Modal cutoff properties in germanium-doped photonic crystal fiber.
The germanium-doped photonic crystal fiber (PCF) has some characteristics that differentiate it from pure-silica PCF for a germanium element being doped in the core, such as the intensified nonlinearity, the enhanced photosensitivity, and so on. To pave the way for the application of the Ge-doped PCF successfully, it is necessary to study its properties. We investigated the modal cutoff properties of Ge-doped PCF quantitatively by using the beam propagation method. The numerical results show that the effective refractive indices and the normalized frequency V of Ge-doped PCF not only depend on the normalized pitch delta/lambda but also depend on the normalized hole size d/delta, the modal cutoff boundary for the single mode-multimode of the Ge-doped PCF shift to the low d/delta side in contrast to the pure-silica PCF.
The authors are with the Institute of Modern Optics, Nankai University, Tianjin, China. luckyigliu@163.com
Jianguo
J
Liu
Guiyun
G
Kai
Lifang
L
Xue
Zhi
Z
Wang
Yange
Y
Liu
Yan
Y
Li
Chunshu
C
Zhang
Tingting
T
Sun
Xiaoyi
X
Dong