Coherent optical emission of free induction decay (FID) excited by the multiple-photon resonance has been recently observed in nitrogen ions produced by intense femtosecond laser pulses.Here we report that orbit angul...Coherent optical emission of free induction decay (FID) excited by the multiple-photon resonance has been recently observed in nitrogen ions produced by intense femtosecond laser pulses.Here we report that orbit angular momentum (OAM) of the pump laser pulses can be transferred to the much longer pulsed free induction decay emission with the OAM conserved.It was found that when the pump laser frequency approaches the fraction of the 391.4 nm emission (ν_(0)/5),an FID emission is emitted whereas its topological charge was identified to be 5 times of the pump laser.Due to the reduced laser intensity with a vortex pump compared to the conventional Gaussian beam,the resonant pump laser wavelength presents a redshift,and the FID signal is significantly weaker.展开更多
Transparent absorbers, with a functional integration of broadband electromagnetic shielding, microwave camouflage,and optical transparency, have attracted increasing attention in the past decades. Metal mesh, an artif...Transparent absorbers, with a functional integration of broadband electromagnetic shielding, microwave camouflage,and optical transparency, have attracted increasing attention in the past decades. Metal mesh, an artificial, optically transparent, conducting material composed of periodic metallic gratings, is the optimal choice for the microwave shielding layer of transparent absorbers because of its excellent compatibility between high transparency and low resistance. However, the micrometer-level periodicity of metallic grating concentrates the diffraction of light, which degrades the imaging quality of cameras and sensors in common. In this study, we report on a generalized Thiessenpolygon-randomization method that prevents the concentration of the diffraction of light in periodic metallic grating and demonstrate an ultrawide-band optically transparent diffraction-immune metamaterial absorber. The absorber is constructed with a multilayer indium-tin-oxide-based metasurface and a Thiessen-polygon-randomized metal-mesh reflector. The lossy metasurface provides multimode absorption, whereas the Thiessen-polygon randomization prevents the concentration of the diffraction of light. The practical sample achieves a 10 dB absorptivity and shielding effectiveness over a range of 8–26.5 GHz, and the optical transparency is also preserved over the entire visible and near-infrared regions. The point spread function and field of view are both improved by using the antidiffraction absorber. Our study paves the way for the application of optically transparent electromagnetic devices, display, and optoelectronic integration in a more practical stage. ? 2023 Chinese Laser Press.展开更多
The publisher regrets the omission of the below footnote for the author Dr.Nu Zhang.The publisher would like to apologise for any inconvenience caused.
Solar energy is regarded as one of the most plentiful sources of renewable energy. An extraordinary light-harvesting property of a germanium periodic nanopyramid array is reported in this Letter. Both our theoretical ...Solar energy is regarded as one of the most plentiful sources of renewable energy. An extraordinary light-harvesting property of a germanium periodic nanopyramid array is reported in this Letter. Both our theoretical and experimental results demonstrate that the nanopyramid array can achieve perfect broadband absorption from 500- to 800-nm wavelength. Especially in the visible regime, the experimentally measured absorption can even reach 100%. Further analyses reveal that the intrinsic antireflection effect and slow-light waveguide mode play an important role in the ultra-high absorption, which is helpful for the research and development of photovoltaic devices.展开更多
Physical signals provided by the extracellular matrix(ECM)are key microenvironmental parameters for the fate decision of hematopoietic stem and progenitor cells(HSPC)in bone marrow.Insights into cell-ECM interactions ...Physical signals provided by the extracellular matrix(ECM)are key microenvironmental parameters for the fate decision of hematopoietic stem and progenitor cells(HSPC)in bone marrow.Insights into cell-ECM interactions are critical for advancing HSC-based tissue engineering.Herein,we employed collagen hydrogels and collagen-alginate hydrogels of defined stiffness to study the behaviors of hematopoietic progenitor cells(HPCs).Three-dimensional(3D)collagen hydrogels with a stiffness of 45 Pa were found to promote HPC maintenance and colony formation of monocyte/macrophage progenitors.Using single-cell RNA sequencing(scRNA-seq),we also characterized the comprehensive transcriptional profiles of cells randomly selected from two-dimensional(2D)and 3D hydrogels.A distinct maturation trajectory from HPCs into macrophages within the 3D microenvironment was revealed by these results.3D-derived macrophages expressed high levels of various cytokines and chemokines,such as Saa3,Cxcl2,Socs3 and Tnf.Furthermore,enhanced communication between 3D-macrophages and other hematopoietic clusters based on ligand-repair interactions was demonstrated through bioinformatic analyses.Our research underlines the regulatory role of matrix-dimensionality in HPC differentiation and therefore probably be applied to the generation of specialized macrophages.展开更多
基金supported in part by the National Natural Science Foundation of China (Nos.12034013 and 12204308)the Shanghai Science and Technology Commission (No.22ZR1444100)。
文摘Coherent optical emission of free induction decay (FID) excited by the multiple-photon resonance has been recently observed in nitrogen ions produced by intense femtosecond laser pulses.Here we report that orbit angular momentum (OAM) of the pump laser pulses can be transferred to the much longer pulsed free induction decay emission with the OAM conserved.It was found that when the pump laser frequency approaches the fraction of the 391.4 nm emission (ν_(0)/5),an FID emission is emitted whereas its topological charge was identified to be 5 times of the pump laser.Due to the reduced laser intensity with a vortex pump compared to the conventional Gaussian beam,the resonant pump laser wavelength presents a redshift,and the FID signal is significantly weaker.
