中文摘要：

基于CO2激光熔融技术与模间干涉原理,提出一种CO2激光熔融塌陷型光子晶体光纤（PCF）Mach-Zehnder干涉仪（MZI）。在一段较短的PCF上,通过采用CO2激光熔融烧蚀改变PCF包层空气孔结构,由包层模和纤芯模的干涉构成MZI。整个PCF传感器塌陷区长为419.01μm,塌陷区最细处直径为58.69μm,干涉条纹对比度可达10.6dB,并研究了其温度传感特性以及折射率传感特性。将制备完成的传感器分别置于温度控制箱和不同折射率的甘油水溶液中,两端分别连接至ASE宽带光源（1 520~1 610nm）和光谱仪（OSA）上,光源输出功率为16dBm,测量其传输光谱。实验结果表明,在30~70℃温度范围内,测得其温度灵敏度仅为0.005 1nm/℃;1.352 5~1.413 4折射率范围内,测得其折射率灵敏度为33.388 4nm/RIU。

英文摘要：

Based on the COX laser fusion technology and mode interference principle, a collapsed photonic crystal fiber （PCF） Mach-Zehnder interferometer （MZI） is proposed and experimentally demonstrated. By changing the structure of PCF＇s cladding air holes, the Mach-Zehnder interferometer is realized by COx laser fusion method,and the interference happens between cladding mode and core mode. Using the microscope to measure the PCF sensor,it can be obtained that the length of collapse area is 419.01μm, and the smallest diameter of this area is 58. 69μm. The interference fringe contrast of the transmission spectra can be up to 10. 6 dB and the temperature sensor and refractive index sensing characteristics are studied and analyzed. The fabricated Mach-Zehnder interferometer based on PCF is placed in the temperattire control cabinet and glycerin aqueous solution with different refractive indices respectively, with both ends of it connected with an amplified spontaneous emission （ASE） source and a spectrometer,respec- tively. The output power of light source is 16 dBm. Therefore, a transmission spectrum can be obtained. Moreover, the temperature and refractive index sensing characteristics are studied. The experimental results show that the temperature sensitivity is only 0. 005 1 nm/℃ in the range of 30-70 ℃ ,and the re- fractive index sensitivity is 33. 388 4 nrn/RIU in the range of 1. 3525-1. 413 4.