Multimode interference in outer cladding large‐core, air‐clad photonic crystal fiber

It is described a large-core air-clad photonic crystal fiber-based sensing structure using the outer cladding as a light guide, which is highly sensitive to refractive index. The sensing head is based on multimodal interference, and relies on a single mode/large-core air-clad photonic crystal fiber/single mode fiber configuration. Using this configuration and controlling the light to travel in a segment of the outer cladding multimode fiber, it was possible to implement a sensing head and the results were obtained independently from variations of temperature, strain and refractive index. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1009–1011, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26726