This paper demonstrates an all-optical switching model system comprising a single pulsed pump beam at 355 nm and a CW He-Ne signal beam at 632.8 nm with 2-（2＇-hydroxyphenyl）benzothiazole （HBT） in ethanol solution...This paper demonstrates an all-optical switching model system comprising a single pulsed pump beam at 355 nm and a CW He-Ne signal beam at 632.8 nm with 2-（2＇-hydroxyphenyl）benzothiazole （HBT） in ethanol solution. The origins of the optical switching effect were discussed. By the study of nonlinear optical properties for HBT in ethanol solvent, this paper verified that the excited-state intramolecular proton transfer （ESIPT） effect of HBT and the thermal effect of solvent worked on quite different time scales and together induced the change of the refractive index of HBT solution, leading to the signal beam deflection. The results indicated that the HBT molecule could be an excellent candidate for high-speed and high-sensitive optical switching devices.展开更多
The heating and helicity effects induced by circularly polarized laser excitation are entangled in the helicity-dependent all-optical switching(HD-AOS),which hinders understanding the magnetization dynamics involved.H...The heating and helicity effects induced by circularly polarized laser excitation are entangled in the helicity-dependent all-optical switching(HD-AOS),which hinders understanding the magnetization dynamics involved.Here,applying a dual-pump laser excitation,first with a linearly polarized(LP) laser pulse followed by a circularly polarized(CP) laser pulse,the timescales and contribution from heating and helicity effects in HD-AOS were identified with a Pt/Co/Pt triple-layer.When the LP laser pulses preheat the sample to a nearly fully demagnetized state,the CP laser pulses with a power reduced by 80% switch the sample’s magnetization.By varying the time delay between the two pump pulses,the results show that the helicity effect,which gives rise to the deterministic helicity-induced switching,arises almost instantly within 200 fs close to the pulse width upon laser excitation.The results reveal that the transient magnetization state upon which CP laser pulses impinge is the key factor for achieving HD-AOS,and importantly,the tunability between heating and helicity effects with the unique dualpump laser excitation approach will enable HD-AOS in a wide range of magnetic material systems having wideranging implications for potential ultrafast spintronics applications.展开更多
Antiferromagnets offer great potential for high-speed data processing applications,as they can expend spintronic devices from a static storage and gigahertz frequency range to the terahertz range.However,their zero ne...Antiferromagnets offer great potential for high-speed data processing applications,as they can expend spintronic devices from a static storage and gigahertz frequency range to the terahertz range.However,their zero net magnetization makes them difficult to manipulate and detect.In recent years,there has been a lot of attention given to the ultrafast manipulation of magnetic order using ultra-short single laser pulses,but it remains unknown whether a similar scenario can be observed in antiferromagnets.In this work,we demonstrate the manipulation of antiferromagnets with a single femtosecond laser pulse in perpendicular exchange-biased Co/Ir Mn/Co Gd trilayers.We study the dual exchange bias interlayer interaction in quasi-static conditions and competition in ultrafast antiferromagnet rearrangement.Our results show that,compared to conventional ferromagnetic/antiferromagnetic systems,the Ir Mn antiferromagnet can be ultrafast and efficiently manipulated by the coupled Co Gd ferrimagnetic layer,which paves the way for potential energy-efficient spintronic devices.展开更多
In recent years, most studies have focused on the perfect absorption and high-efficiency quantum memory of the onesided system, ignoring the characteristics of its optical switching contrast. Thus, the performance of ...In recent years, most studies have focused on the perfect absorption and high-efficiency quantum memory of the onesided system, ignoring the characteristics of its optical switching contrast. Thus, the performance of all-optical switching and optical transistors is limited. Herein, we propose a localized surface plasmon(LSP) mode-assisted cavity QED system which consists of a Λ-shaped three-level quantum emitter(QE), a metal nanoparticle and a one-sided optical cavity with a fully reflected mirror. In this system, the QE coherently couples to the cavity and LSP mode respectively, which is manipulated by the control field. As a result, considerably high and stable switch contrast of 90% can be achievable due to the strong confined field of the LSP mode and perfect absorption of the optical medium. In addition, we obtain a power dependent effect between the control field and the transmitted frequency as a result of the converted dark state. We employ the Heisenberg–Langevin equation and numerical master equation formalisms to explain high switching, controllable output light and the dark state. Our system introduces an effective method to improve the performance of optical switches based on the one-sided system in quantum information storage and quantum communication.展开更多
基金Project supported by the National Natural Science Foundation of China （Grant No 60178025） and the Key Laboratory of 0ptoelectronics Information Technical Science of Ministry of Education, Institute of Modern 0ptics, Nankai University, China.
