Polyvinyl chloride gel-based Fresnel zone plate fabricated by solvent evaporation under a DC electric field

Abstract

In this work, a facile method was developed for the fabrication of a polyvinyl chloride (PVC) gel-based Fresnel zone plate (FZP). To this end, a concentric zoned electrode with odd zones connected to the anode and even zones connected to the cathode was used to shape the PVC gels solution. Next, the solvent of PVC gels solution was evaporated under a 60 V DC applied electric field at room temperature. During this process, the electric charge injected from the cathode was carried by the plasticizer toward the anode to accumulate on its surface. After full evaporation of the solvent, the PVC gels formed undulated shapes with concentric zoned patterns due to the electrostatic repulsions. The focal length of the as-obtained PVC gel-based FZP was estimated to 40 cm, and maximum diffraction efficiency was ∼ 79.4 % . In sum, the proposed PVC gel-based FZP with the simple fabrication process, compact structure, high transmittance, good optical isotropy, and low power consumption looks very promising for applications in long-distance optical communication, space navigation, and optical trapping.