Enhancement of Surface Wettability by Intra-Helium Plasma for Liquid Core Fiber Lens

Abstract

We generated an atmospheric pressure helium plasma inside a silica hollow optical fiber (HOF) and the surface wettability of the inside wall was flexibly controlled by the plasma intensity. By filling the glycerol into the HOF, we experimentally investigated the surface characteristics by contact angle measurements. Liquid-fiber optic lenses with various numerical apertures were proposed and the light intensity patterns through liquid core lens to the air were investigated numerically.