文摘This paper demonstrates an all-optical switching model system comprising a single pulsed pump beam at 355 nm and a CW He-Ne signal beam at 632.8 nm with 2-（2＇-hydroxyphenyl）benzothiazole （HBT） in ethanol solution. The origins of the optical switching effect were discussed. By the study of nonlinear optical properties for HBT in ethanol solvent, this paper verified that the excited-state intramolecular proton transfer （ESIPT） effect of HBT and the thermal effect of solvent worked on quite different time scales and together induced the change of the refractive index of HBT solution, leading to the signal beam deflection. The results indicated that the HBT molecule could be an excellent candidate for high-speed and high-sensitive optical switching devices.
基金financially supported by the National Key Research and Development Program of China (No. 2016YFA0300803)the National Natural Science Foundation of China (Nos.61427812 and 11774160)+4 种基金the Natural ScienceFoundation of Jiangsu Province of China (No.BK20192006)support of National Key R&D Program of China (No.2021YFB3601600)the Natural Science Foundation of Jiangsu Province of China (No.BK20200307)support of the UK EPSRC (No.EP/T027916/1)supported by the EPSRC TER AS WITCH project (project ID EP/T027916/1)。
文摘The heating and helicity effects induced by circularly polarized laser excitation are entangled in the helicity-dependent all-optical switching(HD-AOS),which hinders understanding the magnetization dynamics involved.Here,applying a dual-pump laser excitation,first with a linearly polarized(LP) laser pulse followed by a circularly polarized(CP) laser pulse,the timescales and contribution from heating and helicity effects in HD-AOS were identified with a Pt/Co/Pt triple-layer.When the LP laser pulses preheat the sample to a nearly fully demagnetized state,the CP laser pulses with a power reduced by 80% switch the sample’s magnetization.By varying the time delay between the two pump pulses,the results show that the helicity effect,which gives rise to the deterministic helicity-induced switching,arises almost instantly within 200 fs close to the pulse width upon laser excitation.The results reveal that the transient magnetization state upon which CP laser pulses impinge is the key factor for achieving HD-AOS,and importantly,the tunability between heating and helicity effects with the unique dualpump laser excitation approach will enable HD-AOS in a wide range of magnetic material systems having wideranging implications for potential ultrafast spintronics applications.
基金National Key Research and Development Program of China(Grant No.2022YFB4400200)the National Natural Science Foundation of China(Grant Nos.12104030,12104031,and 61627813)+10 种基金the Program of Introducing Talents of Discipline to Universities(Grant No.B16001)the Beijing Municipal Science and Technology Project(Grant No.Z201100004220002)China Postdoctoral Science Foundation(Grant No.2022M710320)China Scholarship Councilsupported by the ANR-15-CE24-0009 UMAMI and the ANR-20-CE09-0013by the Institute Carnot ICEEL for the project“Optic-switch”and Matelasby the Région Grand Estby the Metropole Grand Nancyby the impact project LUE-N4Spart of the French PIA project“Lorraine Universitéd’Excellence,”reference ANR-15-IDEX-04-LUEby the“FEDERFSE Lorraine et Massif Vosges 2014-2020,”a European Union Program。
文摘Antiferromagnets offer great potential for high-speed data processing applications,as they can expend spintronic devices from a static storage and gigahertz frequency range to the terahertz range.However,their zero net magnetization makes them difficult to manipulate and detect.In recent years,there has been a lot of attention given to the ultrafast manipulation of magnetic order using ultra-short single laser pulses,but it remains unknown whether a similar scenario can be observed in antiferromagnets.In this work,we demonstrate the manipulation of antiferromagnets with a single femtosecond laser pulse in perpendicular exchange-biased Co/Ir Mn/Co Gd trilayers.We study the dual exchange bias interlayer interaction in quasi-static conditions and competition in ultrafast antiferromagnet rearrangement.Our results show that,compared to conventional ferromagnetic/antiferromagnetic systems,the Ir Mn antiferromagnet can be ultrafast and efficiently manipulated by the coupled Co Gd ferrimagnetic layer,which paves the way for potential energy-efficient spintronic devices.
基金support from the National Natural Science Foundation of China (Grant Nos. 62075004 and 11804018)the Beijing Natural Science Foundation (Grant No. 4212051)。
文摘In recent years, most studies have focused on the perfect absorption and high-efficiency quantum memory of the onesided system, ignoring the characteristics of its optical switching contrast. Thus, the performance of all-optical switching and optical transistors is limited. Herein, we propose a localized surface plasmon(LSP) mode-assisted cavity QED system which consists of a Λ-shaped three-level quantum emitter(QE), a metal nanoparticle and a one-sided optical cavity with a fully reflected mirror. In this system, the QE coherently couples to the cavity and LSP mode respectively, which is manipulated by the control field. As a result, considerably high and stable switch contrast of 90% can be achievable due to the strong confined field of the LSP mode and perfect absorption of the optical medium. In addition, we obtain a power dependent effect between the control field and the transmitted frequency as a result of the converted dark state. We employ the Heisenberg–Langevin equation and numerical master equation formalisms to explain high switching, controllable output light and the dark state. Our system introduces an effective method to improve the performance of optical switches based on the one-sided system in quantum information storage and quantum communication.
