Cen Mengjia, Liu Jianxun, Wang Jiawei, Li Ye, Cai Wenfeng, Cheng Ming, Kong Delai, Tang Xiaoying, Cao Tun, Lu Yan-Qing, Liu Yan Jun
Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
State Key Laboratory of Optical Fiber and Cable Manufacture Technology, Southern University of Science and Technology, Shenzhen 518055, China.
ACS Nano. 2024 Jul 14. doi: 10.1021/acsnano.4c05719.
Dynamic control of circularly polarized photoluminescence has aroused great interest in quantum optics and nanophotonics. Chiral plasmonic metasurfaces enable the manipulation of the polarization state via plasmon-photon coupling. However, current plasmonic light-emitting metasurfaces for effective deterministic modulation of spin-dependent emission at near-infrared wavelengths are underexplored in terms of dissymmetry and tunability. Here, we demonstrate a microfluidic hybrid emitting system of a suspended twisted stacking metasurface coated with PbS quantum dots. The suspended metasurface is fabricated with a single step of electron beam exposure, exhibiting a strong optical chirality of 309° μm with a thickness of less than λ/10 at key spectral locations. With significant chiral-selective interactions, enhanced photoluminescence is achieved with strong dissymmetry in circular polarization. The dissymmetry factor of the induced circularly polarized emission can reach 1.54. More importantly, altering the refractive index of the surrounding medium at the bottom surface of the metasurface can effectively manipulate the chiroptical responses of the hybrid system, hence leading to chirality-reversed emission. This active hybrid emitting system could be a resultful platform for chirality-switchable light emission from achiral quantum emitters, holding great potential for anticounterfeiting, biosensing, light sources, imaging, and displays.
圆偏振光致发光的动态控制在量子光学和纳米光子学领域引起了极大的关注。手性等离子体超表面能够通过等离子体-光子耦合来操纵偏振态。然而，目前用于在近红外波长下对自旋相关发射进行有效确定性调制的等离子体发光超表面，在不对称性和可调谐性方面尚未得到充分研究。在此，我们展示了一种微流体混合发射系统，该系统由涂有硫化铅量子点的悬浮扭曲堆叠超表面组成。该悬浮超表面通过单步电子束曝光制备而成，在关键光谱位置处，厚度小于λ/10时，展现出309°μm的强光学手性。通过显著的手性选择性相互作用，可以实现具有强圆偏振不对称性的增强光致发光。诱导圆偏振发射的不对称因子可达1.54。更重要的是，改变超表面底面周围介质的折射率可以有效地操纵混合系统的手性光学响应，从而实现手性反转发射。这种有源混合发射系统可能成为一个实现非手性量子发射器可切换手性发光的有效平台，在防伪、生物传感、光源、成像和显示等方面具有巨大潜力。
