active ions of Eu^(2+)exhibit strong and broadband emission with the full width at half maximum reaching 190 nm,and the photoluminescence(PL)is flexibly tunable in the whole visible region by regulating the alkaline earth metal ions in the glasses.The developed technology and materials will be of great significance in photonic applications such as long-term ODS.
基金supported in part by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB160203)the National Natural Science Foundation of China(Nos.11875311 and 11421505).
文摘Investigating deuteron–deuteron(DD)fusion reactions in a plasma environment similar to the early stages of the Big Bang is an important topic in nuclear astrophysics.In this study,we experimentally investigated such reactions,using eight laser beams with the third harmonic impacting on a deuterated polyethylene target at the ShenGuang-II Upgrade laser facility.This work focused on the application of range-filter(RF)spectrometers,assembled from a 70 lm aluminum filter and two CR-39 nuclear track detectors,to measure the yields of primary DD-protons.Based on the track diameter calibration results of 3 MeV protons used to diagnose the tracks on the RF spectrometers,an approximate primary DD-proton yield of(8.5±1.7)×10^6 was obtained,consistent with the yields from similar laser facilities worldwide.This indicates that the RF spectrometer is an effective way to measure primary DD-protons.However,due to the low yields of D^3He-protons and its small track diameter,CR-39 detectors were unable to distinguish it from the background spots.Using other accurate detectors may help to measure these rare events.
基金Supported by the National MCF Energy R&D Program(Grant Nos.2018YFE0304100,2018YFE0311300 and 2017YFE0301300)the National Natural Science Foundation of China(Grant Nos.11675256,11675257,11835016,11875067 and 11705275)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB16010300)the Key Research Program of Frontier Science of the Chinese Academy of Sciences(Grant No.QYZDJ-SSW-SYS016)the External Cooperation Program of the Chinese Academy of Sciences(Grant No.112111KYSB20160039)。
文摘The energetic-particle-induced geodesic acoustic mode(EGAM)is studied using gyrokinetic particle simulations in tokamak plasmas.In our simulations,exponentially growing EGAMs are excited by energetic particles with a slowing-down distribution.The frequencies of EGAMs are always below the frequencies of GAMs,which is due to the non-perturbative contribution of energetic particles(EPs).The mode structures of EGAMs are similar to the corresponding mode structures of GAMs.Our gyrokinetic simulations show that a high EP density can enhance the EGAM growth rate,due to high EP free energy,and that EPs’temperature and the pitch angle of the distribution modify the EGAM frequency/growth rate by means of the resonance condition.Kinetic effects of the thermal electrons barely change the EGAM frequency,and have a weak damping effect on the EGAM.Benchmarks between the gyrokinetic particle simulations and a local EGAM dispersion relation exhibit good agreement in terms of EGAM frequency and growth rate.
基金the National Natural Science Foundation of China(Nos.12004353,11975214,11991071,11905202,and 12174350)Key Laboratory Foundation of the Sciences and Technology on Plasma Physics Laboratory(No.6142A04200103)Independent Scientific Research(No.JCKYS2021212011).
文摘In this paper,we propose a novel stacked laser dielectric acceleration structure.This structure is based on the inverse Cherenkov effect and represented by a parametric design formulation.Compared to existing dielectric laser accelerators relying on the inverse Smith–Purcell effect,the proposed structure provides an extended-duration synchronous acceleration field without requiring the pulse front tilting technique.This advantage significantly reduces the required pulse duration.In addition,the easy to integrate layered structure facilitates cascade acceleration,and simulations have shown that low-energy electron beams can be cascaded through high gradients over extended distances.These practical advantages demonstrate the potential of this new structure for future chip accelerators.
基金Project supported by the State Key Laboratory of Low Dimensional Quantum Physics Research Program,Tsinghua University(Grant No.KF201707).
文摘Light shift is important and inevitably affects the long-term stability of an atomic clock.In this work,considering two unbalanced branches of the spontaneous decay rate in a three-level system,we studied the frequency shifts of electromagnetically induced transparency(EIT)and coherent population trapping(CPT)clocks operating under the pulse sequence regime by numerically solving the Liouville density matrix equations.The results show that the frequency shifts are larger when the two branches of spontaneous emission rate are not equal compared to the equal case.In addition,in EIT-Ramsey,the effect of the unbalanced branches of the spontaneous decay rate and relaxations of low-energy states on the frequency shift is greater than that of Rabi frequency.In CPT-Ramsey,the relaxations of low-energy states play a dominant role in frequency shift.
基金Supported by the National Natural Science Foundation of China(Grant Nos.11774410 and 91850209)the Strategic Priority Research Program of CAS(Grant No.XDB16030200).
