title: Technique for characterizing single-mode operability in optical fibers by utilizing variable-aperture technique.
abstract: We propose a technique, new to our knowledge, for characterizing single-mode operability by monitoring far-field patterns via a variable aperture. We clarify the applicability of our proposed technique to cutoff wavelength measurement, which agrees well with cutoff wavelength obtained by a conventional multimode reference technique. We also show the applicability of our proposed technique to holey fibers including photonic crystal fibers (PCFs) with uniform air-hole structure and effectively W-shaped air-hole structure. We can clearly characterize the single-mode operability of the PCF. The bend dependence of the single-mode bandwidth is also revealed by utilizing our proposed technique.
authors: NTT Access Network Service Systems Laboratories, Nippon Telegraph and Telephone Corporation, Tsukuba-shi, Ibaraki, Japan. tmatsui@ansl.ntt.co.jp
authors: Takashi
authors: T
authors: Matsui
authors: Kazuhide
authors: K
authors: Nakajima
authors: Yukihoro
authors: Y
authors: Goto
authors: Toshio
authors: T
authors: Kurashima