Optical Rotation and Thermometry of Laser Tweezed Silicon Nanorods
Journal article, 2020

Optical rotation of laser tweezed nanoparticles offers a convenient means for optical to mechanical force transduction and sensing at the nanoscale. Plasmonic nanoparticles are the benchmark system for such studies, but their rapid rotation comes at the price of high photoinduced heating due to Ohmic losses. We show that Mie resonant silicon nanorods with characteristic dimensions of ∼220 × 120 nm2 can be optically trapped and rotated at frequencies up to 2 kHz in water using circularly polarized laser light. The temperature excess due to heating from the trapping laser was estimated by phonon Raman scattering and particle rotation analysis. We find that the silicon nanorods exhibit slightly improved thermal characteristics compared to Au nanorods with similar rotation performance and optical resonance anisotropy. Altogether, the results indicate that silicon nanoparticles have the potential to become the system of choice for a wide range of optomechanical applications at the nanoscale.



optical tweezers


Raman scattering

optical rotation


Pawel Karpinski

Chalmers, Physics, Bionanophotonics

Wrocław University of Science and Technology

Steven Jones

Chalmers, Physics, Nano and Biophysics

Hana Jungová

Chalmers, Physics, Nano and Biophysics

Ruggero Verre

Chalmers, Physics, Nano and Biophysics

Mikael Käll

Chalmers, Physics, Nano and Biophysics

Nano Letters

1530-6984 (ISSN) 1530-6992 (eISSN)

Vol. 20 9 6494-6501

Subject Categories

Energy Engineering

Atom and Molecular Physics and Optics

Other Physics Topics





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