文摘We demonstrated a nonlinear temporal filter based on the self-diffraction(SD)process.Temporal contrast enhancement,angular dispersion and spectrum broadening properties of the SD process are investigated in experiment and simulation.Driven by spectral phase well compensated laser pulses with bandwidth of 28 nm,the filter produced clean pulses with a temporal contrast higher than 10^(10) and excellent spatial profile,the spectrum of which was smoothed and broadened to 64 nm.After implementing this filter into a home-made 30 TW Ti:sapphire amplifier,temporal contrast of the amplified pulses was enhanced to 10^(10) within the time scale of−400 ps.
基金Supported by the Innovation Program of Shanghai Municipal Education Commission(Grant No.2021-01-07-00-08-E00100)the National Natural Science Foundation of China(Grant Nos.11874155,91436211,11374104)+6 种基金the Basic Research Project of Shanghai Science and Technology Commission(20JC1416100)the Natural Science Foundation of Shanghai(Grant No.17ZR1442900)Minhang Leading Talents(Grant No.201971),the Program of Scientific and Technological Innovation of Shanghai(Grant No.17JC1400401)the Shanghai Sailing Program(Grant No.21YF1410800)the National Basic Research Program of China(Grant No.2016YFA0302103)the Shanghai Municipal Science and Technology Major Project(Grant No.2019SHZDZX01)the 111 Project(Grant No.B12024).
文摘We experimentally demonstrate a low-noise phase-sensitive amplifier(PSA)scheme that is able to amplify bright entangled beams at a high level intensity gain of up to 4.4.Moreover,we demonstrate that the PSA scheme introduces much less uncorrelated extra noise to the entangled state than the phase-insensitive amplifier scheme with the same intensity gain.This PSA scheme has potential applications for quantum communication in continuous variable regimes.
基金Project supported by the National Natural Science Fundation of China (Grant Nos.92050105,92250301,and 12227807)。
文摘Besides the diverse investigations on the interactions between intense laser fields and molecular systems,extensive research has been recently dedicated to exploring the response of nanosystems excited by well-tailored femtosecond laser fields.Due to the fact that nanostructures hold peculiar effects when illuminated by laser pulses,the underlying mechanisms and the corresponding potential applications can make significant improvements in both fundamental research and development of novel techniques.In this review,we provide a summarization of the strong field ionization occurring on the surface of nanosystems.The molecules attached to the nanoparticle surface perform as the precursor in the ionization and excitation of the whole nanosystem,the fundamental processes of which are yet to be discovered.We discuss the influence on nanoparticle constituents,geometric shapes and sizes,as well as the specific waveforms of the excitation laser fields.The intriguing characteristics observed in surface ion emission reflect how enhanced near field affects the localized ionizations and nanoplasma expansions,thereby paving the way for further precision controls on the light-and-matter interactions in the extreme spatial temporal levels.
基金financial supports from the National Key R&D Program of China(No.2021YFB2800500)the National Natural Science Foundation of China(Grant Nos.U20A20211,51902286)Key Research Project of Zhejiang Lab.
文摘The past two decades have seen a drastic progress in the development of semiconducting metal-halide perovskites(MHPs)from both the fundamentally scientific and technological points of view.The excellent optoelectronic properties and device performance make perovskites very attractive to the researchers in materials,physics,chemistry and so on.To fully explore the potential of perovskites in the applications,various techniques have been demonstrated to synthesize perovskites,modify their structures,and create patterns and devices.Among them,photo-processing has been revealed to be a facile and general technique to achieve these aims.In this review,we discuss the mechanisms of photo-processing of perovskites and summarize the recent progress in the photo-processing of perovskites for synthesis,patterning,ion exchange,phase transition,assembly,and ion migration and redistribution.The applications of photo-processed perovskites in photovoltaic devices,lasers,photodetectors,light-emitting diodes(LEDs),and optical data storage and encryption are also discussed.Finally,we provide an outlook on photo-processing of perovskites and propose the promising directions for future researches.This review is of significance to the researches and applications of perovskites and also to uncover new views on the light-matter interactions.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.U1930107 and 11827807)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grants Nos.XDA25030100,XDA25010000,and XDB16010200).
文摘A two-dimensional dose detector for ion beam is required in many high energy density physics experiments.As a solid detector,the GAFChromic film offers a good spatial resolution and dosimetric accuracy.For an absolute dose measurement,the relative effectiveness,which represents the darkening efficiency of the film to a radiation source,needs to be taken into consideration.In this contribution,the dose-response of HD-V2 to argon ions is presented for the first time.The calibration was taken over the dose range of 65 Gy-660 Gy with 8-keV argon ions.The response of net optical density is from 0.01 to 0.05.Triple-color dose-response functions are derived.The relative effectiveness for the argon ion beams is about 5%,much lower than that of protons and carbon ions.To explain this effect,the inactivation probability based on track theory of ion bombardment is proposed.Furthermore,a theoretical prediction of the relative effectiveness for single ion is presented,showing the dependence of the darkening efficiency on the atomic number and the incident energy of ions.
