Kim S, Jeong Y, Kim S, Kwon J, Park N, Lee B
Appl Opt. 2000 May 1;39(13):2038-42. doi: 10.1364/ao.39.002038.
We have analyzed the effects of the fiber cladding radius on the characteristics of long-period fiber gratings. By etching the cladding of a common single-mode fiber, we verified the characteristics experimentally. When by etching we reduce the cladding radius of a common single-mode fiber on which a long-period refractive-index modulation has been imposed, the coupling strength of the core and the cladding modes increases. In addition, the difference in the propagation constants (for a fixed wavelength) between the core mode and the cladding modes increases; hence the resonant transmission dip wavelengths shift to longer wavelengths. The proposed method can be useful in making and detuning long-period fiber grating filters.
我们分析了光纤包层半径对长周期光纤光栅特性的影响。通过蚀刻普通单模光纤的包层，我们对这些特性进行了实验验证。当通过蚀刻减小已施加长周期折射率调制的普通单模光纤的包层半径时，纤芯与包层模式之间的耦合强度会增加。此外，纤芯模式与包层模式之间（对于固定波长）的传播常数差异增大；因此，谐振传输凹陷波长会向更长波长移动。所提出的方法在制作和调节长周期光纤光栅滤波器方面可能会很有用。
