Edge-enhanced microscopy of complex objects using scalar and vectorial vortex filtering

• Published in: Optics express Vol. 31; no. 23; pp. 38388 - 38399
• Main Authors: Zangpo, Jigme, Kawabe, Tomohiro, Kobayashi, Hirokazu
• Format: Journal Article
• Language: English
• Published: 06.11.2023
• ISSN: 1094-4087; 1094-4087
• DOI: 10.1364/OE.502890

Recently, a 4 f system containing a q-plate has been used to perform edge detection and enhancement of amplitude or phase objects. However, only a few studies have concentrated on edge enhancement of complex phase-amplitude objects. Here we experimentally verified the functional difference between scalar and vectorial vortex filtering with the q-plate using an onion cell as a complex object and the vectorial vortex filtering successfully enhanced the edges of phase and amplitude objects in the phase-amplitude object. One problem, however, is indistinguishability of the equally-enhanced edges of the phase and amplitude objects. To address this issue, we propose a method to isolate the edge of the phase object from the edge of the amplitude object using off-axis beam illumination. We theoretically calculated the isolation of the edge of the phase object from the amplitude object, and verified via numerical simulations.