Nanoscale displacement sensing based on the interaction of a Gaussian beam with dielectric nano-dimer antennas.

Measuring nanoscale displacement is crucial for optical nanometrology and optical calibration. Here, we present a comprehensive analysis of the far-field scattering of dielectric nano-dimer antennas excited precisely by a Gaussian beam. We demonstrated that the interaction of a Gaussian beam with a dielectric nanoantenna will lead to remarkable sensitivity of the far-field scattering to the displacement at a scale much smaller than the wavelength. The electric/magnetic dipole-dipole interaction model is drawn to analyze the far-field scattering and the results are in good agreement with numerical simulations. This study will pave a simple way to a novel position detection and displacement sensing based on the interaction of general Gaussian beam with nanoantennas.