Focusing characteristics of optical fiber axicon-microlens for near-field spectroscopy: Dependence of tip apex-angle

Young-Jun Yu, Haneol Noh, Mun-Heon Hong, Heung-Ryoul Noh, Yasuhiko Arakawa, and Wonho Jhe, ”Focusing characteristics of optical fiber axicon-microlens for near-field spectroscopy: Dependence of tip apex-angle”, Opt. Commun. 267 (1), 264-270 (2006)