基于液晶填充的全内反射型光子晶体光纤的温度传感特性

在实心光子晶体光纤包层的空气柱中填充向列相液晶,选用液晶的折射率在所研究的温度和波长范围内小于光纤背景玻璃的折射率,形成全内反射型光子晶体光纤.采用空间填充基模折射率法求得填充液晶包层的有效折射率,用阶跃有效折射率模型研究了液晶填充光子晶体光纤的温度传感特性,并进行了数值计算.结果表明,液晶填充全内反射型光子晶体光纤的有效折射率和等效芯半径随温度升高而增大,在温度接近液晶相变点附近增大更快,二阶模截止波长随温度升高而减小,在温度接近液晶相变点附近减小更快.

Temperature sensor properties in total internal reflection-photonic crystal fibers based on liquid crystal filling

The total internal reflection-photonic crystal fibers (TIR-PCF) are proposed by filling the air hole of solid-core PCF clad with nematic liquid crystal which the refractive index is less than that of background glass within the temperature and wavelength in research. The effective index of clad with filled liquid crystal is put out by the fundamental space filling mode index. The temperature sensor properties in the PCF are studied by the step effective index model, and numerical calculation is carried out. The results show that the effective index of clad and equivalent core radius increase with temperature increasing, and increase quickly about clear point of liquid crystal. The cutoff wavelength of the second mode decrease with temperature increasing, and decrease quickly about clear point of liquid crystal in the PCF infiltrated with liquid crystal.