Moiré pattern generation by dual shearing and its modulation by surface plasmon resonance

Abstract

A novel surface plasmon resonance (SPR)-mediated Moiré fringe generation is theoretically and experimentally investigated using a birefringent lens (BL) and a Wollaston prism. Birefringent lens having two longitudinally shifted focal points provides radial shear, whereas Wollaston prism introduces lateral shear between the two radially sheared patterns for mutual orthogonal polarizations. Thus Moiré-like pattern is produced at the overlapping region of those patterns. Brief theory and experimental demonstration of coherent and incoherent Moiré fringe generation by such dual shearing is presented. The appearance and disappearance of Moiré pattern with the rotation of the analyzer axis has also been demonstrated. A modified experimental setup has also been developed to observe the influence of plasmonic excitation on such patterns which can be further utilized for photonic applications such as sensing and imaging.