Accurate feeding of nano antenna by polarization singularities for lateral and rotational displacement sensing

TL;DR

This paper demonstrates a method for subwavelength displacement sensing using nano antennas precisely fed by polarization singularities, enabling highly sensitive far-field detection beyond the diffraction limit.

Contribution

It introduces a novel approach combining polarization singularities with nano antennas for deep subwavelength displacement sensing in optical nanometrology.

Findings

Achieved subwavelength displacement sensitivity in far-field scattering.

Demonstrated dynamic control of unidirectional scattering.

Established a new deep subwavelength position detection method.

Abstract

Addressing subwavelength object and displacement is crucial in optical nanometrology. We show in this Letter that nano antennas with subwavelength structures can be addressed precisely by incident beams with singularity. This accurate feeding beyond the diffraction limit can lead to dynamic control of the unidirectional scattering in the far field. The combination of polarization discontinuity of the incoming singular beam, along with the rapid phase variation near the antenna leads to remarkable sensitivity of the far field scattering to displacement at deep subwavelength scale. This opens a far field deep subwavelength postion detection method based on the interaction of singular optics with nano antennas.