Topologically protected optical pulling force on synthetic particles through photonic nanojet
Ren Yu-Xuan,
Frueh Johannes,
Zhang Zhisen,
Rutkowski Sven,
Zhou Yi,
Mao Huade,
Kong Cihang,
Tverdokhlebov Sergei I.,
Liu Wen,
Wong Kenneth K. Y.,
Li Bo
Affiliations
Ren Yu-Xuan
Institute for Translational Brain Research, MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200032, China
Frueh Johannes
Weinberg Research Center, School of Nuclear Science & Engineering, National Research Tomsk Polytechnic University, 30 Lenin Avenue, 634050Tomsk, Russian Federation
Zhang Zhisen
Institute of Carbon Neutrality, ShanghaiTech University, Shanghai, 201210, China
Rutkowski Sven
Weinberg Research Center, School of Nuclear Science & Engineering, National Research Tomsk Polytechnic University, 30 Lenin Avenue, 634050Tomsk, Russian Federation
Zhou Yi
Department of Electrical and Electronic Engineering, University of Hong Kong, Pokfulam Road, Hong Kong, SAR999077, China
Mao Huade
Department of Electrical and Electronic Engineering, University of Hong Kong, Pokfulam Road, Hong Kong, SAR999077, China
Kong Cihang
Institute for Translational Brain Research, MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200032, China
Tverdokhlebov Sergei I.
Weinberg Research Center, School of Nuclear Science & Engineering, National Research Tomsk Polytechnic University, 30 Lenin Avenue, 634050Tomsk, Russian Federation
Liu Wen
Department of Optics and Optical Engineering, University of Science and Technology of China, Hefei, 230026, China
Wong Kenneth K. Y.
Department of Electrical and Electronic Engineering, University of Hong Kong, Pokfulam Road, Hong Kong, SAR999077, China
Li Bo
Institute for Translational Brain Research, MOE Frontiers Center for Brain Science, Fudan University, Shanghai, 200032, China
A dielectric microsphere concentrates light into a photonic nanojet (PNJ), and swims towards the near-infrared laser in response to the nanojet-mediated force. In contrast, a Janus particle with an opaque metal layer was thought to be impossible to concentrate light into a stable nanojet. However, the Janus particle may experience optical torque owing to the inhomogeneous composition on both sides even in linearly polarized non-resonant light. Herein, we report on topologically protected PNJ produced by a synthetic Janus particle, and observed the backaction force on the Janus particle. Due to symmetry, the counter-propagating beams can both form PNJ on the respective opposite sides, and pull Janus particles towards respective sources. Furthermore, we unveil that the hysteresis on backaction force with respect to the injection power also exists on synthetic Janus particle compared with their dielectric counterparts. Additionally, the magnitude of the backaction force varies between power increase and decrease stages even with the same laser power. We anticipate that the observation offers great possibilities to pull irregular particles by concentrating light with the particle, and such scheme may be applied for parallel particle manipulation and classification.
