Propagating light with the full cladding of hollow-core photonic crystal fiber

Conventional fiber cladding only has leaking evanescent wave with low energy, which prevents the application of cladding sensing. Guiding light in the full cladding is expected to improve the sensitivity of hollow-core photonic crystal fiber (HC-PCF) application for material sensing. An approach to increase the energy transmitting in the cladding was theoretical analyzed. The light guidance experiments of air-hole cladding of HC-PCF were carried out by using a cold light source and a laser. The contrast experiments between total internal reflection-photonic crystal fiber (TIR-PCF) and single-mode fiber (SMF) were done. The results indicated that, by choosing appropriate wavelength, the light in HC-PCF leaked entirely into the cladding and propagated in the air-suspended silica cores between the air holes, which was different from TIP-PCF and SMF-28.