Dielectric metasurfaces play an increasingly important role in enhancing optical nonlinear generations owing to their ability to support strong light-matter interactions based on Mie-type multipolar resonances.Compare...Dielectric metasurfaces play an increasingly important role in enhancing optical nonlinear generations owing to their ability to support strong light-matter interactions based on Mie-type multipolar resonances.Compared to metasurfaces composed of the periodic arrangement of nanoparticles,inverse,so-called,membrane metasurfaces offer unique possibilities for supporting multipolar resonances,while maintaining small unit cell size,large mode volume and high field enhancement for enhancing nonlinear frequency conversion.Here,we theoretically and experimentally investigate the formation of bound states in the continuum(BICs)from silicon dimer-hole membrane metasurfaces.We demonstrate that our BIC-formed resonance features a strong and tailorable electric near-field confinement inside the silicon membrane films.Furthermore,we show that by tuning the gap between the holes,one can open a leaky channel to transform these regular BICs into quasi-BICs,which can be excited directly under normal plane wave incidence.To prove the capabilities of such metasurfaces,we demonstrate the conversion of an infrared image to the visible range,based on the Third-harmonic generation(THG)process with the resonant membrane metasurfaces.Our results suggest a new paradigm for realising efficient nonlinear photonics metadevices and hold promise for extending the applications of nonlinear structuring surfaces to new types of all-optical near-infrared imaging technologies.展开更多
Macrocyclic compounds,with their unique ring structures and diverse functionalities,offer broad potential in fields such as molecular recognition,catalysis,drug design,optoelectronics,and supramolecular chemistry.Macr...Macrocyclic compounds,with their unique ring structures and diverse functionalities,offer broad potential in fields such as molecular recognition,catalysis,drug design,optoelectronics,and supramolecular chemistry.Macrocyclic compounds are endowed with specific binding sites and functions and exhibit remarkable expandability.The diversification of their functions and the broadening of their applications can be achieved through structural modifications or the introduction of various functional groups.Thiophene-containing molecular building units,including oligothiophenes,fused thiophenes,and their derivatives,are particularly advantageous in the construction of macrocycles due to their versatile structural characteristics.Introducing thiophene units into macrocycles and adjusting their structure,quantity,and positioning allows for the precise control of critical material properties,such as band gaps,optical absorption/emission characteristics,and redox potentials,thereby optimizing their photophysical properties,catalytic activity,and supramolecular interactions[1–3].展开更多
A key concept underlying the specific functionalities of metasurfaces is the use of constituent components to shape the wavefront of the light on demand.Metasurfaces are versatile,novel platforms for manipulating the ...A key concept underlying the specific functionalities of metasurfaces is the use of constituent components to shape the wavefront of the light on demand.Metasurfaces are versatile,novel platforms for manipulating the scattering,color,phase,or intensity of light.Currently,one of the typical approaches for designing a metasurface is to optimize one or two variables among a vast number of fixed parameters,such as various materials’properties and coupling effects,as well as the geometrical parameters.Ideally,this would require multidimensional space optimization through direct numerical simulations.Recently,an alternative,popular approach allows for reducing the computational cost significantly based on a deep-learning-assisted method.We utilize a deep-learning approach for obtaining high-quality factor(high-Q)resonances with desired characteristics,such as linewidth,amplitude,and spectral position.We exploit such high-Q resonances for enhancedlight–matter interaction in nonlinearoptical metasurfaces and optomechanical vibrations,simultaneously.We demonstrate that optimized metasurfaces achieve up to 400-fold enhancement of the third-harmonic generation;at the same time,they also contribute to 100-fold enhancement of the amplitude of optomechanical vibrations.This approach can be further used to realize structures with unconventional scattering responses.展开更多
基金the support from the Royal Society scholarshipsupport from the UK Research and Innovation Future Leaders Fellowship (MR/T040513/1).
