4:30 PM - 4:45 PM
△ [22p-D315-13] Generation of coaxial optical vortices with doubled topological charges using a stacked liquid crystal structure
Keywords:optical vortex, q-plate, liquid crystal
Optical vortices with orbital angular momenta show promise for various optical applications. Q-plates are diffractive optical elements with a geometric structure in which rod-like liquid crystal molecules are rotated a half-integer number of times around a point on the substrate and can generate circularly polarized optical vortices based on the geometric phase. However, the geometric structure limits the topological charge of generated optical vortices. This study found that a stacked liquid crystal structure, which stacked a planar cholesteric liquid crystal on a q-plate with quarter-wave retardation, can reflect coaxially optical vortices with different topological charges. Since the proposed device can generate coaxially optical vortices without using an interference system, we believe that this study contributes to generating helical nanostructures utilizing orbital angular momenta of optical vortices and increasing the capacity of free-space communications by multiplexing optical vortices.