空芯带隙型光子晶体光纤整体空气孔包层导光特性研究

Propagating light with the full cladding of hollow-core photonic crystal fiber

传统光纤包层中仅存在泄漏的倏逝波,能量较小,不利于包层传感的应用。增大包层中的能量,实现整体包层导光是提高光纤传感灵敏度的有效途径。从理论上分析了利用空芯带隙型光子晶体光纤(HC-PCF)包层进行导光的机理。在实验上选用带隙外的冷光源和激光对一种典型结构的HC-PCF进行了空气孔包层的导光实验,并利用折射率引导型光子晶体光纤和单模光纤进行对比实验。结果表明,带隙范围外光波在HC-PCF中传输时将不受禁带效应的约束泄露至包层中重新分布。包层中SiO2与空气孔的周期型结构将光波约束在高折射率介质中,实现HC-PCF整体空气孔包层中光波的稳定传输。PBG-PCF包层的整体导光在传感上有提高灵敏度的潜在价值。

Conventional fiber cladding only has leaking evanescent wave with low energy,which prevents the application of cladding sensing.Guiding light in the full cladding is expected to improve the sensitivity of hollow-core photonic crystal fiber（HC-PCF） application for material sensing.An approach to increase the energy transmitting in the cladding was theoretical analyzed.The light guidance experiments of air-hole cladding of HC-PCF were carried out by using a cold light source and a laser.The contrast experiments between total internal reflection-photonic crystal fiber（TIR-PCF） and single-mode fiber（SMF） were done.The results indicated that,by choosing appropriate wavelength,the light in HC-PCF leaked entirely into the cladding and propagated in the air-suspended silica cores between the air holes,which was different from TIP-PCF and SMF-28.