Optical trapping using focused laser beams has emerged as a powerful tool in the biological and physical sciences. However, scaling this technique to nano-sized objects remains challenging due to the diffraction limit of light and the high power levels required for nanoscale trapping. In this paper, we propose plasmonic coaxial apertures as low-power optical traps for nano-sized specimens. Illumination of a coaxial aperture with a linearly polarized plane wave generates a dual optical trapping potential well. We theoretically show that this potential can stably trap dielectric particles smaller than 10 nm in diameter while keeping the trapping power level below 20 mW. By tapering the thickness of the coaxial dielectric channel, trapping can be extended to sub-2 nm particles. The proposed structures may enable optical trapping and manipulation of dielectric particles ranging from single proteins to small molecules with sizes previously inaccessible.
Saturday, October 6, 2012
Toward efficient optical trapping of sub-10-nm particles with coaxial plasmonic apertures
Amr A. E. Saleh and Jennifer A. Dionne
Optical trapping using focused laser beams has emerged as a powerful tool in the biological and physical sciences. However, scaling this technique to nano-sized objects remains challenging due to the diffraction limit of light and the high power levels required for nanoscale trapping. In this paper, we propose plasmonic coaxial apertures as low-power optical traps for nano-sized specimens. Illumination of a coaxial aperture with a linearly polarized plane wave generates a dual optical trapping potential well. We theoretically show that this potential can stably trap dielectric particles smaller than 10 nm in diameter while keeping the trapping power level below 20 mW. By tapering the thickness of the coaxial dielectric channel, trapping can be extended to sub-2 nm particles. The proposed structures may enable optical trapping and manipulation of dielectric particles ranging from single proteins to small molecules with sizes previously inaccessible.
Optical trapping using focused laser beams has emerged as a powerful tool in the biological and physical sciences. However, scaling this technique to nano-sized objects remains challenging due to the diffraction limit of light and the high power levels required for nanoscale trapping. In this paper, we propose plasmonic coaxial apertures as low-power optical traps for nano-sized specimens. Illumination of a coaxial aperture with a linearly polarized plane wave generates a dual optical trapping potential well. We theoretically show that this potential can stably trap dielectric particles smaller than 10 nm in diameter while keeping the trapping power level below 20 mW. By tapering the thickness of the coaxial dielectric channel, trapping can be extended to sub-2 nm particles. The proposed structures may enable optical trapping and manipulation of dielectric particles ranging from single proteins to small molecules with sizes previously inaccessible.
Subscribe to:
Post Comments (Atom)
No comments:
Post a Comment