文摘Dielectric metasurfaces play an increasingly important role in enhancing optical nonlinear generations owing to their ability to support strong light-matter interactions based on Mie-type multipolar resonances.Compared to metasurfaces composed of the periodic arrangement of nanoparticles,inverse,so-called,membrane metasurfaces offer unique possibilities for supporting multipolar resonances,while maintaining small unit cell size,large mode volume and high field enhancement for enhancing nonlinear frequency conversion.Here,we theoretically and experimentally investigate the formation of bound states in the continuum(BICs)from silicon dimer-hole membrane metasurfaces.We demonstrate that our BIC-formed resonance features a strong and tailorable electric near-field confinement inside the silicon membrane films.Furthermore,we show that by tuning the gap between the holes,one can open a leaky channel to transform these regular BICs into quasi-BICs,which can be excited directly under normal plane wave incidence.To prove the capabilities of such metasurfaces,we demonstrate the conversion of an infrared image to the visible range,based on the Third-harmonic generation(THG)process with the resonant membrane metasurfaces.Our results suggest a new paradigm for realising efficient nonlinear photonics metadevices and hold promise for extending the applications of nonlinear structuring surfaces to new types of all-optical near-infrared imaging technologies.
基金supported by the National Key R&D Program of China(2024YFB3612600)the National Natural Science Foundation of China(22071112,22275098,62288102,and 22302097)+1 种基金the Project of State Key Laboratory of Organic Electronics and Information Displays(GDX2022010005 and GZR2023010001)Natural Science Research Start-up Foundation of Recruiting Talents of Nanjing University of Posts and Telecommunications(NY223180 and NY223068)。
文摘Macrocyclic compounds,with their unique ring structures and diverse functionalities,offer broad potential in fields such as molecular recognition,catalysis,drug design,optoelectronics,and supramolecular chemistry.Macrocyclic compounds are endowed with specific binding sites and functions and exhibit remarkable expandability.The diversification of their functions and the broadening of their applications can be achieved through structural modifications or the introduction of various functional groups.Thiophene-containing molecular building units,including oligothiophenes,fused thiophenes,and their derivatives,are particularly advantageous in the construction of macrocycles due to their versatile structural characteristics.Introducing thiophene units into macrocycles and adjusting their structure,quantity,and positioning allows for the precise control of critical material properties,such as band gaps,optical absorption/emission characteristics,and redox potentials,thereby optimizing their photophysical properties,catalytic activity,and supramolecular interactions[1–3].
基金supported by UNSW Scientia Fellowship and ARC Discovery Project(DP170103778)funding from ARC Discovery Early Career Research Fellowship(DE170100250)+1 种基金financial support from the Russian Foundation for Basic Research(Grants Nos.18-02-00381 and 19-02-00261)the Australian Research Council(DE19010043).
文摘A key concept underlying the specific functionalities of metasurfaces is the use of constituent components to shape the wavefront of the light on demand.Metasurfaces are versatile,novel platforms for manipulating the scattering,color,phase,or intensity of light.Currently,one of the typical approaches for designing a metasurface is to optimize one or two variables among a vast number of fixed parameters,such as various materials’properties and coupling effects,as well as the geometrical parameters.Ideally,this would require multidimensional space optimization through direct numerical simulations.Recently,an alternative,popular approach allows for reducing the computational cost significantly based on a deep-learning-assisted method.We utilize a deep-learning approach for obtaining high-quality factor(high-Q)resonances with desired characteristics,such as linewidth,amplitude,and spectral position.We exploit such high-Q resonances for enhancedlight–matter interaction in nonlinearoptical metasurfaces and optomechanical vibrations,simultaneously.We demonstrate that optimized metasurfaces achieve up to 400-fold enhancement of the third-harmonic generation;at the same time,they also contribute to 100-fold enhancement of the amplitude of optomechanical vibrations.This approach can be further used to realize structures with unconventional scattering responses.