基金supported by the National Natural Science Foundation of China(Nos.92050203,61905264,61925507,61875211,61674023,62005296,and 62105347)the National Key R&D Program of China 2017YFE0123700+1 种基金Shanghai Pilot Program for Basic Research(22JC1403200)the CAS Interdisciplinary Innovation Team。
文摘Lead halide hybrid perovskites(LHP)have emerged as one of the most promising photovoltaic materials for their remarkable solar energy conversion ability.The transportation of the photoinduced carriers in LHP could screen the defect recombination with the help of the large polaron formation.However,the physical insight of the relationship between the superior optical-electronic performance of perovskite and its polaron dynamics related to the electron-lattice strong coupling induced by the substitution engineering is still lack of investigation.Here,the bandgap modulated thin films ofα-FAPbI_(3)with different element substitution is investigated by the time resolved Terahertz spectroscopy.We find the polaron recombination dynamics could be prolonged in LHP with a relatively smaller bandgap,even though the formation of polaron will not be affected apparently.Intuitively,the large polaron mobility in(FAPb I_(3))0.95(MAPbI_(3))0.05thin film is~30%larger than that in(FAPb I_(3))0.85(MAPbBr_(3))0.15.The larger mobility in(FAPb I_(3))0.95(MAPb I_(3))0.05could be assigned to the slowing down of the carrier scattering time.Therefore,the physical origin of the higher carrier mobility in the(FAPb I_(3))0.95(MAPbI_(3))0.05should be related with the lattice distortion and enhanced electron–phonon coupling induced by the substitution.In addition,(FAPbI_(3))0.95(MAPbI_(3))0.05will lose fewer active carriers during the polaron cooling process than that in(FAPb I_(3))0.85(MAPbBr_(3)),indicating lower thermal dissipation in(FAPbI_(3))0.95(MAPbI_(3))0.05.Our results suggest that besides the smaller bandgap,the higher polaron mobility improved by the substitution engineering inα-FAPbI_(3)can also be an important factor for the high PCE of the black phaseα-FAPbI_(3)based solar cell devices.
基金the National Natural Science Foundation of China(Grant Nos.61625501 and 62027822)the Open Fund of the State Key Laboratory of High Field Laser Physics(SIOM)。
文摘We investigate N_(2)^(+) air lasing at 391 nm,induced by strong laser fields in a nitrogen glow discharge plasma.We generate forward N_(2)^(+) air lasing on the B^(2)Σ_(u)^(+)(v’=0)-X^(2)Σ_(g)^(+)(v"=0) transition at 391 nm by irradiating an intense 35-fs,800-nm laser in a pure nitrogen gas,finding that the 391-nm lasing quenches when the nitrogen gas is electrically discharged.In contrast,the 391-nm fluorescence measured from the side of the laser beam is strongly enhanced,demonstrating that this discharge promotes the population in the B^(2)Σ_(u)^(+)(v’=0) state.By comparing the lasing and fluorescence spectra of the nitrogen gas obtained in the discharged and laser-induced plasma,we show that the quenching of N_(2)^(+) lasing is caused by the efficient suppression of population inversion between the B^(2)Σ_(u)^(+) and X^(2)Σ_(g)^(+) states of N_(2)^(+),in which a much higher population occurs in the X^(2)Σ_(g)^(+) state in the discharge plasma.Our results clarify the important role of population inversion in generating N_(2)^(+) air lasing,and also indicate the potential for the enhancement of N_(2)^(+) lasing via further manipulation of the population in the X^(2)Σ_(g)^(+) state in the discharged medium.
基金Supported by the National MCF Energy R&D Program(Grant Nos.2018YFE0304100,2018YFE0311300,and 2017YFE0301300)the National Natural Science Foundation of China(Grant Nos.11675256,11675257,11835016,and 11705275)+2 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB16010300)the Key Research Program of Frontier Science of Chinese Academy of Sciences(Grant No.QYZDJ-SSW-SYS016)the External Cooperation Program of Chinese Academy of Sciences(Grant No.112111KYSB20160039).
文摘The influences of the temperature gradient and toroidal effects on drift-tearing modes have been studied using the Gyrokinetic Toroidal code.After the thermal force term is introduced into the parallel electron force balance equation,the equilibrium temperature gradient can cause a significant increase in the growth rate of the drift-tearing mode and a broadening of the mode structure.The simulation results show that the toroidal effects increase the growth rate of the drift-tearing mode,and the contours of the perturbation field“squeeze”toward the stronger field side in the poloidal section.Finally,the hybrid model for fluid electrons and kinetic ions has been studied briefly,and the dispersion relation of the drift-tearing mode under the influence of ion finite Larmor radius effects is obtained.Compared with the dispersion relation under the fluid model,a stabilizing effect of the ion finite Larmor radius is observed.
