摘要
从耦合模理论出发,采用三层介质光纤模型,用数值计算的方法分析了长周期光纤光栅纤芯模和包层模的有效折射率,一阶低次包层模的耦合系数随波长以及阶次的变化关系.研究发现,低次包层模的最大耦合系数对应的模次随波长增大而减小,不同光纤参数下耦合系数随波长变化的规律不同.耦合系数直接影响到光栅透射谱损耗峰峰值,这对长周期光栅的设计有一定的参考价值.
Based on the three-layer fiber model and the coupling theory, the effective refractive index of the core mode and the cladding modes were numencally calculated in Long-period grating （LPG）, and the changing relation of the coupling coefficient of the cladding modes at the lowest few ones with varying wavelength were analyzed. It is revealed that the mode number of the maximum coupling coefficient of the cladding modes decreases with wavelength, the coupling coefficient with wavelength is different in differ- ent fiber parameters. These results are valuable for the design of long period grating, since the coupling coefficient directly affects the peak loss of the grating transmission spectrum.
出处
《湖南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2012年第6期58-62,共5页
Journal of Hunan University:Natural Sciences
基金
中央高校业务专项基金资助项目(53110704334)
关键词
长周期光纤光栅
光纤参数
波长
耦合系数
long-period grating
optical fiber parameters
wavelength
coupling coefficient
