Independent control of circularly polarized light with exceptional topological phase coding metasurfaces:erratum

The funding in this article[1]needs to be supplemented.Coupled-mode theory analysis has been supported by the Priority 2030 Federal Academic Leadership Program.CST simulations have been supported by Russian Science Foundation(project 23-72-10059).

Independent control of circularly polarized light with exceptional topological phase coding metasurfaces

Exceptional points,as degenerate points of non-Hermitian parity-time symmetric systems,have many unique physical properties.Due to its flexible control of electromagnetic waves,a metasurface is frequently used in the field of nanophotonics.In this work,we developed a parity-time symmetric metasurface and implemented the 2πtopological phase surrounding an exceptional point.Compared with Pancharatnam-Berry phase,the topological phase around an exceptional point can achieve independent regulation of several circular polarization beams.We combined the Pancharatnam-Berry phase with the exceptional topological phase and proposed a composite coding metasurface to achieve reflection decoupling of different circular polarizations.This work provides a design idea for polarimetric coding metasurfaces in the future.

All-optical generation of static electric field in a single metal-semiconductor nanoantenna

Electric field is a powerful instrument in nanoscale engineering,providing wide functionalities for control in various optical and solid-state nanodevices.The development of a single optically resonant nanostructure operating with a charge-induced electrical field is challenging,but it could be extremely useful for novel nanophotonic horizons.Here,we show a resonant metal-semiconductor nanostructure with a static electric field created at the interface between its components by charge carriers generated via femtosecond laser irradiation.We study this field experimentally,probing it by second-harmonic generation signal,which,in our system,is time-dependent and has a non-quadratic signal/excitation power dependence.The developed numerical models reveal the influence of the optically induced static electric field on the second harmonic generation signal.We also show how metal work function and silicon surface defect density for different charge carrier concentrations affect the formation of this field.We estimate the value of optically-generated static electric field in this nanoantenna to achieve≈10^(8)V/m.These findings pave the way for the creation of nanoantenna-based optical memory,programmable logic and neuromorphic devices.

A fluid-guided printing strategy for patterning high refractive index photonic microarrays

High refractive index(HRI,n>1.8)photonic structures offer strong light confinement and refractive efficiencies,cover the entire visible spectrum and can be tuned by designing geometric arrayed features.However,its practical applications are still hindered by the applicability and material limitation of lithography-based micro/nano fabrication approaches.Herein,we demonstrate a fluid-guided printing process for preparing HRI selenium microarrays.The microstructured flexible template is replicated from the diced silicon wafer without any lithography-based methods.When heated above the glass transition temperature,the flow characteristics of selenium endows the structure downsizing and orientation patterning between the target substrate and the template.Near 10 times narrowing selenium microarrays(1.9μm width)are patterned from the non-lithography template(18μm width).HRI selenium microarrays offer high refractive efficiencies and strong optical confinement abilities,which achieve angledependent structurally coloration and polarization.Meanwhile,the color difference can be recognized under the one degree distinction of the angle between incident and refracted light.This printing platform will facilitate HRI optical metasurfaces in a variety of applications,ranging from photonic sensor,polarization modulation to light manipulation.

Color-preserving passive radiative cooling for an actively temperature-regulated enclosure

Active temperature control devices are widely used for the thermal management of enclosures,including vehicles and buildings.Passive radiative cooling has been extensively studied;however,its integration with existing actively temperature regulated and decorative enclosures has slipped out of the research at status quo.Here,we present a photonic-engineered dual-side thermal management strategy for reducing the active power consumption of the existing temperature-regulated enclosure without sacrificing its aesthetics.By coating the exterior and interior of the enclosure roof with two visible-transparent films with distinctive wavelength-selectivity,simultaneous control over the energy exchange among the enclosure with the hot sun,the cold outer space,the atmosphere,and the active cooler can be implemented.A power-saving of up to 63%for active coolers of the enclosure is experimentally demonstrated by measuring the heat flux compared to the ordinary enclosure when the set temperature is around 26℃.This photonic-engineered dual-side thermal management strategy offers facile integration with the existing enclosures and represents a new paradigm toward carbon neutrality.