Optical metamaterials offer the possibility of controlling the behavior of photons similarly to what has been done about electrons in semiconductors.However,most optical metamaterials are narrowband,and they achieve n...Optical metamaterials offer the possibility of controlling the behavior of photons similarly to what has been done about electrons in semiconductors.However,most optical metamaterials are narrowband,and they achieve negative refraction within a small window of incident angles,making them impractical for common visible light systems that operate effectively over a wide range of frequencies and directions.Considerable resistive loss at the resonant frequency of these metamaterials further prevents them from being deployed in the real world.Here,we develop a novel metamaterial randomly assembled by a list of narrowband,omnidirectional,and ultralow-loss meta-cluster systems using a bottom-up approach.Weak interactions among numerous meta-cluster sets greatly broaden the effective bandwidth of the overall structure,exhibiting frequency selectivity and spatial modulation when responding to white-light illumination.We observe negative refraction in the 490–730 nm band,and observe an inverse Doppler effect at green,yellow,and red frequencies,across most of the visible spectrum.Our method allows for low-cost fabrication of sizable broadband omnidirectional three-dimensional metamaterial samples,which opens the door to the rapid development of optical metamaterials,micro–nano assembly and preparation,tunable optical device engineering,etc.展开更多
Optical metamaterials present opportunities and challenges for manipulation of light. However, metamaterials with visible and near infrared responses are still particularly challenging to fabricate due to the complex ...Optical metamaterials present opportunities and challenges for manipulation of light. However, metamaterials with visible and near infrared responses are still particularly challenging to fabricate due to the complex preparation process and high loss. Here, a visible light poly(amidoamine)(PAMAM)-Ag metamaterial is prepared with the assistance of fifth-generation PAMAM(5G PAMAM), based on the dendritic structure. The large area of metamaterials, where Ag nanoparticles are spherical with diameters of ~9 nm and distributed in a multilevel netlike sphere, results in broadband resonance. The negative Goos–Hanchen shift and anomalous spin Hall effect of light generated by 5G PAMAM-Ag in visible broadband are observed, and a strong slab focusing effect at 750–1050 nm is demonstrated. In addition, the simulation shows possible application of the dendritic structure in topological photonics. The results offer advances in the preparation of large-scale visible light metamaterials, showing the potential for subwavelength super-resolution imaging and quantum optical information fields.展开更多
基金National Natural Science Foundation of China (52272306,11674267).
文摘Optical metamaterials offer the possibility of controlling the behavior of photons similarly to what has been done about electrons in semiconductors.However,most optical metamaterials are narrowband,and they achieve negative refraction within a small window of incident angles,making them impractical for common visible light systems that operate effectively over a wide range of frequencies and directions.Considerable resistive loss at the resonant frequency of these metamaterials further prevents them from being deployed in the real world.Here,we develop a novel metamaterial randomly assembled by a list of narrowband,omnidirectional,and ultralow-loss meta-cluster systems using a bottom-up approach.Weak interactions among numerous meta-cluster sets greatly broaden the effective bandwidth of the overall structure,exhibiting frequency selectivity and spatial modulation when responding to white-light illumination.We observe negative refraction in the 490–730 nm band,and observe an inverse Doppler effect at green,yellow,and red frequencies,across most of the visible spectrum.Our method allows for low-cost fabrication of sizable broadband omnidirectional three-dimensional metamaterial samples,which opens the door to the rapid development of optical metamaterials,micro–nano assembly and preparation,tunable optical device engineering,etc.
基金National Natural Science Foundation of China(11674267,51272215).
文摘Optical metamaterials present opportunities and challenges for manipulation of light. However, metamaterials with visible and near infrared responses are still particularly challenging to fabricate due to the complex preparation process and high loss. Here, a visible light poly(amidoamine)(PAMAM)-Ag metamaterial is prepared with the assistance of fifth-generation PAMAM(5G PAMAM), based on the dendritic structure. The large area of metamaterials, where Ag nanoparticles are spherical with diameters of ~9 nm and distributed in a multilevel netlike sphere, results in broadband resonance. The negative Goos–Hanchen shift and anomalous spin Hall effect of light generated by 5G PAMAM-Ag in visible broadband are observed, and a strong slab focusing effect at 750–1050 nm is demonstrated. In addition, the simulation shows possible application of the dendritic structure in topological photonics. The results offer advances in the preparation of large-scale visible light metamaterials, showing the potential for subwavelength super-resolution imaging and quantum optical information fields.
