Han Tingting, Liu Yan-ge, Wang Zhi, Guo Junqi, Wu Zhifang, Wang Shuanxia, Li Zhili, Zhou Wenyuan
Key Laboratory of Optical Information Science and Technology, Ministry of Education, Institute of Modern Optics, Naikai University, Tianjin 300071, China.
Opt Express. 2013 Jan 14;21(1):122-8. doi: 10.1364/OE.21.000122.
We demonstrate a Sagnac interferometer (SI) based on a selective-filling photonic crystal fiber (SF-PCF), which is achieved by infiltrating a liquid with higher refractive index than background silica into two adjacent air holes of the innermost layer. The SF-PCF guides light by both index-guiding and bandgap-guiding. The modal birefringence of the SF-PCF is decidedly dependent on wavelength, and the modal group birefringence has zero value at a certain wavelength. We also theoretically and experimentally investigate in detail the transmission and temperature characteristics of the SI. Results reveal that the temperature sensitivity of the interference spectrum is also acutely dependent on wavelength and temperature, and an ultrahigh even theoretically infinite sensitivity can be achieved at a certain temperature by choosing proper fiber length. An ultrahigh sensitivity with -26.0 nm/°C (63,882 nm/RIU) at 50.0 °C is experimentally achieved.
我们展示了一种基于选择性填充光子晶体光纤（SF-PCF）的萨格纳克干涉仪（SI），它是通过将折射率高于背景二氧化硅的液体渗入最内层的两个相邻气孔来实现的。SF-PCF通过折射率引导和带隙引导来传导光。SF-PCF的模式双折射明显依赖于波长，并且模式群双折射在特定波长处具有零值。我们还从理论和实验上详细研究了SI的传输和温度特性。结果表明，干涉光谱的温度灵敏度也强烈依赖于波长和温度，并且通过选择合适的光纤长度，在特定温度下理论上甚至可以实现超高甚至无限的灵敏度。在50.0°C时实验实现了-26.0 nm/°C（63,882 nm/RIU）的超高灵敏度。
