Filling Technologies of Photonic Crystal Fibers and Their Applications
In this chapter, we shortly review the filling technologies of photonic crystal fibers (PCFs), including the selectively filling method by collapsing air holes, by splicing to a SMF with a lateral offset, and by femtosecond (fs) laser micromachining. Moreover, we demonstrate their applications in optical fiber devices, including a partially liquid-filled hollow-core PCF polarizer, a fiber in-line Mach-Zehnder interferometer constructed by selective infiltration of two air holes in PCF, and an embedded coupler based on selectively infiltrated PCF. For the applications in optical fiber temperature sensors, we demonstrate temperature sensors based on an alcohol-filled PCF Sagnac loop interferometers, temperature sensors with excellent temporal stability based on PCF with two infiltrated air holes, and a selectively infiltrated PCF with ultrahigh temperature sensitivity. Further, for the applications in gas sensors, we demonstrate a PCF loop mirror-based chemical vapor sensor, a chemical vapor sensor based on a simplified hollow-core PCF, and a hydrogen sensor based on selectively infiltrated PCF with Pt-loaded WO3 coating and discuss their sensing mechanisms. Finally, we will demonstrate a passively mode-locked fiber laser based on a hollow-core photonic crystal fiber filled with few-layered graphene oxide solution.
KeywordsPCF filling Selective filling Partial filling and selective infiltration
- A. Yariv, Optical Electronics in Modern Communications, 5th ed. London, U.K.: Oxford Univ. Press, (1997)Google Scholar