title: Bending sensitivity of long-period fiber gratings inscribed in holey fibers depending on an axial rotation angle.
abstract: We discuss bending properties of a long-period fiber grating (LPFG) inscribed into a holey fiber (HF) depending on an axial rotation angle. High quality of the HF-based LPFG with a high extinction ratio of more than 20 dB is achieved. The proposed HF-based LPFG has bending insensitivity under a certain range of the bending curvature. As the bending curvature is higher than 4 m(-1), the center wavelength of the grating is shifted into the shorter wavelength. Bending sensitivity of the HF-based LPFG is changed by an axial rotation angle, which shows its dependence on the rotational orientation. We measure the transmission characteristics of the HF-based LPFG with the ambient index change. The HF-based LPFG has ambient index insensitivity because of the air holes in the inner cladding.
authors: Young-Geun
authors: YG
authors: Han
authors: Gilhwan
authors: G
authors: Kim
authors: Kwanil
authors: K
authors: Lee
authors: Sang Bae
authors: SB
authors: Lee
authors: Chang Hyun
authors: CH
authors: Jeong
authors: Chi Hwan
authors: CH
authors: Oh
authors: Hee Jeon
authors: HJ
authors: Kang