Hollow-Core Antiresonant Fibers

Hollow-core fibers (HCFs)Hollow-core fibers (HCFs) are special waveguides that can confine light waves in a low refractive index air region. They have much lower dispersion, nonlinearity, thermal sensitivity, and transmission delay than traditional solid-core fibers. At present, there are two types of HCFs, hollow-core antiresonant fibersAntiresonant fibers (HC-ARFs) and hollow-core photonic band gap fibersPhotonic band gap fibers (HC-PBGFs). Experiments have shown that HC-ARFs can achieve lower transmission loss and larger transmission bandwidth than HC-PBGFs. This chapter focuses on the development history, waveguide principle, loss mechanism, and advanced applications of HC-ARFs. At the same time, we compare the properties of HC-ARFs with those of HC-PBGFs. Section C introduces the origination and evolution of HC-ARFs, including different designs of fiber cross sections, as well as the advantages and disadvantages of different structures. Especially, the process of reducing losses of HC-ARFs is discussed in detail. The fundamental waveguide principle of HC-ARFs is introduced in Section D where the effects of antiresonant reflectionAntiresonant reflection and core-cladding mode phase mismatching are analyzed. Section E introduces three main factors causing loss in HC-ARFs: mode leakage, core-cladding mode coupling, and effects of cladding structures. The advanced applications of HC-ARFs including data transmission, supercontinuum generation, optical frequency comb distribution, and gas detection are introduced in Section F.