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Monday, June 24, 2019

Optical trapping of sub-wavelength objects with point-like slot waveguides

Mufei Xiao

An optical tweezer capable of picking up dielectric as well as metallic objects of sizes much smaller than the light wavelength is proposed based on point-like two-dimensionally slotted waveguides. Slot waveguides transport light based on evanescent modes, therefore, with sub-wavelength resolution. A point-like slot waveguide confines light within a sub-wavelength cross-section, and a strong gradient electric field is formed. A radiation force is induced by the strong gradient field, and the force is strong enough for optically trapping and manipulating small objects of different sizes and refractive indice with sub-wavelength resolution. As an example, the proposed device is numerically simulated with a rectangular slot waveguide so as to confirm its feasibility. Since the assumed device profile and materials are common for chip formation, the proposed device has the potential to become a lab-on-a-chip opto-electric tool for biologic analysis.

DOI

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