Exotic forms of wave control have been emerging by engineering matter in space and time.In this framework,temporal photonic interfaces,i.e.,abrupt changes in the electromagnetic properties of a material,have been show...Exotic forms of wave control have been emerging by engineering matter in space and time.In this framework,temporal photonic interfaces,i.e.,abrupt changes in the electromagnetic properties of a material,have been shown to induce temporal scattering phenomena dual to spatial reflection and refraction,at the basis of photonic time crystals and space-time metamaterials.Despite decades-old theoretical studies on these topics,and recent experimental demonstrations,the careful modeling of these phenomena has been lagging behind.Here,we develop from first principles a rigorous model of the electrodynamics of temporal photonic interfaces,highlighting the crucial role of the mechanisms driving time variations.We demonstrate that the boundary conditions and conservation laws associated with temporal scattering may substantially deviate from those commonly employed in the literature,based on their microscopic implementation.Our results open new vistas for both fundamental investigations over light–matter interactions in time-varying structures and for the prospect of their future implementations and applications in optics and photonics.展开更多
Photon emission during contact electrification(CE)has recently been observed,which is called as CE-induced interface photon emission spectroscopy(CEIIPES).Physical mechanisms of CEIIPES are essential for interpreting ...Photon emission during contact electrification(CE)has recently been observed,which is called as CE-induced interface photon emission spectroscopy(CEIIPES).Physical mechanisms of CEIIPES are essential for interpreting the structure and electronic interactions of a contacted interface.Using the methods of density functional theory(DFT)and time-dependent DFT(TDDFT),it is confirmed theoretically that the spectrum of emitted photons is contributed from electron transfer and transition during CE.Specifically,the excited electrons from higher energy state in one material may transfer to a lower energy state of another material followed by a transition;and/or some unstable excited electrons at a higher energy level of one material may transit to a lower energy state of itself,both of which result in CEIIPES.Furthermore,the CE-induced interface absorption spectrum(CEIIAS)has been demonstrated,due to the intermolecular electron transfer excitation.展开更多
Generation of a cavity-enhanced nondegenerate narrow-band photon pair source is a potential way to realize a perfect photonic quantum interface for a hybrid quantum network. However, to ensure the high quality of the ...Generation of a cavity-enhanced nondegenerate narrow-band photon pair source is a potential way to realize a perfect photonic quantum interface for a hybrid quantum network. However, to ensure the high quality of the photon source, the pump laser for the narrow-band photon source should be generated in a special way. Here, we experimentally generate the blue 453 nm laser with a sum frequency generation process in a periodically poled lithium niobate waveguide. A 13 mW laser at 453 nm can be achieved with a low-power 880 nm laser and 935 nm laser input, and the internal conversion efficiency is 21.6% after calculation. The frequency of a 453 nm laser is stabilized by locking two pump lasers on one ultrastable optical cavity. The single pass process without employ- ing cavity enhancement can ensure a good robustness of the whole system.展开更多
基金Simons Foundation(733684,855344,SFI-MPSEWP-00008530-04,Collaboration on Extreme Wave Phenomena,A.A.,N.E.,E.G.)Air Force Office of Scientific Research(A.A.,N.E.,E.G.)+1 种基金Department of Defense Small Business Innovation ResearchSpanish Ministry of Universities under a María Zambrano Grant(DMS).
文摘Exotic forms of wave control have been emerging by engineering matter in space and time.In this framework,temporal photonic interfaces,i.e.,abrupt changes in the electromagnetic properties of a material,have been shown to induce temporal scattering phenomena dual to spatial reflection and refraction,at the basis of photonic time crystals and space-time metamaterials.Despite decades-old theoretical studies on these topics,and recent experimental demonstrations,the careful modeling of these phenomena has been lagging behind.Here,we develop from first principles a rigorous model of the electrodynamics of temporal photonic interfaces,highlighting the crucial role of the mechanisms driving time variations.We demonstrate that the boundary conditions and conservation laws associated with temporal scattering may substantially deviate from those commonly employed in the literature,based on their microscopic implementation.Our results open new vistas for both fundamental investigations over light–matter interactions in time-varying structures and for the prospect of their future implementations and applications in optics and photonics.
基金supported by the National Natural Science Foundation of China(Nos.62001031,52192610,51702018,and 51432005)the Youth Innovation Promotion Association,CAS,the Fundamental Research Funds for the Central Universities(No.E0E48957)the National Key R&D Program from Minister of Science and Technology(No.2016YFA0202704).
文摘Photon emission during contact electrification(CE)has recently been observed,which is called as CE-induced interface photon emission spectroscopy(CEIIPES).Physical mechanisms of CEIIPES are essential for interpreting the structure and electronic interactions of a contacted interface.Using the methods of density functional theory(DFT)and time-dependent DFT(TDDFT),it is confirmed theoretically that the spectrum of emitted photons is contributed from electron transfer and transition during CE.Specifically,the excited electrons from higher energy state in one material may transfer to a lower energy state of another material followed by a transition;and/or some unstable excited electrons at a higher energy level of one material may transit to a lower energy state of itself,both of which result in CEIIPES.Furthermore,the CE-induced interface absorption spectrum(CEIIAS)has been demonstrated,due to the intermolecular electron transfer excitation.
基金supported by the National Key Research and Development Program of China(No.2017YFA0304100)the National Natural Science Foundation of China(Nos.61327901,11325419,and11474268)+2 种基金the Key Research Program of Frontier Sciences,CAS(No.QYZDY-SSW-SLH003)the National Program for Support of Topnotch Young Professionals(No.BB2470000005)the Fundamental Research Funds for the Central Universities(Nos.WK2470000026and WK2470000018)
文摘Generation of a cavity-enhanced nondegenerate narrow-band photon pair source is a potential way to realize a perfect photonic quantum interface for a hybrid quantum network. However, to ensure the high quality of the photon source, the pump laser for the narrow-band photon source should be generated in a special way. Here, we experimentally generate the blue 453 nm laser with a sum frequency generation process in a periodically poled lithium niobate waveguide. A 13 mW laser at 453 nm can be achieved with a low-power 880 nm laser and 935 nm laser input, and the internal conversion efficiency is 21.6% after calculation. The frequency of a 453 nm laser is stabilized by locking two pump lasers on one ultrastable optical cavity. The single pass process without employ- ing cavity enhancement can ensure a good robustness of the whole system.
