Chirality transfer induced circularly polarized luminescence of achiral dye molecules by plasmonic nanohelicoid

Optical materials with circularly polarized luminescence(CPL)features have attracted a growing interest due to their crucial role in biological sensing,display,spintronics,information storage,and so forth.However,CPL emissions in hybrid nanoparticle systems,in particular,chirality transfer induced CPL from chiral plasmonic nanoparticles,have rarely been explored due to a lack of effective bottom-up synthesis method.Herein,we creatively take advantage of the newly introduced chiral plasmonic nanoparticles-gold nanohelicoid(GNH)to excite the CPL of achiral Rhodamine 6G(R6G).The fabricated GNH@R6G-SiO_(2)shows obvious CPL signals with|g_(lum)|up to 0.014.Compared with the single GNH,the photoluminescence(PL)dissymmetry factor of the single GNH@R6G-SiO_(2)is similar,but with 25 folds higher PL intensities under different circular polarization.Our research not only offers an effective and feasible method to fabricate single-particle level CPL-active materials,but also provides guidelines on how to regulate the CPL of achiral luminophores from chiral plasmonic nanostructures,thereby enlarging the category and quantity of CPL-active materials that can be applied for photonic technologies and visualization biosensing,especially some intracellular chirality related detection.

Spin-decoupled meta-coupler empowered multiplexing and multifunction of guided wave radiation

Employing couplers to convert guided waves into free-space modes and flexibly control their wavefront is one of the key technologies in chip-integrated displays and communications.Traditional couplers are mainly composed of gratings,which have limitations in footprint,bandwidth,as well as controllability.Though the resonant/geometric metasurface newly emerges as a promising interface for bridging guided waves with free-space ones,it either relies on complex optimizations of multiple parameters,or is subject to the locked phase response of opposite spins,both of which hinder the functional diversity and practical multiplexing capability.Here,we propose and experimentally demonstrate an alternative with a spin-decoupled meta-coupler,simultaneously integrating triple functions of guided wave radiation,polarization demultiplexing,and dual-channel wavefront manipulation into a single device.By endowing polarization-dependent functionalities into a pure geometric metasurface,the out-coupled left-handed and right-handed circular polarization guided waves intelligently identify the predesigned phase modulation and reconstruct desired wavefronts,like bifocal focusing and holography multiplexing,with a polarization extinction ratio over 13.4 dB in experiments.We envision that the robust,broadband,and multifunctional meta-coupler could pave a way for the development of versatile multiplexed waveguide-based devices.