基金National Natural Science Foundation of China (61901437, 62175083, 61935015)Fundamental Research Funds for the Central UniversitiesNatural Science Foundation of Jilin Province (20230101359JC)。
文摘Transparent absorbers, with a functional integration of broadband electromagnetic shielding, microwave camouflage,and optical transparency, have attracted increasing attention in the past decades. Metal mesh, an artificial, optically transparent, conducting material composed of periodic metallic gratings, is the optimal choice for the microwave shielding layer of transparent absorbers because of its excellent compatibility between high transparency and low resistance. However, the micrometer-level periodicity of metallic grating concentrates the diffraction of light, which degrades the imaging quality of cameras and sensors in common. In this study, we report on a generalized Thiessenpolygon-randomization method that prevents the concentration of the diffraction of light in periodic metallic grating and demonstrate an ultrawide-band optically transparent diffraction-immune metamaterial absorber. The absorber is constructed with a multilayer indium-tin-oxide-based metasurface and a Thiessen-polygon-randomized metal-mesh reflector. The lossy metasurface provides multimode absorption, whereas the Thiessen-polygon randomization prevents the concentration of the diffraction of light. The practical sample achieves a 10 dB absorptivity and shielding effectiveness over a range of 8–26.5 GHz, and the optical transparency is also preserved over the entire visible and near-infrared regions. The point spread function and field of view are both improved by using the antidiffraction absorber. Our study paves the way for the application of optically transparent electromagnetic devices, display, and optoelectronic integration in a more practical stage. ? 2023 Chinese Laser Press.
文摘The publisher regrets the omission of the below footnote for the author Dr.Nu Zhang.The publisher would like to apologise for any inconvenience caused.
文摘Solar energy is regarded as one of the most plentiful sources of renewable energy. An extraordinary light-harvesting property of a germanium periodic nanopyramid array is reported in this Letter. Both our theoretical and experimental results demonstrate that the nanopyramid array can achieve perfect broadband absorption from 500- to 800-nm wavelength. Especially in the visible regime, the experimentally measured absorption can even reach 100%. Further analyses reveal that the intrinsic antireflection effect and slow-light waveguide mode play an important role in the ultra-high absorption, which is helpful for the research and development of photovoltaic devices.
基金supported by grants from National Natural Science Foundation of China(Nos.12002285,11672227,61927810)Natural Science Basic Research Plan in Shaanxi Province of China(Nos.2018JQ1033,2020JZ-11)Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University(No.CX202058).
文摘Physical signals provided by the extracellular matrix(ECM)are key microenvironmental parameters for the fate decision of hematopoietic stem and progenitor cells(HSPC)in bone marrow.Insights into cell-ECM interactions are critical for advancing HSC-based tissue engineering.Herein,we employed collagen hydrogels and collagen-alginate hydrogels of defined stiffness to study the behaviors of hematopoietic progenitor cells(HPCs).Three-dimensional(3D)collagen hydrogels with a stiffness of 45 Pa were found to promote HPC maintenance and colony formation of monocyte/macrophage progenitors.Using single-cell RNA sequencing(scRNA-seq),we also characterized the comprehensive transcriptional profiles of cells randomly selected from two-dimensional(2D)and 3D hydrogels.A distinct maturation trajectory from HPCs into macrophages within the 3D microenvironment was revealed by these results.3D-derived macrophages expressed high levels of various cytokines and chemokines,such as Saa3,Cxcl2,Socs3 and Tnf.Furthermore,enhanced communication between 3D-macrophages and other hematopoietic clusters based on ligand-repair interactions was demonstrated through bioinformatic analyses.Our research underlines the regulatory role of matrix-dimensionality in HPC differentiation and therefore probably be applied to the generation of specialized macrophages.
