title: High-accuracy measurement of cladding noncircularity based on phase velocity difference between acoustic polarization modes.
abstract: A high-accuracy measurement method for the noncircularity (ellipticity) of silica glass fibers is demonstrated. This method makes use of the phase velocity difference between two eigen polarization modes of the lowest-order acoustic flexural wave in an optical fiber. The relationship between the acoustic phase velocity difference and the fiber ellipticity is formulated. Three types of optical fibers were examined; photonic crystal fiber, elliptical core fiber, and standard single-mode fiber. Fiber ellipticity of less than 0.001 was successfully measured.
authors.affiliation: Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 305-701, South Korea. sdlim1976@gmail.com
authors.forename: Sun Do
authors.initials: SD
authors.lastname: Lim
authors.forename: Hyun Chul
authors.initials: HC
authors.lastname: Park
authors.forename: Kwanil
authors.initials: K
authors.lastname: Lee
authors.forename: Sang Bae
authors.initials: SB
authors.lastname: Lee
authors.forename: Byoung Yoon
authors.initials: BY
authors.lastname: Kim
mesh_terms: D000162:Acoustics / Q000295:instrumentation*; D000465:Algorithms; D004867:Equipment Design; D019544:Equipment Failure Analysis / Q000379:methods*; D055100:Optical Fibers; D012031:Refractometry / Q000295:instrumentation*