TY - JOUR
T1 - Twisted Surface Plasmons with Spin-Controlled Gold Surfaces
AU - Tsai, Wei Yi
AU - Sun, Quan
AU - Hu, Guangwei
AU - Wu, Pin Chieh
AU - Lin, Ren Jie
AU - Qiu, Cheng Wei
AU - Ueno, Kosei
AU - Misawa, Hiroaki
AU - Tsai, Din Ping
N1 - Funding Information:
W.Y.T., Q.S., and G.H. contributed equally to this work. The authors acknowledge financial support from the Ministry of Science and Technology, Taiwan (Grant Nos. MOST-107-2112-M-001-042-MY3, MOST-107-2923-M-001-010-MY3, MOST-107-2911-I-001-508, and MOST-107-2911-I-001-510) and Academia Sinica (Grant Nos. AS-TP-108-M12, AS-iMATE-108-41), the UK Engineering and Physical Sciences Research Council (Grant No.: EP/M009122/1), and the Singapore Ministry of Education (Grant No.: MOE2011-T3-1-005). The authors are also grateful to the National Center for Theoretical Sciences, NEMS Research Center of National Taiwan University, and the National Center for High-Performance Computing, Taiwan, and Research Center for Applied Sciences, Academia Sinica, Taiwan, for their supports. The authors acknowledge Mr. Hanfa Song for the assistance in some of PEEM measurements. This work was also partially supported by the Nanotechnology Platform (Hokkaido University), and the Dynamic Alliance for Open Innovation Bridging Human, Environment and Materials (Five-Star Alliance) of MEXT. H.M. and K.U. also acknowledge the support from JSPS KAKENHI (Nos. JP18H05205, JP17H01041, JP17H05245, and JP17H05459).
Publisher Copyright:
© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2019/4/18
Y1 - 2019/4/18
N2 - Twisted photon, associated with orbital angular momentum (OAM), is a physical notion that has long captivated the intriguing imagination and wide applications. Owing to the native orthogonality between different topological charges of the vortices, it will be of significant value to generate, access, and discriminate the vortex on integrated chips. Archimedean spirals or multiple split gratings are commonly employed to generate OAMs on plasmonic films. However, the single-crystalline plasmonic surface sets a very stringent condition of probing the on-chip OAM dynamics at sub-femtosecond scale. In previous reports, spins of the incident light and actual topological charge of the on-chip OAM generator are also hybridized due to the intrinsic spin-to-orbital angular momentum conversion, making the direct discrimination of plasmonic vortex impossible. Here, a paradigm of generating twisted surface plasmons is presented in a fully spin-controlled fashion. With the two-photon photoemission electron microscopy, the dynamics of OAM formation is demonstrated at subwavelength spatial resolution and sub-femtosecond temporal resolution simultaneously, revealing its OAM-dependent angular velocity. In addition, this scheme of twisting on-chip plasmons shows that the challenging crystalline requirement of the thin film can be significantly alleviated. The results open up a distinct way to multiplex, record, and read the information with plasmons.
AB - Twisted photon, associated with orbital angular momentum (OAM), is a physical notion that has long captivated the intriguing imagination and wide applications. Owing to the native orthogonality between different topological charges of the vortices, it will be of significant value to generate, access, and discriminate the vortex on integrated chips. Archimedean spirals or multiple split gratings are commonly employed to generate OAMs on plasmonic films. However, the single-crystalline plasmonic surface sets a very stringent condition of probing the on-chip OAM dynamics at sub-femtosecond scale. In previous reports, spins of the incident light and actual topological charge of the on-chip OAM generator are also hybridized due to the intrinsic spin-to-orbital angular momentum conversion, making the direct discrimination of plasmonic vortex impossible. Here, a paradigm of generating twisted surface plasmons is presented in a fully spin-controlled fashion. With the two-photon photoemission electron microscopy, the dynamics of OAM formation is demonstrated at subwavelength spatial resolution and sub-femtosecond temporal resolution simultaneously, revealing its OAM-dependent angular velocity. In addition, this scheme of twisting on-chip plasmons shows that the challenging crystalline requirement of the thin film can be significantly alleviated. The results open up a distinct way to multiplex, record, and read the information with plasmons.
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U2 - 10.1002/adom.201801060
DO - 10.1002/adom.201801060
M3 - Article
AN - SCOPUS:85064556747
SN - 2195-1071
VL - 7
JO - Advanced Optical Materials
JF - Advanced Optical Materials
IS - 8
M1 - 1801060
ER -