Arbitrary polarized vortex beam induced by polarization singularity offers a new platform for both classical optics and quantum entanglement applications.Bound states in the continuum(BICs)have been demonstrated to be...Arbitrary polarized vortex beam induced by polarization singularity offers a new platform for both classical optics and quantum entanglement applications.Bound states in the continuum(BICs)have been demonstrated to be associated with topological charge and vortex polarization singularities in momentum space.For conventional symmetric photonic crystal slabs(PhCSs),BIC is enclosed by linearly polarized far fields with winding angle of 2π,which is unfavorable for high-capacity and multi-functionality integration-optics applications.Here,we show that by breakingσz-symmetry of the PhCS,asymmetry in upward and downward directions and arbitrarily polarized BIC can be realized with a bilayer-twisted PhCS.It exhibits elliptical polarization states with constant ellipticity angle at every point in momentum space within the vicinity of BIC.The topological nature of BIC reflects on the orientation angle of polarization state,with a topological charge of 1 for any value of ellipticity angle.Full coverage of Poincarésphere(i.e.,-π/4≤X≤4 and-π/2≤ψ≤π/2)and higher-order Poincarésphere can be realized by tailoring the twist angles.Our findings may open up new avenues for applications in structured light,quantum optics,and twistronics for photons.展开更多
可见光和近红外光双波段光电探测器因其高选择性和灵活多功能,在信号检测、生物成像、光通信和安全监控方面具有应用潜力.本文报道了一种基于钙钛矿/有机异质结结构的双波段探测器,实现了可见光波段和近红外波段具有电压可调制的光电响...可见光和近红外光双波段光电探测器因其高选择性和灵活多功能,在信号检测、生物成像、光通信和安全监控方面具有应用潜力.本文报道了一种基于钙钛矿/有机异质结结构的双波段探测器,实现了可见光波段和近红外波段具有电压可调制的光电响应.即正向偏压下探测器仅对可见光具有光电响应,反向偏压下又仅对近红外光具有光电响应.探测器包括1个吸收可见光(500~810 nm)的钙钛矿层和1个用于近红外光吸收(810~950 nm)的有机层,吸光层顶部和底部的N型载流子传输层则实现了对钙钛矿/有机层中光生载流子的电压可控传输,进而实现可电压调制的可见光/红外光响应.该器件在可见光和近红外波段的峰值响应率分别为93.5和102.2 m A/W,对近红外光的探测度达到了1012 Jones,并在可见光模式和近红外模式下都具有宽动态范围(>120 d B).本文同时实现了这种可电压调制的双波段探测器在可见光和近红外成像中的应用.展开更多
The Dongshuimen Bridge over the Yangtze River and the Qiansimen Bridge over the Jialing River in Chongqing,China are located at the tip of the Yuzhong Peninsula.Together,they are called the Twin River Bridges.Both are...The Dongshuimen Bridge over the Yangtze River and the Qiansimen Bridge over the Jialing River in Chongqing,China are located at the tip of the Yuzhong Peninsula.Together,they are called the Twin River Bridges.Both are double deck structures carrying four lanes of traffic on their upper decks and two transit tracks on their lower decks.The girders are steel truss structures with orthotropic plates and the towers are made of concrete.Aesthetics were carefully considered for the design of these bridges because of their visibility in the city and their neighboring landmarks.展开更多
基金support from the National Natural Science Foundation of China(no.12204264)the Shenzhen Stability Support Program(no.WDZC20220810152404001)+2 种基金the Cross-Disciplinary Research Fund of Tsinghua Shenzhen International Graduate School(SIGS),Tsinghua University(JC2022001),and the startup funding in Tsinghua Shenzhen International Graduate School(SIGS),Tsinghua University(no.01030100006)support from the National Natural Science Foundation of China(No.62205246)the Fundamental Research Funds for the Central Universities.C-W.Q.acknowledges financial support from the NRF,Prime Minister's Office,Singapore under the Competitive Research Program Award(NRF-CRP26-2021-0063).
文摘Arbitrary polarized vortex beam induced by polarization singularity offers a new platform for both classical optics and quantum entanglement applications.Bound states in the continuum(BICs)have been demonstrated to be associated with topological charge and vortex polarization singularities in momentum space.For conventional symmetric photonic crystal slabs(PhCSs),BIC is enclosed by linearly polarized far fields with winding angle of 2π,which is unfavorable for high-capacity and multi-functionality integration-optics applications.Here,we show that by breakingσz-symmetry of the PhCS,asymmetry in upward and downward directions and arbitrarily polarized BIC can be realized with a bilayer-twisted PhCS.It exhibits elliptical polarization states with constant ellipticity angle at every point in momentum space within the vicinity of BIC.The topological nature of BIC reflects on the orientation angle of polarization state,with a topological charge of 1 for any value of ellipticity angle.Full coverage of Poincarésphere(i.e.,-π/4≤X≤4 and-π/2≤ψ≤π/2)and higher-order Poincarésphere can be realized by tailoring the twist angles.Our findings may open up new avenues for applications in structured light,quantum optics,and twistronics for photons.
基金supported by the National Natural Science Foundation of China(52027817 and 03012800001)Shenzhen Science and Technology Innovation Committee(JCYJ20200109144614514)+1 种基金the support from the Hong Kong Research Grant Council for the GRF grant(11314122)the Guangdong Major Project of Basic and Applied Basic Research(2019B030302007)。
文摘可见光和近红外光双波段光电探测器因其高选择性和灵活多功能,在信号检测、生物成像、光通信和安全监控方面具有应用潜力.本文报道了一种基于钙钛矿/有机异质结结构的双波段探测器,实现了可见光波段和近红外波段具有电压可调制的光电响应.即正向偏压下探测器仅对可见光具有光电响应,反向偏压下又仅对近红外光具有光电响应.探测器包括1个吸收可见光(500~810 nm)的钙钛矿层和1个用于近红外光吸收(810~950 nm)的有机层,吸光层顶部和底部的N型载流子传输层则实现了对钙钛矿/有机层中光生载流子的电压可控传输,进而实现可电压调制的可见光/红外光响应.该器件在可见光和近红外波段的峰值响应率分别为93.5和102.2 m A/W,对近红外光的探测度达到了1012 Jones,并在可见光模式和近红外模式下都具有宽动态范围(>120 d B).本文同时实现了这种可电压调制的双波段探测器在可见光和近红外成像中的应用.
文摘The Dongshuimen Bridge over the Yangtze River and the Qiansimen Bridge over the Jialing River in Chongqing,China are located at the tip of the Yuzhong Peninsula.Together,they are called the Twin River Bridges.Both are double deck structures carrying four lanes of traffic on their upper decks and two transit tracks on their lower decks.The girders are steel truss structures with orthotropic plates and the towers are made of concrete.Aesthetics were carefully considered for the design of these bridges because of their visibility in the city and their neighboring landmarks.
