Compact terahertz(THz)functional devices are greatly sought after for high-speed wireless communication,biochemical sensing,and non-destructive inspection.However,controlled THz generation,along with transport and det...Compact terahertz(THz)functional devices are greatly sought after for high-speed wireless communication,biochemical sensing,and non-destructive inspection.However,controlled THz generation,along with transport and detection,has remained a challenge especially for chip-scale devices due to low-coupling efficiency and unavoidable absorption losses.Here,based on the topological protection of electromagnetic waves,we demonstrate nonlinear generation and topologically tuned confinement of THz waves in an engineered lithium niobate chip forming a wedge-shaped Su-Schrieffer-Heeger lattice.Experimentally measured band structures provide direct visualization of the THz localization in the momentum space,while robustness of the confined mode against chiral perturbations is also analyzed and compared for both topologically trivial and nontrivial regimes.Such topological control of THz waves may bring about new possibilities in the realization of THz integrated circuits,promising for advanced photonic applications.展开更多
Optical Kerr effect, in which input light intensity linearly alters the refractive index, has enabled the generation ofoptical solitons, supercontinuum spectra, and frequency combs, playing vital roles in the on-chip ...Optical Kerr effect, in which input light intensity linearly alters the refractive index, has enabled the generation ofoptical solitons, supercontinuum spectra, and frequency combs, playing vital roles in the on-chip devices, fibercommunications, and quantum manipulations. Especially, terahertz Kerr effect, featuring fascinating prospects in futurehigh-rate computing, artificial intelligence, and cloud-based technologies, encounters a great challenge due to therather low power density and feeble Kerr response. Here, we demonstrate a giant terahertz frequency Kerr nonlinearitymediated by stimulated phonon polaritons. Under the influences of the giant Kerr nonlinearity, the power-dependentrefractive index change would result in a frequency shift in the microcavity, which was experimentally demonstratedvia the measurement of the resonant mode of a chip-scale lithium niobate Fabry-Pérot microcavity. Attributed to theexistence of stimulated phonon polaritons, the nonlinear coefficient extracted from the frequency shifts is orders ofmagnitude larger than that of visible and infrared light, which is also theoretically demonstrated by nonlinear Huangequations. This work opens an avenue for many rich and fruitful terahertz Kerr effect based physical, chemical, andbiological systems that have terahertz fingerprints.展开更多
基金This work was supported by the National Key Research and Development Program of China(2017YFA0303800,2017YFA0305100)PCSIRT(IRT_13R29)+3 种基金Higher Education Discipline Innovation Project(B07013)the National Natural Science Foundation of China(12134006,12074201,11922408)the China Postdoctoral Science Foundation(BX2021134,2021M701790)as well as NSERC and the CRC program in Canada.
文摘Compact terahertz(THz)functional devices are greatly sought after for high-speed wireless communication,biochemical sensing,and non-destructive inspection.However,controlled THz generation,along with transport and detection,has remained a challenge especially for chip-scale devices due to low-coupling efficiency and unavoidable absorption losses.Here,based on the topological protection of electromagnetic waves,we demonstrate nonlinear generation and topologically tuned confinement of THz waves in an engineered lithium niobate chip forming a wedge-shaped Su-Schrieffer-Heeger lattice.Experimentally measured band structures provide direct visualization of the THz localization in the momentum space,while robustness of the confined mode against chiral perturbations is also analyzed and compared for both topologically trivial and nontrivial regimes.Such topological control of THz waves may bring about new possibilities in the realization of THz integrated circuits,promising for advanced photonic applications.
基金supported by the National Natural Science Foundation of China(62205158 and 11974192)the Foundation of State Key Laboratory of laser Interaction with Matter(SKLLIM2101)the 111 Project(B23045).
文摘Optical Kerr effect, in which input light intensity linearly alters the refractive index, has enabled the generation ofoptical solitons, supercontinuum spectra, and frequency combs, playing vital roles in the on-chip devices, fibercommunications, and quantum manipulations. Especially, terahertz Kerr effect, featuring fascinating prospects in futurehigh-rate computing, artificial intelligence, and cloud-based technologies, encounters a great challenge due to therather low power density and feeble Kerr response. Here, we demonstrate a giant terahertz frequency Kerr nonlinearitymediated by stimulated phonon polaritons. Under the influences of the giant Kerr nonlinearity, the power-dependentrefractive index change would result in a frequency shift in the microcavity, which was experimentally demonstratedvia the measurement of the resonant mode of a chip-scale lithium niobate Fabry-Pérot microcavity. Attributed to theexistence of stimulated phonon polaritons, the nonlinear coefficient extracted from the frequency shifts is orders ofmagnitude larger than that of visible and infrared light, which is also theoretically demonstrated by nonlinear Huangequations. This work opens an avenue for many rich and fruitful terahertz Kerr effect based physical, chemical, andbiological systems that have terahertz fingerprints.
