Plasmonic chiral contrast agents for optical coherence tomography: numerical study.

Optical coherence tomography (OCT) is a widely used morphological imaging modality. Various contrast agents, which change localized optical properties, are used to extend the applicability of OCT, where intrinsic contrast is not sufficient. In this paper we propose the use of a dual-rod gold nano-structure as a polarization sensitive contrast agent. Using numerical simulation, we demonstrated that the proposed structure has tunable chiral response. Enhanced cross-section due to Plasmon resonance in gold nanoparticles, along with the chiral behavior can provide enhanced detection sensitivity. The proposed contrast agents may extend the applicability of OCT to the problems that require the molecular contrast with enhanced sensitivity.