Ren Haoran, Wang Xiaoxia, Li Chenhao, He Chenglin, Wang Yixiong, Pan Anlian, Maier Stefan A
Chair in Hybrid Nanosystems, Nanoinstitute Munich, Faculty of Physics, Ludwig-Maximilians-Universität München, München 80539, Germany.
MQ Photonics Research Centre, Department of Physics and Astronomy, Macquarie University, Macquarie Park, New South Wales 2109, Australia.
Nano Lett. 2021 Jul 28;21(14):6220-6227. doi: 10.1021/acs.nanolett.1c01979. Epub 2021 Jul 15.
Plasmonic nanostructures can enable compact multiplexing of the orbital angular momentum (OAM) of light; however, strong dissipation of the highly localized OAM-distinct plasmonic fields in the near-field region hinders on-chip OAM transmission and processing. Superior transmission efficiency is offered by semiconductor nanowires sustaining highly confined optical modes, but only the polarization degree of freedom has been utilized for their selective excitation. Here we demonstrate that incident OAM beams can selectively excite single-crystalline cadmium sulfide (CdS) nanowires through coupling OAM-distinct plasmonic fields into nanowire waveguides for long-distance transportation. This allows us to build an OAM-controlled hybrid nanowire circuit for optical logic operations including AND and OR gates. In addition, this circuit enables the on-chip photoluminescence readout of OAM-encrypted information. Our results open exciting new avenues not only for nanowire photonics to develop OAM-controlled optical switches, logic gates, and modulators but also for OAM photonics to build ultracompact photonic circuits for information processing.
等离子体纳米结构能够实现光的轨道角动量(OAM)的紧凑型复用;然而,近场区域中高度局域化的、具有不同OAM的等离子体场的强烈耗散阻碍了片上OAM传输和处理。维持高度受限光学模式的半导体纳米线具有卓越的传输效率,但仅利用了其偏振自由度进行选择性激发。在此,我们证明入射OAM光束可通过将具有不同OAM的等离子体场耦合到纳米线波导中以实现长距离传输,从而选择性地激发单晶硫化镉(CdS)纳米线。这使我们能够构建用于光学逻辑运算(包括与门和或门)的OAM控制混合纳米线电路。此外,该电路能够对OAM加密信息进行片上光致发光读出。我们的结果不仅为纳米线光子学开发OAM控制的光开关、逻辑门和调制器,也为OAM光子学构建用于信息处理的超紧凑型光子电路开辟了令人兴奋的新途径。