We report the femtosecond(fs)laser fabrication of biomimetic omnidirectional iridescent metallic surfaces exhibiting efficient diffraction for practically any angle of light incidence.Such diffractive behavior is real...We report the femtosecond(fs)laser fabrication of biomimetic omnidirectional iridescent metallic surfaces exhibiting efficient diffraction for practically any angle of light incidence.Such diffractive behavior is realized by means of multi-directional low-spatial-frequency,laser-induced periodic surface structures(LSFL)formed upon exploiting the cylindrical symmetry of a cylindrical vector(CV)fs field.We particularly demonstrate that the multi-directional gratings formed on stainless steel surface by a radially polarized fs beam,could mimic the omnidirectional structural coloration properties found in some natural species.Accordingly,the fabricated grating structures can spatially disperse the incident light into individual wavelength with high efficiency,exhibiting structural iridescence at all viewing angles.Analytical calculations using the grating equation reproduced the characteristic variation of the vivid colors observed as a function of incident angle.We envisage that our results will significantly contribute to the development of new photonic and light sensing devices.展开更多
The method has been developed to accurately identify the magnitude of health risks and provide scientific evidence for implementation of risk management in food safety.It combines two parameters including consequence ...The method has been developed to accurately identify the magnitude of health risks and provide scientific evidence for implementation of risk management in food safety.It combines two parameters including consequence and likelihood of adverse effects based on risk matrix.Score definitions and classification for the consequence and the likelihood of adverse effects are proposed.The risk score identifies the intersection of consequence and likelihood in risk matrix represents its health risk level with different colors：‘low＇,‘medium＇,‘high＇.Its use in an actual case is shown.展开更多
Taking inspiration from beautiful colors in nature,structural colors produced from nanostructured metasurfaces have shown great promise as a platform for bright,highly saturated,and high-resolution colors.Both plasmon...Taking inspiration from beautiful colors in nature,structural colors produced from nanostructured metasurfaces have shown great promise as a platform for bright,highly saturated,and high-resolution colors.Both plasmonic and dielectric materials have been employed to produce static colors that fulfil the required criteria for high-performance color printing,however,for practical applications in dynamic situations,a form of tunability is desirable.Combinations of the additive color palette of red,green,and blue enable the expression of further colors beyond the three primary colors,while the simultaneous intensity modulation allows access to the full color gamut.Here,we demonstrate an electrically tunable metasurface that can represent saturated red,green,and blue pixels that can be dynamically and continuously controlled between on and off states using liquid crystals.We use this to experimentally realize ultrahigh-resolution color printing,active multicolor cryptographic applications,and tunable pixels toward high-performance full-color reflective displays.展开更多
文摘We report the femtosecond(fs)laser fabrication of biomimetic omnidirectional iridescent metallic surfaces exhibiting efficient diffraction for practically any angle of light incidence.Such diffractive behavior is realized by means of multi-directional low-spatial-frequency,laser-induced periodic surface structures(LSFL)formed upon exploiting the cylindrical symmetry of a cylindrical vector(CV)fs field.We particularly demonstrate that the multi-directional gratings formed on stainless steel surface by a radially polarized fs beam,could mimic the omnidirectional structural coloration properties found in some natural species.Accordingly,the fabricated grating structures can spatially disperse the incident light into individual wavelength with high efficiency,exhibiting structural iridescence at all viewing angles.Analytical calculations using the grating equation reproduced the characteristic variation of the vivid colors observed as a function of incident angle.We envisage that our results will significantly contribute to the development of new photonic and light sensing devices.
基金supported by the Health and Family Planning Commission&National Major Scientific and Technological Special Project(2014ZX09304307)
文摘The method has been developed to accurately identify the magnitude of health risks and provide scientific evidence for implementation of risk management in food safety.It combines two parameters including consequence and likelihood of adverse effects based on risk matrix.Score definitions and classification for the consequence and the likelihood of adverse effects are proposed.The risk score identifies the intersection of consequence and likelihood in risk matrix represents its health risk level with different colors：‘low＇,‘medium＇,‘high＇.Its use in an actual case is shown.
基金This work was supported by the Samsung Research Funding&Incubation Center for Future Technology grant(SRFC-T1901-05)funded by Samsung Electronicsthe POSCO-POSTECH-RIST Convergence Research Center program funded by POSCO+3 种基金the National Research Foundation(NRF)grants(NRF-2019R1A2C3003129,CAMM-2019M3A683030637,NRF-2019R1A5A8080290,NRF-2020K1A3A1A21024374,NRF-2021K2A9A2A15000174,NRF-2021K1A3A 1A17086079)funded by the Ministry of Science and ICT(MSIT)of the Korean governmentY-KK acknowledges the NRF grants(NRF-2021R1A4A1030944,NRF.2021R1A2C2095010)funded by the MSIT of the Korean governmentJK acknowledges the POSTECH Alchemist fellowshiplK acknowledges the NRF Sejong Science fellowship(NRF-2021R1C1C2004291)funded by the MSIT of the Korean government.
文摘Taking inspiration from beautiful colors in nature,structural colors produced from nanostructured metasurfaces have shown great promise as a platform for bright,highly saturated,and high-resolution colors.Both plasmonic and dielectric materials have been employed to produce static colors that fulfil the required criteria for high-performance color printing,however,for practical applications in dynamic situations,a form of tunability is desirable.Combinations of the additive color palette of red,green,and blue enable the expression of further colors beyond the three primary colors,while the simultaneous intensity modulation allows access to the full color gamut.Here,we demonstrate an electrically tunable metasurface that can represent saturated red,green,and blue pixels that can be dynamically and continuously controlled between on and off states using liquid crystals.We use this to experimentally realize ultrahigh-resolution color printing,active multicolor cryptographic applications,and tunable pixels toward high-performance full-color reflective displays.
