Influence of depressed-index outer ring on evanescent tunneling loss in tapered double-cladding fibers.
A tapered fiber with a depressed-index outer ring is fabricated and dispersion engineered to generate a widely tunable (1250-1650 nm) fundamental-mode leakage loss with a high cutoff slope (-1.2 dB/nm) and a high attenuation for stop band (>50 dB) by modification of both waveguide and material dispersions. The higher cutoff slope is achieved with a larger cross angle between the two refractive index dispersion curves of the tapered fiber and surrounding optical liquids through the use of depressed-index outer ring structures in double-cladding fibers.
Chen
Nan-Kuang
NK
Department of Electro-Optical Engineering, National United University, Miaoli 360, Taiwan. nkchen@nuu.edu.tw
Hsu
Kuei-Chu
KC
Liaw
Shien-Kuei
SK
Lai
Yinchieh
Y
Chi
Sien
S